DEVELOPMENT AND VALIDATION OF SECOND ORDER DERIVATIVE SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF ATENOLOL AND NIFEDIPINE IN COMBINED DOSAGE FORM

A simple, precise, accurate and reproducible spectrophotometric method has been developed for Simultaneous estimation of Atenolol and Nifedipine by employing second order UV derivative Spectrophotometric method in Water: ACN (60:40). The Second order derivative absorption at 245.63 nm (zero cross point of Nifedipine) was used for quantification of Atenolol and 218.7 nm (zero cross point of Atenolol) for quantification of Nifedipine. The linearity was established over the concentration range of 50-150 μg/ml and 20-60 μg/ml for Atenolol and Nifedipine with correlation coefficient (r²) of 0.999 and 0.998 respectively. Interday and intraday studies showed repeatability of the method. The mean % recoveries were found to be in the range of 99.25% – 101.15% and 98.56% – 101.85% for Atenolol and Nifedipine, respectively. The method is successfully applied to pharmaceutical formulation, with no interference from excipients as indicated by the recovery study. The proposed method has been validated as per ICH guideline and successfully applied to the simultaneous estimation of Atenolol (ATN) and Nifedipine (NIF) in their combined Tablet dosage form. So it was recommended for routine analysis. The use of 60% Distilled water as a solvent makes method Cost effective and economical.