Characterization of venlafaxine hydrochloride and compatibility studies with pharmaceutical excipients

The thermal analytical study of venlafaxine hydrochloride, a third generation antidepressant, was investigated using thermogravimetry (TG) and differential scanning calorimetry (DSC). The DSC curves have shown a sharp endothermic event at 211 °C and TG demonstrated a single stage of mass loss between 254 and 283 °C. Solid-state characterization was carried out by DRIFT, SEM, and XRPD demonstrating the drug physicochemical properties including crystallinity. Drug-excipient compatibility studies investigated by DSC have shown a possible physical interaction of the drug with magnesium stearate, microcrystalline cellulose and starch. Nevertheless, these results where not confirmed by DRIFT and SEM analyses.