title: Degradation of hydrocortisone in a zinc oxide lotion.
abstract: An extemporaneous topical steroid formulation, prepared from a zinc oxide lotion and hydrocortisone lotion BPC, had poor stability. Hydrocortisone decomposed mainly to the 21-aldehyde, but other degradation products were also identified by HPLC. The decomposition process could be described by first-order kinetics. Stabilization methods employing pH adjustment, antioxidants and chelating agents were unsuccessful. The study emphasizes the dangers of diluting commercial formulations with unrecommended bases and indicates the modes of decomposition of hydrocortisone in a formulation.
mesh_terms: D004355:Drug Stability; D006854:Hydrocortisone; D015032:Zinc; D015034:Zinc Oxide
chemical_list: D015032:Zinc; D015034:Zinc Oxide; D006854:Hydrocortisone