title: Optimized microemulsions and solid microemulsion systems of simvastatin: characterization and in vivo evaluation.
abstract: The study describes development of solid microemulsions (SME) for improved delivery of simvastatin (SMV). Pseudo-ternary phase diagrams were constructed and MEs were optimized for oil and drug content. SMEs were prepared using colloidal silicon dioxide to adsorb the liquid ME. MEs were characterized for mean globule size in aqueous medium and the SMEs were evaluated for powder characteristics, mean globule size after dilution with water, dissolution profile and for in vivo efficacy in rats. X-ray diffraction studies indicated complete amorphization and/or solubilization of SMV in the SMEs. It was supported by scanning electronic microscopic 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 as compared to plain drug. All the formulations provided significant reduction in the total cholesterol levels in hyperlipidemic rats with reference to rats of control group (p < 0.05). The proposed SMEs have potential to deliver water insoluble drugs like SMV by oral route for better efficacy.
authors.affiliation: Department of Pharmaceutics, Bombay College of Pharmacy, Kalina, Santacruz (East), Mumbai 400098, India.
authors.forename: Rahul P
authors.initials: RP
authors.lastname: Dixit
authors.forename: Mangal S
authors.initials: MS
authors.lastname: Nagarsenker
mesh_terms: D000284:Administration, Oral; D000327:Adsorption; D000818:Animals; D002626:Chemistry, Pharmaceutical; D002784:Cholesterol / Q000097:blood; D003102:Colloids / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry; D004339:Drug Compounding; D004655:Emulsions; D005260:Female; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage*; D008855:Microscopy, Electron, Scanning; D009821:Oils / Q000737:chemistry; D011208:Powders; D051381:Rats; D017207:Rats, Sprague-Dawley; D012822:Silicon Dioxide / Q000737:chemistry; D019821:Simvastatin / Q000008:administration & dosage*; D012995:Solubility; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D003102:Colloids; D004337:Drug Carriers; D004655:Emulsions; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D009821:Oils; D011208:Powders; D014867:Water; D012822:Silicon Dioxide; D002784:Cholesterol; D019821:Simvastatin