Protection of cyclodextrin on the structure of lactone form of 10-hydroxycamptothecin

Objective:To study the inclusion complex of lactone moiety of 10-hydroxycamptothecin and SBE-β-CD for keeping its lactone moiety and improving its solubility.Methods:The formulary of the inclusion complex of 10-hydroxycamptothecin's lactone moiety and ring cleavage moiety with SBE-β-CD was calculated by computer simulation and UV spectra method,respectively.The inclusion compound was prepared by acid-base method.The solubility and stability of inclusion complex was determined by UV method.The content of lactone moiety of 10-hydroxycamptothecin was determined by HPLC method.Results:The results showed that the solubility of 10-hydroxycamptothecin was increased by 5 000 times from 0.22 μg·mL-1 to 1.01 mg·mL-1 after being included into SBE-β-CD with lactone moiety.The content of lactone moiety was increased from 63.2% to 96.8%.The inclusion complex was stable within 12 months at room temperature.Conclusion:SBE-β-CD could improve the solubility of 10-hydroxycamptothecin and keep its lactone moiety.It is feasible that SBE-β-CD could be used to improve the performance of 10-hydroxycamptothecin hydrochloride formulary.