Derivative Spectrophotometic Methods for Simultaneous Estimation of Acetaminophen and Guaiphenesin in their Combined Dosage Form

Abstract

Derivative spectroscopy offers a useful approach for the analysis of drugs in mixtures. In this study First order derivative spectrophotometric method was developed for the simultaneous determination of Acetaminophen (ACET) and Guaiphenesin (GUAI) in bulk and combined tablet dosage form. The derivative spectrum for the method was obtained in methanol and the linearity was obtained in the concentration range of 2.0 - 10.0 µg/mL for Acetaminophen and 1.2 - 6.1 µg/mL for Guaiphenesin. The zero order spectrums are obtained at wavelengths 250nm for Acetaminophen and 274nm for Guaiphenesin. First order derivative spectrophotometric method was based on the determination of both the drugs at their respective zero crossing point (ZCP). The determinations were made at 209 nm (ZCP of Guaiphenesin) for Acetaminophen and 250 nm (ZCP of Acetaminophen) for Guaiphenesin. The mean % recovery was 100.4 and 99.8 % for Acetaminophen and Guaiphenesin respectively. The method was found to be simple, sensitive, accurate and precise and was applicable for the simultaneous determination of Acetaminophen and Guaiphenesin in pharmaceutical tablet dosage form. The results of analysis have been validated statistically and by recovery studies.