Studies of a reference sample of glycyrrhizic acid during the drying process

Qualitative and quantitative assessments of water content in a reference sample of glycyrrhizic acid (RS GA) are presented. A DSM-10M differential scanning microcalorimeter of Russian origin was used for thermal analysis of RS GA and identification of the temperature ranges for phase transitions of the reference sample of glycerrhizic acid during drying. RS GA was shown to contain two types of water: weakly bound and tightly bound. HPLC studies showed that drying for 3 h at 105°C had virtually no effect on the quality of the RS GA.