Fractional determination of sodium chondroitin sulfate/hydroxypropylmethylcellulose mixture using Alucian Blue 8GX

Using Alucian Blue 8GX (AB), a simple fractional determination method was developed for sodium chondroitin sulfate (ChS-Na) and hydroxypropylmethylcellulose (HPMC) respectively in a drug. From a sample solution containing both ChS-Na and HPMC, ChS-Na was precipitated selectively as the ChS-Na-AB complex under a low-pH condition. After dissolution of the ChS-Na-AB complex in an alkali solution, ChS-Na was determined by the absorbance at 615 nm. The supernatant of the sample solution was subjected to gel permeation chromatography (GPC). The amount of HPMC was determined by the peak height of HPMC. These methods have safty, high-specificity and high-repeatability. These methods are therefore useful for drugs which contain both acidic mucopolysaccharide and a non-ionic polymer.