Rheological analysis of the structural properties effecting the percutaneous absorption and stability in pharmaceutical organogels

This study presents the organogels of glyceryl monostearate emulsifiers and coconut oil as an alternative for developing the traditional organogels. We investigated how the emulsifier type affects the semisolid consistency and the drug release. In these aspects we compared glyceryl monostearate organogels (GMSO) to commercially available references, while studying the effect of the individual constituents on the structural and functional properties.Rheology provided indirect information on the structure, relevant from an application point of view. We observed that glyceryl monostearate as an organogelator results in a network with elastic nature and moderate crosslink energy. The products had low viscosity and low yield value which means practically an easily spreadable pharmaceutical dosage form with soft consistency.Modelling the percutaneous absorption in vitro, we observed that the diffusion of the piroxicam incorporated was significantly affected by the thermodynamical potency of piroxicam, which was favoured by the emulsifier. The glyceryl monostearate enhanced the partition of the suspended drug, resulting in higher drug release.This paper was presented at the first Annual European Rheology Conference (AERC) held in Guimarães, Portugal, September 11-13, 2003.