Lipossomas contendo paromomicina: desenvolvimento, caracterização e estudos de permeação cutânea in vitro

• Ano de defesa: 2007
• Autor(a) principal: Guilherme Carneiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Lipossomas; in vitro; caracterização; Lipossomos; Leishmaniose Tratamento; Farmácia; Antibióticos; Soluções parenterais
• Link de acesso: http://hdl.handle.net/1843/FARD-7E6P24

Paromomycin (PA), an aminoglicoside antibiotic, has been used as an alternative for topical treatment of the cutaneous leishmaniasis (CL). Although this treatment has shown promising results, it has not been successful in accelerating the recovery in most cases. This could be attributed, at least in part, to the low skin penetration of PA. Considering that liposomal formulations usually provide skin penetrationenhancement, the aim of this study was to prepare and to characterize liposomal formulations containing PA and to investigate their potential as topical delivery systems of this antibiotic. Large unilamellar vesicles (LUVs) were prepared by reverse-phase evaporation method. The lipids used were soybean phosphatidylcholine (PC), PC/Cholesterol (Chol) (molar ratio 60:40), dipalmitoylphosphatidylcholine (DPPC) and DPPC/Chol (molar ratio 60:40). Permeation experiments using pig ear skin were performed in Franz diffusion cells. Three models of skin were used: intact, stripped and without epidermis. The removal of the stratum corneum (SC 30 strippings) was confirmed by the determination of transepidermal water loss (TEWL) values and by histological analysis, which demonstrated an almost complete removal of EC. The removal of the epidermis was confirmed by histological analysis. PA permeation through intact skin was negligible, independent of the formulation tested. However, the skin penetration (as % dose applied) was 7.2 ± 0.2%, 4.8 ± 0.2% and 1.9 ± 0.1% for PC, PC/Chol and aqueous solution, respectively. Drug permeation across stripped skin was 19.6 ± 0.8%, 6.1 ± 0.5% and 1.0 ± 0.6% for PC, PC/Chol and aqueous solution, respectively, whereas permeation across skin without epidermis was 7.3 ± 0.7%, 10 ± 2% and 26 ± 3%. Thus, liposomes provided significant PA penetration and permeation enhancement across intact and stripped skin while controlled topical delivery was observed in permeation across skin without epidermis.