Identification of andrographolide hydroxypropyl-?-cyciodextrin inclusion compound and study on its thermodynamic stability / 中草药

ABSTRACT

Objective To prepare and identify the andrographolide-hydroxypropyl-?-cyclodextrin(an- drographolide-HP-?-CD)inclusion compound.The tool ratio between andrographolide and HP-?-CD and the thermodynamic constants in inclusion were studied simultaneously.Methods The andrographolide- HP-?-CD inclusion compound was prepared with lyophilization technique.Meanwhile,the inclusion com- pound was identified by differential scanning calorimetry(DSC)methods,infrared spectrometry(IR),and X-ray diffraction(XRD),respectively.The tool ratio between host and guest moleculars and the thermo- dynamic constants during the inclusion process were also researched by phase solubility method.Results An 11 molar ratio inclusion complex of andrographolide with HP-?-CD could be formed at 25,35,and 45 C.The phase diagram was A_L type and the procedure of inclusion was a heat release process.Conclusion The solubility of andrographolide-HP-?-CD inclusion compound can be increased obviously by the above- mentioned preparing techniques.