Vol. 5, Issue 9 (2016)

Author(s):
Felix Ahamefule Onyegbule, Sunday Adewale Adelusi and Chukwueweiwe Jonathan Eboka

Abstract:
Quality control and assurance of antimalarials is vital in malaria treatment success. This research developed an extractive spectrophotometric method for routine assay of quinine, for enhanced quality control and assurance. The developed method is based on the formation of coloured ion-pair complex between quinine and bromocresol green in phthalate buffer, pH 5. The ion-pair was extracted into chloroform and re-extracted into 0.1M sodium hydroxide. The 0.1M sodium hydroxide extract was determined at 620nm. Relevant method validation requirements were determined, in line with International Standards Requirements. The ion-pair extract stoichiometry was 1:1. Beer's law was obeyed in the concentration range of 1-50 x 10^-4 M, with good linearity (R> 0.99). The extract showed good stability over 48 hours. A good accuracy was obtained from recovery studies in standard solutions, in the presence of common excipients, in tablets and suspension. The developed method complied with International Standards Requirements for analytical method development. The recovery data of the developed method were not statistically different from recovery data obtained using non-aqueous titration. The developed method was successfully applied in the determination of quinine in bulk drug, tablets and suspension. No significant interference was observed from excipients commonly used as pharmaceutical aids with the developed method.