Quantitative thin-layer chromatography in accelerated stability studies for prediction of inherent sensitivity of...

This paper discusses a novel technique for studying the inherent sensitivity of materials toward oxygen and the utility of quantitative thin-layer chromatography, as a tool in such studies. The degradation generally followed first order kinetics up to about 60% decomposition, indicating that the usual kinetic treatment applied to homogeneous systems can be used. The method can also detect degradation products, in many cases adding a considerable diagnostic element to its predictive value. Among the model compounds tested testosterone was the most stable with ca. 95% recovery following a 190-h exposure to air on standard silica gel plates. The half-life time of the other model substances under similar experimental conditions was estimated by means of direct measurements or by extrapolation, and found to range from approximately 300 h to 1 h 10 min with cortisone marking the upper value and cholesta-3,5-diene the lower one.