It is used topically for the treatment of muscular spasms and for rheumatologic, orthopaedic, and Depsipeptide inhibitors traumatologic disorders.4 Various UV, HPLC, and stability indicating methods for dexketoprofen and thiocolchicoside have been

reported individually or in combination with other drugs.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and 21 To our knowledge there is no RP-HPLC-PDA method reported for the combination, availability of an HPLC method with high sensitivity and selectivity will be very useful for the estimation of DKP and TCS in combined pharmaceutical dosage forms. Therefore the aim of the study was to develop and validate sensitive, precise, accurate and specific RP-HPLC-PDA method for the determination of DKP and TCS simultaneously in formulation. The proposed method was developed, optimized and validated as per the International conference on Harmonization (ICH) guidelines. GPCR Compound Library manufacturer Tablet used for analysis were ESNIL (from two batches, Formulation Batch No.01A11001 (Formulation A) and 01A11210 (Formulation B)) manufactured by Emcure Pharmaceuticals

Pvt. Ltd., Pune, containing dexketoprofen (DKP) 25 mg and thiocolchicoside (TCS) 4 mg per tablet. Pure drug sample of dexketoprofen, 99.86%and thiocolchicoside, 99.92% purity were obtained as a gift sample from Emcure Pharmaceutical Pvt. Ltd., Pune and Medley Pharmaceuticals Pvt. Ltd., Andheri, Mumbai, respectively. These samples were used without further purification. HPLC grade methanol was procured from Merck Chemicals (Mumbai, India), double distilled water and placebo tablets were made at lab scale only. The HPLC system consisted of a binary pump (model Waters 515 HPLC pump), auto sampler (model 717 plus auto sampler), column

heater and PDA detector (Waters 2998). Data collection and analysis were performed Astemizole using Empower – version 2 software. Separation was achieved on Kromasil C18 column (250 mm × 4.6 mm, 5.0 μ) maintained at 35 °C using column oven. Isocratic elution with methanol: water (60:40% v/v) mobile phase at the flow rate of 0.7 ml/min was carried out. The detection was monitored at 254 nm and injection volume was 10 μl. The peak purity was checked with the PDA detector. Standard stock solution of DKP and TCS (1000 μg/ml) were prepared separately in methanol. To study the linearity range of each component serial dilutions of DKP and TCS were made from 3.125 to 125 μg/ml and 0.5–20.00 μg/ml, respectively in mobile phase and injected into column. Calibration curves were plotted as concentration of drugs versus peak area response. From the standard stock solutions, a mixed standard solution was prepared containing the analytes in the given ratio and injected into column. The SST ensures the validity of the analytical procedure as well as confirms the resolution between different peaks of interest. All critical parameters tested met the acceptance criteria on all days.