Abstract

SEMISOLIDS SYSTEMS ON A LIQUID-CRYSTALINE STRUCTURE BASE FOR THE PROLONGED RELEASE OF LIPOSOLUBLE ACTIVE INGREDIENTS.

Gastón Lillini, Claudia Salerno, Ricardo Pasquali†, Cristian Pedemonte, Carlos Bregni and Susana Lavaselli*

Abstract

In the present work we set as objective to investigate the diffusion invitro over 48 h using Franz cells of a liposoluble active principle,Econazole (ECZ), incorporated in emulsion prepared by conventionaltechniques and in emulsions with liquid crystalline structure. Theconcentration release of ECZ was determined by high performanceliquid chromatography (HPLC), using a mobile phase of methanolwater (50:50) on a gradient elution and a column of phase reverse C18was used for the chromatographic separation. The conventionalemulsions exhibits a kinetic liberation that adjusts to the Higuchimodel during the 48 h of study, while the emulsions with liquidcrystalline characteristics adjusts to a kinetic liberation of order zero inthe firsts 8 h of study, such release is associated with the ECZdissolved outside of the liquid crystalline structure, and then with thedisintegration of the multilayer from the liquid crystalline, the ECZ incorporated in theirstructure is released, allowing a controlled release.

Keywords: Liquid crystals, econazole, prolonged release, emulsions.