Abstract:

The moisture and temperature plane of a drug was determined based on the dispersive principle of uniform design. Then, kinetic parameters were obtained by a single time point experiment. The stability of aspirin, as a solid state model, was investigated. We found that the results obtained from this proposed method were comparable to those from isothermal studies at constant humidity and also comparable to those from the programmed humidifying and heating experiments. Under the same experimental conditions, the estimates of the kinetic parameters (Ea, m, A) obtained from the new method were significantly more accurate and precise than those obtained from the programmed humidifying and heating experiments. No specific computer-controlled environmental chamber needs to be used in our new method. By comparison to isothermal experiments at constant humidity, our proposed method saved time, labor, and materials.

Key words: Plane single time point experiments, Classical isothermal experiment at constant humidity, Programmed humidifying and heating experiment, Simulated test, Aspirin