UV Spectrophotometric Simultaneous Estimation of UV Spectrophotometric Simultaneous Estimation of UV Spectrophotometric Simultaneous Estimation of UV Spectrophotometric Simultaneous Estimation of UV Spectrophotometric Simultaneous Estimation of

The present work deals with the development of a simple, accurate and economical method for the simultaneous estimation of valdecoxib and paracetamol in combined tablet dosage form by Vierodt’s UV spectrophotometric method. The λ max values of valdecoxib and paracetamol in 0.1 N NaOH were 244 nm and 257 nm respectively. Both the drugs followed Beer’s law in the concentration range of 1-6 µg/ml and 5-30 µg/ml respectively. The A1% 1 cm values for valdecoxib and paracetamol at 244 nm and 257 nm were 520 and 420, 510.8 and 636.8 respectively. Valdecoxib, chemically 4,5,(5-methyl-3-phenylisoxazol-4-yl) prepared in 0.1 N NaOH. For the verification of Beer’s benzene sulphonamide, is a new COX-2 inhibitor and an law, a series of diluted solutions of valdecoxib and antiinflammatory drug 1,2 . It is yet not official in any paracetamol ranging from 1-6 µg/ml and 5-30 µg/ml pharmacopoeia. Paracetamol is an antipyretic and respectively, and mixture of both the drugs were analgesic, official in Indian Pharmacopoeia 3 and in prepared in 0.1 N NaOH. It was observed that valdecoxib Martindale 4 . Chemically, it is N-(4-hydroxyphenyl) and paracetamol individually, as well as in their mixtures, acetamide. Both the drugs in combination are used for the gave a good linearity response. synergistic activity. Literature survey revealed various methods for the determination of paracetamol in For the estimation of pure drugs by the proposed combination with other drugs 5-9 , but no method was found method, solutions of 1 µg/ml valdecoxib and 25 µg/ml of to be developed for its estimation with valdecoxib in paracetamol and a mixture containing 1 µg/ml and 25 µg/ combined dosage forms. The authors have hence ml of both the drugs were selected for determination of developed Vierodt’s method 10 for the simultaneous absorbance values. The contents were calculated using estimation of valdecoxib and paracetamol in the following equations. C X =(A pharmaceutical solid dosage form. C Y =(A 1 ax 2 -A 2 ax 1 )/(ax 2 ay 1 -ax 1 ay