Design and Formulation for Enhancement of Solubility and Dissolution Rate of Atorvastatin using Solid Dispersion

The solubility and dissolution rate of Atorvastatin, a drug used for the treatment of hyperlipidaemia. Atorvastatin is a selective competitive inhibitor of HMG Co-A reductase. However its absolute bioavailability is 5%. To increase the solubility of drug solid dispersion was prepared. Solid dispersion preliminary solubility analysis was carried out for the selection of the carrier and solid dispersion was prepared with Hydroxy Propyl Methyl Cellulose (HPMC) and Methyl Cellulose (MC). These solid dispersions were analyzed for the solubility and in-vitro dissolution profile solid dispersion of drug with polymer has shown enhanced solubility with improved dissolution rate. Further FTIR, X-Ray studies were carried out. Solid dispersion prepared with polymer in 1:5 ratios shows the presence of amorphous form confirmed by the characterization study. The present investigations showed that solubility of Atorvastatin Sodium was markedly increased by its solid dispersion using PVP K30 as carrier. The formulation SDF₈ containing (1:8) shows highest dissolution rate. Hence the solid dispersion a way is useful technique in providing fastest onset of action of Atorvastatin Sodium as well as enhanced dissolution rate. The study also shows that dissolution rate of pravastatin can be enhanced to considerable extent by solid dispersion technique with Polymer.