Extractive Colourimetric Determination of Pipazethate HCl by Ion-pair Complex Formation in Pure Form, Dosage Form, Urine and in Presence of its Degradation Products

A simple ,sensitive and accurate spectrophotometric method based on extractable ion-pair formation of pipazethate HCl with chromazurol S., exh ibits an absorption maximum at 512 nm, was described. Beer’s law was obeyed over the concentration range of 12 – 92 μg mL, apparent molar absorpitivity, limit of detection (LOD) and limit of quantitation. (LOQ) were 3.4x10 molL cm, 3.36 and 11.2 μg mL, respectively. Precision of results, expressed as intra-day and inter-day relative standard deviation values, are satisfactory. The method was successfully applied for the determination of pipazethate HCl in dosage forms and in spiked human urine, no interference was observed from common pharmaceutical additives. Statistical comparison of the results with reference method showed an excellent agreement and indicated no significant difference in precision. Pipazethate HCl was subjected to the stress conditions of acidic, basic, oxidative, hydrolytic, thermal and photolytic degradations. The method retain its accuracy in the presence of basic, acid ic and oxidative degradants.because basic degradants give no reaction with chromazurol S while both acidic and oxidative degradants gave yellow co lour which was measured at 453nm and 457 nm respectively.