title: Stability-indicating high performance liquid chromatographic determination of raubasine in its binary mixture with kinetic study of raubasine acid degradation.
abstract: Stability-indicative determination of raubasine (RAB) in the presence of its degradate and its binary mixture with almitrine dismesylate (ALM) was investigated. The degradation product had been isolated, via acid-degradation, characterized and confirmed. Selective quantification of RAB and ALM in bulk form, pharmaceutical formulations and/or in the presence of RAB degradate was demonstrated. The analytical technique adopted for quantification was high performance liquid chromatography (HPLC). Separation was performed using a ZORBAX ODS column with a mobile phase consisting of acetonitrile+phosphate buffer pH 3.4 80:20 (v/v) with UV detection at 254 nm. The method showed high sensitivity with good linearity over the concentration range of 5-120 and 5-60 μg mL(-1) for RAB and ALM respectively. The HPLC method was used to study the kinetics of RAB acid degradation that was found to follow a first-order reaction. The activation energy could be estimated from the Arrhenius plot and it was found to be 18.152 kcal mol(-1).
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Umm Al-Qura University, P.O. Box 715, Makkah, Saudi Arabia. boodim3@yahoo.com
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: El-Sayed
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D004952:Esters; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015203:Reproducibility of Results; D046948:Secologanin Tryptamine Alkaloids / Q000737:chemistry*; D014665:Vasodilator Agents / Q000737:chemistry*
chemical_list: D004952:Esters; D046948:Secologanin Tryptamine Alkaloids; D014665:Vasodilator Agents; C005709:raubasine