RELEASE OF ROOPEROL TETRAACETATE FROM TOPICAL BASES - IN-VITRO STUDIES USING SILICONE MEMBRANE

The influence of the vehicle on the delivery of rooperol tetra-acetate , a lipophilic drug, from a gel, oil-in-water, water-in-oil and ointme nt vehicle was investigated using an in vitro membrane permeation syst em. Diffusion studies were performed under occluded and unoccluded con ditions using polydimethylsiloxane membrane. The results obtained show ed that after 8 h of diffusion, the occluded and unoccluded gel system s, followed by the occluded and unoccluded oil-in-water systems most e ffectively promoted the delivery of rooperol tetra-acetate. The mean c alculated flux rate was 22.50 +/- 4.65 mg/cm(2) per h from the occlude d gel vehicles compared to 8.23 +/- 3.23 mg/cm(2) per h from the occlu ded oil-in-water vehicle. The remaining two systems studied exhibited lower flux rates with the ointment base showing the least drug release . The data obtained fi-om the in vitro permeation studies performed he re call be used as a predictive model for the release characteristics of rooperol tetra-acetate from topical vehicles. (C) 1998 Elsevier Sci ence B.V.