RESUMO
<p><b>OBJECTIVE</b>To prepare an inclusion complex of daidzein and hydropropyl-beta-cyclodextrin to enhance the solubility of daidzein.</p><p><b>METHOD</b>The inclusion complex of daidzein was prepared by the solution stirring method. The binary system of daidzein and HP-beta-CD was confirmed by differential thermal, thermogravimetry analysis, infrared spectroscopy and X-ray diffractometry.</p><p><b>RESULT</b>The drug content in the inclusion complex was 6. 76% and the solubility was 13.68 mg x mL(-1). The identification results showed that the inclusion complex was formed.</p><p><b>CONCLUSION</b>The preparation method of the inclusion complex of daidzein and hydropropyl-beta-cyclodextrin is simple and available, with a increased solubility of daidzein.</p>