Studies on the Stability of Drugs. IV

Glutethimide is easily decomposed into 2-ethyl-2-phenylglutaramide (I) in alkaline solution. This decomposition occurs in sodium hydroxide or carbonate solution by the second-order reaction, but not in sodium hydrogen carbonate solution. The degradation velocity constants at 20°, 30°, and 40° in 0.01N sodium hydroxide solution were 7.66×10-1, 1.67, and 3.56, and those in 0.01M sodium carbonate solution were 3.56×10-1, 7.50×10-1, and 1.83, respectively. The activation energies in 0.01N sodium hydroxide and 0.01M sodium carbonate solution were 14.3 and 14.6 kcal., respectively.