Spectrophotometric estimation of eflornithine hydrochloride by using ion-pair reagents

Four newer, cost effective and sensitive ion-pair complex methods were estimated for the determination of eflornithine hydrochloride drug in pharmaceutical formulation. In these methods eflornithine hydrochloride react with bromocresol green (buffer of pH 4), bromophenol blue (buffer pH 4.5), methyl orange (buffer of pH 5.5) and bromothymol blue (buffer of pH 5) respectively. The chloroform was used for extraction of ion-pair complexes. The measurement of complexes was done at 413, 416, 417 and 425 nm respectively. Under the described conditions the proposed methods are linear over the concentration range of 3-18, 4-16, 6-30 and 2-12 μg/ml and the coefficient of determination were >0.999 (n=6) with a relative standard deviation of <1% (n=6). The average recovery of the target compound is >100% with a limit of quantification (LOQ) of 20, 0.869, 2 and 4.167 μg/ml and the limit of detection (LOD) 6.6, 0.287, 0.66 and 1.375 μg/ml. The mechanism of the derivatization reaction is proposed and advantages of the proposed method are discussed.