Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then ...Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then the properties and in vitro drug release behavior of MC were examined. An analysis of variance (ANOVA) was used to test the statistical significance. Then, multiple comparisons were made with a T method between levels to examine the significance of difference further. For all the results a P value 】0 05 was considered statistically insignificant . Results Under the same conditions, the water adding speed and the particle size had significant effects ( P 【0 01) on the entrapment efficiency of MC; the water adding speed and the concentration of PLA in the oil phase had significant effects ( P 【0 01) on the diameter MC in medium. Release of E 2 from MC was influenced significantly ( P 【0 01) by the water adding speed and the type and molecule weight of the polymers. But the differences between levels of the variates were not all significant. Conclusion E 2 PLA/PLGA MC with various properties can be formed when the formulation and the technology were changed accordingly.展开更多
Aim Polylactic acid (PLA) or polylactide-co-glycolide (PLGA) was used asbiodegradable and biocom-patible carriers to achieve sustained release ofestradial-PLGA/PLA-Microspheres (E_2-PLGA/PLA-MS). THF was added in the ...Aim Polylactic acid (PLA) or polylactide-co-glycolide (PLGA) was used asbiodegradable and biocom-patible carriers to achieve sustained release ofestradial-PLGA/PLA-Microspheres (E_2-PLGA/PLA-MS). THF was added in the organic phase to study itseffects on the properties of MS. Methods MS were formed by an emulsification-solvent extractionmethod with mixture of ethyl acetate (EtoAc) and tetrahydrofuran (THF) as the organic solvents, andthen the properties and in vitro drug release behavior were examined. Results The results indicatedthat the drug loading efficiency decreased when THF added, but when the ratio of EtoAc was more than50% , there was no obvious effect of THF ratio, but the particle size increased accordingly. Thecarriers' properties and the drug contents were the main factors influencing the in vitro drugrelease. Conclusions By controlling the technology and formulation, we can get sustained-release E_2biodegradable microsperes with proper particle size, drug content and low burst-release, althoughTHF with readily solubility in water was used in the organic phase.展开更多
To obtain a kind of biodegradable polymer material with satisfactory properties, a new biodegradable copolyester poly（lactic acid-co-glycol terephthalate） （PETA）, was synthesized from three monomers of lactic acid...To obtain a kind of biodegradable polymer material with satisfactory properties, a new biodegradable copolyester poly（lactic acid-co-glycol terephthalate） （PETA）, was synthesized from three monomers of lactic acid, glycol and terephthalic acid. The resulting copolyesters, PETA, were characterized by FT-IR, ^1H-NMR, DSC, TGA and by the ways of weight loss rate to characterize their biodegradability. The findings in this work indicated that, the Tins and Tas of copolyesters PETA increased with increasing contents of the terephthalic acid units. From the biodegradation tests in natural soil, boiling water, acid buffer solution and alkali buffer solution, it was shown that the biodegradability of copolyesters PETA decreased with increasing contents of the terephthalic acid units.展开更多
文摘Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then the properties and in vitro drug release behavior of MC were examined. An analysis of variance (ANOVA) was used to test the statistical significance. Then, multiple comparisons were made with a T method between levels to examine the significance of difference further. For all the results a P value 】0 05 was considered statistically insignificant . Results Under the same conditions, the water adding speed and the particle size had significant effects ( P 【0 01) on the entrapment efficiency of MC; the water adding speed and the concentration of PLA in the oil phase had significant effects ( P 【0 01) on the diameter MC in medium. Release of E 2 from MC was influenced significantly ( P 【0 01) by the water adding speed and the type and molecule weight of the polymers. But the differences between levels of the variates were not all significant. Conclusion E 2 PLA/PLGA MC with various properties can be formed when the formulation and the technology were changed accordingly.
文摘Aim Polylactic acid (PLA) or polylactide-co-glycolide (PLGA) was used asbiodegradable and biocom-patible carriers to achieve sustained release ofestradial-PLGA/PLA-Microspheres (E_2-PLGA/PLA-MS). THF was added in the organic phase to study itseffects on the properties of MS. Methods MS were formed by an emulsification-solvent extractionmethod with mixture of ethyl acetate (EtoAc) and tetrahydrofuran (THF) as the organic solvents, andthen the properties and in vitro drug release behavior were examined. Results The results indicatedthat the drug loading efficiency decreased when THF added, but when the ratio of EtoAc was more than50% , there was no obvious effect of THF ratio, but the particle size increased accordingly. Thecarriers' properties and the drug contents were the main factors influencing the in vitro drugrelease. Conclusions By controlling the technology and formulation, we can get sustained-release E_2biodegradable microsperes with proper particle size, drug content and low burst-release, althoughTHF with readily solubility in water was used in the organic phase.
文摘To obtain a kind of biodegradable polymer material with satisfactory properties, a new biodegradable copolyester poly（lactic acid-co-glycol terephthalate） （PETA）, was synthesized from three monomers of lactic acid, glycol and terephthalic acid. The resulting copolyesters, PETA, were characterized by FT-IR, ^1H-NMR, DSC, TGA and by the ways of weight loss rate to characterize their biodegradability. The findings in this work indicated that, the Tins and Tas of copolyesters PETA increased with increasing contents of the terephthalic acid units. From the biodegradation tests in natural soil, boiling water, acid buffer solution and alkali buffer solution, it was shown that the biodegradability of copolyesters PETA decreased with increasing contents of the terephthalic acid units.
