Obtenção e caracterização de lipossomas unilamelares pequenos contendo cafeína

Abstract

Devido à grande dificuldade de penetração de substâncias ativas através da pele, diferentes sistemas organizados, como os lipossomas, têm sido estudos com o objetivo de aumentar a penetração percutânea. O objetivo deste trabalho foi obter e caracterizar lipossomas unilamelares pequenos contendo cafeína (CAF). Lipossomas compostos por fosfatidilcolina de soja - PC (40 mM) ou PC hidrogenada - PCH (40 mM), acrescidos ou não de colesterol - CHO (6 mM) e CAF (30 mg/mL), foram caracterizados por distribuição de tamanho, determinação de diâmetro médio e eficiência de encapsulação. Observou-se distribuição de tamanho uniforme com baixa polidispersidade. Os diâmetros médios obtidos foram: PC/CHO (64 nm), PC (80 nm), PCH/CHO (85 nm), PC/CAF (145 nm), PC/CHO/CAF (147 nm), PCH/CHO/CAF (152 nm), PCH (166 nm) e PCH/CAF (481 nm). Obteve-se eficiência de encapsulação de 10,84% para PCH/CHO/CAF, seguido de PC/CHO/CAF (6,61%), PCH/CAF (3,07%) e PC/CAF (1,57%).

Due to great difficulty of penetration of drugs through skin, different organized systems, such as liposomes, have been studied in order to increase percutaneous penetration. The aims of this work were to obtain and characterize small unilamellar liposomes containing caffeine (CAF). Liposomes composed by soy phosphatidylcholine - PS (40 mM) or hydrogenated PS - PSH (40 mM), with and without cholesterol - CHO (6 mM) and CAF (30 mg/mL), were characterized by size distribution, determination of mean diameter and encapsulation efficiency. Uniform size distribution with low polidispersity was observed. The mean of diameters obtained were: PS/CHO (64 nm), PS (80 nm), PSH/CHO (85 nm), PS/CAF (145 nm), PS/CHO/CAF (147 nm), PSH/CHO/CAF (152 nm), PSH (166 nm) and PSH/CAF (481 nm). The obtained encapsulation efficiency was 10.84% for PSH/CHO/CAF, followed by PS/CHO (6.61%), PSH/CAF (3.07%) and PS/CAF (1.57%).