Thermal, spectroscopic and dissolution studies of lovastatin solid dispersions with acetylsalicylic acid

Lovastatin (LOV) is widely used for the treatment of hypercholesterolemia. The poor water solubility of LOV leads to its poor gastrointestinal absorption and results in poor bioavailability. In this study, a preparation of solid dispersions with acetylsalicylic acid (ASA) was studied to improve the dissolution rate of LOV. Solid dispersions were prepared using various mass ratios of both components through the grinding method. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRPD) were used to characterize prepared solid dispersions. Their dissolution behaviors were also compared. LOV and ASA formed a simple eutectic phase diagram as indicated by DSC. The results obtained from FTIR spectroscopy and XRPD showed no evidence of drug-drug interaction. The dissolution studies indicated that the in vitro dissolution rate of LOV released from solid dispersions containing 10, 20, 40 and 60 mass% LOV was improved compared with the drug alone.