Development and validation of UV spectroscopic Q-absorbance ratio method for zonisamide and aripirazole in synthetic mixture

A simple, specific, accurate and precise Q-Absorbance ration spectrophotometric method was developed and validated for estimation of Zonisamide and Aripirazole in Synthetic Mixture. Zonisamide and Aripirazole showed and iso-absorptive point at 230.50nm in Distilled water. The second wavelength used was 240.60nm which is λmax of Aripirazole in distilled water. The concentration of the drugs was determined by using ratio of absorbance at iso-absorptive point (λ1 =240.60 nm) and at the λmax of Aripirazole (λ2 =230.50 nm). This method is linear for both drugs; in range 10-30 μg/ml at λ1 R2 = 0.996 at λ2 (R2 = 0.997) for Aripirazole, and in the range of 10–30 μg/mL for Zonisamide found at λ1 (R2 = 0.990) and at λ2 (R2 = 0.996). The % Recovery was 101.12 % of Aripirazole and 101.89 % of Zonisamide by standard addition method. The LOD was found to be 0.084 μg/mL and 0.110 μg/mL for both drugs at λ1 and λ2 respectively. The LOQ was found to be 0.257 μg/mL and 0.330 μg/mL for both drugs at λ1 and λ2 respectively. The method was found to be precise as % RSD was less than 2.00 in Repeatability, Interday and Intraday precision for Zonisamide and Aripirazole. The % assay of analyte drugs in synthetic mixture was found to be 100.48 % of Zonisamide which showed good applicability of the developed method.