A pharmaceutical compound (10 mg/mL) was dissolved at pH 4 and at pH 10, then both samples were simultaneously heated in a MC-DSC. Thermal activity was evident, indicative of chemical reactions occurring in the samples. Under basic conditions the reaction was endothermic, while in acidic conditions the reaction was exothermic. When the logarithm of the thermal activity was plotted versus the reciprocal temperature, it became apparent that there were at least two reaction pathways with different activation energies at pH 10, while at pH 4 there was only evidence of a single degradative reaction. This information would be very useful in designing traditional HPLC stability screening studies since under basic conditions, this compound 首ld clearly be stressed at lower rather than higher temperatures. 差示掃描量熱儀 NANO DSC