In the present study,
Simvastatin was incorporated in
emulsion of
soybean oil and
propylene glycol monocaprylate as oily phase and
Tween 80 and
Cremophor EL as
surfactants and also their mixtures. Dry adsorbed
emulsions were prepared by using colloidal
silicon dioxide in varying proportions to adsorb the liquid
emulsion. Liquid
emulsions were characterized for viscosity and mean globule size, and the dry adsorbed
emulsions were evaluated for
powder characteristics and reconstitution properties, dissolution profile, and for in vivo efficacy in rats. DSC and X-ray diffraction studies indicated complete amorphization and/or solubilization of
Simvastatin in the dry adsorbed
emulsion. It was supported by SEM studies, which did not show evidence of precipitation of the
drug on the surface of the carrier. Dissolution studies revealed remarkable increase in dissolution of the
drug compared to plain
drug. One of the optimized formulations provided 10-fold enhancement in the dissolution compared to
drug powder. After 24 hr of induction of
hyperlipidemia in rats using
poloxamer F127, administration of dry adsorbed
emulsions effected significant reduction in the total
cholesterol with levels of 439 mg/dL compared to 585 mg/dL of
drug treated group (p < 0.01). Significant increase in the
high-density lipoprotein levels were also observed after 4 days of treatment compare to positive control (p < 0.01).