APPLICATION OF DIFFERENTIAL SCANNING CALORIMETRY TO THE STUDY OF DRUG-EXCIPIENT COMPATIBILITY

Differential scanning calorimetry (DSC) has been used to investigate d rug-excipient interactions and, in consequence, their compatibility. I n particular, binary mixtures of nefazodone with magnesium stearate an d lactose, and fosinopril with the same excipients were prepared and a nalysed, after proper conditioning. The thermoanalytical results were compared with those obtained by spectroscopic (UV, IR) and chromatogra phic (HPLC) analysis. We believe that changes in DSC runs cannot alway s be a sufficient condition to prove that some interaction occurs betw een drug and excipient during storage at room temperature. Some data o n the spectroscopic characteristics of nefazodone and fosinopril drugs and their thermal behaviour are also reported.