Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of C...Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of CFX-PLA-MS preparation. Microspheres werecharacterized in terms of morphology, size, encapsulation efficiency, drug loading and in vitro drugrelease. Results The physical state of CFX-PLA-MS was determined by scanning electron microscopy(SEM) and differential scanning calorimetry (DSC) . Microspheres formed were spherical with smoothsurfaces. Drug was enveloped in microspheres without mixing physically with PLA. The averageparticle size was 280.80 ± 0.15 μm, with over 90% of microspheres falling in the range of 250 -390 μm. The encapsulation efficiency was 65.8% ± 0.58% and the drug loading was 34.1% ± 0.51% .In vitro release study revealed a profile of sustained release of Ciprofloxacin from CFX-PLA-MS. Theaccumulated release percentage and half-life (T_(1/2) of Ciprofloxacin microspheres were 84.0% in53.2 h, and 31.9 h, respectively. Higuchi equation was Q= -0.0043 + 0.003 9 t^(1/2), r = 0.9941.Conclusion Ciprofloxacin microspheres have been successfully prepared and sustained release of CFXfrom microspheres is achieved.展开更多
High-performance liquid chromatography （HPLC） was employed to determine drug release rates based on emamectin benzoate concentrations in the medium. Release kinetics equations were used to fit the drug release behav...High-performance liquid chromatography （HPLC） was employed to determine drug release rates based on emamectin benzoate concentrations in the medium. Release kinetics equations were used to fit the drug release behavior. The effects of particle size and release medium pH on the release rate were also investigated. The indoor toxicity of emamectin benzoate-loaded polylactic acid microspheres on the diamondback moth larva （Plutella xylostella） was studied to explore drug sustained-release performance. In acidic and neutral media, the drug release behavior of the microspheres was in accord with the first-order kinetics equation. Increasing the spray dosage of emamectin benzoate-loaded polylactic acid microspheres initially resulted in an equivalent insecticidal efficacy with the conventional emamectin benzoate microemulsion. However, the drug persistence period was four-fold longer than that observed using the conventional formulation. The developed emamectin benzoate-loaded polylactic acid microspheres showed dramatic sustained-release performance. A treatment threshold of greater than 35 mg mL-1 was established for an efficient accumulated release concentration of emamectin benzoate-loaded microspheres.展开更多
AIM: To prepare polylactic acid microspheres of Erythromycin for Lung targeting. METHEDS: The orthogonal test design was used to optimize the technology of preparation. The character of the microspheres, drug release ...AIM: To prepare polylactic acid microspheres of Erythromycin for Lung targeting. METHEDS: The orthogonal test design was used to optimize the technology of preparation. The character of the microspheres, drug release in vitro, stability and tissue distribution were examined. RESULTS: The Erythromycin polylactic acid microspheres was regular in its morphology. Drug was enveloped in microspheres but not physically mixed with PDLLA. The average particle size was 11.65mm with over 94% of the microspheres being in the range of 5~20mm; The drug loading and the incorporation efficiency were 18% and 60% respectively. The microspheres were stable for three month at 4℃ and room temperature. The in vitro release properties could be expressed by the Higuchi抯 equation: y = 28.067 + 3.8515t1/2 (r = 0.9834). Comparing with injection, the drug in microspheres was more concentrated in lung tissue. CONCLUSION: Erythromycin polylactic acid microspheres showed significant sustained release and lung targeting.展开更多
[Objectives]To prepare donepezil hydrochloride microspheres and evaluate their quality.[Methods]The donepezil hydrochloride microspheres were prepared by emulsification-solvent evaporation method.The morphology was ob...[Objectives]To prepare donepezil hydrochloride microspheres and evaluate their quality.[Methods]The donepezil hydrochloride microspheres were prepared by emulsification-solvent evaporation method.The morphology was observed by scanning electron microscopy and the particle size distribution was determined by Laser Diffraction Method.The encapsulation efficiency,drug loading capacity,and in vitro release were determined by HPLC.[Results]The prepared donepezil hydrochloride microspheres were spherical with the average particle diameter of 15.927 μm.The drug loading capacity was 35.62%.The encapsulation efficiency was 90.32%.The drug release in vitro lasted for14 d.The release curve accorded with the first-order kinetic equation.[Conclusions]The prepared donepezil hydrochloride microspheres performed good sustained release effect in vitro,and it was expected to be used for research on Parkinson's disease.展开更多
Biodegradable polymer microspheres that can be used as drug carriers are of great importance in biomedical applications,however,there are still challenges in controllable preparation of microsphere surface morphology ...Biodegradable polymer microspheres that can be used as drug carriers are of great importance in biomedical applications,however,there are still challenges in controllable preparation of microsphere surface morphology and improvement of bioactivity.In this paper,firstly,poly(L-lactic acid)(PLLA)was synthesised by ring-opening polymerisation under anhydrous anaerobic conditions and further combined with the emulsion method,biodegradable PLLA microspheres(PM)with sizes ranging from 60-100μm and with good sphericity were prepared.In addition,to further improve the surface morphology of PLLA microspheres and enhance their bioactivity,functionalised porous PLLA microspheres loaded with magnesium oxide(MgO)/magnesium carbonate(MgCO_(3))(PMg)were also prepared by the emulsion method.The results showed that the loading of MgO/MgCO_(3)resulted in the formation of a porous structure on the surface of the microspheres(PMg)and the dissolved Mg^(2+)could be released slowly during the degradation of microspheres.In vitro cellular experiments demonstrated the good biocompatibility of PM and PMg,while the released Mg^(2+)further enhanced the anti-inflammatory effect and osteogenic activity of PMg.Functionalised PMg not only show promise for controlled preparation of drug carriers,but also have translational potential for bone regeneration.展开更多
The present study aims to investigate the motional dynamics of risperidone within polylactic co-glycolic acid(PLGA)microsphere by employing solution state'H and 19F nuclear magnetic resonance(NMR)measurements.Risp...The present study aims to investigate the motional dynamics of risperidone within polylactic co-glycolic acid(PLGA)microsphere by employing solution state'H and 19F nuclear magnetic resonance(NMR)measurements.Risperidone,a second-generation fluorinated antipsychotic drug used for the treatment of schizophrenia is commercially marketed as PLGA microsphere formulation resulting in prolonged release of the drug in solution.Although the current trend in the pharmaceutical market is to develop drug formulation with long-acting release(LAR)products,complete physicochemical characterization of such formulations are scarce.Especially the effects of microsphere encapsulation on the motional properties and diffusion behavior of the drugs are not discussed adequately in any of the earlier reports.We therefore,have employed NMR relaxation and diffusion measurements to decipher the interaction of PLGA cavity water with risperidone.A detailed analysis of NMR relaxation rates confirmed the event of encapsulation and the presence of local motion in the non-fluorinated end of risperidone.Further,the relaxation data indicated a significant alteration in 19F chemical shift anisotropy(CSA)and CSA/dipole-dipole(DD)cross-correlated relaxation mechanism and decreased effect of solvent relaxation pointing out reduced water concentration within the microsphere cavity.'H and 19F diffusion coefficients of risperidone led to the information about hydrodynamic radius of risperidone in free and encapsulated states.Measurement of hydrodynamic radius supported the presence of limited water in PLGA cavity allowing higher translational mobility of risperidone after the encapsulation.展开更多
以聚乳酸/羟基乙酸(PLGA)共聚物为药物装载材料、油酸改性的四氧化三铁(Fe 3 O 4@OA)纳米颗粒为磁性功能材料,制备姜黄素/PLGA磁性微球,考察了乳化方法、高速均质速度、水油相体积比、PLGA用量、水相聚乙烯醇(PVA)质量分数、Fe 3 O 4@O...以聚乳酸/羟基乙酸(PLGA)共聚物为药物装载材料、油酸改性的四氧化三铁(Fe 3 O 4@OA)纳米颗粒为磁性功能材料,制备姜黄素/PLGA磁性微球,考察了乳化方法、高速均质速度、水油相体积比、PLGA用量、水相聚乙烯醇(PVA)质量分数、Fe 3 O 4@OA用量和姜黄素用量对磁性微球粒径的影响,并通过光学显微镜、激光粒度仪、紫外分光光度计、振动样品磁强计、热重分析仪等对其形貌及理化性能进行分析。研究结果显示:姜黄素/PLGA磁性微球的最佳制备工艺为选用搅拌-均质两步乳化法、高速均质15000 r/min、水油相体积比10∶1、PLGA用量100 mg、水相PVA质量分数1%、Fe 3 O 4@OA用量40 mg和姜黄素用量40 mg,此条件下制备的微球表面光滑,粒径较均一,多分散性指数(PDI)为0.38,平均粒径为3.60μm,微球的磁感应强度为14.12(A·m^(2))/kg,含磁量约为27.98%。载药微球的包封率为97.09%,载药率为6.40%,在体外释放实验中表现出明显的缓释效果。展开更多
基金National Natural Science Foundation of Guangdong Province (020885,980504).
文摘Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of CFX-PLA-MS preparation. Microspheres werecharacterized in terms of morphology, size, encapsulation efficiency, drug loading and in vitro drugrelease. Results The physical state of CFX-PLA-MS was determined by scanning electron microscopy(SEM) and differential scanning calorimetry (DSC) . Microspheres formed were spherical with smoothsurfaces. Drug was enveloped in microspheres without mixing physically with PLA. The averageparticle size was 280.80 ± 0.15 μm, with over 90% of microspheres falling in the range of 250 -390 μm. The encapsulation efficiency was 65.8% ± 0.58% and the drug loading was 34.1% ± 0.51% .In vitro release study revealed a profile of sustained release of Ciprofloxacin from CFX-PLA-MS. Theaccumulated release percentage and half-life (T_(1/2) of Ciprofloxacin microspheres were 84.0% in53.2 h, and 31.9 h, respectively. Higuchi equation was Q= -0.0043 + 0.003 9 t^(1/2), r = 0.9941.Conclusion Ciprofloxacin microspheres have been successfully prepared and sustained release of CFXfrom microspheres is achieved.
基金supported by the National Key Research and Development Program of China (2016YFD0200502, 2017YFD0200301)
文摘High-performance liquid chromatography （HPLC） was employed to determine drug release rates based on emamectin benzoate concentrations in the medium. Release kinetics equations were used to fit the drug release behavior. The effects of particle size and release medium pH on the release rate were also investigated. The indoor toxicity of emamectin benzoate-loaded polylactic acid microspheres on the diamondback moth larva （Plutella xylostella） was studied to explore drug sustained-release performance. In acidic and neutral media, the drug release behavior of the microspheres was in accord with the first-order kinetics equation. Increasing the spray dosage of emamectin benzoate-loaded polylactic acid microspheres initially resulted in an equivalent insecticidal efficacy with the conventional emamectin benzoate microemulsion. However, the drug persistence period was four-fold longer than that observed using the conventional formulation. The developed emamectin benzoate-loaded polylactic acid microspheres showed dramatic sustained-release performance. A treatment threshold of greater than 35 mg mL-1 was established for an efficient accumulated release concentration of emamectin benzoate-loaded microspheres.
基金Guangdong Provincial Natural Science Foundation of China
文摘AIM: To prepare polylactic acid microspheres of Erythromycin for Lung targeting. METHEDS: The orthogonal test design was used to optimize the technology of preparation. The character of the microspheres, drug release in vitro, stability and tissue distribution were examined. RESULTS: The Erythromycin polylactic acid microspheres was regular in its morphology. Drug was enveloped in microspheres but not physically mixed with PDLLA. The average particle size was 11.65mm with over 94% of the microspheres being in the range of 5~20mm; The drug loading and the incorporation efficiency were 18% and 60% respectively. The microspheres were stable for three month at 4℃ and room temperature. The in vitro release properties could be expressed by the Higuchi抯 equation: y = 28.067 + 3.8515t1/2 (r = 0.9834). Comparing with injection, the drug in microspheres was more concentrated in lung tissue. CONCLUSION: Erythromycin polylactic acid microspheres showed significant sustained release and lung targeting.
基金Supported by National Innovative Training Program for College Students(201610443020)
文摘[Objectives]To prepare donepezil hydrochloride microspheres and evaluate their quality.[Methods]The donepezil hydrochloride microspheres were prepared by emulsification-solvent evaporation method.The morphology was observed by scanning electron microscopy and the particle size distribution was determined by Laser Diffraction Method.The encapsulation efficiency,drug loading capacity,and in vitro release were determined by HPLC.[Results]The prepared donepezil hydrochloride microspheres were spherical with the average particle diameter of 15.927 μm.The drug loading capacity was 35.62%.The encapsulation efficiency was 90.32%.The drug release in vitro lasted for14 d.The release curve accorded with the first-order kinetic equation.[Conclusions]The prepared donepezil hydrochloride microspheres performed good sustained release effect in vitro,and it was expected to be used for research on Parkinson's disease.
基金National Key R&D Program of China,Nos.2018YFE0201500,2022YFC2405802National Natural Science Foundation of China,No.51973060.
文摘Biodegradable polymer microspheres that can be used as drug carriers are of great importance in biomedical applications,however,there are still challenges in controllable preparation of microsphere surface morphology and improvement of bioactivity.In this paper,firstly,poly(L-lactic acid)(PLLA)was synthesised by ring-opening polymerisation under anhydrous anaerobic conditions and further combined with the emulsion method,biodegradable PLLA microspheres(PM)with sizes ranging from 60-100μm and with good sphericity were prepared.In addition,to further improve the surface morphology of PLLA microspheres and enhance their bioactivity,functionalised porous PLLA microspheres loaded with magnesium oxide(MgO)/magnesium carbonate(MgCO_(3))(PMg)were also prepared by the emulsion method.The results showed that the loading of MgO/MgCO_(3)resulted in the formation of a porous structure on the surface of the microspheres(PMg)and the dissolved Mg^(2+)could be released slowly during the degradation of microspheres.In vitro cellular experiments demonstrated the good biocompatibility of PM and PMg,while the released Mg^(2+)further enhanced the anti-inflammatory effect and osteogenic activity of PMg.Functionalised PMg not only show promise for controlled preparation of drug carriers,but also have translational potential for bone regeneration.
文摘The present study aims to investigate the motional dynamics of risperidone within polylactic co-glycolic acid(PLGA)microsphere by employing solution state'H and 19F nuclear magnetic resonance(NMR)measurements.Risperidone,a second-generation fluorinated antipsychotic drug used for the treatment of schizophrenia is commercially marketed as PLGA microsphere formulation resulting in prolonged release of the drug in solution.Although the current trend in the pharmaceutical market is to develop drug formulation with long-acting release(LAR)products,complete physicochemical characterization of such formulations are scarce.Especially the effects of microsphere encapsulation on the motional properties and diffusion behavior of the drugs are not discussed adequately in any of the earlier reports.We therefore,have employed NMR relaxation and diffusion measurements to decipher the interaction of PLGA cavity water with risperidone.A detailed analysis of NMR relaxation rates confirmed the event of encapsulation and the presence of local motion in the non-fluorinated end of risperidone.Further,the relaxation data indicated a significant alteration in 19F chemical shift anisotropy(CSA)and CSA/dipole-dipole(DD)cross-correlated relaxation mechanism and decreased effect of solvent relaxation pointing out reduced water concentration within the microsphere cavity.'H and 19F diffusion coefficients of risperidone led to the information about hydrodynamic radius of risperidone in free and encapsulated states.Measurement of hydrodynamic radius supported the presence of limited water in PLGA cavity allowing higher translational mobility of risperidone after the encapsulation.
文摘以聚乳酸/羟基乙酸(PLGA)共聚物为药物装载材料、油酸改性的四氧化三铁(Fe 3 O 4@OA)纳米颗粒为磁性功能材料,制备姜黄素/PLGA磁性微球,考察了乳化方法、高速均质速度、水油相体积比、PLGA用量、水相聚乙烯醇(PVA)质量分数、Fe 3 O 4@OA用量和姜黄素用量对磁性微球粒径的影响,并通过光学显微镜、激光粒度仪、紫外分光光度计、振动样品磁强计、热重分析仪等对其形貌及理化性能进行分析。研究结果显示:姜黄素/PLGA磁性微球的最佳制备工艺为选用搅拌-均质两步乳化法、高速均质15000 r/min、水油相体积比10∶1、PLGA用量100 mg、水相PVA质量分数1%、Fe 3 O 4@OA用量40 mg和姜黄素用量40 mg,此条件下制备的微球表面光滑,粒径较均一,多分散性指数(PDI)为0.38,平均粒径为3.60μm,微球的磁感应强度为14.12(A·m^(2))/kg,含磁量约为27.98%。载药微球的包封率为97.09%,载药率为6.40%,在体外释放实验中表现出明显的缓释效果。
