title: Studies on the cyclosporin A loaded stearic acid nanoparticles.
abstract: Stearic acid nanoparticles were prepared in this study by melt-homogenization to investigate the possibility of them as a new kind of drug carrier system. Some physicochemical properties of stearic acid nanoparticles were studied and morphology examined by transmission electron microscope. Cyclosporin A as a model drug was then encapsulated into stearic acid nanoparticles. Following the establishment of high performance liquid chromatography assay for cyclosporin A analysis in stearic acid nanoparticles or blood samples, the encapsulation ratio of cyclosporin A to stearic acid nanoparticles was estimated and pharmacokinetics as well as bioavailability of cyclosporin A stearic acid nanoparticles after oral administration to Wistar rats were studied, using the Sandimmun Neoral(R) (an available microemulsion system of cyclosporin A) as a reference. The mean diameter of cyclosporin A stearic acid nanoparticles was 316.1 nm, while the encapsulation ratio of cyclosporin A to stearic acid nanoparticles reached to 88.36%. It was demonstrated by IR spectra and differential scanning calorimetry that there was no chemical reaction occurred between the cyclosporin A and stearic acid. The relative bioavailability of cyclosporin A stearic acid nanoparticles over reference was nearly 80%, and the time to reach maximum concentration (T(max)) of cyclosporin A after oral administration of cyclosporin A stearic acid nanoparticles was delayed significantly than the reference, suggesting an obvious sustained release effect. The stearic acid nanoparticles might be a very potential drug carrier.
authors.affiliation: Department of Pharmacy, School of Pharmaceutical Sciences, Beijing Medical University, 100083, Beijing, People's Republic of China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: G
authors.initials: G
authors.lastname: Yie
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: Q
authors.initials: Q
authors.lastname: Yang
authors.forename: T
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D016572:Cyclosporine / Q000097:blood / Q000493:pharmacokinetics*; D004337:Drug Carriers; D016503:Drug Delivery Systems; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D013229:Stearic Acids / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D007166:Immunosuppressive Agents; D013229:Stearic Acids; C031183:stearic acid; D016572:Cyclosporine