Résumé
Pluronic modified polyamidoamine (PAMAM) conjugate (PF127-PAMAM) was prepared and the inhibiting effect of MDR against MCF-7/ADR was investigated with doxorubicin (DOX) as model drug. 1H NMR and FTIR spectra showed that the conjugate was synthesized successfully. Element analysis accurately measured that 27.63% amino of per PAMAM was modified by pluronic (PAMAM : PF127, 1 : 35.37 mole ratio). PF127-PAMAM showed an increased size and a reduced zeta potential compared to PAMAM. PF127-PAMAM had lower hemolytic toxicity and cytotoxicity due to the reduced zeta potential and the protection of PF127. Each PF127-PAMAM molecular could load 19.58 DOX molecules, and the complex exhibited sustained and pH-sensitive release behavior. PF127-PAMAM/DOX exhibited weaker cytotoxicity than free DOX in MCF-7 cells; while the complex showed much stronger reverse effect of drug resistance in MCF-7/ADR cells, and resistance reversion index (RRI) was as high as 33.15.
Résumé
PEG-modified magnetic Fe3O4 (Fe3O4-PEG) nanoparticles were sythesized using a solvothermal reaction and characterized with transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The photothermal effect and photothermal destruction of cancer cells were evaluated. Then the doxorubicin loaded Fe3O4-PEG (DOX-Fe3O4-PEG) nanoparticles were prepared. The cytotoxicity and combined chemotherapy/photothermal therapy (PTT) effect were investigated. Uniform PEG coated Fe3O4 nanoparticles with particle size of 155 nm were obtained in the experiment. The loading and release of doxorubicin on Fe3O4-PEG were pH-dependent. The drug loading capacity in water was 21%. The results of MTT indicated a good biocompatiblity of Fe3O4-PEG nanoparticles and high cytotoxicity of DOX-Fe3O4-PEG. In combined therapy experiment, photothermal therapy demonstrated unambiguously enhanced chemotherapy efficacy. In conclusion, the obtained Fe3O4-PEG nanoparticles which exhibit good photothermal effect and drug loading capacity can be used for chemotherapy and photothermal therapy. The synergetic anti-tumor activity indicates the potential for the combined application of chemotherapy and photothermal therapy in cancer treatment.
Résumé
This study is to prepare the pantoprazole sodium enteric-coated tablet which is compacted by pellets. The enteric-coated pantoprazole sodium pellets were prepared by fluid bed coating technology. The pantoprazole sodium enteric-coated tablets were prepared by direct compression of the enteric-coated pellets and suitable excipients. In vitro dissolution method and scanning electron microscope method were used for the observation of the drug release behavior before and after compression of the pellets. The optimized formulation is: the coating level is 55%, the plasticizer content is 20%, the ratio of Eudragit L30D-55/NE30D is 8 : 2, enteric-coated pellets/excipients (MCC/PPVP/PEG 6000 = 2 : 1 : 1) is 5 : 5, the enteric-coated tablets release in artificial gastric fluid in 2 h is less than 10%, while in artificial intestinal fluid in 1 h is more than 85%. The release behavior of pantoprazole sodium enteric-coated pellets-type tablet is quite well. And it may be used in industrial production.
Résumé
The study is to prepare taste masking and enteric-coated clarithromycin granules by melting and fluid bed coating technology. Clarithromycin and matrix materials were melted at a certain temperature, and then made into particles by fluidized bed coating. X-ray powder diffraction and scanning electron microscopy were used to identify the crystal and morphology of drug loading granules. In vitro dissolution method was used for the observation of the drug release behavior. The results showed that the drug particles size range was 0.2 - 0.6 mm; the crystal form of clarithromycin in the granule did not change; enteric-coated granules accumulated release in 0.1 mol L(-1) hydrochloric acid in 2 h was less than 10%, while in pH 6.8 phosphate buffer in 1 h was more than 80%. The taste masking and enteric-coated clarithromycin granules not only have good taste masking effect, but also have a good release behavior. It is expected to have better clinical application.
Résumé
Objective To investigate the genotoxicity of heavy rare-earth holmium to bone-marrow cells of mice.Methods Kunming mice were randomly divided into six groups and were given holmium-trioxide-HCl by gavage at several doses of 0,10,20,40,80 and 160 mg/kg bw respectively one time a day for two days;other Kunming mice were randomly divided into 3 groups and holmium nitrate was given i.p.at doses of 10,40 and 80 mg/kg bw respectively one time a day for two days.24 hours after the last treatment,the bone-marrow cells of thighbone were collected for micronuclei analysis and single cell gel electrophoresis (SCGE).Results Frequencies of micronuclei were increased by the 2 kinds of holmium solutions at the dosage from 10 to 80 mg/kg bw with a dose-effect relationship,but at the dose of 160 mg/kg bw,it was lower than the negative control.In SCGE,the average tail length increased significantly (P