不同密度滚轮微针对维A酸经皮渗透的影响

目的：探讨不同密度滚轮微针对维A酸经皮渗透的影响。方法：采用改良Franz扩散池法考察体外经皮渗透特性，以裸鼠离体皮肤为屏障，对照组、192针、540针滚轮微针处理组分别于2、4、6、8、10、12 h取接收液0.2 ml，用HPLC法测定维A酸含量，计算累积渗透量，并测定皮肤内维A酸滞留量。采用激光共聚焦显微镜考察在体经皮渗透特性，405 nm激发光波长下扫描，观察维A酸在皮肤内的渗透及分布。结果：离体实验中，HPLC法以平均峰面积（A）与对照品浓度（c）作线性回归，得标准曲线方程A=170 733 c-1 534.8（r=0.999 9），线性范围为0.01~10.00 μg/ml，回收率均＞95%。192针、540针微针处理组的维A酸累积渗透量分别是对照组的2.5和6.8倍，相应的皮肤内滞留量分别是对照组的2.5和2.8倍。在体实验中，相同力度（350~400 g）下，使用192针、540针两种密度微针处理2 h后，两种微针组药物可渗透至皮肤深度分别是60和50 μm。结论：滚轮微针能有效提高维A酸的经皮渗透量，且不同密度微针的促透作用不同。

Effect of different density microneedle-roller on transdermal delivery of tretinoin

Objective： To study the promoting effect of different density microneedle-roller arrays on transdermal delivery of tretinoin. Methods： The in vitro permeation characteristics through isolated nude mouse skin were studied by modified Franz diffusion cells. Contents of tretinoin in the receptor solution of the control group,the 192 needles, the 540 needles microneedle- rooler groups were determined at 2,4,6,8,10 and 12 h by HPLC method. Then by taking the skin on diffusion cell and under-going tissue homogenate, the residuaI quantity of tretinoin in skin were determined. Confocal laser scanning microscope was used to observe the penetration and distribution of tretinoin in vivo at 405 nm excitation wavelength. Results： In vitro study, the standard curve was A=170 733 c-1 534.8 （r=0. 999 9） ,as A expressed the average peak area and c expressed the control concentration. The linearity range was 0.01-10.00μg/ml, and the recovery was higher than 95%. The cumulative infiltration volume of tretinion in the 192 needles group was about 2.5 times of the control samples,and 540 needles 6.8 times,while skin retention volume was 2.5 times and 2.8 times higher than the control group, respectively. In vivo study, under the same strength（350-400 g）, the penetration depths of tretinoin in skin were 60μm and 60 μm respectively,when 540 needles and 192 needles microneedles were used for treatment for 2 hours. Conclusion： Microneedles could greatly promote the skin permeability of tretinoin,and the promoting effect of different density microneedle roller was variable.