Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Inclusion Mechanism and Heat Stability of the Complex of 4-Hydroxychalcone and Hydroxypropyl-6-Cyclodextrin

Yancheng Guo¹ , Yuzhen Chen², Hanjun Ma¹

¹School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; ²School of Mathematical Sciences, Henan Institute of Science and Technology, Xinxiang 453003, China.

For correspondence:- Yancheng Guo Email: yancheng258@163.com

Received: 16 July 2014 Revised: 4 November 2014 Published: 15 December 2014

Citation: Guo Y, Chen Y, Ma H. Inclusion Mechanism and Heat Stability of the Complex of 4-Hydroxychalcone and Hydroxypropyl-6-Cyclodextrin. Trop J Pharm Res 2014; 13(12):1971-1977 doi: 10.4314/tjpr.v13i12.3

© 2014 The authors.
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Abstract

Purpose: To study the inclusion mechanism and heat stability of the complex formed between 4-hydroxychalcone and hydroxypropyl-β-cyclodextrin (HP-β-CD).

Methods: The inclusion mechanism of the complex of 4-hydroxychalcone and HP-β-CD was investigated by phase solubility method. The physicochemical properties of the complex were evaluated by Fourier transform infrared spectroscopy (FT-IR) and x-ray diffractometry (XRD) while the heat stability of the complex was measured by thermogravimetric/differential scanning calorimetry (TG/DSC).

Results: The stability constants of the complexes were higher than those of β-CD at all temperatures. For the formation of the complex, Gibbs energy (-16.87 KJ/mol at 20 °C) was negative, and positive entropy (31.15 KJ/mol) along with a slightly positive enthalpic change (163.89 J/mol) was also found. IR and XRD analysis showed that the physical phase of 4-hydroxylchalcone was changed and completely dispersed in HP-β-CD while TG/DSC data indicate that the starting decomposition temperature of 4-hydroxychalcone (200 °C) was significantly enhanced to 397 °C due to the formation of inclusion complex with HP-β-CD in the solid state.

Conclusion: The stability constant of HP-β-CD for 4-hydroxychalcone is higher than that of β-CD. The inclusion is a spontaneous process, driven by hydrophobic forces. The heat stability of 4’-hydroxychalcone is significantly enhanced by complexing with HP-β-CD.

Keywords: 4-Hydroxychalcone, Hydroxypropyl-6-cyclodextrin, Inclusion complex, Phase solubility, Thermogravimetry, Differential scanning calorimetry