5-Fluorouracil in topical liposome gels for anticancer treatment--formulation and evaluation.

Liposome gels bearing an antineoplastic agent, 5-fluorouracil, intended for topical application have been prepared and drug release properties in vitro have been evaluated. Different formulations of liposomes were prepared by the film hydration method by varying the lipid phase composition (PL 90H/cholesterol mass ratio) and hydration conditions of dry lipid film (drug/aqueous phase mass ratio). Topical liposome gels were prepared by incorporation of lyophilized liposomes into a structured vehicle (1%, m/m, chitosan gel base). Also, hydrogels containing different concentrations of 5-fluorouracil were prepared and drug release properties were investigated. The rate of drug release from liposome gels was found to be dependent on the bilayer composition and the dry lipid film hydration conditions. Also, liposomes embedded into a structured vehicle of chitosan showed significantly slower release than hydrogels. The drug release obeyed the Higuchi diffusion model, while liposomes acted as reservoir systems for continuous delivery of the encapsulated drug.