Determination of sodium chondroitin sulfate in tablets based on precipitate formation with Alcian Blue

The carbazole-sulfuric acid method (determination Of D-glucuronic acid) has been used as a general determination method for sodium chondroitin sulfate (ChS-Na) in dosage forms. However, this method requires a complicated column pretreatment to isolate ChS-Na in the dosage form. Among the various determination methods for ChS-Na, we focused on a determination method using Alcian Blue (AB method), and examined the analytical conditions necessary to apply to tablets. As a result, we not only found that this was a simple determination method, but also established it as an excellent method, which shows good specificity, linearity, accuracy and precision. The ChS-Na content in bulk powder products, measured by the AB method, had a comparatively high correlation with the sulfur content (r = 0.81) measured by oxygen flask combustion and the D-glucuronic acid content (r = 0.87), measured by the carbazole-sulfuric acid method, which are the conventional determination methods.