Development and Validation of Spectrophotometric Methods for Simultaneous Estimation of Escitalopram oxalate and Etizolam in their Combined Tablet Dosage Form

Three simple, rapid, accurate, precise and cost-effective UV spectrophotometric methods have been developed and validated for simultaneous estimation of Escitalopram oxalate and Etizolam in tablet dosage form. The UV methods have been developed utilizing concept of standard addition utilizing 0.1 N HCl as a solvent. Method I is estimation using simultaneous equation method at 238.2 nm (λmax of Escitalopram oxalate) and 251.6 nm (λmax of Etizolam). Method II is Q ratio (absorbance ratio) method utilize absorbance measurement at 238.2 nm and 248.8 nm (isoabsorptive point). Method III is absorbance correction method utilize absorbance measurement at 238.2 nm for Escitalopram oxalate and 292.8 nm for Etizolam. Linearity was observed in range of 10-60 μg/ml and 5-30 μg/ml for Escitalopram oxalate and Etizolam respectively for all three methods .The correlation coefficient value was found to be 0.9989-0.9998. All methods were statistically validated as per ICH guidelines and can be successively applied for analysis for tablets formulation.