Abstract

Determination of chlorzoxasone in presence of its alkaline degradation product with three spectrophotometric methods

Author(s): Samah S.Abbas, Hebat Allah M.Essam*, Mohammad G.El-Bardicy

Three sensitive, selective and accurate methods are presented for the determination of chlorzoxazone (CHZ) in presence of its alkaline degradation product 2-amino-4-chlorophenol (ACP) and in its dosage form. Method A based on the ratio subtraction spectrophotometry by measuring the maximum absorbance of chlorzoxazone (CHZ) at 282.6nm after the subtraction of its degradant (ACP) interference. BeerÂ’s law was obeyed in the concentration range of 5.00-50.00g.mL-1 withmean percentage recovery of 99.64 ± 1.036.Method B utilized the complexation reaction of the degradation product (ACP), after complete alkaline hydrolysis of chlorzoxazone (CHZ), with Cu (II) acetate solution to produce a colored complex measured after the second derivative at 477nm. Method C based on the oxidation-reduction reaction between the degradation product (ACP), after complete alkaline hydrolysis of chlorzoxazone (CHZ), and Folin-Ciocalteu reagent (F-C) to produce a blue color measured at 655.5nm. The linearity range was 2.50- 20.00g.mL-1 for both methods with mean percentage recovery of 99.81 ± 0.953 and 100.03 ± 0.947 for methods B and C, respectively. All variables were studied to optimize the reaction conditions. The proposed methods have been successfully applied to the analysis of chlorzoxazone in pharmaceutical dosage form. Results were statistically compared with the official method and no significant difference was observed regarding accuracy and precision.