SPECTROSCOPIC CHARACTERIZATION OF IBUPROFEN 2-HYDROXYPROPYL-BETA-CYCLODEXTRIN INCLUSION COMPLEX/

Ibuprofen has been used widely as an anti-inflammatory and anti-pyreti c agent. It is slightly soluble in water. Several investigators have c onducted studies to improve the dissolution rate of ibuprofen using cy clodextrin complexation. In this study, the geometry and the structura l features of the ibuprofen/hydroxypropyl-beta-cyclodextrin (HP beta C D) inclusion complex were studied by NMR and fluorescence spectroscopy . The fluorescence intensity of ibuprofen increased as the concentrati on of HP beta CD increased. Continuous variation plots by NMR study su ggested that 1:1 stoichiometric complex was formed in solution. The sp ectral analysis of H-1- and C-13-NMR measurements showed that the sign als of the aromatic protons of ibuprofen were shifted upheld, probably resulting from the interaction of HP beta CD with aromatic ring of ib uprofen. We also postulated the optimized structure of ibuprofen/HP be ta CD inclusion complex through a molecular modeling program (SYBYL 6. 4) and we found that the features of this postulated structure were in a good agreement with the H-1- and C-13-NMR spectra. (C) 1998 Elsevie r Science B.V. All rights reserved.