DETERMINATION OF THE DEGREE OF SUBSTITUTION OF HYDROXYPROPYLATED BETA-CYCLODEXTRINS BY DIFFERENTIAL SCANNING CALORIMETRY

The general specifications of commercially available hydroxypropylated beta-cyclodextrins (HPBCDs) usually give information on the solubilit y, solubilizing potency and average degree of substitution (DS) of a g iven product. The DS value is regarded as suitable for quality control purposes. This paper describes a differential scanning calorimetric m ethod to determine the DS, based on the fact that the glass temperatur e interval of the amorphous part of the sample depends on the degree o f substitution of the HPBCD.