In vitro release behavior and in situ absorption of evodiamine loaded microemulsion / 中国药理学通报

Aim To study the characteristics of in vitro release and in situ absorption of evodiamine load-ed microemulsion (EDM).Methods EDM was pre-pared, its release in pH 1.2 HCl solution and pH 6.8 phosphate buffer solution were studied by dialysis , and the cumulative release rates were calculated .The sin-gle-pass intestinal perfusion was used to study the ab-sorption of EDM in duodenum , jejunum , ileum and co-lon, the absorption in stomach was also studied , and the absorption rate constant ( Ka ) and effective perme-ability (Pef ) of the drug were calculated.The concen-tration of ED was measured by HPLC .Results The cumulative release rate of EDM and ED in pH 1.2 HCl solution was ( 64.76 ±0.73 )％, ( 13.98 ±0.49 )％, respectively , and that of EDM was 4.63 times of ED . In pH 6.8 phosphate buffer solution the cumulative re-lease rate was ( 91.72 ± 0.51 )％, ( 18.34 ± 0.20)％, respectively, which was 5.01 times of ED. The Ka of EDM was more than 3 times of ED, and Pef was more than 2 times of ED .Conclusion Microe-mulsion can improve in vitro release and in situ absorp-tion of ED.

In vivo and in vitro correlation of azithromycin cationic micron niosomes / 中国药理学通报

Aim To evaluate the correlation between in vitro release and in vivo absorption of azithromycin cat-ionic micron niosomes (ACMNS)by Wagner-Nelson method and deconvolution method. Methods The in vitro release behavior of ACMNS was studied by dy-namic membrane dialysis. After a single dose of intra-gastric administration with ACMNS and AM in rats,the AM concentrations in plasma were determined by high performance liquid chromatography(HPLC). Wagner-Nelson and deconvolution method were used to reveal the in vitro / in vivo correlation. Results X used as cu-mulative in vitro release and Fa as the absorption per-centage,the regression equation was established:F a =3. 0524X - 5. 7709,r = 0. 8976,and X used as cumu-lative in vitro release and R as input function,the re-gression equation was established:R = 2. 3413X -58. 687,r = 0. 5217. r < r( 2,0. 05) = 0. 9500 (P <0. 05). Conclusion There is no correlation between in vitro release and in vivo absorption of ACMNS.

Stabilities and related mechanism of sulfobutyl ether-β-cyclodextrin liposomes loaded with asparaginase / 中国药理学通报

Aim To investigate the stabilities and related mechanism of sulfobutyl ether-β-cyclodextrin liposomes loaded with asparaginase(ASDL).Methods Reverse evaporating method was used for the preparation of ASDL,and the acid-base stability,thermal stability,antitrypsin stability,plasma stability and storage stability of ASDL were tested.Moreover,fluorescence spectrum method was utilized to explore the stability enhancement mechanisms of ASDL.Results The results of stability showed that the acid-base stability,thermal stability,antitrypsin stability,plasma stability and storage stability of ASDL were all superior to asparaginase.Fluorescence experiment results indicated that the improved characteristics of ASDL might be related to the changes of the surrounding microenvironment of fluorescent chromophore or the structure of hydrophobic.Conclusion ASDL can effectively protect asparaginase from the external environment,such as hydrolase,pH,temperature and so on,to improve the stabilities of asparaginase.