可降解聚碳酸亚丙酯-毒死蜱微胶囊的制备及缓释性能评价

以聚碳酸亚丙酯(PPC)为壁材,聚乙烯醇-1788(PVA-1788)为连续相稳定剂,采用乳化溶剂挥发法制备了包裹毒死蜱的可降解微胶囊。测定了PVA-1788的质量分数、PPC的质量浓度以及PPC与毒死蜱的质量比对微胶囊性能的影响。采用土壤悬浊拟环境实验法评价了PPC的降解性能;通过光学显微镜(OM)、扫描电子显微镜(SEM)、广角X射线衍射(W-XRD)、激光粒度分布仪和高效液相色谱(HPLC)等表征了PPC-毒死蜱微胶囊的性能,同时采用柱层析法探讨了其缓释性能。结果表明:PPC具有生物可降解性;PVA-1788质量分数、PPC质量浓度以及PPC与毒死蜱的质量比对微胶囊的性能有显著影响,当PVA-1788的质量分数为1.0%、PPC的质量浓度为110 mg/mL,PPC与毒死蜱的质量比为1∶2时,可获得球形规整、粒径较小、包封率与载药量较高的微胶囊,其平均粒径为7.3 μm,载药量为16.75%,包封率为89.34%。缓释性能研究结果表明,PPC微胶囊对毒死蜱具有明显的缓释效应, 27 d的累积释药率达86.87%。

Preparation of degradable poly(propylene carbonate)-chlorpyrifos micocapsule and performance evaluation on its controlled release

Degradable microcapsules of chlorpyrifos were prepared by emulsion solvent volatilization method using poly(propylene carbonate)(PPC) as wall material and polyvinyl alcohol-1788(PVA-1788) as emulsifier.The effects of PVA-1788 concentration,PPC concentration and mass ratio of PPC and chlorpyrifos on the performance of microcapsules were investigated.The degradation performance of PPC was evaluated by simulated soil suspension environment experiment.The PPC-chlorpyrifos microcapsule was charactered by scanning electron microscope(SEM),optical microscope(OM),wide-angle X-ray diffraction spectra(W-XRD) and high performance liquid chromatograph(HPLC),and performance of its controlled-release was studied by column chromatography.The results showed that PPC had a favorable biodegradation and all of the concentration of PVA-1788 and PPC and mass ratio of PPC and chlorpyrifos showed a significant effect on performance of chlorpyrifos microcapsules.When PVA-1788 quality score was 1.0%,PPC concentration was 110 mg/mL,mass ratio of PPC and chlorpyrifos was 1∶2,microcapsule with regular sphere and higher entrapment efficiency and drug-loading rate could be obtained.Under these conditions,average diameter of chlorpyrifos microcapsule was 7.3 μm,drug-loading rate and entrapment efficiency were respectively 16.75% and 89.34%.The results also showed that PPC microcapsule had a significant effect on controlled-release and the accumulated drug release reached 86.87% in 27 days.