Solid Dispersions with Polyethylene Glycol for the Improvement of Simvastatin’s Dissolving Rate and Solubility

Simvastatin, which is in BCS Class II, is poorly soluble in water, which means that it has poor oral bioavailability. The aim of this study was to improve the solubility and dissolution rate of simvastatin as solid dispersions (SDs) in PEG 4000 and PEG 6000. Solid dispersions were prepared by solvent evaporation at different drug-to-polymer ratios (i.e., 1:1:1 to 1:1:3). The SDs were then characterized by FTIR, DSC, and PXRD prior to conducting solubility studies and in vitro dissolution studies. The best formulation (F3) showed a marked improvement in the dissolution rate in comparison to the pure drug. This study demonstrates the ability of PEG-based solid dispersions to improve the bioavailability of poorly water-soluble drugs.