title: Self-microemulsifying drug delivery system for improved oral bioavailability of dipyridamole: preparation and evaluation.
abstract: Dipyridamole shows poor and variable bioavailability after oral administration due to pHdependent solubility, low biomembrane permeability as well as being a substrate of P-glycoprotein. In order to improve the oral absorption of dipyridamole, a self-microemulsifying drug delivery system (SMEDDS) for dipyridamole was prepared and evaluated in vitro and in vivo. The optimum formulation was 18% oleic acid, 12% Labrafac lipophile WL 1349, 42% Solutol HS 15 and 28% isopropyl alcohol. It was found that the performance of self-microemulsification with the combination of oleic acid and Labrafac lipophile WL 1349 increased compared with just one oil. The results obtained from an in vitro dissolution assay indicated that dipyridamole in SMEDDS dissolved rapidly and completely in pH 6.8 aqueous media, while the commercial drug tablet was less soluble. An oral bioavailability study in rats showed that dipyridamole in the SMEDDS formulation had a 2.06-fold increased absorption compared with the simple drug suspension. It was evident that SMEDDS may be an effective approach to improve the oral absorption for drugs having pH-dependent solubility.
authors.affiliation: Department of Pharmacy, Medical College, Nanchang University, No. 461, Bayi Road, Nanchang, Jiangxi Province 330006, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Guo
authors.forename: Haijun
authors.initials: H
authors.lastname: Zhong
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.forename: Baogang
authors.initials: B
authors.lastname: Xie
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
authors.forename: Helin
authors.initials: H
authors.lastname: Xu
authors.forename: Minmin
authors.initials: M
authors.lastname: Liu
authors.forename: Chunlian
authors.initials: C
authors.lastname: Xu
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000187:drug effects; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D004176:Dipyridamole / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems; D004355:Drug Stability; D004655:Emulsions; D005079:Excipients / Q000737:chemistry; D005260:Female; D006863:Hydrogen-Ion Concentration; D008297:Male; D019301:Oleic Acid / Q000737:chemistry; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013229:Stearic Acids / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D004655:Emulsions; D005079:Excipients; D010975:Platelet Aggregation Inhibitors; D013229:Stearic Acids; D013501:Surface-Active Agents; D014280:Triglycerides; C542236:labrafac WL 1349; D019301:Oleic Acid; D011092:Polyethylene Glycols; C067028:Solutol HS 15; D004176:Dipyridamole; D019840:2-Propanol