药物稳定性的表征

The shelf life of a pharmaceutical depends ultimately on the stability of the active pharmaceutical ingredient in the formulation. The most common method for characterizing the stability of a new drug candidate is to stress it at elevated temperatures. Using microcalorimetry, samples can be thermally stressed while simultaneously exposing the compound to other degradative conditions such as high or low pH, high humidity, hydrogen peroxide, etc. The rate of heat evolution by the sample under different stressing conditions provides a direct indication of the stability of the compound under those conditions. Since the measurements are generally completed in a matter of hours, calorimetry provides a rapid approach for screening the stability of compounds; more traditional approaches such as HPLC can then be used to determine the degradation products produced over time.