Development and validation of a photometric titration method for the quantitation of sodium chondroitin sulfate (bovine) in Cosequin® DS chewable tablet

A photometric titration method was developed and validated to quantitate sodium chondroitin sulfate in raw materials and Cosequin® DS chewable tablet 1 1 Cosequin® DS chewable tablet contains glucosamine HCl, sodium chondroitin sulfate, manganese ascorbate, and flavoring agents. . About 0.1% (w/v) cetylpyridinium chloride was used to titrate sodium chondroitin sulfate with photometric indication at wavelengh 420 nm. The standard curves for sodium chondroitin sulfate showed linearity ( r≥0.99) over the selected concentration range from 0.6 to 1.4 mg/ml. The chewable tablet was ground to fine powder and extracted with water and the resulting solutions filtered through a 0.45 μm membrane filter. Recovery between 97 and 103%,. The intra- and inter- day precision as indicated by the relative standard deviation (R.S.D.) were not greater than 0.33 and 0.78%, respectively. The method was found to be specific and with excellent linearity, accuracy and precision and is well suited for the quantitation of sodium chondroitin sulfate in raw material and Cosequin® DS chewable tablet.