Lipossomas deformáveis para encapsulação do bexaroteno: desenvolvimento, caracterização e avaliação da dinâmica molecular dos fosfolipídeos da membrana

• Autor(a) principal: Silva, Halanna Cristina Barbosa
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6287
• topic: Lipossomas deformáveis; Bexaroteno; RPE; Permeação cutânea.; Deformable liposomes; Bexarotene; Kin permeation; EPR; CIENCIAS DA SAUDE::FARMACIA

Bexarotene is an agonist to retinoid X receptors (RXR) clinically used in cutaneous T cell lymphoma (CTCL). The oral bexaroteno therapy results in disagreeable side effects related to lipid metabolism, such that topical administration presents as an alternative to bexaroteno use increasing the drug concentration at the target site. Nanostructured systems, such as the deformable liposomes can be an interesting alternative to facilitate or promote increased cutaneous permeation of bexarotene. So, the aim of this study was the development and characterization of deformable bexarotene liposomes. Three surfactants were evaluated for composition of deformable liposomes (Span 80, Tween 80 and Span 85) in different concentrations (5, 10 and 15%). Liposomes were evaluated for average diameter, PdI and elasticity. And then a full factorial design with 3² triplicate central point was applied to analyze the influence of variables ethanol concentration and surfactant in the elasticity of the vesicles. A global solution was proposed by analyzing the Statistica 7.0 software applying the desirability tool and the deformable liposomes encapsulating bexarotene were prepared from the obtained response. Deformable liposomes were prepared by lipid film hydration and extrusion polycarbonate membrane (200 and 100 nm). The desirability function provided a global solution with 5.25% (v / v) ethanol and 5% (w / v) Span 80. Deformable liposomes had encapsulation efficiency of 99.67±3.4%, diameter average of 93.69±1.95 nm and PDI 0.092±0.02. Lyophilized liposomes showed higher elasticity parameters than non-lyophilized formulations, with elasticity up to 215.5±5.5 (mg.s-1.cm-2) for formulations with sucrose and 22.13±1.04 (mg. s-1.cm-2) for conventional liposomes. EPR studies demonstrated that lyophilized formulations presented higher molecular dynamics of lipids regarding the non lyophilized in all formulations, while the formulations without BXT was most dynamic in formulations in which sucrose was used as cryoprotectant, in formulations with BXT occurs the oposite. In vitro skin permeation studies, BXT deformable liposomes had a penetration rate EC about 5 times greater than the conventional liposomes. Thus, the developed deformable liposomes present as bexarotene the potential permeation enhancer on the skin.