[Stability testing of solid drugs using preferentially thin-layer chromatography and differential thermal analysis....

Beside the temperature etc., certain properties of the crystal surface, the water content, catalytic actions and possible oxidation processes determine the stability of solids. Stability testing of drugs (aiming at fixing time-limits for the storage of drugs) according to the schedule elaborated by the authors provides specific quantitative methods of analysis only for substances of relatively poor storage stability. Already two or three temperature-time experiments (12h/140 degrees C; 20 d/90 degrees C; 43 d/80 degrees C) permit to evaluate the stability of the drugs by thin-layer chromatography and differential thermal analysis. Almost 80% of the substances tested comply with the prerequisites for the recommendation of a time-limit of 10 years for storage.