Absorbance Ratio and First Order Derivative Spectroscopic Methods for Simultaneous Determination of Sacubitril and Valsartan in Bulk and Tablet Dosage Form

Two UV-spectrophotometric methods have been developed and validated for simultaneous estimation of Sacubitril (SAC) and Valsartan (VAL) in bulk and tablet dosage form. The Method A employs absorbance ratio method, which involves formation of Q-absorbance equation at 242.0?nm (isoabsorptive point) and also at 253.5?nm (?max of SAC). Method B employs first order derivative, the wavelengths selected for quantitation were 233.0 nm for VAL (Zero cross for SAC) and 247.0 nm for SAC (Zero cross for VAL). For both the methods drugs were linear between the range of 4.9–24.5?µg/ml for SAC and 5.1–25.5?µg/ml for VAL using methanol and distilled water as solvents. The correlation coefficient was found to be 0.9995 for SAC and 0.9996 for VAL for method A and 0.9998 for SAC and 0.9999 for VAL for method B, respectively. The precision (intraday, interday) of methods was found within limits (RSD < 2%). It could be concluded from the results obtained in the present investigation that the two methods for simultaneous estimation of SAC and VAL in bulk and tablet dosage form are simple, rapid, accurate, precise and economical and can be used, successfully, in the quality control of tablet formulations and other routine laboratory analysis.