Abstract

Stability-indicating high performance liquid chromatographic determination of rivastigmine with kinetic study of rivastigmine alkaline degradation

Author(s): Saud S.Bawazeer, WaleedH.AlMalki, MohammadA.El-Sayed

Stability-indicating high performance liquid chromatographic determination of rivastigmine in its binary mixture with kinetic study of rivastigmine alkaline degradation Stability-indicative determination of rivastigmine hydrogen tartarate (RIV) in the presence of its degradate was investigated. The degradation product was isolated, via alkaline-degradation, characterized and confirmed. Selective quantification of RIV in bulk form, pharmaceutical formulations and/or in the presence of RIV degradate was demonstrated. The analytical technique adopted for quantification was high performance liquid chromatography (HPLC). Separation was performed using a Xbridge ODS column with a mobile phase consisting of phosphate buffer pH (3.4): acetonitrile 70: 30 (v/v) with UV detection at 262 nm. The method showed high sensitivity with good linearity over the concentration range of 20 to 160 µg mL-1 for RIV. The HPLC method was used to study the kinetics of RIV alkaline 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 9.854 Kcalmole-1.