Abstract

Spectrophotometric and conductometric determination of gabapentin in pure form and pharmaceutical preparations

Author(s): Mervat M.Hosny, Sara M.Anis Abdulwahab, Hisham E.Abdellatef, Mohamed N.El- Balkiny

Four simple, sensitive and reproducible methods were developed for the determination of gabapentin (GPT) in pure formand in pharmaceutical preparations. MethodsAand B are based on the reaction of cupric chloride with gabapentin to form stable complex, which could be measured spectrophotometrically at max 246 nm (method A) or by using conductometric technique (method B).While method C and D depends on the formation of ion pair complex between the studied drug and bromothymol blue, bromocresol green respectivelywhichwas extractable withmethylene chloride. The concentration rangeswere 40-95 gml-1, 1-15mg, 100-800 and 10-150 gml-1 for methodsA, B, C and D respectively.The optimization of various experimental conditions were described.The results obtained showed good recoveries, Ringbomoptimumconcentration ranges were calculated, in addition to molar absorpivity, Sandell’s sensitivity, detection and quantification limits. The methodswere successfully applied to the determination of GPT in bulk and pharmaceutical preparations.The results were favorably comparable with the officialmethod. The molar combining ratio for methods (A-B) was found to be (2:1) (drug: reagent) while for method (C-D) it was found to be (1:1).