Liposome-mediated drug targeting in topical and regional therapies

Liposome-mediated drug targeting is reviewed in four major categories of topical and regional therapies: wounds and burns, ocular, intraperitoneal, and pulmonary. A survey of the data in the field is preceded by definitions of carrier-mediated drug targeting, in particular for topical and regional treatments. The ability of liposomes to meet essential requirements for task performance and liposome surface-modification as the major approach to endow liposomes with targeting abilities are reviewed. Analysis of current findings in the field shows that (1) most studies explored regular liposomes that were unable to meet the essential requirements for targeting and (2) in vivo drug targeting in topical and regional therapies has been achieved rarely and seldom attempted, yet there are encouraging indications from a few studies that using surface modified liposomes such targeting is feasible. Both established and novel liposomal systems attest to this feasibility and point out future directions. The former can be found by revisiting immunoliposomes that were initially designed for systemic administration but might well fit topical and regional cases. The latter is exemplified by bioadhesive liposomes, designed specifically for topical/regional therapies. It is concluded that careful implementation of such approaches could be successful for the achievement of liposome-mediated drug targeting in topical and regional therapies.