Chinese Journal of Pharmaceuticals, Volume. 56, Issue 7, 945(2025)
Thermodynamics of Cannabidiol in Different Solvents
ZHAO Xiaojun1, DUAN Jiajing1, LI Yang1、*, WANG Pu2, ZHANG Yuntao2, and GAO Wei1
Author Affiliations
1Hebei Key Lab. of Comprehensive Utilization of Plant Resource, Chenguang Biotech Group Co., Quzhou 0572502Tengchong Chenguang Yunma Biotechnology Co., Ltd., Tengchong 679100show less
The solubility values of cannabidiol (1) in n-hexane, n-heptane, 80% ethanol, and 90% ethanol were determined, then these solubility data were fitted using the Apelblat equation. After that, the Gibbs free energy change of dissolution (ΔG), the enthalpy change of dissolution (ΔH), and the change of dissolution (ΔS) of 1 were calculated in different solvents using the van’t Hoff equation. On this basis, the crystallization thermodynamicsof 1 was studied. The results showed that the solubility of 1 exhibited a positive correlation with temperature, and its solubility in the aforementioned solvents follows the descending order: 90% ethanol>80% ethanol>n-hexane>n-heptane. The correlation coefficients R2 of the Apelblat’s equations were all greater than 0.99, indicating a good correlation. Both ΔH and ΔS were greater than 0 during the dissolution process of 1, showing this process was an endothermic and entropy-increasing process. These results could provide certain guidance for the extraction and crystallization of 1 during the processing.
