• propionylpromazine hydrochloride;
  • degradates;
  • liquid chromatography;
  • HPLC/mass spectrometry


An analytical method to evaluate propionylpromazine hydrochloride (PPZHCl) in tranquilizer formulations was developed using high-performance liquid chromatography (HPLC). During analysis of aged quality-control samples, a previously unreported chromatographic response was observed at a shorter retention time than PPZHCl. Further investigation of formulations stored in trap tap devices at temperatures ranging from 5 to 40 °C during field trials at four different locations confirmed the degradation of the active ingredient. Further investigation using HPLC/tandem mass spectrometry revealed two to five degradates, with the major degradates being oxidation products of the active ingredient, PPZHCl. As PPZHCl formulations must be stable when stored at 5 to 40 °C for 6 to 12 months, reformulation with the anti-oxidant ascorbic acid was utilized to achieve the required PPZHCl stability. Copyright © 2005 Society of Chemical Industry