TITLE:
New Ethenzamide-Trimesic Acid Cocrystal: Equilibrium Solubility
AUTHORS:
Shuting Lin, Jiarong Zhang, Weijie Sun, Penghui Ren, Jiayi Jiang, Chengjun Jiang
KEYWORDS:
Pharmaceutical, Cocrystal, Ethenzamide, Crystal Engineering, Solubility
JOURNAL NAME:
Open Access Library Journal,
Vol.10 No.6,
June
19,
2023
ABSTRACT: Ethenzamide, a non-steroidal anti-inflammatory drug, is used to treat pain, inflammation, fever and rheumatism. However, it has low solubility and belongs to class II of the biopharmaceutical classification system. In order to improve the solubility of ethenzamide, the cocrystal of ethenzamide was prepared and characterized according to the synthesis principle of hydrogen bond supramolecular synthons in crystal engineering. The ETZ·2TMA·MeOH cocrystal was obtained by the solution evaporation crystallization method. The cocrystal structure was characterized by Single Crystal X-ray Diffractometer. The single crystal belongs to orthorhombic crystal system with space group P212121 (no.19), a = 12.9863 (9) Å, b = 16.6603 (11) Å, c = 25.9260 (16) Å, V = 5609.2 (6) Å3, Z = 8, T = 170.00 K. The main forces are the formation of intermolecular hydrogen bonds between the amide groups on ethenzamide and the carboxyl groups on trimesic acid and the hydroxyl group on methanol. In addition, the solubility of ethenzamide and ETZ·2TMA·MeOH cocrystal was determined. The results show that, in contrast to most cocrystal systems that improve solubility, the solubility of ETZ·2TMA·MeOH decreased to 19.30% of pure ethenzamide.