Preformulation compatibility studies of etamsylate and fluconazole drugs with lactose by DSC

Chemical compatibility of two drugs, namely, etamsylate and fluconazole was studied with lactose as excipient, employing differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. The DSC patterns recorded for the mixtures of both the drugs with the common excipient (lactose) indicated that fluconazole as well as etamsylate were incompatible with lactose at high temperatures. X-ray diffraction patterns recorded for pure drugs and lactose and the mixtures of individual drugs with lactose prepared at room temperature by intimate grinding of the components revealed incompatibility of both the drugs with lactose also at room temperature.