Development and Bioavailability assessment of simvastatin nanoparticle formulation

Aim: The aim of the present study is to prepare and evaluate nanoparticles containing Simvastatin using chitosan as the polymer. Methods: The Simvastatin loaded nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate anions. Nanoparticles of different core: coat ratio were formulated and evaluated for process yield, loading efficiency, particle size, zeta potential, in vitro drug release, kinetic studies and stability studies. Results: The prepared nanoparticles were white, free flowing and spherical in shape. The infrared spectra showed stable character of Simvastatin in the drug-loaded nanoparticles and revealed the absence of drug polymer interactions. The chitosan nanoparticles have a particle diameter ranging approximately 132.1±5.60 to 774.8±2.60nm and a zeta potential 11.93 to 43.23mV. The formulation with the initial Simvastatin concentration of 0.5 mg/ml provided the highest loading capacity. The in vitro release behavior from all the drug loaded batches were found to follow zero order and provided sustained release over a period of 10 h. No appreciable difference was observed in the extent of degradation of product during 90 days in which nanoparticles were stored at various temperatures. Conclusion: The best-fit release kinetics was achieved with zero order mechanism. The release of Simvastatin was influenced by the drug to polymer ratio and particle size. These results indicate that Simvastatin nanoparticles could be effective in sustaining drug release for a prolonged period.