title: Kinetic study on the degradation of meclophenoxate hydrochloride in alkaline aqueous solutions by high performance liquid chromatography.
abstract: A high performance liquid chromatographic method was developed and validated for determination of meclophenoxate hydrochloride (I) in the presence of its degradation product (p-chlorophenoxy acetic acid) (II). Separation of (I) from (II) was performed using a ZORBAX ODS column with a mobile phase consisting of 0.2% triethylamine in 0.01 M ammonium carbonate: acetonitrile (70:30 v/v). The method showed high sensitivity with good linearity over the concentration range of 50 to 400 mug/ml. The method was successfully applied to the analysis of a pharmaceutical formulation containing (I) with excellent recovery. A kinetics investigation of the alkaline hydrolysis of (I) was carried out in sodium hydroxide solutions of 1, 1.5 and 2 N by monitoring the parent compound itself. The reaction order of (I) followed pseudo-first order kinetics. The activation energy could be estimated from the Arrhenius plot and it was found to be 12.331 kcal/mole.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
authors.forename: Mohammad Galal
authors.initials: MG
authors.lastname: El-Bardicy
authors.forename: Hayam Mahmoud
authors.initials: HM
authors.lastname: Lotfy
authors.forename: Mohammad Abdalla
authors.initials: MA
authors.lastname: El-Sayed
authors.forename: Mohammad Fayez
authors.initials: MF
authors.lastname: El-Tarras
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000031:analogs & derivatives; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002504:Meclofenoxate / Q000302:isolation & purification / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity; D012972:Sodium Hydroxide; D012996:Solutions; D014867:Water
chemical_list: D012996:Solutions; D014867:Water; D015084:2,4-Dichlorophenoxyacetic Acid; C007017:4-chlorophenoxyacetic acid; D012972:Sodium Hydroxide; D002504:Meclofenoxate