Yip Y W, Li Wan Po A, Irwin W J
J Pharm Sci. 1983 Jul;72(7):776-81. doi: 10.1002/jps.2600720715.
The stability of hydrocortisone butyrate in semiaqueous and formulated gel systems has been investigated. It was shown that hydrocortisone butyrate underwent reversible isomerization to the C-21 ester of butyric acid. This ester then hydrolyzed to hydrocortisone, which in turn degraded to a complex mixture of compounds. This step is metal catalyzed and can be inhibited by the addition of EDTA [disodium(ethylenedinitrilo)tetraacetate]. The kinetics of decomposition is modeled using nonlinear regression analysis, and the rate constants for the various decomposition pathways are quantified.
已对丁酸氢化可的松在半水和配方凝胶体系中的稳定性进行了研究。结果表明，丁酸氢化可的松发生可逆异构化，生成丁酸的C-21酯。该酯随后水解为氢化可的松，氢化可的松又降解为复杂的化合物混合物。这一步骤是金属催化的，可通过添加乙二胺四乙酸二钠（EDTA）来抑制。使用非线性回归分析对分解动力学进行建模，并对各种分解途径的速率常数进行了量化。
