以二乙烯三胺五乙酸、氢氧化钠和溴代十二烷为原料,通过中和反应和亲核取代反应合成了一种甜菜碱表面活性剂——N,N',N''-十二烷基二乙烯三胺五乙酸钠(DDTP),通过核磁氢谱和红外光谱对化合物的结构进行表征,测定了不同浓度...以二乙烯三胺五乙酸、氢氧化钠和溴代十二烷为原料,通过中和反应和亲核取代反应合成了一种甜菜碱表面活性剂——N,N',N''-十二烷基二乙烯三胺五乙酸钠(DDTP),通过核磁氢谱和红外光谱对化合物的结构进行表征,测定了不同浓度的DDTP水溶液的表面张力,得出表面张力曲线,进而算出其他相关参数。实验结果证明:合成的化合物结构与预期的表面活性剂结构相吻合,在25℃时,临界胶束浓度ccmc=1.1×10-2mmol/L,相应的表面张力γcmc=33.2 m N/m;表面张力降低20 m N/m时所需表面活性剂浓度的负对数p C20=3.22,饱和吸附量Γmax=5.15×10-3mol/cm2,平均每个分子占有的最小面积Amin=3.1 nm2,表明N,N',N''-十二烷基二乙烯三胺五乙酸钠具有较好的表面活性。展开更多
In normal condition, intestine mucosa possesses bar-rier function. When the barrier function of intestine mucosa was damaged, intestinal bacteria, endotoxin, or
This study examined the corneal permeability of topical eye drop solutions added with various corneal penetrating accelerators and gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) by nuclear magnetic resonanc...This study examined the corneal permeability of topical eye drop solutions added with various corneal penetrating accelerators and gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) by nuclear magnetic resonance imaging (MRI).Twenty-four New Zealand rabbits were randomly divided into 3 groups according to the random digits table:Gd-DTPA group,in which the rabbits received 23.45% Gd-DTPA;hyaluronic acid group,in which 23.45% Gd-DTPA plus 0.2% hyaluronic acid was administered;azone group,in which 23.45% Gd-DTPA with 0.2% azone was given.Fifty microliters of the eye drops was instilled into the conjunctive sac every 5 min,for a total of 6 applications in each group.Contrast medium signals in the cornea,anterior chamber,posterior chamber,and vitreous body were scanned successively by MRI.The morphology and cell density of the corneal endothelium were examined before and 24 h after the treatment.The results showed that the residence time of Gd-DTPA in the conjunctival sac in the hyaluronic acid and azone groups was longer than that in the Gd-DTPA group.The signals in the anterior chamber of the Gd-DTPA and hyaluronic acid groups were increased slightly,and those in the azone group strengthened sharply.The signal intensity continuously rose over 80 min before reaching plateau.The strengthening rate of signals in the anterior chamber was 19.63% in the Gd-DTPA group,53.42% in the sodium hyaluronate group,and 226.94% in the azone group.No signal was detected in the posterior chamber or vitreous body in all the 3 groups.Corneal morphology and cell density did not show any significant changes after the treatment in all the 3 groups.It was concluded that azone can significantly improve the corneal permeability of drugs that are similar to Gd-DTPA in molecular weight and molecular size,and MRI is a noninvasive technique that can dynamically detect eye drop metabolism in real time.展开更多
文摘以二乙烯三胺五乙酸、氢氧化钠和溴代十二烷为原料,通过中和反应和亲核取代反应合成了一种甜菜碱表面活性剂——N,N',N''-十二烷基二乙烯三胺五乙酸钠(DDTP),通过核磁氢谱和红外光谱对化合物的结构进行表征,测定了不同浓度的DDTP水溶液的表面张力,得出表面张力曲线,进而算出其他相关参数。实验结果证明:合成的化合物结构与预期的表面活性剂结构相吻合,在25℃时,临界胶束浓度ccmc=1.1×10-2mmol/L,相应的表面张力γcmc=33.2 m N/m;表面张力降低20 m N/m时所需表面活性剂浓度的负对数p C20=3.22,饱和吸附量Γmax=5.15×10-3mol/cm2,平均每个分子占有的最小面积Amin=3.1 nm2,表明N,N',N''-十二烷基二乙烯三胺五乙酸钠具有较好的表面活性。
文摘In normal condition, intestine mucosa possesses bar-rier function. When the barrier function of intestine mucosa was damaged, intestinal bacteria, endotoxin, or
文摘This study examined the corneal permeability of topical eye drop solutions added with various corneal penetrating accelerators and gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) by nuclear magnetic resonance imaging (MRI).Twenty-four New Zealand rabbits were randomly divided into 3 groups according to the random digits table:Gd-DTPA group,in which the rabbits received 23.45% Gd-DTPA;hyaluronic acid group,in which 23.45% Gd-DTPA plus 0.2% hyaluronic acid was administered;azone group,in which 23.45% Gd-DTPA with 0.2% azone was given.Fifty microliters of the eye drops was instilled into the conjunctive sac every 5 min,for a total of 6 applications in each group.Contrast medium signals in the cornea,anterior chamber,posterior chamber,and vitreous body were scanned successively by MRI.The morphology and cell density of the corneal endothelium were examined before and 24 h after the treatment.The results showed that the residence time of Gd-DTPA in the conjunctival sac in the hyaluronic acid and azone groups was longer than that in the Gd-DTPA group.The signals in the anterior chamber of the Gd-DTPA and hyaluronic acid groups were increased slightly,and those in the azone group strengthened sharply.The signal intensity continuously rose over 80 min before reaching plateau.The strengthening rate of signals in the anterior chamber was 19.63% in the Gd-DTPA group,53.42% in the sodium hyaluronate group,and 226.94% in the azone group.No signal was detected in the posterior chamber or vitreous body in all the 3 groups.Corneal morphology and cell density did not show any significant changes after the treatment in all the 3 groups.It was concluded that azone can significantly improve the corneal permeability of drugs that are similar to Gd-DTPA in molecular weight and molecular size,and MRI is a noninvasive technique that can dynamically detect eye drop metabolism in real time.
