Simultaneous Determination of Paracetamol and Chlorzoxazone Using Orthogonal Functions- Ratio Spectrophotometry

An investigation of the ethanolic extract of the pods of Albizzia lebbeck (L.) Benth. afforded a Orthogonal functions-ratio spectrophotometry has been developed and applied to the determination of paracetamol and chlorzoxazone in authentic mixtures and capsules. A basic computer program was used to facilitate the calculations behind the method. The methods have been validated. The accuracy as determined by the analysis of laboratory prepared mixtures was found to be 99.0 to 100.3 % with repeatability of less than 1% (RSD). Linearity ranges were found to be 3.0-21.0 and 5.0-40.0 ug per ml, respectively. The methods were found to be robust to ± 0.5 nm shift in the wavelength scale. Certain ratios have been developed to prove specificity.