title: Evidence for the degradation of maleate moiety in chlorpheniramine maleate solution using a stability-indicating HPLC method.
abstract: The degradation phenomenon of maleate moiety of chlorpheniramine maleate in solution has been demonstrated by means of a peculiar ion-pair HPLC method developed by the authors, which permits the simultaneous determination of chlorpheniramine and maleate. A commercial cough drug containing chlorpheniramine maleate was dissolved in water with m-hydroxybenzoic acid as an internal standard, and then kept for several days at room temperature. It was recognized that the maleate content in the drug solution had gradually decreased, whereas chlorpheniramine content had not decreased. A simple solution of maleic acid was also kept for several days at room temperature, and it was also recognized that the maleate content in the solution preserved at the same concentration as the solution of the commercial cough drug had gradually decreased, and the percent of remaining maleate reached zero. The degraded peaks on HPLC chromatogram were not detected at all by UV detector, and the disappearance of maleate was ascertained by GC-MS. No detectable example of maleate of chlorpheniramine maleate in a commercial cough syrup has suggested that maleate moiety of chlorpheniramine maleate decomposed to carbon dioxide.
authors.affiliation: Department of Pharmaceutical Analytical Chemistry, Niigata College of Pharmacy, Japan. yamatos@niigata-pharm.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Yamato
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
authors.forename: N
authors.initials: N
authors.lastname: Kawakami
authors.forename: K
authors.initials: K
authors.lastname: Shimada
authors.forename: E
authors.initials: E
authors.lastname: Tachikawa
authors.forename: S
authors.initials: S
authors.lastname: Ohta
authors.forename: H
authors.initials: H
authors.lastname: Zenda
mesh_terms: D002744:Chlorpheniramine / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D008401:Gas Chromatography-Mass Spectrometry; D006634:Histamine H1 Antagonists / Q000737:chemistry*; D012996:Solutions
chemical_list: D006634:Histamine H1 Antagonists; D012996:Solutions; D002744:Chlorpheniramine