USP美国药典 233元素杂质-检查法

231HEAVY METALSThis test is provided to demonstrate that the content of metallic impurities that are colored by sulfide ion, under the specified test conditions, does not exceed the Heavy metals limit specified in the individual monograph in percentage (by weight) of lead in the test substance, as determined by concomitant visual comparison (see Visual Comparison in the section Procedure underSpectrophotometry and Light-Scattering 851) with a control prepared from a Standard Lead Solution. [NOTE—Substances that typically will respond to this test are lead, mercury, bismuth, arsenic, antimony, tin, cadmium, silver, copper, and molybdenum.]Determine the amount of heavy metals by Method I, unless otherwise specified in the individual monograph. Method I is used for substances that yield clear, colorless preparations under the specified test conditions. Method II is used for substances that do not yield clear, colorless preparations under the test conditions specified for Method I, or for substances that, by virtue of their complex nature, interfere with the precipitation of metals by sulfide ion, or for fixed and volatile oils. Method III, a wet-digestion method, is used only in those cases where neither Method I nor Method II can be used.Special ReagentsLead Nitrate Stock Solution— Dissolve 159.8 mg of lead nitrate in 100 mL of water to which has been added 1 mL of nitric acid, then dilute with water to 1000 mL. Prepare and store this solution in glass containers free from soluble lead salts.Standard Lead Solution— On the day of use, dilute 10.0 mL of Lead Nitrate Stock Solution with water to 100.0 mL. Each mL of Standard Lead Solution contains the equivalent of 10 µg of lead. A comparison solution prepared on the basis of 100 µL of Standard Lead Solution per g of substance being tested contains the equivalent of 1 part of lead per million parts of substance being tested.METHOD IpH 3.5 Acetate Buffer— Dissolve 25.0 g of ammonium acetate in 25 mL of water, and add 38.0 mL of 6 N hydrochloric acid. Adjust, if necessary, with 6 N ammonium hydroxide or 6 N hydrochloric acid to a pH of 3.5, dilute with water to 100 mL, and mix.Standard Preparation— Into a 50-mL color-comparison tube pipet 2 mL of Standard Lead Solution (20 µg of Pb), and dilute with water to 25 mL. Using a pH meter or short-range pH indicator paper as external indicator, adjust with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0, dilute with water to 40 mL, and mix.Test Preparation— Into a 50-mL color-comparison tube place 25 mL of the solution prepared for the test as directed in the individual monograph; or, using the designated volume of acid where specified in the individual monograph, dissolve in and dilute with water to 25 mL the quantity, in g, of the substance to be tested, as calculated by the formula:2.0/(1000L),in which L is the Heavy metals limit, as a percentage. Using a pH meter or short-range pH indicator paper as external indicator, adjust with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0, dilute with water to 40 mL, and mix.Monitor Preparation— Into a third 50-mL color-comparison tube place 25 mL of a solution prepared as directed for Test Preparation, and add 2.0 mL of Standard Lead Solution. Using a pH meter or short-range pH indicator paper as external indicator, adjust with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0, dilute with water to 40 mL, and mix. Procedure— To each of the three tubes containing the Standard Preparation, the Test Preparation, and the Monitor Preparation, add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL, mix, allow to stand for 2 minutes, and view downward over a white surface *: the color of the solution from the Test Preparation is not darker than that of the solution from the Standard Preparation, and the color of the solution from the Monitor Preparation is equal to or darker than that of the solution from the Standard Preparation. [NOTE—If the color of the Monitor Preparation is lighter than that of the Standard Preparation, use Method II instead of Method I for the substance being tested.]METHOD IINOTE—This method does not recover mercury.pH 3.5 Acetate Buffer— Prepare as directed under Method I.Standard Preparation— Pipet 4 mL of the Standard Lead Solution into a suitable test tube, and add 10 mL of 6 N hydrochloric acid.Test Preparation— Use a quantity, in g, of the substance to be tested as calculated by the formula:4.0/(1000L),in which L is the Heavy metals limit, as a percentage. Transfer the weighed quantity of the substance to a suitable crucible, add sufficient sulfuric acid to wet the substance, and carefully ignite at a low temperature until thoroughly charred. (The crucible may be loosely covered with a suitable lid during the charring.) Add to the carbonized mass 2 mL of nitric acid and 5 drops of sulfuric acid, and heat cautiously until white fumes no longer are evolved. Ignite, preferably in a muffle furnace, at 500to 600, until the carbon is completely burned off (no longer than 2 hours). If carbon remains, allow the residue to cool, add a few drops of sulfuric acid, evaporate, and ignite again. Cool, add 5 mL of 6 N hydrochloric acid, cover, and digest on a steam bath for 10 minutes. Cool, and quantitatively transfer the solution to a test tube. Rinse the crucible with a second 5-mL portion of 6 N hydrochloric acid, and transfer the rinsing to the test tube.Monitor Preparation— Pipet 4 mL of the Standard Lead Solution into a crucible identical to that used for the Test Preparation and containing a quantity of the substance under test that is equal to 10% of the amount required for the Test Preparation. Evaporate on a steam bath to dryness. Ignite at the same time, in the same muffle furnace, and under the same conditions used for the Test Preparation. Cool, add 5 mL of 6 N hydrochloric acid, cover, and digest on a steam bath for 10 minutes. Cool, and quantitatively transfer to a test tube. Rinse the crucible with a second 5-mL portion of 6 N hydrochloric acid, and transfer the rinsing to the test tube.Procedure— Adjust the solution in each of the tubes containing the Standard Preparation, the Test Preparation, and the Monitor Preparation with ammonium hydroxide, added cautiously and dropwise, to a pH of 9. Cool, and adjust with glacial acetic acid, added dropwise, to a pH of 8, then add 0.5 mL in excess. Using a pH meter or short-range pH indicator paper as external indicator, check the pH, and adjust, if necessary, with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0. Filter, if necessary, washing the filter with a few mL of water, into a 50-mL color-comparison tube, and then dilute with water to 40 mL. Add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL, mix, allow to stand for 2 minutes, and view downward over a white surface*: the color of the solution from the Test Preparation is not darker than that of the solution from the Standard Preparation, and the color of the solution from the Monitor Preparation is equal to or darker than that of the solution from the Standard Preparation. [NOTE—If the color of the solution from the Monitor Preparation is lighter than that of the solution from the Standard Preparation, proceed as directed for Method III for the substance being tested.]METHOD IIIpH 3.5 Acetate Buffer— Prepare as directed under Method I.Standard Preparation— Transfer a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid to a clean, dry, 100-mL Kjeldahl flask, and add a further volume of nitric acid equal to the incremental volume of nitric acid added to the Test Preparation. Heat the solution to the production of dense, white fumes; cool; cautiously add 10 mL of water; and, if hydrogen peroxide was used in treating the Test Preparation, add a volume of 30 percent hydrogen peroxide equal to that used for the substance being tested. Boil gently to the production of dense, white fumes. Again cool, cautiously add 5 mL of water, mix, and boil gently to the production of dense, white fumes and to a volume of 2 to 3 mL. Cool, dilute cautiously with a few mL of water, add 2.0 mL of Standard Lead Solution (20 µg of Pb), and mix. Transfer to a 50-mL color-comparison tube, rinse the flask with water, adding the rinsing to the tube until the volume is 25 mL, and mix.Test Preparation— Unless otherwise indicated in the individual monograph, use a quantity, in g, of the substance to be tested as calculated by the formula:2.0/(1000L),in which L is the Heavy metals limit, as a percentage.If the substance is a solid— Transfer the weighed quantity of the test substance to a clean, dry, 100-mL Kjeldahl flask. [NOTE—A 300-mL flask may be used if the reaction foams excessively.] Clamp the flask at an angle of 45, and add a sufficient quantity of a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid to moisten the substance thoroughly. Warm gently until the reaction commences, allow the reaction to subside, and add portions of the same acid mixture, heating after each addition, until a total of 18 mL of the acid mixture has been added. Increase the amount of heat, and boil gently until the solution darkens. Cool, add 2 mL of nitric acid, and heat again until the solution darkens. Continue the heating, followed by addition of nitric acid until no further darkening occurs, then heat strongly to the production of dense, white fumes. Cool, cautiously add 5 mL of water, boil gently to the production of dense, white fumes, and continue heating until the volume is reduced to a few mL. Cool, cautiously add 5 mL of water, and examine the color of the solution. If the color is yellow, cautiously add 1 mL of 30 percent hydrogen peroxide, and again evaporate to the production of dense, white fumes and a volume of 2 to 3 mL. If the solution is still yellow, repeat the addition of 5 mL of water and the peroxide treatment. Cool, dilute cautiously witha few mL of water, and rinse into a 50-mL color-comparison tube, taking care that the combined volume does not exceed 25 mL.If the substance is a liquid— Transfer the weighed quantity of the test substance to a clean, dry, 100-mL Kjeldahl flask. [NOTE—A 300-mL flask may be used if the reaction foams excessively.] Clamp the flask at an angle of 45, and cautiously add a few mL of a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid. Warm gently until the reaction commences, allow the reaction to subside, and proceed as directed for If the substance is a solid,beginning with ―add portions of the same acid mixture.‖Monitor Preparation— Proceed with the digestion, using the same amount of sample and the same procedure as directed in the subsection If the substance is a solid in the section Test Preparation, until the step ―Cool, dilute cautiously with a few mL of water.‖ Add 2.0 mL of Lead Standard Solution (20 µg of lead), and mix. Transfer to a 50-mL color comparison tube, rinse the flask with water, adding the rinsing to the tube until the volume is 25 mL, and mix. Procedure— Treat the Test Preparation, the Standard Preparation, and the Monitor Preparation as follows. Using a pH meter or short-range pH indicator paper as external indicator, adjust the solution to a pH between 3.0 and 4.0 with ammonium hydroxide (a dilute ammonia solution may be used, if desired, as the specified range is approached), dilute with water to 40 mL, and mix.To each tube add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL, mix, allow to stand for 2 minutes, and view downward over a white surface*: the color of the Test Preparation is not darker than that of the Standard Preparation, and the color of the Monitor Preparation is equal to or darker than that of the Standard Preparation.。

摘要美国药典 (USP) 组织正在开发有关药品和原料药中元素杂质测定的新通则。

USP<232> 规定了分析物的限量，而 USP<233> 则规定了样品制备选项（包括密闭容器微波消解）并推荐使用现代仪器，例如多元素 ICP-MS 和 ICP-OES 技术。

根据 USP<233> 的规定，分析仪器的检定须基于性能测试，包括需要论证仪器的准确性、重现性以及能够可靠鉴定分析物。

在本文中，我们列出的数据表明依照 USP<232>/<233> 成功验证了 Agilent 7700x ICP-MS 检测明胶胶囊样品中元素杂质的应用。

参照美国药典通则 <232>/<233> 草案验证 Agilent 7700x ICP-MS 在测定原料药元素杂质中的应用应用简报作者Samina Hussain Exova 美国Amir Liba and Ed McCurdy 安捷伦科技公司 美国制药所有规定的元素都通过了 USP<233> 的可接受标准，包括那些可能遭受基质干扰（比如 Cl 叠加在 V、Cr 和 As 上）的元素。

在 USP<232> 所要求的元素中，有些在氯化物基质中更易溶解或在化学上更加稳定，尤其是低浓度汞和铂族元素 (PGE)，因此可在所有水溶液和酸消化样品中加入低百分比浓度的 HCl 使它们稳定。

由于通过氦反应池气体（7700 的标准操作模式）能可靠地消除基于 Cl 的多原子干扰，因此，在常规操作中加入 HCl 来稳定样品对于 ICP-MS 方法来说已不再是问题。

引言美国药典 (USP) 组织目前正在开发药物中无机（元素性）杂质的新监测方法。

新通则 USP<232>（限量）和 <233> （规程）将在 2013 年实施。

USP<232> 为覆盖面更广的无机（元素）杂质（As、Cd、Hg、Pb、V、Cr、Ni、Mo、Mn、Cu、Pt、Pd、Ru、Rh、Os 和 Ir）规定了新的、更低的允许日接触量 (PDE) [1]。

元素杂质方法验证
元素杂质是指不同于主要成分的微量元素或化合物。

为了保证药品的质量和安全性，需要对药品中的元素杂质进行验证。

以下是几种常用的元素杂质方法验证：
1. 原子荧光光谱法（AA）：该方法是根据不同元素的原子吸收特性，利用吸收光谱测定其中某些元素的含量。

AA法具有灵敏度高、分辨率好、选择性强等优点，是常用的元素杂质分析方法之一。

2. 感应耦合等离子体质谱法（ICP-MS）：该方法可以同时测定元素杂质的多个元素，具有高精度和高分析速度等优点。

3. 原子荧光光度法（AED）：使用激发光源使样品中的元素发生激发态，然后测量其发射光谱，从而确定其中的元素种类和含量。

该方法具有很高的检测灵敏度和多元素分析的能力。

4. 燃烧离子色谱法（CIC）：CIC法主要用于测定药品中的卤素含量，该方法具有独特的分离能力和极高的灵敏度。

5. 紫外-可见分光光度法（UV-Vis）：该方法主要用于有色元素的检测，如铁、铜、镍等金属离子。

通过测量样品的吸收光谱，可以确定其中的元素含量。

232元素杂质—限度介绍本通则明确了药品中各元素杂质的限度。

元素杂质包括催化剂、环境污染物，可能存在于原料药、赋形剂、制剂中。

这些杂质或自然产生，或有意添加，或由于不注意而引入（例如，与处理设备相互作用）。

当知道元素杂质存在，或有意添加，或有引入的可能性，应当保证这些杂质符合限度要求。

可以采用基于风险的控制策略来确保产品满足限度标准。

由于砷、镉、铅和汞普遍存在的特性，风险控制策略至少应考虑这四种元素。

不管采用什么分析方法，所有药品均应满足元素杂质限度标准。

本章提出的限度标准不适用于赋形剂与原料药，除非本章或各论中明确说明。

然而赋形剂与原料药中元素杂质水平必须报告。

本章提出的限度标准同样不适用于兽用产品和常规疫苗。

饮食补充剂和它们的成份的相关规定见于《饮食补充剂中的元素杂质》2232 .1形态分析对于元素氧化态、有机络合态、化合态的测定，称为形态分析。

每种元素可能存在不同的氧化态或络合态。

然而，砷和汞应特别关注，因为它们的无机态和络合有机态具有不同的毒性。

砷的限度标准是基于无机态（毒性最大）。

假定样品中所有砷都是无机态，可用总砷测定法检测。

当总砷法结果超过限度标准，应当使用能够对不同形态砷定量的分析方法，以确定无机态砷是否满足法定要求。

汞的限度标准是基于无机（2+）氧化态。

甲基汞（毒性最强），但对于药品，通常不是问题。

这样，汞限度标准的确定是基于汞最常见的无机形态。

对于可能含有甲基汞的产品（例如，从鱼中得到的物质），相应的汞限度标准将在各论中提及。

接触途径元素杂质的毒性跟接触程度（生物利用度）有关。

对于每一种元素杂质接触程度取决于给药途径：口服、肠外注射、吸入。

这些限度确定是基于慢性接触。

为建立标准需要，另两种给药途径，黏膜和局部接触可认为跟口服相同，而表1中的PDE值也适用于这些产品[注意—药品的给药途径在制剂通则中介绍制剂通则1151. ]Change to read:药品表1的第二至第四栏给出的限度值是一些元素杂质的基本日剂量PDE值（病人按指定给药途径服用）。

原料药中元素杂质的法规要求及控制方法张再奇元素杂质又称重金属，重金属原义指比重大于5的金属，元素杂质包括可能存在于原料、辅料或制剂中，来源于合成中催化剂残留、药品生产制备过程中引入或辅料中存在的、生产设备引入、或容器密闭系统引入。

某些元素杂质不仅对药品的稳定性、保质期产生不利影响，还可能因为潜在的毒性引发药物副反应。

因此欧盟、美国对杂质的控制越来越严格，对此项不断修订，中国在加入ICH后对此项检测应该也会向国际靠拢，因此了解法规对元素杂质的要求、建立有效的检测方法变得尤为重要。

一、各国法规变更史（1）EMA、EP关于元素杂质的修订EP最新版为9.0版，其中保留了2.4.8金属测试方法A-H；2.4.20章节金属催化剂和金属试剂残留检测；5.20金属催化剂或金属试剂残留。

但在9.3增补版（2018年1月1日实施）中5.20项下规定，元素杂质限度遵循ICH要求。

EMA对元素杂质的修订如下表1。

（2）ICH对元素杂质的修订历程ICH于2009年10月批准了Q3D，经多方讨论后，修订版本的Q3D step4于2014年12月16日生效，其中列出了24种元素杂质的三种给药途径的PDE 值，确定实施日期为：新上市许可为2016年6月生效，已上市品种为2017年12月生效。

（3）USP对元素杂质的修订历程FDA规定在2018年1月1日之后，针对USP药典品种，提交新的NDA、ANDA 应该符合USP<232>、<233>。

针对非USP药典品种，申请人提交新的NDA、ANDA时，应该遵循Q3D。

美国对元素杂质的规定与ICH规定在不同时期，内容不一致，但从2017年12月之后，USP对元素种类和限量均与ICH保持一致。

修订历程详见下表2。

（4）中国药典对重金属检测的修订中国药典对重金属检测的修订主要体现在表3中，名称仍然为重金属，方法仍采用比色法，2017年中国成为了ICH成员国，未来中国的药政监管将遵循ICH指南规定，元素杂质与国际接轨也是大势所趋。

231重金属检查法本试验系在规定的试验条件下，金属离子与硫化物离子反应显色，通过与制备的标准铅溶液目视比较测定，以确证供试品中重金属杂质含量不超过各论项下规定的限度（以供试品中铅的百分比表示，以重量计）。

【见分光光度法和光散射项下测定法目视比较法<851>】【注意：对本试验有反应的典型物质有铅、汞、铋、砷、锑、锡、镉、银、铜和钼等】除各论另有规定外，按第一法测定重金属。

第一法适用于在规定试验条件下，能产生澄清、无色溶液的物质。

第二法适用于在第一法规定试验条件下不能产生澄清、无色溶液的物质，或者适用于由于性质复杂，易干扰硫化物离子与金属离子形成沉淀的物质，或者是不易挥发的和易挥发的油类物质。

第三法为湿消化法，仅用于第一法、第二法都不适合的情况。

特殊试剂硝酸铅贮备液制备：取硝酸铅159.8mg，溶于100ml水中，加1ml硝酸，用水稀释至1000ml。

制备和贮存本溶液的玻璃容器应不含可溶性铅。

标准铅溶液制备：使用当天，取硝酸铅贮备液10.0ml，用水稀释至100.0ml。

每1mL的标准铅溶液含相当于10µg的铅。

按每克供试品取100µL标准铅溶液制备的对照溶液，相当于供试品含百万分之一的铅。

在上述二试管中，分别加入pH3.5的醋酸盐缓冲液2mL，然后再加硫代乙酰胺—甘油试液1.2mL，用水稀释至50mL，混匀，放置2分钟，在白色平面自上向下观察：供试品溶液产生的颜色与标准品溶液产生的颜色相比，不得更深。

EP 版的重金属分析方法重金属方法A供试溶液：12ml待测水溶液，2ml pH为3.5的缓冲溶液，混合后加1.2ml的硫代乙酰胺试液，立即混合。

对照溶液：10ml的标准铅溶液（1ppm or 2ppm Pb），2ml pH为3.5的缓冲溶液，2ml的待测液，混合后加1.2ml的硫代乙酰胺试液，立即混合。

空白溶液：10ml的水，2ml pH为3.5的缓冲溶液，2ml的测试溶液。

232元素杂质—限度123介绍4本通则明确了药品中各元素杂质的限度。

元素杂质包括催化剂、环境污染物，5可能存在于原料药、赋形剂、制剂中。

这些杂质或自然产生，或有意添加，或6由于不注意而引入（例如，与处理设备相互作用）。

当知道元素杂质存在，或7有意添加，或有引入的可能性，应当保证这些杂质符合限度要求。

可以采用基8于风险的控制策略来确保产品满足限度标准。

由于砷、镉、铅和汞普遍存在的9特性，风险控制策略至少应考虑这四种元素。

不管采用什么分析方法，所有药10品均应满足元素杂质限度标准。

11本章提出的限度标准不适用于赋形剂与原料药，除非本章或各论中明确说12明。

然而赋形剂与原料药中元素杂质水平必须报告。

13本章提出的限度标准同样不适用于兽用产品和常规疫苗。

饮食补充剂和它们14的成份的相关规定见于《饮食补充剂中的元素杂质》2232 .11516形态分析17对于元素氧化态、有机络合态、化合态的测定，称为形态分析。

每种元素可能存在不同的氧化态或络合态。

然而，砷和汞应特别关注，因为它们的无机态1819和络合有机态具有不同的毒性。

20砷的限度标准是基于无机态（毒性最大）。

假定样品中所有砷都是无机态，可用总砷测定法检测。

当总砷法结果超过限度标准，应当使用能够对不同形态2122砷定量的分析方法，以确定无机态砷是否满足法定要求。

23汞的限度标准是基于无机（2+）氧化态。

甲基汞（毒性最强），但对于药品，24通常不是问题。

这样，汞限度标准的确定是基于汞最常见的无机形态。

对于可25能含有甲基汞的产品（例如，从鱼中得到的物质），相应的汞限度标准将在各26论中提及。

27282930接触途径31元素杂质的毒性跟接触程度（生物利用度）有关。

对于每一种元素杂质接触程度取决于给药途径：口服、肠外注射、吸入。

这些限度确定是基于慢性接触。

3233为建立标准需要，另两种给药途径，黏膜和局部接触可认为跟口服相同，而表1中的PDE值也适用于这些产品[注意—药品的给药途径在制剂通则中介绍制剂通34则1151. ]35Change to read:363738药品39表1的第二至第四栏给出的限度值是一些元素杂质的基本日剂量PDE值（病40人按指定给药途径服用）。

摘要美国药典（USP ）正在开发药品及其成分中有机杂质的新检测方法。

人们普遍认为目前的 USP<231>“重金属限量检测”在范围、准确性、灵敏度和专属性等方面均存在不足，将在 2013 年被新通则 USP<232>（限度）和 <233>（方法）所取代。

新方法将克服当前方法的局限，特别是关于分析物列表、样品制备、挥发性分析物的保留以及密闭容器样品消解和现代仪器技术的应用，以实现单个分析物的精确回收和浓度测定。

本白皮书提供了新通则的开发背景，并介绍了安捷伦 700x ICP-MS 如何应对该新方法的要求。

元素杂质的 USP 新通则 <232> 和 <233>：ICP-MS 在药物分析中的应用白皮书作者Amir Liba 和 Ed McCurdy 安捷伦科技公司美国前言药品中杂质的存在受到关注，不仅是由于某些污染物具有毒性，而且还因为它们可能对药品的稳定性、保质期产生不利影响，或可能引发有害的副作用。

因此，必须对药品生产所用原料、中间体和活性成分（API）、赋形剂（稳定剂、填充剂、粘结剂、着色剂、调味剂、糖衣等），以及最终药物产品中所含的有机和无机（元素）杂质进行监测和控制。

对生产过程中可能引入的杂质，如催化剂和来自生产工艺设备的污染物，也必须进行监测。

在美国，用于监测制药材料中污染物（包括元素杂质）的限度和方法由美国药典（USP）制定，但负责强制执行的监管部门是 FDA。

现在 USP 正在开发监测药物材料中无机（元素）杂质的新方法。

提出的新通则 USP<232>（限度）和<233>（方法）将于 2013 年起执行。

监测药物样品中有机污染物的现行方法是有着 100 年历史的比色法，USP 通则 <231> 中有明确规定。

该方法被称为“重金属限度检测法”，其原理是 10 种元素（Ag、As、Bi、Cd、Cu、Hg、Mo、Pb、Sb 和 Sn）与硫代乙酰胺反应生成硫化物沉淀。

Method III pH 3.5 Acetate Buffer—Prepare as directed under Method I.Standard Preparation—Transfer a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid to a clean, dry, 100-mL Kjeldahl flask, and add a further volume of nitric acid equal to the incremental volume of nitric acid added to the Test Preparation . Heat the solution to the production of dense, white fumes; cool; cautiously add 10 mL of water; and, if hydrogen peroxide was used in treating the Test Preparation , add a volume of 30 percent hydrogen peroxide equal to that used for the substance be-ing tested. Boil gently to the production of dense, white fumes. Again cool, cautiously add 5 mL of water, mix, and boil gently to the production of dense, white fumes and to a volume of 2 to 3 mL. Cool, dilute cautiously with a few mL of water, add 2.0mL of Standard Lead Solution (20 m g of Pb), and mix. Transfer to a 50-mL color-comparison tube, rinse the flask with water,adding the rinsing to the tube until the volume is 25 mL, and mix.Test Preparation—Unless otherwise indicated in the individual monograph, use a quantity, in g, of the substance to be tested as calculated by the formula:2.0/(1000L)in which L is the Heavy metals limit, as a percentage.If the substance is a solid—Transfer the weighed quantity of the test substance to a clean, dry, 100-mL Kjeldahl flask.[NOTE —A 300-mL flask may be used if the reaction foams excessively.] Clamp the flask at an angle of 45°, and add a sufficient quantity of a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid to moisten the substance thoroughly. Warm gently until the reaction commences, allow the reaction to subside, and add portions of the same acid mixture, heating after each addi-tion, until a total of 18 mL of the acid mixture has been added. Increase the amount of heat, and boil gently until the solutiondarkens. Cool, add 2 mL of nitric acid, and heat again until the solution darkens. Continue the heating, followed by addition ofnitric acid until no further darkening occurs, then heat strongly to the production of dense, white fumes. Cool, cautiously add 5 mL of water, boil gently to the production of dense, white fumes, and continue heating until the volume is reduced to a fewmL. Cool, cautiously add 5 mL of water, and examine the color of the solution. If the color is yellow, cautiously add 1 mL of 30percent hydrogen peroxide, and again evaporate to the production of dense, white fumes and a volume of 2 to 3 mL. If thesolution is still yellow, repeat the addition of 5 mL of water and the peroxide treatment. Cool, dilute cautiously with a few mL of water, and rinse into a 50-mL color-comparison tube, taking care that the combined volume does not exceed 25 mL.If the substance is a liquid—Transfer the weighed quantity of the test substance to a clean, dry, 100-mL Kjeldahl flask.[N OTE —A 300-mL flask may be used if the reaction foams excessively.] Clamp the flask at an angle of 45°, and cautiously add a few mL of a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid. Warm gently until the reaction commences, allow the reaction to subside, and proceed as directed for If the substance is a solid , beginning with “add portions of the same acid mix-ture.”Monitor Preparation—Proceed with the digestion, using the same amount of sample and the same procedure as directed in the subsection If the substance is a solid in the section Test Preparation , until the step “Cool, dilute cautiously with a few mL of water.” Add 2.0 mL of Lead Standard Solution (20 m g of lead), and mix. Transfer to a 50-mL color comparison tube, rinse the flask with water, adding the rinsing to the tube until the volume is 25 mL, and mix.Procedure—Treat the Test Preparation , the Standard Preparation , and the Monitor Preparation as follows. Using a pH meter or short-range pH indicator paper as external indicator, adjust the solution to a pH between 3.0 and 4.0 with ammonium hy-droxide (a dilute ammonia solution may be used, if desired, as the specified range is approached), dilute with water to 40 mL,and mix.To each tube add 2 mL of pH 3.5 Acetate Buffer , then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50mL, mix, allow to stand for 2 minutes, and view downward over a white surface*: the color of the Test Preparation is not darker than that of the Standard Preparation , and the color of the Monitor Preparation is equal to or darker than that of the Standard Preparation .Official:January 1, 2018(RB 1-Apr-2015)(Official 1-Jan-2018)á232ñ ELEMENTAL IMPURITIES—LIMITSINTRODUCTIONThis general chapter specifies limits for the amounts of elemental impurities in drug products. Elemental impurities include catalysts and environmental contaminants that may be present in drug substances, excipients, or drug products. These impuri-ties may occur naturally, be added intentionally, or be introduced inadvertently (e.g., by interactions with processing equip-ment and the container closure system). When elemental impurities are known to be present, have been added, or have the potential for introduction, assurance of compliance to the specified levels is required. A risk-based control strategy may be ap-268 á231ñ Heavy Metals / Chemical Tests USP 39propriate when analysts determine how to assure compliance with this standard. Due to the ubiquitous nature of arsenic, cad-mium, lead, and mercury, they (at the minimum) must be considered in the risk assessment. Regardless of the approach used, compliance with the limits specified is required for all drug products unless otherwise specified in an individual monograph or excluded in paragraph three of this introduction.The drug products containing purified proteins and polypeptides (including proteins and polypeptides produced from re-combinant or non-recombinant origins), their derivatives, and products of which they are components (e.g., conjugates) are within the scope of this chapter, as are drug products containing synthetically produced polypeptides, polynucleotides, and oligosaccharides.This chapter does not apply to radiopharmaceuticals, vaccines, cell metabolites, DNA products, allergenic extracts, cells, whole blood, cellular blood components or blood derivatives including plasma and plasma derivatives, dialysate solutions not intended for systemic circulation, and elements that are intentionally included in the drug product for therapeutic benefit. This chapter does not apply to products based on genes (gene therapy), cells (cell therapy), and tissue (tissue engineering).The limits presented in this chapter do not apply to excipients and drug substances, except where specified in this chapter or in the individual monograph. However, elemental impurity levels present in drug substances and excipients must be known, documented, and made available upon request.This chapter does not apply to articles intended only for veterinary use. Requirements listed in this chapter also do not apply to total parenteral nutritions (TPNs) and dialysates. Dietary supplements and their ingredients are addressed in Elemental Con-taminants in Dietary Supplements á2232ñ.SPECIATIONThe determination of the oxidation state, organic complex, or combination is termed speciation. Each of the elemental im-purities has the potential to be present in differing oxidation or complexation states. However, arsenic and mercury are of par-ticular concern because of the differing toxicities of their inorganic and complexed organic forms.The arsenic limits are based on the inorganic (most toxic) form. Arsenic can be measured using a total-arsenic procedure under the assumption that all arsenic contained in the material under test is in the inorganic form. Where the limit is exceeded using a total-arsenic procedure, it may be possible to show via a procedure that quantifies the different forms that the inorgan-ic form meets the specification.The mercury limits are based upon the inorganic (2+) oxidation state. The methyl mercury form (most toxic) is rarely an issue for pharmaceuticals. Thus, the limit was established assuming the most common (mercuric) inorganic form. Limits for articles that have the potential to contain methyl mercury (e.g., materials derived from fish) are to be provided in the monograph.ROUTES OF EXPOSUREThe toxicity of an elemental impurity is related to its extent of exposure (bioavailability). The extent of exposure has been determined for each of the elemental impurities of interest for three routes of administration: oral, parenteral, and inhalational. These limits are based on chronic exposure. Consider the oral permissible daily exposures (PDEs) in Table 1, as a starting point in developing specific PDEs for other routes of administration except where otherwise stated in the individual monograph. [N OTE—The routes of administration of drug products are defined in Pharmaceutical Dosage Forms á1151ñ.]DRUG PRODUCTSThe limits described in the second through fourth columns of Table 1 are the base daily dose PDEs of the elemental impuri-ties of interest for a drug product taken by a patient according to indicated routes of administration.Parenteral ProductsParenteral drug products with maximum daily volumes up to 2 L may use the maximum daily volume to calculate permissi-ble concentrations from PDEs. For products whose daily volumes, as specified by labeling and/or established by clinical prac-tice, may exceed 2 L (e.g., saline, dextrose, TPNs, solutions for irrigation), a 2-L volume may be used to calculate permissible concentrations from PDEs.Table 1. Elemental Impurities for Drug ProductsElementOral DailyDose PDE a(m g/day)Parenteral DailyDose PDE(m g/day)Inhalational DailyDose PDE(m g/day)Cadmium522Lead555Inorganic arsenic a15152a See Speciation section.USP 39Chemical Tests / á232ñ Elemental Impurities—Limits 269Table 1. Elemental Impurities for Drug Products (Continued)Element Oral Daily Dose PDE a (m g/day)Parenteral Daily Dose PDE (m g/day)Inhalational DailyDose PDE(m g/day)Inorganic mercury a 3031Iridium 100101Osmium 100101Palladium 100101Platinum 100101Rhodium 100101Ruthenium 100101Chromium 1100011003Molybdenum 3000150010Nickel 200205Vanadium 100101Copper 300030030a See Speciationsection.Options for Demonstrating ComplianceDRUG PRODUCT ANALYSIS OPTIONThe results obtained from the analysis of a typical dosage unit, scaled to a maximum daily dose, are compared to the DailyDose PDE .Daily Dose PDE ³ measured value (m g/g) × maximum daily dose (g/day)The measured amount of each impurity is NMT the Daily Dose PDE , unless otherwise stated in the individual monograph.SUMMATION OPTIONSeparately add the amounts of each elemental impurity (in m g/g) present in each of the components of the drug product:Daily Dose PDE ³ [S M 1(C M × W M )] × D DM = each ingredient used to manufacture a dosage unitCM = element concentration in component (drug substance or excipient) (m g/g)W M = weight of component in a dosage unit (g/dosage unit)D D = number of units in the maximum daily dose (unit/day)The result of the summation of each impurity is NMT the Daily Dose PDE , unless otherwise stated in the individual mono-graph. Before products can be evaluated using this option, the manufacturer must ensure that additional elemental impurities cannot be inadvertently added through the manufacturing process or via the container closure system over the shelf life of the product.INDIVIDUAL COMPONENT OPTIONFor drug products with a daily dose of NMT 10g, if all drug substances and excipients in a formulation meet the concentra-tion limits shown in Table 2, then these components may be used in any proportion. No further calculation is necessary. While elemental impurities derived from the manufacturing process or the container closure system are not specifically provided for in the Individual Component Option , it is expected that the drug product manufacturer will ensure that these sources do not contribute significantly to the total content of elemental impurities.Change to read:DRUG SUBSTANCE AND EXCIPIENTSThe concentration of elemental impurities in drug substances and excipients must be controlled and, where present, docu-mented. The acceptable levels for these impurities depend on the material's ultimate use. Therefore, drug product manufactur-ers must determine the acceptable level of elemental impurities in the drug substances and excipients used to produce their products.270 á232ñ Elemental Impurities—Limits / Chemical Tests USP 39The values provided in Table 2 are example concentration limits for components (drug substances and excipients) of drug products dosed at a maximum daily dose of 10g/day. These values serve as default concentration limits to aid discussions be-tween drug product manufacturers and the suppliers of the components of their drug products. [N OTE—Individual compo-nents may need to be limited at levels different from those in the table depending on monograph-specific mitigating factors.]ANALYTICAL TESTINGIf, by process monitoring and supply-chain control, manufacturers can demonstrate compliance, then further testing may not be needed. When testing is done to demonstrate compliance, proceed as directed in Elemental Impurities—Proceduresá233ñ and minimally include arsenic, cadmium, lead, and mercury in the Target Elements evaluation.á233ñ ELEMENTAL IMPURITIES—PROCEDURESINTRODUCTIONThis chapter describes two analytical procedures (Procedures 1 and 2) for the evaluation of the levels of the elemental impuri-ties. The chapter also describes criteria for acceptable alternative procedures. By means of validation studies, analysts will con-firm that the analytical procedures described herein are suitable for use on specified material.Use of Alternative ProceduresThe chapter also describes criteria for acceptable alternative procedures. Alternative procedures that meet the validation re-quirements herein may be used in accordance with General Notices and Requirements 6.30, Alternative and Harmonized Methods and Procedures. Information on the Requirements for Alternate Procedure Validation is provided later in this chapter.SpeciationThe determination of the oxidation state, organic complex, or combination is termed speciation. Analytical procedures for speciation are not included in this chapter, but examples may be found elsewhere in USP–NF and in the literature.COMPENDIAL PROCEDURES 1 AND 2System standardization and suitability evaluation using applicable reference materials should be performed on the day of analysis.USP 39Chemical Tests / á233ñ Elemental Impurities—Procedures 271。

USP 36-233 修订公告20130128 （中英文）<232> Elemental Impurities—Limits and <233> Elemental Impurities—Procedures<232>元素杂质---限度和<233>元素杂质—检测方法Pursuant to a Revision Bulletin posted on November 15, 2012 and updated on November 21, 2012, and in accordance with the Rules and Procedures of the 2010–2015 Council of Experts, the Executive Committee of the Council of Experts (CoE EC) postponed the official dates of <232> Elemental Impurities—Limits and <233> Elemental Impurities—Procedures. The purpose for the postponement was to allow adequate time for the CoE EC to adjudicate and render a decision on three appeals related to the two general chapters. Due to the similarity of issues raised, these appeals were consolidated and considered simultaneously as a single appeal. As noted in the prior Revision Bulletin, the portion of the appeal that was allowed to proceed and was considered by the CoE EC was that related to the content of the general chapters and their official dates. The portion of the appeal that related to the planned implementation of these chapters effective May 2014 through a proposed General Notices provision was denied as untimely, as the General Notices proposal at issue had not yet appeared in Pharmacopeial Forum (PF) forpublic notice and comment.在2012年11月15日修订公告贴出，在2012年11月21日更新后，根据2010-2015专家委员会规则和程序，专家执行委员会推迟了<232>【元素杂质—限度】和<233>【元素杂质---方法】的公布时间。

5634〈232〉 Elemental Impurities—Limits / Chemical TestsSecond Supplement to USP 35–NF 30Table 1. Elemental Impurities for Drug Products (Continued)Individual components may need to be limited at levels dif-ferent from those in the table depending on monograph-Paren-Inhala-specific mitigating factors.]Oral teral tional LVP Daily Daily Daily Compo-Table 2. Default Concentration Limits for Drug Substances andDose Dose Dose nent ExcipientsPDE a PDE PDE LimitElement (µg/day)(µg/day)(µg/day)(µg/g)Concentra-Concentra-Concentra-Nickel 50050 1.5 5.0tion Limits tion Limits tion Limits Vanadium 1001030 1.0(µg/g) for (µg/g) for (µg/g) for Oral Drug Parenteral Inhalational Copper 10001007025Products Drug Prod-Drug Prod-a PDE = Permissible daily exposure based on a 50-kg person.with a ucts with a ucts with a b See Speciation section.Maximum Maximum Maximum *Not a safety concern.Daily Dose Daily Dose Daily Dose Element of ≤10 g/dayof ≤10 g/dayof ≤10 g/dayOptions for Demonstrating ComplianceCadmium 2.50.250.15Lead0.50.50.5Inorganic DRUG PRODUCT ANALYSIS OPTIONarsenic 0.150.150.15Inorganic The results obtained from the analysis of a typical dosage mercury 1.50.150.15unit, scaled to a maximum daily dose, are compared to the Iridium 10 1.00.15Daily Dose PDE .Osmium 10 1.00.15Daily Dose PDE ≥ measured value (µg/g) × maximum dailyPalladium 10 1.00.15dose (g/day)Platinum 10 1.00.15Rhodium 10 1.00.15The measured amount of each impurity is NMT the Daily Ruthenium 10010 1.5Dose PDE , unless otherwise stated in the individual monograph.Chromium ** 2.5Molybdenum 10 1.025Nickel 50 5.00.15SUMMATION OPTIONVanadium 1001030Copper 100107Separately add the amounts of each elemental impurity (in µg/g) present in each of the components of the drug *Not a safety concern.product using the following equation:ANALYTICAL TESTINGDaily Dose PDE ≥ [ΣM 1(C M × W M )] × D DIf, by validated processes and supply-chain control, manu-wherefacturers can demonstrate the absence of impurities, then M = each ingredient used to manufacture a dosage unit further testing is not needed. When testing is done to C M = element concentration in component (drug sub-demonstrate compliance, proceed as directed in general stance or excipient) (µg/g)chapter Elemental Impurities—Procedures 〈233〉, and mini-W M = weight of component in a dosage unit (g/dosage mally include As, Cd, Pd, and Hg in the Target Element eval-unit)uation.s 2S (USP35)D D = number of units in the maximum daily dose (unit/day)The result of the summation of each impurity is NMT the Daily Dose PDE , unless otherwise stated in the individual monograph. Before products can be evaluated using this option, the manufacturer must validate that additional ele-mental impurities cannot be inadvertently added through Add the following:the manufacturing process.DRUG SUBSTANCE AND EXCIPIENTSs〈233〉 ELEMENTAL IMPURITIES—The presence of elemental impurities in drug substances PROCEDURESand excipients must be controlled and, where present, re-ported. The acceptable levels for these impurities depend on the material’s ultimate use. Therefore, drug product manu-facturers must determine the acceptable level of elemental impurities in the drug substances and excipients used to INTRODUCTIONproduce their products.This chapter describes two analytical procedures (Proce-The values provided in Table 2 represent concentration dures 1 and 2) for the evaluation of the levels of the ele-limits for components (drug substances and excipients) of mental impurities. The chapter also describes criteria for ac-drug products dosed at a maximum daily dose of ≤10 g/ceptable alternative procedures. Alternative procedures that day. These values serve as default concentration limits to aid meet the validation requirements described herein may be discussions between drug product manufacturers and the considered equivalent to Procedures 1 and 2 for the pur-suppliers of the components of their drug products. [N OTE —poses of this test. In addition, system standardization andSecond Supplement to USP 35–NF 30Chemical Tests / 〈233〉 Elemental Impurities—Procedures5635suitability evaluation using applicable reference materials COMPENDIAL PROCEDURES 1 AND 2 should be performed on the day of analysis. The require-ment for an elemental impurity test is specified in GeneralNotices and Requirements or in the individual monograph. Bymeans of verification studies, analysts will confirm that the Procedure and Detection Technique analytical procedures described herein, as well as alternativeanalytical procedures, are suitable for use on specified Procedure 1 can be used for elemental impurities generally material.amenable to detection by inductively coupled plas-ma–atomic (optical) emission spectroscopy (ICP–AES orICP–OES). Procedure 2 can be used for elemental impurities Speciation generally amenable to detection by ICP–MS. Before initialuse, the analyst should verify that the procedure is appropri-The determination of the oxidation state, organic complex ate for the instrument and sample used (procedural verifica-or combination is termed speciation. Analytical procedures tion) by meeting the Alternative Procedure Validation require-for speciation are not included in this chapter but examples ments below.may be found elsewhere in the USP–NF and in the literature.Sample PreparationDefinitionsForms of sample preparation include Neat, Direct Aqueous Concentrated Acid:Concentrated ultra-pure nitric, sulfu-Solution, Direct Organic Solution, and Indirect Solution. The ric, hydrochloric, or hydrofluoric acids or Aqua Regia.selection of the appropriate sample preparation depends onthe material under test and is the responsibility of the ana-Aqua Regia:Aqua regia is a mixture of concentrated hy-lyst. When a sample preparation is not indicated in the drochloric and nitric acids, typically at ratios of 3:1 or 4:1,monograph, an analyst may use any of the following appro-respectively.priately verified preparation procedures. In cases where spik-Matched Matrix:Solutions having the same solvent com-ing of a material under test is necessary to provide an ac-position as the Sample solution. In the case of an aqueous ceptable signal intensity, the blank should be spiked with solution, Matched Matrix would indicate that the same acids,the same Target Elements, and where possible, using the acid concentrations, and mercury stabilizer are used in both same spiking solution. Standard solutions may contain mul-preparations.tiple Target Elements. [NOTE—All liquid samples should be Target Elements:Elements with the potential of being weighed.]present in the material under test. Include As, Cd, Pd, and Neat:Used for liquids or alternative procedures that allows Hg in the target element evaluation when testing is done to the examination of unsolvated samples.demonstrate compliance. Target elements should also in-Direct Aqueous Solution:Used when the sample is solu-clude any elements that may be added through materialble in an aqueous solvent.processing or storage, and any elements whose presencemay interfere with the operation of the analytical proce-Direct Organic Solution:Used where the sample is solu-dures.ble in an organic solvent.Target Limit or Target Concentration:The acceptance Indirect Solution:Used when a material is not directly sol-value for the elemental impurity being evaluated. Exceeding uble in aqueous or organic solvents. Digest the sample us-the target limit indicates that a material under test exceeds ing a closed-vessel digestion procedure, similar to the proce-the acceptable value. The determination of compliance is dure provided below. The sample preparation scheme addressed in other chapters. [N OTE—When applying this should yield sufficient sample to allow quantification of each chapter to Elemental Impurities—Limits 〈232〉 and Elemental element at the limit specified in the corresponding mono-Contaminants in Dietary Supplements 〈2232〉,1Target Limits graph or chapter.can be approximated by dividing the Daily Dose PDEs by the Closed Vessel Digestion:This sample-preparation proce-maximum daily dose for the Drug Product Analysis Option in dure is designed for samples that must be digested in a〈232〉 or the Daily Serving PDE divided by the maximum Concentrated Acid using a closed-vessel digestion apparatus. daily serving size in 〈2232〉]Closed-vessel digestion minimizes the loss of volatile impuri-J:The concentration (w/w) of the element(s) of interest at ties. The choice of a Concentrated Acid depends on the sam-the Target Limit, appropriately diluted to the working range ple matrix. The use of any of the Concentrated Acids may be of the instrument. For example, if the target elements are appropriate, but each introduces inherent safety risks. There-Pb and As for an analysis of an oral solid drug product with fore, appropriate safety precautions should be used at alla daily dose of 10g/day using an inductively coupled plas-times. [N OTE—Weights and volumes provided may be ad-ma–mass spectrometry (ICP-MS). The target limit for these justed to meet the requirements of the digestion apparatus elements would be 0.5 µg/g and 0.15 µg/g (see Table 2 in used.]chapter 〈232〉). However, in this case, the linear dynamic An example procedure that has been shown to have range of the ICP-MS is known to extend from 0.01 ng/mL broad applicability is the following. Dehydrate and predigest to 0.1 µg/mL for these elements. Therefore, a dilution factor0.5 g of primary sample in 5 mL of freshly prepared Concen-of at least 1:10 is required to ensure that the analysis occurs trated Acid. Allow to sit loosely covered for 30 minutes in a in the linear dynamic range of the instrument. J would thus fume hood. Add an additional 10 mL of Concentrated Acid, equal 0.05 µg/mL and 0.015 µg/mL for Pb and As, respec-and digest, using a closed vessel technique, until digestion tively, when the dilution factor is added.or extraction is complete. Repeat if necessary by adding anadditional 5 mL of Concentrated Acid. [N OTE—Where closed Appropriate Reference Materials:Where Appropriate Ref-vessel digestion is necessary, follow the manufacturer’s rec-erence Materials are specified in the chapter, certified refer-ommended procedures to ensure safe use.]ence materials (CRM) from a national metrology institute(NMI), or reference materials that are traceable to the CRM Reagents:All reagents used for the preparation of sample of a NMI should be used. An example of a NMI in the and standard solutions should be free of elemental impuri-United States is the National Institute of Standards and ties, in accordance with Plasma Spectrochemistry 〈730〉. Technology.1This dietary supplement chapter is still under revision and will appear onlinein PF 38(3) [May–June 2012].5636〈233〉 Elemental Impurities—Procedures / Chemical Tests Second Supplement to USP 35–NF 30system well (60 seconds) before introducing the Sample in Procedure 1: ICP-AESorder to minimize carryover.]Analysis:Analyze according to the manufacturer’s sugges-Standardization solution 1:2J of the Target Element(s) intions for program and m/z. Calculate and report resultsa Matched Matrixbased on the original sample size. [N OTE—Appropriate Standardization solution 2:0.5J of the Target Element(s)measures must be taken to correct for matrix-induced inter-in a Matched Matrix ferences (e.g., argon chloride interference with arsenic Sample stock solution:Proceed as directed in Sample determinations.]Preparation above. Allow the sample to cool, if necessary.For mercury determination, add an appropriate stabilizer.ALTERNATE PROCEDURE VALIDATION Sample solution:Dilute the Sample Stock Solution with anappropriate solvent to obtain a final concentration of theIf a specified compendial procedure does not meet the Target Elements at NMT 2J.needs of a specific application, an alternative procedure may Blank:Matched Matrixbe used (see General Notices 6.30). Alternative procedures Elemental spectrometric system must be validated and must be acceptable and therefore (See Plasma Spectrochemistry 〈730〉.)equivalent to the compendial procedures for the purposes Mode:ICP of the test. The principles of validation are provided in gen-Detector:Optical detection system eral chapter Validation of Compendial Procedures 〈1225〉. Thelevel of validation necessary to ensure that an alternative Rinse:Diluent usedprocedure is acceptable depends on whether a limit test or Standardization:Standardization solution 1, Standardi- a quantitative determination is necessary. The requirementszation solution 2, and Blank for validation of an elemental impurities procedure for either System suitability type of determination are described below. Where this infor-Sample:Standardization solution 1mation differs from that presented in Validation of Com-pendial Procedures 〈1225〉, the parameters and acceptance Suitability requirementscriteria presented in this chapter take precedence. Any alter-Drift:Compare results obtained from Standardizationnative procedure that has been validated and meets the ac-solution 1 before and after the analyis of the Sampleceptance criteria that follow is considered to be equivalent solutions.to the compendial procedures for the purposes of this test.Suitability criteria:NMT 20% for each Target Element.[N OTE—If samples are high in mineral content, rinse systemwell (60 seconds) before introducing the Sample in order to LIMIT PROCEDURESminimize carryover.]The following section defines the validation parameters Analysis:Analyze according to the manufacturer’s sugges-for the acceptability of alternative limit procedures. Meeting tions for program and wavelength. Calculate and report re-these requirements must be demonstrated experimentally sults on the basis of the original sample size. [N OTE—Appro-using an appropriate system suitability procedure and refer-priate measures must be taken to correct for matrix-inducedence material. Meeting these requirements demonstrates interferences (e.g., Wavelength overlaps).]that the procedure is equivalent to the compendial proce-dure as a limit procedure for the Target Element.Procedure 2: ICP-MS The suitability of the method must be determined byconducting studies with material or mixture under test sup-plemented with known concentrations of each Target Ele-Standardization solution 1:2J of the Target Element(s) inment of interest at the appropriate acceptance limit concen-a Matched Matrixtration. The material or mixture under test must be spiked Standardization solution 2:0.5J of the Target Element(s)before any sample preparation steps are performed.in a Matched MatrixSample stock solution:Proceed as directed for SamplePreparation above. Allow the sample to cool, if necessary. DetectabilityFor mercury determination, add an appropriate stabilizer.Sample solution:Dilute the Sample stock solution with an Standard solution: A preparation of reference materials for appropriate solvent to obtain a final concentration of the the Target Element(s) at the Target Concentrations.Target Elements at NMT 2J.Spiked sample solution 1:Prepare a solution of sample Blank:Matched Matrix under test, spiked with appropriate reference materials forthe Target Elements at the Target Concentration, solubilized Elemental spectrometric systemor digested as described in Sample Preparation.(See Plasma Spectrochemistry 〈730〉.)Spiked sample solution 2:Prepare a solution of the sam-Mode:ICP. [N OTE—An instrument with a cooled sprayple under test, spiked with appropriate reference materials chamber is recommended. (A collision cell or reaction cellat 80% of the Target Concentration for the Target Elements, may also be beneficial.)]solubilized or digested as described in Sample Preparation.Detector:Mass spectrometerUnspiked sample solution: A sample of material under Rinse:Diluent usedtest, solubilized or digested in the same manner as the Sam-Standardization:Standardization solution 1, Standardi-ple solutions.zation solution 2, and BlankAcceptance criteriaSystem suitabilityNon-instrumental procedures:Spiked sample solution 1 Sample:Standardization solution 1provides a signal or intensity equivalent to or greater thanSuitability requirements that of the Standard Solution. Spiked sample solution 2 must Drift:Compare results obtained from Standardization provide a signal or intensity less than that of the Spiked solution 1 before and after the analysis of the Sample sample solution 1. [N OTE—The signal from each Spiked sam-solutions.ple solution is NLT the Unspiked sample solutiondetermination.]Suitability criteria:Drift NMT 20% for each Target Ele-ment. [N OTE—If samples are high in mineral content, rinse Instrumental procedures:The average value of thethree replicate measurements of Spiked sample solution 1 isSecond Supplement to USP 35–NF 30Physical Tests / 〈616〉 Bulk Density and Tapped Density of Powders 5637within (±15%) of the average value obtained for the repli-RUGGEDNESScate measurements of the Standard solution . The average value of the replicate measurements of Spiked sample solu-Perform the Repeatability analysis over three independent tion 2 must provide a signal intensity or value less than that events using the following events or combinations thereof:of the Standard solution . [N OTE —Correct the values obtained 1.on different days, orfor each of the spiked solutions using the Unspiked sample 2.with different instrumentation, or solution .]3.with different analysts.Acceptance criteriaRelative standard deviation:NMT 25% for each Target Precision for Instrumental MethodsElement(Repeatability)[N OTE —Non-instrumental precision is demonstrated by Specificitymeeting the Detectability requirement above.]Sample solutions:Six independent samples of the mate-The procedure must be able to unequivocally assess (see rial under test, spiked with appropriate reference materials Validation of Compendial Procedures 〈1225〉) each Target Ele-for the Target Elements at the Target Concentration .ment in the presence of components that may be expected Acceptance criteriato be present, including other Target Elements , and matrix components.Relative standard deviation:NMT 20% for each Target Element .Limit of Quantitation, Range, and LinearitySpecificityDemonstrated by meeting the Accuracy requirement.s 2S (USP35)The procedure must be able to unequivocally assess (see Validation of Compendial Procedures 〈1225〉) each Target Ele-ment in the presence of components that may be expected to be present, including other Target Elements , and matrix components.Physical Tests and QUANTITATIVE PROCEDURESDeterminationsThe following section defines the validation parameters for the acceptability of alternative quantitative procedures.Meeting these requirements must be demonstrated experi-mentally, using an appropriate system suitability procedure 〈616〉 BULK DENSITY AND and reference materials. Meeting these requirements dem-onstrates that the procedure is equivalent to the compendial TAPPED DENSITY OF POWDERSprocedure for the purpose of quantifying the Target Elements .AccuracyChange to read:Standard solutions:Prepare solutions containing the Tar-get Elements at concentrations ranging from 50% to 150%of J , using appropriate reference materials.BULK DENSITYTest samples:Prepare samples of the material under test spiked with appropriate reference materials before any sam-This general chapter has been harmonized with the corre-ple preparation steps (digestion or solubilization) at concen-sponding texts of the European Pharmacopoeia and/or the trations ranging from 50% to 150% of J for each Target Japanese Pharmacopoeia . 3The portion that is not harmo-Element .nized is marked with symbols (33) to specify this fact.3Acceptance criteriaThe bulk density of a powder is the ratio of the mass of Spike recovery:70%–150% for the mean of three rep-an untapped powder sample and its volume including the licate preparations at each concentrationcontribution of the interparticulate void volume. Hence, the bulk density depends on both the density of powder parti-cles and the spatial arrangement of particles in the powder Precisionbed. The bulk density is expressed in grams per mL (g/mL)although the international unit is kilograms per cubic meter (1g/mL = 1000kg/m 3) because the measurements aremade using cylinders. It may also be expressed in grams per REPEATABILITYcubic centimeter (g/cm 3). The bulking properties of a pow-der are dependent upon the preparation, treatment, and Test samples:Six independent samples of material understorage of the sample, i.e., how it was handled. The parti-test (taken from the same lot) spiked with appropriate refer-cles can be packed to have a range of bulk densities; how-ence materials for the Target Element(s) at the indicated ever, the slightest disturbance of the powder bed may result level.in a changed bulk density. Thus, the bulk density of a pow-Acceptance criteriader is often very difficult to measure with good reproducibil-ity and, in reporting the results, it is essential to specify how Relative standard deviation:NMT 20% for each Target the determination was made. The bulk density of a powder Elementis determined by measuring the volume of a known weight of powder sample, that may have been passed through a s sieve s 2S (USP35), into a graduated cylinder (Method I ), or by。

原料药中元素杂质的法规要求及控制方法张再奇元素杂质又称重金属，重金属原义指比重大于5的金属，元素杂质包括可能存在于原料、辅料或制剂中，来源于合成中催化剂残留、药品生产制备过程中引入或辅料中存在的、生产设备引入、或容器密闭系统引入。

某些元素杂质不仅对药品的稳定性、保质期产生不利影响，还可能因为潜在的毒性引发药物副反应。

因此欧盟、美国对杂质的控制越来越严格，对此项不断修订，中国在加入ICH后对此项检测应该也会向国际靠拢，因此了解法规对元素杂质的要求、建立有效的检测方法变得尤为重要。

一、各国法规变更史（1）EMA、EP关于元素杂质的修订EP最新版为9.0版，其中保留了2.4.8金属测试方法A-H；2.4.20章节金属催化剂和金属试剂残留检测；5.20金属催化剂或金属试剂残留。

但在9.3增补版（2018年1月1日实施）中5.20项下规定，元素杂质限度遵循ICH要求。

EMA对元素杂质的修订如下表1。

（2）ICH对元素杂质的修订历程ICH于2009年10月批准了Q3D，经多方讨论后，修订版本的Q3D step4于2014年12月16日生效，其中列出了24种元素杂质的三种给药途径的PDE 值，确定实施日期为：新上市许可为2016年6月生效，已上市品种为2017年12月生效。

（3）USP对元素杂质的修订历程FDA规定在2018年1月1日之后，针对USP药典品种，提交新的NDA、ANDA 应该符合USP<232>、<233>。

针对非USP药典品种，申请人提交新的NDA、ANDA时，应该遵循Q3D。

美国对元素杂质的规定与ICH规定在不同时期，内容不一致，但从2017年12月之后，USP对元素种类和限量均与ICH保持一致。

修订历程详见下表2。

（4）中国药典对重金属检测的修订中国药典对重金属检测的修订主要体现在表3中，名称仍然为重金属，方法仍采用比色法，2017年中国成为了ICH成员国，未来中国的药政监管将遵循ICH指南规定，元素杂质与国际接轨也是大势所趋。

美国药典对正文修订的杂质检查新要求最近，美国药典对申报正文修订时的杂质检查有新的要求，非复杂有效成分、生物制品和生物技术制品、辅料、疫苗的正文修订申报指导原则（USP guideline for submitting requests for revision to the USP-NF）正在征求意见。

现将其中非复杂有效成分正文修订中的杂质部分简述如下：正文有关内容修订所用术语可参考文件ICH Q3A（R）。

其中指定杂质包括已知杂质（identified impurity）和未知杂质(unidentified impurity)。

原料药中的杂质原料药中的杂质检查，对指定杂质（specified impurities）应规定限量，并且对所有非指定杂质（unspecified impurities）的限量定为0.10%( The impurity test of a drug substance monograph is intended to limit all specified impurities, with a further limit of 0.10% for all unspecified impurities)。

新的正文要求用表1中的命名。

表1杂质检查杂质类型Q3A杂质分类USP传统检查新的USP检查有机起始原料普通杂质色谱纯度有关物质——的限度指定杂质副产物中间体降解产物指定和未指定杂质试剂，配位体，催化剂指定杂质无机试剂，配位体，催化剂无指定杂质重金属和其他残留金属重金属——的限度重金属无机盐炽灼残渣炽灼残渣残留溶剂有机挥发性杂质——的限度有机挥发性杂质USP正文原料药仅检查实际存在的杂质，不检查理论存在的。

如果采用不同的合成工艺，由此产生不同的杂质，则需要用不同的杂质检查方法，并在包装中标明可行的检查方法。

如果杂质的毒性已经FDA评价过，则在修订报告中应包括毒性数据。

有机杂质常用液相和气相法检查，对杂质鉴别和定量，最好用外标法，而不用内标法，用内标法可能混入其他杂质。

á233ñ ELEMENTAL IMPURITIES—PROCEDURESINTRODUCTIONThis chapter describes two analytical procedures (Procedures 1 and 2) for the evaluation of the levels of the elemental impuri-ties. The chapter also describes criteria for acceptable alternative procedures. By means of validation studies, analysts will confirm that the analytical procedures described herein are suitable for use on specified material.Use of Alternative ProceduresThe chapter also describes criteria for acceptable alternative procedures. Alternative procedures that meet the validation re-quirements herein may be used in accordance with General Notices and Requirements 6.30, Alternative and Harmonized Meth-ods and Procedures . Information on the Requirements for Alternate Procedure Validation is provided later in this chapter.SpeciationThe determination of the oxidation state, organic complex, or combination is termed speciation . Analytical procedures for spe-ciation are not included in this chapter, but examples may be found elsewhere in USP–NF and in the literature.PROCEDURES• C OMPENDIAL P ROCEDURES 1 AND 2System standardization and suitability evaluation using applicable reference materials should be performed on the day of analysis.Procedure and detection technique:Procedure 1 can be used for elemental impurities generally amenable to detection byinductively coupled plasma–atomic (optical) emission spectroscopy (ICP–AES or ICP–OES). Procedure 2 can be used for ele-mental impurities generally amenable to detection by ICP–MS. Before initial use, the analyst should verify that the proce-dure is appropriate for the instrument and sample used (procedural verification) by meeting the alternative procedure vali-dation requirements below.Sample preparation:Forms of sample preparation include Neat , Direct aqueous solution , Direct organic solution , and Indi-rect solution . The selection of the appropriate sample preparation depends on the material under test and is the responsibil-ity of the analyst. When a sample preparation is not indicated in the monograph, an analyst may use any of the followingappropriately validated preparation procedures. In cases where spiking of a material under test is necessary to provide an acceptable signal intensity, the blank should be spiked with the same Target elements , and where possible, using the same spiking solution. Standard solutions may contain multiple Target elements . [N OTE —All liquid samples should be weighed.]Neat:Used for liquids or alternative procedures that allow the examination of unsolvated samples.Direct aqueous solution:Used when the sample is soluble in an aqueous solvent.Direct organic solution:Used where the sample is soluble in an organic solvent.Indirect solution:Used when a material is not directly soluble in aqueous or organic solvents. Total metal extraction is the preferred sample preparation approach to obtain an Indirect solution . Digest the sample using the Closed vessel diges-tion procedure provided below or one similar to it. The sample preparation scheme should yield sufficient sample to allow quantification of each element at the limit specified in the corresponding monograph or chapter.Closed vessel digestion:This sample preparation procedure is designed for samples that must be digested in a Concen-trated acid using a closed vessel digestion apparatus. Closed vessel digestion minimizes the loss of volatile impurities. The choice of a Concentrated acid depends on the sample matrix. The use of any of the Concentrated acids may be appropri-ate, but each introduces inherent safety risks. Therefore, appropriate safety precautions should be used at all times.[N OTE —Weights and volumes provided may be adjusted to meet the requirements of the digestion apparatus used.]An example procedure that has been shown to have broad applicability is the following. Dehydrate and predigest 0.5 g of primary sample in 5 mL of freshly prepared Concentrated acid . Allow to sit loosely covered for 30 min in a fume hood.Add an additional 10 mL of Concentrated acid , and digest, using a closed vessel technique, until digestion or extraction is complete. Repeat, if necessary, by adding an additional 5 mL of Concentrated acid . [N OTE —Where closed vessel digestion is necessary, follow the manufacturer’s recommended procedures to ensure safe use.]Alternatively, leachate extraction may be appropriate with justification following scientifically validated metal disposition studies, which may include animal studies, speciation, or other means of studying disposition of the specific metal in the drug product.Reagents:All reagents used for the preparation of sample and standard solutions should be free of elemental impurities,in accordance with Plasma Spectrochemistry á730ñ.• P ROCEDURE 1: ICP–OESStandardization solution 1: 1.5J of the Target element(s) in a Matched matrixStandardization solution 2:0.5J of the Target element(s) in a Matched matrixSample stock solution:Proceed as directed in Sample preparation above. Allow the sample to cool, if necessary. For mer-cury determination, add an appropriate stabilizer.Sample solution:Dilute the Sample stock solution with an appropriate solvent to obtain a final concentration of the Target elements at NMT 1.5J .Blank:Matched matrix298 á233ñ Elemental Impurities—Procedures / Chemical Tests USP 40Elemental spectrometric system(See Plasma Spectrochemistry á730ñ.)Mode:ICPDetector:Optical detection systemRinse:Diluent usedStandardization:Standardization solution 1, Standardization solution 2, and BlankSystem suitabilitySample:Standardization solution 1Suitability requirementsDrift:Compare results obtained from Standardization solution 1 before and after the analysis of the Sample solution.Suitability criteria:NMT 20% for each Target element. [N OTE—If samples are high in mineral content, rinse system well before introducing the Sample in order to minimize carryover.]Analysis:Analyze according to the manufacturer's suggestions for program and wavelength. Calculate and report results on the basis of the original sample size. [N OTE—Appropriate measures must be taken to correct for matrix-induced inter-ferences (e.g., wavelength overlaps).]• P ROCEDURE2: ICP–MSStandardization solution 1: 1.5J of the Target element(s) in a Matched matrixStandardization solution 2:0.5J of the Target element(s) in a Matched matrixSample stock solution:Proceed as directed for Sample preparation above. Allow the sample to cool, if necessary. For mercury determination, add an appropriate stabilizer.Sample solution:Dilute the Sample stock solution with an appropriate solvent to obtain a final concentration of the Target elements at NMT 1.5J.Blank:Matched matrixElemental spectrometric system(See Plasma Spectrochemistry á730ñ.)Mode:ICP. [N OTE—An instrument with a cooled spray chamber is recommended. (A collision cell or reaction cell may also be beneficial.)]Detector:Mass spectrometerRinse:Diluent usedStandardization:Standardization solution 1, Standardization solution 2, and BlankSystem suitabilitySample:Standardization solution 1Suitability requirementsDrift:Compare results obtained from Standardization solution 1 before and after the analysis of the Sample solution.Suitability criteria:Drift NMT 20% for each Target element. [N OTE—If samples are high in mineral content, rinse sys-tem well before introducing the Sample in order to minimize carryover.]Analysis:Analyze according to the manufacturer's suggestions for program and m/z. Calculate and report results based on the original sample size. [N OTE—Appropriate measures must be taken to correct for matrix-induced interferences (e.g., argon chloride interference with arsenic determinations).]REQUIREMENTS FOR ALTERNATE PROCEDURE VALIDATIONIf the specified compendial procedures do not meet the needs of a specific application, an alternative procedure may be devel-oped (see General Notices and Requirements 6.30, Alternative and Harmonized Methods and Procedures). Alternative proce-dures must be validated and shown to be acceptable, in accordance with the validation requirements for alternative proce-dures as described below. The level of validation necessary to ensure that an alternative procedure is acceptable depends on whether a limit test or a quantitative determination is specified in the monograph. The requirements for the validation of an elemental impurities procedure for each type of determination are described below. Any alternative procedure that has been validated and meets the acceptance criteria that follow is considered to be suitable for use.LIMIT PROCEDURESThe following section defines the validation parameters for the acceptability of alternative limit procedures. Meeting these re-quirements must be demonstrated experimentally using an appropriate system suitability procedure and reference material. The suitability of the method must be determined by conducting studies with the material or mixture under test supplemen-ted with known concentrations of each Target element of interest at the appropriate acceptance limit concentration. The ma-terial or mixture under test must be spiked before any sample preparation steps are performed.• D ETECTABILITYStandard solution: A preparation of reference materials for the Target element(s) at the Target concentrationSpiked sample solution 1:Prepare a solution of sample under test, spiked with appropriate reference materials for the Target elements at the Target concentration, solubilized or digested as described in Sample preparation.Spiked sample solution 2:Prepare a solution of the sample under test, spiked with appropriate reference materials at 80% of the Target concentration for the Target elements, solubilized or digested as described in Sample preparation.Unspiked sample solution: A sample of material under test, solubilized or digested in the same manner as the SamplesolutionsUSP 40Chemical Tests / á233ñ Elemental Impurities—Procedures 299Acceptance criteriaNon-instrumental procedures:Spiked sample solution 1 provides a signal or intensity equivalent to or greater than that of the Standard solution . Spiked sample solution 2 must provide a signal or intensity less than that of Spiked sample solu-tion 1. [N OTE —The signal from each Spiked sample solution is NLT the Unspiked sample solution determination.]Instrumental procedures:The average value of the three replicate measurements of Spiked sample solution 1 is within ±15% of the average value obtained for the replicate measurements of the Standard solution . The average value of the replicate measurements of Spiked sample solution 2 must provide a signal intensity or value less than that of the Standard solution . [N OTE —Correct the values obtained for each of the spiked solutions using the Unspiked sample solution .]• P RECISION FOR I NSTRUMENTAL M ETHODS (R EPEATABILITY )[N OTE —Non-instrumental precision is demonstrated by meeting the Detectability requirement above.]Sample solutions:Six independent samples of the material under test, spiked with appropriate reference materials for the Target elements at the Target concentrationAcceptance criteriaRelative standard deviation:NMT 20% for each Target element• S PECIFICITYThe procedure must be able to unequivocally assess (see Validation of Compendial Procedures á1225ñ) each Target element in the presence of components that may be expected to be present, including other Target elements , and matrix compo-nents.QUANTITATIVE PROCEDURESThe following section defines the validation parameters for the acceptability of alternative quantitative procedures. Meetingthese requirements must be demonstrated experimentally, using an appropriate system suitability procedure and referencematerials. Meeting these requirements demonstrates that the procedure is equivalent to the compendial procedure for thepurpose of quantifying the Target elements .• A CCURACYStandard solutions:Prepare solutions containing the Target elements at concentrations ranging from 50% to 150% of J ,using appropriate reference materials.Test samples:Prepare samples of the material under test spiked with appropriate reference materials before any sample preparation steps (digestion or solubilization) at concentrations ranging from 50% to 150% of J for each Target element .Acceptance criteriaSpike recovery:70%–150% for the mean of three replicate preparations at each concentration• P RECISIONRepeatabilityTest samples:Six independent samples of material under test (taken from the same lot) spiked with appropriate refer-ence materials for the Target element(s) at the indicated levelAcceptance criteriaRelative standard deviation:NMT 20% (N = 6) for each Target elementIntermediate precision (ruggedness)Perform the Repeatability analysis again either on a different day, with a different instrumentation, with a different analyst,or a combination thereof. Combine the results of this analysis with the Repeatability analysis so the total number of anal-yses is 12.Acceptance criteriaRelative standard deviation:NMT 25% (N = 12) for each Target element• S PECIFICITYThe procedure must be able to unequivocally assess (see á1225ñ) each Target element in the presence of components that may be expected to be present, including other Target elements , and matrix components.• L IMIT OF Q UANTITATION , R ANGE , AND L INEARITYDemonstrated by meeting the Accuracy requirement.GLOSSARYConcentrated acid:Concentrated ultra-pure nitric, sulfuric, hydrochloric, or hydrofluoric acids or Aqua regiaAqua regia:Aqua regia is a mixture of concentrated hydrochloric and nitric acids, typically at ratios of 3:1 or 4:1, respective-ly.Matched matrix:Solutions having the same solvent composition as the Sample solution . In the case of an aqueous solution,Matched matrix would indicate that the same acids, acid concentrations, and mercury stabilizer are used in both prepara-tions.Target elements:Elements with the potential of being present in the material under test. Include arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in the target element evaluation when testing is done to demonstrate compliance. Target elements should also include any elements that may be added through material processing or storage.Target limit or Target concentration:The acceptance value for the elemental impurity being evaluated. Exceeding the Tar-get limit indicates that a material under test exceeds the acceptable value. The determination of compliance is addressed in other chapters. [N OTE —When applying this chapter to Elemental Impurities—Limits á232ñ andElemental Contaminants in Diet-300 á233ñ Elemental Impurities—Procedures / Chemical Tests USP 40ary Supplements á2232ñ, Target limits can be approximated by dividing the Daily Dose PDEs by the maximum daily dose for the Drug Product Analysis Option in á232ñ or the Daily Serving PDE divided by the maximum daily serving size in á2232ñ.]J:The concentration (w/w) of the element(s) of interest at the Target limit, appropriately diluted to the working range of the instrument. For example, if the target elements are lead and arsenic for an analysis of an oral solid drug product with a daily dose of 10g/day using inductively coupled plasma–mass spectrometry (ICP–MS), the target limit for these elements would be 0.5 m g/g and 1.5 m g/g (see Table 2 in á232ñ). However, in this case, the linear dynamic range of the ICP–MS is known to extend from 0.01 ng/mL to 0.1 m g/mL for these elements. Therefore, a dilution factor of at least 1:100 is required to ensure that the analysis occurs in the linear dynamic range of the instrument. J would thus equal 5 ng and 15 ng/mL for lead and arsenic, respectively, when the dilution factor is added.Appropriate reference materials:Where Appropriate reference materials are specified in the chapter, certified reference ma-terials (CRM) from a national metrology institute (NMI), or reference materials that are traceable to the CRM of an NMI should be used. An example of an NMI in the United States is the National Institute of Standards and Technology.á241ñ IRONThis limit test is provided to demonstrate that the content of iron, in either the ferric or the ferrous form, does not exceed the limit for iron specified in the individual monograph. The determination is made by concomitant visual comparison with a control prepared from a standard iron solution.SPECIAL REAGENTSStandard Iron SolutionDissolve 863.4 mg of ferric ammonium sulfate [FeNH4(SO4)2·12H2O] in water, add 10 mL of 2N sulfuric acid, and dilute with water to 100.0 mL. Pipet 10 mL of this solution into a 1000-mL volumetric flask, add 10 mL of 2N sulfuric acid, dilute with water to volume, and mix. This solution contains the equivalent of 0.01 mg (10 m g) of iron per mL.Ammonium Thiocyanate SolutionDissolve 30g of ammonium thiocyanate in water to make 100 mL.STANDARD PREPARATIONInto a 50-mL color-comparison tube pipet 1 mL of Standard Iron Solution (10 m g of Fe), dilute with water to 45 mL, add 2 mL of hydrochloric acid, and mix.TEST PREPARATIONInto a 50-mL color comparison tube place the solution prepared for the test as directed in the individual monograph and if necessary dilute with water to 45 mL; or, dissolve in water, and dilute with water to 45 mL the quantity, in g, of the substance to be tested, as calculated by the formula:1.0/(1000L)in which L is the Iron limit in percentage. Add 2 mL of hydrochloric acid, and mix.PROCEDURETo each of the tubes containing the Standard Preparation and the Test Preparation add 50 mg of ammonium peroxydisulfate crystals and 3 mL of Ammonium Thiocyanate Solution, and mix: the color of the solution from the Test Preparation is not darker than that of the solution from theStandard Preparation.USP 40Chemical Tests / á241ñ Iron 301。

First Supplement to USP 40–NF 35Chemical Tests / á232ñ Elemental Impurities—Limits 8065á232ñ ELEMENTAL IMPURITIES—LIMITSChange to read:INTRODUCTIONor drug products. These impurities may occur naturally, be added intentionally, or be introduced inadvertently (e.g., by inter-actions with processing equipment and the container–closure system). When elemental impurities are known to be present, have been added, or have the potential for introduction, assurance of compliance to the specified levels is required. A risk-based control strategy may be appropriate when analysts determine how to assure compliance with this standard. Due to theSPECIATIONThe determination of the oxidation state, organic complex, or combination is termed “speciation”. Each of the elemental impurities has the potential to be present in differing oxidation or complexation states. However, arsenic and mercury are of particular concern because of the differing toxicities of their inorganic and complexed organic forms.The arsenic limits are based on the inorganic (most toxic) form. Arsenic can be measured using a total-arsenic procedure under the assumption that all arsenic contained in the material under test is in the inorganic form. Where the limit is exceeded using a total-arsenic procedure, it may be possible to show, via a procedure that quantifies the different forms, that the inor-ganic form meets the specification.The mercury limits are based upon the inorganic (2+) oxidation state. The methyl mercury form (most toxic) is rarely an issue for pharmaceuticals. Thus, the limit was established assuming the most common (mercuric) inorganic form. Limits for articles that have the potential to contain methyl mercury (e.g., materials derived from fish) are to be provided in the monograph.Change to read:ROUTES OF EXPOSUREdetermined for each of the elemental impurities of interest for three routes of administration: oral, parenteral, and inhalational.These limits are based on chronic exposure. Consider the oral permissible daily exposures (PDEs) in Table 1 as a starting point in developing specific PDEs for other routes of administration, except where otherwise stated in the individual monograph.[N OTE —The routes of administration of drug products are defined in Pharmaceutical Dosage Forms á1151ñ.]Change to read:DRUG PRODUCTSTable 1 are the base daily dose PDEs of theParenteral ProductsParenteral drug products with maximum daily volumes up to 2 L may use the maximum daily volume to calculate permissi-missible concentrations from PDEs.8066 á232ñ Elemental Impurities—Limits / Chemical TestsFirst Supplement to USP 40–NF 35First Supplement to USP 40–NF 35Chemical Tests / á232ñ Elemental Impurities—Limits 8067Recommendations for Elements to be Considered in the Risk AssessmentTable 2 identifies elemental impurities for inclusion in the risk assessment. This table can be applied to all sources of elemen-tal impurities in the drug product.Options for Demonstrating ComplianceDRUG PRODUCT ANALYSIS OPTIONThe results obtained from the analysis of a typical dosage unit, scaled to a maximum daily dose, are compared to the Daily Dose PDE.Daily Dose PDE³ measured value (m g/g) × maximum daily dose (g/day)The measured amount of each impurity is NMT the Daily Dose PDE, unless otherwise stated in the individual monograph.SUMMATION OPTIONSeparately, add the amounts of each elemental impurity (in m g/g) present in each of the components of the drug product:Daily Dose PDE³ [S M1(CM× WM)] × DDM= each ingredient used to manufacture a dosage unitC M = element concentration in component (drug substance or excipient) (m g/g)WM = weight of component in a dosage unit (g/dosage unit)D D = number of units in the maximum daily dose (unit/day)The result of the summation of each impurity is NMT the Daily Dose PDE, unless otherwise stated in the individual mono-graph. Before products can be evaluated using this option, the manufacturer must ensure that additional elemental impurities cannot be inadvertently added through the manufacturing process or via the container–closure system over the shelf life of the product.INDIVIDUAL COMPONENT OPTIONFor drug products with a daily dose of NMT 10g, if all drug substances and excipients in a formulation meet the concentra-tion limits shown in Table 3, then these components may be used in any proportion. No further calculation is necessary. While elemental impurities derived from the manufacturing process or the container–closure system are not specifically provided for in the Individual Component Option, it is expected that the drug product manufacturer will ensure that these sources do not contribute significantly to the total content of elemental impurities.Change to read:DRUG SUBSTANCE AND EXCIPIENTSproducts dosed at a maximum daily dose of 10g/day. These values serve as default concentration limits to aid discussions be-tween drug product manufacturers and the suppliers of the components of their drug products. [N OTE—Individual compo-nents may need to be limited at levels different from those in the table depending on monograph-specific mitigating factors.]8068á232ñ Elemental Impurities—Limits / Chemical Tests First Supplement to USP 40–NF 35Change to read:ANALYTICAL TESTINGIf, by process monitoring and supply-chain control, manufacturers can demonstrate compliance, then further testing may Elemental Impurities—Procedures á233ñOTHER TESTS AND ASSAYSDelete the following:All radioactive determinations required by this method should be made with a suitable counting assembly over a period of time optimal for the particular counting assembly used. All procedures should be performed in replicate to obtain the greatest accuracy.USP REFERENCE STANDARD á11ñUSP Cyanocobalamin RS .CYANOCOBALAMIN TRACER REAGENTDilute an accurately measured volume of a solution of radioactive cyanocobalamin* with water to yield a solution having a radioactivity between 500 and 5000 counts per minute per mL. Add 1 drop of cresol per L of solution prepared, and store in a refrigerator.StandardizationPrepare a solution of a weighed quantity of USP Cyanocobalamin RS in water to contain 20 to 50 m g per mL. Perform the entire assay on a 10.0-mL portion of this solution, proceeding as directed under Assay Preparation , beginning with “Add water to make a measured volume.”First Supplement to USP 40–NF 35Chemical Tests / á371ñ Cobalamin Radiotracer Assay 8069。

231HEAVY METALSThis test is provided to demonstrate that the content of metallic impurities that are colored by sulfide ion, under the specified test conditions, does not exceed the Heavy metals limit specified in the individual monograph in percentage (by weight) of lead in the test substance, as determined by concomitant visual comparison (see Visual Comparison in the section Procedure underSpectrophotometry and Light-Scattering 851) with a control prepared from a Standard Lead Solution. [NOTE—Substances that typically will respond to this test are lead, mercury, bismuth, arsenic, antimony, tin, cadmium, silver, copper, and molybdenum.]Determine the amount of heavy metals by Method I, unless otherwise specified in the individual monograph. Method I is used for substances that yield clear, colorless preparations under the specified test conditions. Method II is used for substances that do not yield clear, colorless preparations under the test conditions specified for Method I, or for substances that, by virtue of their complex nature, interfere with the precipitation of metals by sulfide ion, or for fixed and volatile oils. Method III, a wet-digestion method, is used only in those cases where neither Method I nor Method II can be used.Special ReagentsLead Nitrate Stock Solution— Dissolve 159.8 mg of lead nitrate in 100 mL of water to which has been added 1 mL of nitric acid, then dilute with water to 1000 mL. Prepare and store this solution in glass containers free from soluble lead salts.Standard Lead Solution— On the day of use, dilute 10.0 mL of Lead Nitrate Stock Solution with water to 100.0 mL. Each mL of Standard Lead Solution contains the equivalent of 10 µg of lead. A comparison solution prepared on the basis of 100 µL of Standard Lead Solution per g of substance being tested contains the equivalent of 1 part of lead per million parts of substance being tested.METHOD IpH 3.5 Acetate Buffer— Dissolve 25.0 g of ammonium acetate in 25 mL of water, and add 38.0 mL of 6 N hydrochloric acid. Adjust, if necessary, with 6 N ammonium hydroxide or 6 N hydrochloric acid to a pH of 3.5, dilute with water to 100 mL, and mix.Standard Preparation— Into a 50-mL color-comparison tube pipet 2 mL of Standard Lead Solution (20 µg of Pb), and dilute with water to 25 mL. Using a pH meter or short-range pH indicator paper as external indicator, adjust with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0, dilute with water to 40 mL, and mix.Test Preparation— Into a 50-mL color-comparison tube place 25 mL of the solution prepared for the test as directed in the individual monograph; or, using the designated volume of acid where specified in the individual monograph, dissolve in and dilute with water to 25 mL the quantity, in g, of the substance to be tested, as calculated by the formula:2.0/(1000L),in which L is the Heavy metals limit, as a percentage. Using a pH meter or short-range pH indicator paper as external indicator, adjust with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0, dilute with water to 40 mL, and mix.Monitor Preparation— Into a third 50-mL color-comparison tube place 25 mL of a solution prepared as directed for Test Preparation, and add 2.0 mL of Standard Lead Solution. Using a pH meter or short-range pH indicator paper as external indicator, adjust with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0, dilute with water to 40 mL, and mix. Procedure— To each of the three tubes containing the Standard Preparation, the Test Preparation, and the Monitor Preparation, add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL, mix, allow to stand for 2 minutes, and view downward over a white surface *: the color of the solution from the Test Preparation is not darker than that of the solution from the Standard Preparation, and the color of the solution from the Monitor Preparation is equal to or darker than that of the solution from the Standard Preparation. [NOTE—If the color of the Monitor Preparation is lighter than that of the Standard Preparation, use Method II instead of Method I for the substance being tested.]METHOD IINOTE—This method does not recover mercury.pH 3.5 Acetate Buffer— Prepare as directed under Method I.Standard Preparation— Pipet 4 mL of the Standard Lead Solution into a suitable test tube, and add 10 mL of 6 N hydrochloric acid.Test Preparation— Use a quantity, in g, of the substance to be tested as calculated by the formula:4.0/(1000L),in which L is the Heavy metals limit, as a percentage. Transfer the weighed quantity of the substance to a suitable crucible, add sufficient sulfuric acid to wet the substance, and carefully ignite at a low temperature until thoroughly charred. (The crucible may be loosely covered with a suitable lid during the charring.) Add to the carbonized mass 2 mL of nitric acid and 5 drops of sulfuric acid, and heat cautiously until white fumes no longer are evolved. Ignite, preferably in a muffle furnace, at 500to 600, until the carbon is completely burned off (no longer than 2 hours). If carbon remains, allow the residue to cool, add a few drops of sulfuric acid, evaporate, and ignite again. Cool, add 5 mL of 6 N hydrochloric acid, cover, and digest on a steam bath for 10 minutes. Cool, and quantitatively transfer the solution to a test tube. Rinse the crucible with a second 5-mL portion of 6 N hydrochloric acid, and transfer the rinsing to the test tube.Monitor Preparation— Pipet 4 mL of the Standard Lead Solution into a crucible identical to that used for the Test Preparation and containing a quantity of the substance under test that is equal to 10% of the amount required for the Test Preparation. Evaporate on a steam bath to dryness. Ignite at the same time, in the same muffle furnace, and under the same conditions used for the Test Preparation. Cool, add 5 mL of 6 N hydrochloric acid, cover, and digest on a steam bath for 10 minutes. Cool, and quantitatively transfer to a test tube. Rinse the crucible with a second 5-mL portion of 6 N hydrochloric acid, and transfer the rinsing to the test tube.Procedure— Adjust the solution in each of the tubes containing the Standard Preparation, the Test Preparation, and the Monitor Preparation with ammonium hydroxide, added cautiously and dropwise, to a pH of 9. Cool, and adjust with glacial acetic acid, added dropwise, to a pH of 8, then add 0.5 mL in excess. Using a pH meter or short-range pH indicator paper as external indicator, check the pH, and adjust, if necessary, with 1 N acetic acid or 6 N ammonium hydroxide to a pH between 3.0 and 4.0. Filter, if necessary, washing the filter with a few mL of water, into a 50-mL color-comparison tube, and then dilute with water to 40 mL. Add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL, mix, allow to stand for 2 minutes, and view downward over a white surface*: the color of the solution from the Test Preparation is not darker than that of the solution from the Standard Preparation, and the color of the solution from the Monitor Preparation is equal to or darker than that of the solution from the Standard Preparation. [NOTE—If the color of the solution from the Monitor Preparation is lighter than that of the solution from the Standard Preparation, proceed as directed for Method III for the substance being tested.]METHOD IIIpH 3.5 Acetate Buffer— Prepare as directed under Method I.Standard Preparation— Transfer a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid to a clean, dry, 100-mL Kjeldahl flask, and add a further volume of nitric acid equal to the incremental volume of nitric acid added to the Test Preparation. Heat the solution to the production of dense, white fumes; cool; cautiously add 10 mL of water; and, if hydrogen peroxide was used in treating the Test Preparation, add a volume of 30 percent hydrogen peroxide equal to that used for the substance being tested. Boil gently to the production of dense, white fumes. Again cool, cautiously add 5 mL of water, mix, and boil gently to the production of dense, white fumes and to a volume of 2 to 3 mL. Cool, dilute cautiously with a few mL of water, add 2.0 mL of Standard Lead Solution (20 µg of Pb), and mix. Transfer to a 50-mL color-comparison tube, rinse the flask with water, adding the rinsing to the tube until the volume is 25 mL, and mix.Test Preparation— Unless otherwise indicated in the individual monograph, use a quantity, in g, of the substance to be tested as calculated by the formula:2.0/(1000L),in which L is the Heavy metals limit, as a percentage.If the substance is a solid— Transfer the weighed quantity of the test substance to a clean, dry, 100-mL Kjeldahl flask. [NOTE—A 300-mL flask may be used if the reaction foams excessively.] Clamp the flask at an angle of 45, and add a sufficient quantity of a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid to moisten the substance thoroughly. Warm gently until the reaction commences, allow the reaction to subside, and add portions of the same acid mixture, heating after each addition, until a total of 18 mL of the acid mixture has been added. Increase the amount of heat, and boil gently until the solution darkens. Cool, add 2 mL of nitric acid, and heat again until the solution darkens. Continue the heating, followed by addition of nitric acid until no further darkening occurs, then heat strongly to the production of dense, white fumes. Cool, cautiously add 5 mL of water, boil gently to the production of dense, white fumes, and continue heating until the volume is reduced to a few mL. Cool, cautiously add 5 mL of water, and examine the color of the solution. If the color is yellow, cautiously add 1 mL of 30 percent hydrogen peroxide, and again evaporate to the production of dense, white fumes and a volume of 2 to 3 mL. If the solution is still yellow, repeat the addition of 5 mL of water and the peroxide treatment. Cool, dilute cautiously witha few mL of water, and rinse into a 50-mL color-comparison tube, taking care that the combined volume does not exceed 25 mL.If the substance is a liquid— Transfer the weighed quantity of the test substance to a clean, dry, 100-mL Kjeldahl flask. [NOTE—A 300-mL flask may be used if the reaction foams excessively.] Clamp the flask at an angle of 45, and cautiously add a few mL of a mixture of 8 mL of sulfuric acid and 10 mL of nitric acid. Warm gently until the reaction commences, allow the reaction to subside, and proceed as directed for If the substance is a solid,beginning with ―add portions of the same acid mixture.‖Monitor Preparation— Proceed with the digestion, using the same amount of sample and the same procedure as directed in the subsection If the substance is a solid in the section Test Preparation, until the step ―Cool, dilute cautiously with a few mL of water.‖ Add 2.0 mL of Lead Standard Solution (20 µg of lead), and mix. Transfer to a 50-mL color comparison tube, rinse the flask with water, adding the rinsing to the tube until the volume is 25 mL, and mix. Procedure— Treat the Test Preparation, the Standard Preparation, and the Monitor Preparation as follows. Using a pH meter or short-range pH indicator paper as external indicator, adjust the solution to a pH between 3.0 and 4.0 with ammonium hydroxide (a dilute ammonia solution may be used, if desired, as the specified range is approached), dilute with water to 40 mL, and mix.To each tube add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL, mix, allow to stand for 2 minutes, and view downward over a white surface*: the color of the Test Preparation is not darker than that of the Standard Preparation, and the color of the Monitor Preparation is equal to or darker than that of the Standard Preparation.。

化学原料药中元素杂质的风险评估元素杂质主要是指药品生产或贮藏过程中生成、加入或无意引入的物质。

由于药品中元素杂质不能给病人提供任何治疗益处（个别药品除外），而且还可能引发不良反应，或可能对药品的稳定性、保质期产生不利影响，因而建立旨在减少存在于药物中的元素杂质，或者对允许可接受的元素杂质浓度范围进行分析评估尤为重要。

2014年12月人用药品注册技术要求国际协调会（ICH）更新关于金属杂质的指南，该指导原则对元素杂质进行了重新分类，监控的元素杂质种类增加至24种，包含了毒性较大的非金属元素如砷、汞、硒及各种常用的金属催化剂、重金属等，并于2015年9月更名为ICH_ Q3D元素杂质指导原则（Q3D Guideline for elements impurities）。

自ICH 更新Q3D元素杂质指南后，欧洲药品管理局（EMA）和美国FDA相继更新了这一指南，与ICH高度保持一致，由此可见控制的杂质种类已经从传统的重金属扩展到非金属元素，对元素杂质的监控越来越严格，范围也变宽。

无论是ICH_Q3D还是EMA和美国FDA，都说明了元素杂质控制在生产中的重要性，而如何建立科学的控制策略，以有效控制实际生产中元素杂质的风险，保证产品质量显得尤为关键。

本文评估分析了原料药生产工艺、设备等因素可能产生的元素杂质，并基于风险评估，为药品制订合理的元素控制种类提供参考。

1、元素杂质的分类基于元素毒性及在药品中出现的可能性，将元素杂质分为三类：1类：砷、镉、汞和铅，毒性明显，通常来源于矿物赋形剂，药品生产中不得使用或限制使用，所有给药途径必须对该4种元素评估。

2类：有毒性，与给药途径相关。

根据元素出现概率，分为2A和2B类。

2A类包括钴、镍、钒，这些元素在制剂及设备中出现的可能性较高，需对所有潜在来源和给药途径进行风险评估；2B类元素在药品中出现的可能性较低，除非在生产中有意添加，否则可不评估。

3类：口服毒性低，对注射和吸入给药药品，若给药途径的PDE（permitted daily exposure，允许日暴露）值不超过500 mg/d，则需评估；若该类元素在生产中被有意加入均需评估。