Formulation And Evaluation Solid Dispersion Of Simvastatin Using Solid Dispersion Technique For Enhancement Of Aqueous Solubility

Abstract

The present study was aimed at the development and evaluation of mixed hydrotropic solid dispersion formulations of Simvastatin to improve its aqueous solubility and dissolution characteristics. Simvastatin, a poorly water-soluble BCS Class II drug, exhibits limited oral bioavailability due to its low solubility. To overcome this limitation, mixed hydrotropic solid dispersions were prepared using Nicotinamide, Sodium Benzoate, Sodium Citrate, and PEG 6000 by the solvent evaporation technique. The prepared formulations were evaluated for percentage yield, drug content, micromeritic properties, saturation solubility, and in vitro drug release. The percentage yield of formulations ranged from 88.00% to 93.20%, while drug content values showed satisfactory uniformity. Micromeritic studies demonstrated acceptable flow properties with Carr’s index ranging from 12.50% to 19.23%, Hausner ratio from 1.14 to 1.24, and angle of repose from 26.72° to 33.84°. Solubility studies revealed significant enhancement in aqueous solubility of Simvastatin in all formulations compared to pure drug. Among all formulations, F4 exhibited maximum saturation solubility (1.084 mg/mL), highest fold enhancement (31.88-fold), and maximum drug release at 60 minutes (98.62%). The enhanced solubility and dissolution behavior were attributed to synergistic hydrotropic action, improved wettability, molecular dispersion, and reduction in crystallinity of the drug. The study concluded that mixed hydrotropic solid dispersion is an effective and promising strategy for improving the solubility and dissolution performance of poorly water-soluble drugs like Simvastatin.