Resumo

CHAVEZ, Fabiola; OLVERA, Blanca Inés; GANEM, Adriana  e  QUINTANAR, David. Liberación de sustancias lipofílicas a partir de nanocápsulas poliméricas. Rev. Soc. Quím. Méx [online]. 2002, vol.46, n.4, pp.349-356. ISSN 0583-7693.

Size < 500 nm nanocapsules (NC) were prepared using the emulsification-diffusion technique with high encapsulation rate and process efficiency. Isopycnic evaluations showed that the ratio octyl methoxicinnamate:cellulose acetate phthalate (OMC:CAP) 5:2 is the optimal for encapsulation. The NC vesicular structure was made evident by a direct MEB technique without use of freeze-fracture. The OMC release from the NC was evaluated through the permeation cell technique. It was found that the transport mechanism is non-fickian and the release rate depends on time, according to the semi-empiric model dM / dt = kt^n-1. The OMC release was not described through a tricompartmental model. The results indicate that the release responds to a first order kinetics.

Palavras-chave : Nanocapsules; nanoparticles; octyl methoxycinnamate; emulsification-diffusion; drug release.

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