Burgess, June 28, 2001
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LIPOSOME FORMULATION
Processing methods:
Extrusion, ultrasonication and microfluidization for hydrophobic drugs and
Reversed phase and freeze-thaw for hydrophilic drugs.
- Modified to reduce negative charge, decrease fluidity and cause steric hinderance to phagocytosis
- Properties altered (e.g. by incorporation of cholesterol) - Polymerized liposomes more stable and less “leaky” - Polyetheylene glycol, “pegylated” liposomes, avoid
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SELECTION OF DELIVERY SYSTEM
Liposomes – targeted delivery. They can deliver agents directly into cells. Routes: i.v., s.c., i.m., topical, pulmonary
Microspheres - can provide continuous drug delivery over periods of months to years. Systemic and localized. i.m., s.c., oral, pulmonary