Objective:To synthesize poly (2-ethyl-2-oxazoline)-poly(lactic acid) copolymer (PEOz-PLA), prepare pH-sensitive paclitaxel-loaded polymeric micelles, and evaluate the in vitro properties. Methods: The structures of all the synthesized copolymers were confirmed by 1 HNMR and Fourier transform infrared spectroscopy ( FTIR) . The drug-loaded micelles were prepared by a dialysis method. The micelles solution was freeze-dried and the lyoprotectants were screened. The critical micelle concentrations ( CMC) of the copolymers were measured by pyrene fluorescent probe technique. The distribution of particle size was measured by dynamic light scat-tering ( DLS) . The in vitro release behavior of the loaded micelles at different pH conditions was studied by a dialysis method. Re-sults:The CMC of micelles was 25. 63 mg·ml-1 . When 10% polyethylene glycol 4000 was used as the lyoprotectant, the re-solubili-ty of micelles was good and the distribution of particle size was narrow. The drug loading rate of micelles was 8. 12% and the encapsu-lation efficiency was 69. 33%. The average particle size of freeze-dried micelles was 183. 7 nm. The in vitro release of the drug-loaded micelles showed that the drug released slowly at pH 7. 4 and fast at pH 5. 0, which indicated that the change of pH could affect the drug release. Conclusion:The preparation of PEOz-PLA polymer micelles is simple. The particle size, entrapment efficiency and drug loading are controllable. The micelles have a certain sustained-release effect, which provides basis for further pharmacological study and clinical application.

Objective:To analyze and optimize the extraction technology of Geum aleppicum by Box-Behnken design and response surface methodology. Methods:With the content of total flavonoids as the index, the effects of three factors including the solvent-solid ratio, ethanol concentration and extraction time on the content of total flavonoids were studied by single factor experiment, and the ex-traction technology was optimized by Box-Behnken design and response surface methodology. Results: The optimal extraction condi-tions of Geum aleppicum were as follows:the solvent-solid ratio was 4. 2, the ethanol concentration was 50% and the extraction time was 80 min. Under the above conditions, the average yield was 12. 590 0 mg·g-1 . Conclusion: Optimizing extraction technology of the total flavonoids in Geum aleppicum by Box-Behnken design and response surface methodology is reasonable, and the mathematical mod-el is consistent with the experimental data, which has good predictability.

Objective:To optimize the alcohol extraction process of herbal pair puerarin-berberine.Methods:Based on the etha-nol reflux extraction,the extraction quantity of total flavonoids,total alkaloid,puerarin and berberine hydrochloride were used as the e-valuation index,and the independent variables included the drug particle,ratio of solid to liquid, ethanol concentration, reflux dura-tion and reflux times. Significance analysis was evaluated by Plackett-Burman design,and then the extraction process was optimized by Box-Behnken response surface methodology.Results:The optimal extraction conditions of drug pair puerarin-berberine were as follows:the drug particle was 80 mesh,the ratio of solid to liquid was 1:13,the ethanol concentration was 75%,the reflux time was 60 min, and the reflux times was 4. Under the above conditions, the extraction quantity of total flavonoids, alkaloid, puerarin and berberine hydrochloride was 120.34,56.99,109.63 and 39.26 mg ·ml-1, respectively.Conclusion: The extraction process of herbal pair puerarin-berberine is reasonable and feasible optimized by Plackett-Burman design and Box-Behnken response surface methodology.