Solubility and Crystallization of Glucosamine Hydrochloride in Water with the Presence of Additives.

Glucosamine hydrochloride (GAH) is a kind of natural hexose, which is used to promote the synthesis of mucopolysaccharides and improve the metabolism of articular cartilage. In this paper, the solubility of GAH in pure water and aqueous system with the presence of three kinds of additives (HCl, NaCl, KCl) at temperatures ranging from 278.15 K to 323.15 K was determined by gravimetric method. When there are additives in water, the solubility of GAH increases with the increase of temperature and decreases with the increase of concentration of the three kinds of additives. When the additives were at similar mole fractions, HCl led to the lowest solubility of GAH. The modified Apelblat model and van't Hoff model were used to correlate the solubility data. The average relative deviation (ARD) data of Apelblat and van't Hoff models were less than 5%, indicating good fitting results. Based on the thermodynamic data, the cooling crystallization process of GAH was performed. It was found that the additives could affect the crystal morphology, particle size, and yield of GAH products. This study supplemented the thermodynamic data of GAH and studied the cooling crystallization process in the presence of GAH additives, which provided important guidance for the optimization of the crystallization process. [ABSTRACT FROM AUTHOR]