Preparação e caracterização de lipossomas encapsulando acido azelaico, bleomicina e 5-fluorouracil para a aplicação na terapia de melanomas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The investigation with vehicles for controlled release of anticancer agents into tumors has been intensified in the last years. Among the vehicles tested, outstand liposomes or lipid vesicles, for drug delivery. The aim of this work was the preparation and characterization of liposomes entrapping compounds of interest in melanoma therapy with potential to be topically administered.The entrapment of 5-fluorouracil and bleomycin in liposomes, in a detailed forro, and of azelaic acid, in a preliminary forro, were analyzed using different incorporation methods. The formulations werw evaluated for stability both concerning to storage and in the presence ofthe surfactant C12Es, to verify the lipid bilayer integrity. Bleomycin was incorporated in liposomes by active loading with pH gradients and by ethanol injection. Both methods have resulted in low encapsulation efficiency.The entrapment of 5-tluorouracil was tested by the hydration of a dríed lipid film, active loading with pH gradients, ethanol injection and reverse-phase evaporation demonstrating that the last method was the most efficient in terms of encapsulation capacity, however this process should be optimized. In the presence ofthe surfactant, it was observed that the drug promotes the stabilization of these vesicles. When stored at 4°E, these lipo_ showed no fusion or aggregation during a month, however the drug was completely released ITom the vesicles in this period. The loading of azelaic acid seemed to be feasible, however the quantification of the encapsulated? drug could not be performed

ASSUNTO(S)

lipossomos tecnologia de liberação controlada agentes antineoplasicos

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