Study on the Supramolecular Interaction of β‐Cyclodextrin with Gemfibrozil by Spectrofluorimetry and Its Analytical Application

Abstract

The supramolecular interaction of gemfibrozil with β-cyclodextrin (β-CD) was studied by spectrofluorimetry. The mechanism of the inclusion was discussed by spectrofluoremetry, infrared spectrum and 1 H NMR spectrum.The results showed that a 1∶1 (β-CD∶gemfibrozil) complex was formed with an apparent association constant of 3.844×10 3 L•mol -1 . Based on the enhancement of the fluorescent intensity of gemfibrozil, a spectrofluorimetric method for the determination of gemfibrozil in bulk aqueous solution in the presence of β-CD was developed. The linear range was 3.30 ng•mL -1 -6.00 µg•mL -1 with the detection limit of 0.980 ng•mL -1 . There was no interference from the excipients normally used in tablet composition and the serum main compositions. The proposed method was then successfully applied to the determination of gemfibrozil in capsules and serum.

A Comprehensive Study of Gemfibrozil Complexation with β-Cyclodextrins in Aqueous Solution Using Different Analytical Techniques

“…The K 1:1 obtained for the complex GEM-β-CD at 25 • C in pH 7.0 aqueous solution (7.6 ± 0.3) × 10 2 M −1 agrees with the value of 757 M −1 reported for the same complex at pH 9.1 by Tang et al (2004) [16], contrasting with the higher values obtained by Huang et al (2007) [12] in the same conditions (around 3000 M −1 ).…”

“…The NMR spectra of the aromatic region of GEM It is well known that studies of complexation with cyclodextrins often lead to discordant values of stability constants depending on the experimental conditions, the analytical technique employed, and the mathematical model used to analyse the experimental data. This is the case of the complex gemfibrozil-β-CD [10,12].…”

Analysis of the complexation of gemfibrozil with γ- and hydroxypropyl-γ-cyclodextrins

“…The values of the stability constants obtained with ␥-CD are higher than those of the ␥-CD complexes formed with benzene, toluene and ethylbenzene [19], probably due to a dependence of the stability constant on chain length in benzene derivatives. The complexation constants obtained with ␥-CD are lower than those of the complexes with ␤-CD [4,[8][9][10], probably due to its greater volume and polarity [11].…”

“…It has been proved, using fluorescence, NMR and solubility methods, that the non-polar moiety of gemfibrozil can be housed into the hydrophobic cavity of ␤-CDs [4,[8][9][10]. The volume and polarity of the ␥-CD cavity are higher than those corresponding to ␤-CD [5,11] and these properties condition the value of the binding constants.…”