Abstract
The aim of this study was to study the compatibility of simvastatin (SIM) with levofloxacin hemihydrate (LEV), polyethylene glycol 4000 (PEG4000), polyvinylpyrolidone-K-90 (PVP-K90), carbopol 934 and LEV with carbopol 934. For confirming the compatibility of all ingredients together, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) were used as screening techniques. The results showed that the DSC curves of binary mixtures of SIM-PEG4000 have a strong interaction between them at increased temperatures. DSC thermogram of LEV and carbopol 934 didn't confirm or deny interaction due to overlap of the characteristic peaks at the same temperature range. However, FTIR showed no chemical reaction between SIM, PEG4000 or LEV and carbopol 934 at room temperature.