ABSTRACT:
Simvastatin is a HMG CoA reductase inhibitor drug (Hypolipidemic Drug) has poor aqueous solubility. The effect of ß-CD and water soluble polymers like polyvinyl pyrrolidone (PVP) and Hydroxypropyl methyl cellulose (HPMC) on aqueous solubility and dissolution rate of Simvastatin were investigated. The present study describes the complexation of Simvastatin(SV) with ß-CD for improved solubility property, for further improvement in solubility ternary complex systems were prepared using water soluble polymers like PVP and HPMC. The complexation was studied by phase solubility method. The phase solubility study of SV- ß-CD indicated the formation of complex in the solution. The value of apparent stability constant, Kc was found to be 825.5M-1. The phase solubility studies also indicated the formation of inclusion complexes of SV-ß-CD – polymers. The value of apparent stability constant, Kc was found to be 785.7M-1 for PVP and 766.8M-1 for HPMC. The formation of 1:1M inclusion complexes with ß-CD and along with hydrophilic polymers like PVP and HPMC in the solid state were confirmed by Fourier Transform Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) and comparative study and the in-vitro dissolution were carried out. The complexes were prepared by kneading method. The ternary complexes prepared showed higher dissolution rates and dissolution efficiency values than pure drug and other binary complexes. The order of hydrophilic polymers enhancing dissolution rate of ß-CD complexes was found to be PVP > HPMC.