Inclusion complexes of trihexyphenidyl with natural and modified cyclodextrins

• Published in: SpringerPlus Vol. 4; no. 1; p. 218
• Main Authors: Maeda, Hideko, Tanaka, Risa, Nakayama, Hirokazu
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 07.05.2015; Springer Nature B.V
• Subjects: Chemistry and Materials Science; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Trihexyphenidyl; Inclusion complexes; Sulfobutylether; cyclodextrin; Spectrofluorometry; Solubility; Sulfobutylether-β-cyclodextrin
• ISSN: 2193-1801; 2193-1801
• DOI: 10.1186/s40064-015-0986-7

The solubility of trihexyphenidyl (Thp) was improved by its combination with β -cyclodextrin ( β− CD) and modified β -CDs. The solubility of Thp was found to be increased in the presence of β -CD, hydroxypropyl- β -cyclodextrin (HP- β -CD), methyl- β -cyclodextrin (Me- β -CD) and sulfobutylether- β -cyclodextrin (SBE- β -CD). In particular, the solubility of Thp in conjunction with SBE- β -CD was increased by a factor of 11. The formation constant ( K c ) for the Thp/SBE- β -CD inclusion complex was determined to be 2300 L/mol based on fluorometry data. The structure of the Thp/SBE- β -CD complex in aqueous solution was examined by 1 H- 1 H rotating frame nuclear Overhauser effect spectroscopy (ROESY) NMR, and the phenyl moiety of the Thp was found to coordinate with the secondary hydroxyl face of the SBE- β -CD. A solid Thp/SBE- β -CD inclusion complex was prepared by freeze-drying.