Application of Continuous Wavelet Transform Coupled with Zero-crossing Technique for the Simultaneous Spectrophotometric Determination of Sacubitril and Valsartan in Tablet Dosage Form

A rapid, simple, precise, accurate, and environmentally friendly spectrophotometric method was developed and validated for simultaneous determination of Sacubitril and Valsartan in their combined dosage form, using continuous wavelet transform (CWT) and zero-crossing techniques without using organic solvents and the timeconsuming extraction step. Initially, UV spectra of two pure components in water were processed via various mother wavelet families. Then, applying zero-crossing technique, the optimum points were found to obtain appropriate calibration curves for each point. The calibration curves were linear for both Sacubitril and Valsartan. The validation of these methods was investigated by analyzing several synthetic mixtures with known concentrations. Applying oneway analysis of variance (ANOVA) test and Fisher pairwise comparisons, the following were found to yield the best results Discrete Meyer (dmey) wavelet functions with scaling factor of 61 at 232 nm and Symlet5 (sym5) with 48 at 232 nm for Sacubitril and Meyer (meyr) with 50 at 272 nm, meyr with 59 at 247 nm, Daubechies (db5) with 53 at 237 nm, and sym5 with 59 at 226 nm for Valsartan. The mean recovery values in synthetic mixtures were between 99.09% and 101.16% using the proposed methods, where relative standard deviation (RSD) not more than 1.23% proved to have good precision. The obtained results from the commercial tablets, applying the developed methods, were compared to those yielded by HPLC method by one-way ANOVA test. According to the results, they were in good agreement and showed no significant differences, thereby suggesting successful determination in accordance with green chemistry.