Development and validation of analytical method for simultaneous estimation of diclofenac sodium and benzocaine in gel dosage form

Abstract

The present work involves the development and validation of RP-HPLC method and –UV Visible Spectroscopic method for the estimation of Diclofenac Sodium and Benzocaine in gel dosage form. A specific, precise and selective RP-HPLC method has been developed and validated using Zodiac C18 (150mm x 4.6mm i.d., 5μm). 0.1 % Glacial acetic acid in water: Acetonitrile (35:65) was selected as mobile phase, Flow rate 1.0 ml/min and detector wavelength was 243 nm. The retention time of Diclofenac Sodium and Benzocaine were observed at 6.58 min and 3.68 min respectively. The linearity range was found to be 0.6-4.2 μg/ml and 4-28 μg/ml for Diclofenac Sodium and Benzocaine respectively. The mean recovery was found to be 100.78% and 99.98% for Diclofenac Sodium and Benzocaine respectively. The developed methods were economic, precise and specific. The developed Ratio derivative spectroscopic method using pH 6.8 Phosphate buffer as solvent. Benzocaine and Diclofenac Sodium  has absorbance at 321.5 nm and  233.5nm respectively The linearity was obtained in concentration range 0.6-3.0 μg/ml and 4-20 μg/ml for Diclofenac Sodium and Benzocaine respectively for all UV-Visible method. The mean recovery was 101.25% and 100.52% was obtained for Diclofenac Sodium and Benzocaine respectively.