Determination of captopril in pharmaceutical tablets by anion-exchange HPLC using indirect photometric detection; a study in systematic method development

The development and validation of a significantly cost effective and simple r anion-exchange high performance liquid chromatorgaphic (HPLC) procedure t han the compendial methods for the analysis of captopril in tablet dosage f orms using indirect photometric detection is described, A low capacity anio n-exchange column was used with potassium phthalate as the mobile phase mar ker and indirect detection at 280 nm. The chromatographic conditions were o ptimized using the Box and Behnken factorial experimental design. The metho d was precise and accurate with percent recovery (+/- %R.S.D.) of 99.8 +/- 0.7% (n = 12) with the spiked concentrations ranging between +/-30% of the assay level. Youden and Steiner's robustness test, involving seven chosen v ariables, showed that the method is robust. Using the developed method, com mercially available captopril tablets were assayed and the results were fou nd to be comparable with those obtained by the compendial method. (C) 2001 Elsevier Science B.V. All rights reserved.