Research On The Supramolecular And Product Of Curcumin/mixed Cyclodextrin

Curcumin is a natural kind of small molecular phenolic compound,which is extracted from the rhizome of the ginger family(Zingiberaceae):Radix Curcuma,Rithoma Curcuma and Rhizoma Curcumae.Curcumin is safe and nontoxic,and has a wide range of pharmacological effects.However,it,almost insoluble in water,has low oral absorption and converts in the gut easily,and the majority(75%)is excreted as the prototype.In addition,curcumin is easy to decompose when it is expoxed to light or heat.In this paper,we use ?-CD,?-CD as host molucrlues and curcumin as the guest molecule.A single cyclodextrin or mixed cyclodextrins(?-CD and ?-CD)are used to prepare inclusion complexes in order to improve the solubility,dissolution rate and stability of curcumin.UV-visible spectra is used to predict the possibility of inclusion between curcumin and cyclodextrins.The apparent inclusion constant results indicate that single or mixed cyclodextrins have an inclusion effect on curcumin.The composition ratios of inclusion compounds are obtained by Benesi-Hildebrand equation,phase solubility method and equimolar series method The results suggest that curcumin form inclusion complexes with cyclodextrins at a molar ratio of 1:2.The inclusion complexes are prepared by levigation,validated by scan electron microscopy,thermal analysis,DRIFT,X-ray and 1H-NMR.The solubilization results show that times of solubility improvement of combination of ?-CD and ?-CD(at the molar ratio of 2:3)to curcumin reach 880.00,that the colour of solution turns to dark red.It is obvious that the mixed ?-CD and ?-CD can improve the solution of curcumim,its performance is significantly better than the simple addition of cyclodextrins.Besides,mixed cyclodextrins have the highest price performance ratio.The dissolution tests show that inclusion complexes have better dissolution and dissolution rate than curcumin.The stability of curcumin that the inclusion complex is prepared improved when it is exposed to light or heat.According to Arrhenius equation,we can predict that the period of validity of inclusion complex is 1.2 years,prolonged for another 9.2 times,while the raw material is 0.13 years at 25?.Granules and tablets can be prepared by mixing inclusion complexes with common excipients,and their quality inspection are complied with the Chinese Pharmacopoeia(2010 edition)regulations.Suspension injection made by a-CD inclusion complex is also complied with the Chinese Pharmacopoeia(2010 edition)regulationsCurcumin and mixed cyclodextrins(?-CD and ?-CD)are used to prepare inclusion complexes in this paper,which break the original idea that curcumin can only prepare with a single cyclodextrin,besides mixed cyclodextrins inclusion complexes have a better price/performance ratio.This paper provides a new method to prepare mixed cyclodextrins and a single guest molecule inclusion complex.In addition,the process of preparing inclusion complexes by levigation is simple,which has a good practical value.Further more,DRIFT is more suitable for the identification of inclusion compound.