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Electrospun membranes are widely utilized to enhance the water vapor permeability and drug delivery performance of transdermal drug delivery patches. Due to the lack of adhesion property,however,most of them cannot closely contact with skin,which impedes the delivery of drugs to the skin,thus affecting the transdermal administration. C5 resin is used to endow poly(styrene isoprene styrene)(SIS)electrospun membranes with pressure-sensitive adhesion property. Investigation is performed on how to control the structure,adhesion properties and drug delivery performance of SIS/C5 electrospun membranes loaded with synthetic capsaicin via compositions,drugs and electrospinning conditions. The results demonstrate that the electrospun membrane with a SIS/C5 ratio of 2∶1 has excellent water vapor permeability(7. 17×10-3 g/(h·cm2)and adhesion properties(180(°)peel strength is 0. 2 kN/m,tack force is 0. 64 N/cm2 ,holding power is greater than 7 days). The synthetic capsaicin has good compatibility with the SIS/C5 electrospun membranes,in which no drug crystallizes and the drug loading is beneficial to improve the water vapor permeability. As the drug loading is 8%,the tack force is 0. 6~0. 8 N/cm2 ,the 180(°)peel strength is 0. 2~0. 3 kN/m,the holding power is greater than 7 days,and no residue is left during peeling tests. In vitro drug release indicates that the drug has a behavior of sustained release with a 24-hour cumulative release rate of greater than 50% for all SIS/ C5 electrospun membranes,meeting the requirements of transdermal drug delivery patches. © 2022, Science Press (China). All rights reserved. 相似文献
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将活性阴离子聚合(LAP)与原子转移自由基聚合(ATRP)技术相结合,运用机理转移法制备了分子量可控的聚甲基丙烯酸甲酯-聚丁二烯-聚甲基丙烯酸甲酯(PMMA-PB-PMMA)嵌段共聚物。首先以双官能度的双锂为引发剂,进行丁二烯的活性阴离子聚合得到活性聚合物,之后用环氧丙烷封端,2-溴异丁酰溴进行酯化,生成双末端带有溴原子的聚丁二烯。再用此聚合物为引发剂,N,N,N′,N″,N″-五甲基二亚乙基三胺(PMDETA)为配体,CuBr为催化剂进行甲基丙烯酸甲酯的原子转移自由基聚合,进而得到三嵌段共聚物PMMA-PB-PMMA。采用1H-NMR、FTIR、凝胶渗透色谱仪等对所合成产物的组成和结构进行表征,并通过差示扫描量热法(DSC)研究嵌段共聚物的微相分离行为,DSC曲线上明显出现了两个玻璃化转变温度,结果初步表明三嵌段聚合物具有热塑性弹性体的性能。 相似文献
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玉米麦根酸测定方法研究 总被引:3,自引:0,他引:3
禾本科作物麦根酸类物质(MAs)分泌量的准确、快速测定,对于铁营养高效育种及缺铁耐性的生理研究具有重要价值。以玉米自交系为材料,根据麦根酸类物质的溶铁特性,建立了ICP-AES间接测定麦根酸类物质的方法,改良了脱氧麦根酸(DMA)的UV-HPLC直接测定法,并与传统的比色法测定结果进行比较。结果表明,采用ICP-AES法,以Fe2O3粉末作为活化对象,与采用Fe(OH)3的传统方法测定结果相比,结果稳定,t(ICP-AES)=4.080>t0.05(15)=2.131重复性好,RSD(n=3,%)=3.3,说明ICP-AES法是评价玉米及其它禾谷类作物麦根酸类物质分泌量的一种简单、快速的方法。改良的UV-HPLC法也具有准确、高效的特点,可应用于禾谷类作物DMA分泌量的直接测定。 相似文献
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将活性负离子聚合与原子转移自由基聚合(ATRP)技术相结合,运用机理转移法制备了一种两亲性材料聚丁二烯-b-聚(甲基丙烯酸N,N-二甲氨基乙酯)(PB-b-PDMAEMA)嵌段共聚物.首先通过负离子聚合方法设计合成聚丁二烯,用环氧丙烷封端,2-溴异丁酰溴作酯化剂,合成具有活性端基溴的聚丁二烯大分子引发剂(PB-B r),再用其引发亲水性单体DMAEMA进行原子转移自由基聚合,聚合动力学证实了该聚合反应具有典型的活性/可控自由基聚合的特征.通过差示扫描量热法(DSC)研究嵌段共聚物的微相分离行为.制备的大分子引发剂及两亲性嵌段共聚物经凝胶色谱、红外和核磁表征证实了预定的结构. 相似文献