Formulation and evaluation of solid dispersions of valsartan for dissolution rate enhancement

Objective: The objective of the study was to formulate solid dispersions of Valsartan using hydrophilic carriers in different concentrations and to determine their effect on solubility of drug.Methods: Solid dispersions of Valsartan were prepared using urea, PEG4000 as carriers in different drug: carrier ratios of 1:1, 1:2, and 1:4 by employing solvent evaporation method. Physical mixtures were also prepared for the above ratios. The prepared physical mixtures and solid dispersions were evaluated for flow properties, solubility studies, drug content and In-vitro dissolution studies.Results: The prepared physical mixtures and Solid dispersions of Valsartan showed good flow property and uniformity in drug content. From the saturated solubility studies and In-vitro dissolution studies it was observed that there was increase in solubility of drug and enhanced dissolution rate in solid dispersions compared to physical mixtures respectively. Formulation containing 1:4 ratio of drug: PEG4000 is considered as best formulation as it has shown highest drug release in short time i.e. 99.86 % in 20min. Conclusion: Our studies showed that the solubility of the drug can be significantly enhanced with solid dispersions of the studied polymers. With increase in the carrier content there is increase in the solubility resulting in enhanced dissolution rate.