Physical aging of pharmaceutical substances by advanced thermal analysis

摘要

Physical aging or structural recovery was studied by advanced thermal analysis for pharmaceutical substances. Enthalpy overshoot as a result of physical aging was observed in differential scanning calorimetry heating scan. Measurements of the enthalpy recovery and for amorphous active pharmaceutical ingredients (APIs) and non- active pharmaceutical substances at a different aging temperature below the nominal Tg, for various aging times were presented. The changes of enthalpy recovery (relaxation) versus aging time for the giving temperature were measured for Termisartan, Valsartan, Glucose, Poly(lactic acid) (PLA) and Poly(N-isopropyloacryloamid). One example of advanced thermal analysis based on absolute heat capacities and integral enthalpy of solid and liquid PLA was presented.