An isocratic normal-phase high-performance liquid chromatographic method for the simultaneous determination of benzoyl peroxide and benzoic acid in one pharmaceutical preparation and their stability in different solvents

Abstract

A normal-phase high-performance liquid chromatographic method was developed for the simultaneous determination of benzoyl peroxide (BPO) and benzoic acid (BA). The compounds are separated on a normal phase column Eurospher-100, c18.4.6mmID. The mobile phase is methanol-water (65 + 35, v/v). Solutions are injected into the chromatographic system under isocratic conditions at a constant flow rate of 1 mL /min with UV detection at 240 nm. Analysis of stability samples in deferent solvents showed formation of BPO from BA when it dissolved in ether or methanol and very low degradation of BPO to BA when it dissolved in ether compare with when it dissolved in methanol