NOVEL SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS DETERMINATION OF CURCUMIN AND DICLOFENAC DIETHYLAMINE IN DEVELOPED DOSAGE FORM

Rheumatoid arthritis is an autoimmune disease that involves inflammation of joints. Diclofenac diethylamine, as well as Curcumin, are widely used for symptomatic relief of pain and inflammation. The present study was aimed at providing a simple, accurate and economical spectrophotometric method for simultaneous determination of curcumin and diclofenac diethylamine from topical gel formulation. Simultaneous determination of both drugs namely, curcumin and diclofenac diethylamine was done by Absorbance correction method using phosphate buffer 5.5: ethanol (1:1) as the solvent. A topical gel containing curcumin microspheres and diethylamine were prepared using carbopo l971 as a gelling agent along with propylene glycol, preservatives, and triethanolamine. Diclofenac diethylamine showed an absorbance maximum at 278 nm whereas curcumin showed at 428.4 nm in phosphate buffer 5. 5: ethanol (1:1). The linearity of both drugs was found in the concentration range 2-26 μg/ml for Diclofenac diethylamine and 1-7 μg/ml for Curcumin respectively. This method was then applied successfully to pharmaceutical dosage form gel and no interference of excipients was found. Recovery for curcumin and diclofenac diethylamine was found to be 99.50% and 98.76% respectively. Validation of the method was done as per ICH guidelines to prove the suitability of the method for quantitative determination of both drugs diclofenac diethylamine and curcumin. These results indicated that the proposed method could be used for successful determination of curcumin and diclofenac diethylamine from pharmaceutical dosage form.