OPTIMIZED AND VALIDATED SPECTROPHOTOMETRIC DETERMINATION OF BUTAMIRATE CITRATE IN BULK AND DOSAGE FORMS USING ION-PAIR FORMATION WITH METHYL ORANGE AND BROMOTHYMOL BLUE

Two easy, sensitive, precise and valid spectrophotometric techniques are described for the determination of butamirate citrate (BC) in pure form and pharmaceutical formulations. These methods are based on the formation of ion-pair between butamirate citrate with methyl orange (MO) and bromothymol blue (BTB). The techniques involve the formation of yellow coloured ion-pair in aqueous solution, extraction with dichloromethane and absorbance measurement at 424 nm for BC-MO and 410 nm for BC-BTB ion pairs against a blank solution. Molar ratio of the ion-pairs was determined using Job's Continuous Variation Method. The proposed methods were validated for linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. Beer's law was obeyed in the ranges of 4.0 - 20.0 mu g/mL for BTB and 2.5 - 12.5 mu g/mL for MO.