This study investigated the in vitro transdermal delivery of magnesium ascorbyl phosphate (MAP) through porcine ear skin treated with hyaluronic acid (HA) microneedles (MNs). In this study, the micro-molding method was used to fabricate HA MNs. HA solution (10% w/v) containing 3% of MAP was placed onto a poly(dimethyl siloxane) mold to fill the microchannels under vacuum followed by drying in a desiccator. Scanning electron microscopy was performed to record the dimensions of the MNs. Skin microporation was demonstrated by dye binding. Histological skin sections revealed the shape of microchannels under hematoxylin-eosin staining. The actual depth of the microchannels and drug distribution pathways were studied by confocal microscopy. In vitro permeation on Franz diffusion cells were performed to determine the rate and extent of drug delivery into and across the skin. SEM captured individual MNs from the array, and the length of each MN was found to be ~400 μm. The 10 × 10 MN array prepared, resulted in the formation of 95 to 100 microchannels after 2 mins of treatment. In addition, the histological evaluations showed the formation of microchannels in the skin, complementary in shape to the MNs. The depths of the formed microchannels amounted to ~125 μm as determined by confocal microscopy. The application of the current MN technology enhanced the delivery of MAP into skin (96.8 ± 3.9 μg/cm²) compared to the passive delivery strategy of MAP (44.9 ± 16.3 μg/cm²). HA MNs markedly enhanced the in vitro transdermal delivery of MAP into and across skin.

中文翻译：

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透明质酸微针的制造和表征，以增强抗坏血酸磷酸镁向皮肤的递送。

这项研究调查了透明质酸（HA）微针（MNs）处理过的猪耳皮肤的抗坏血酸磷酸镁（MAP）的体外透皮递送。在这项研究中，微成型方法被用来制造HA MNs。高可用性解决方案（10％w / v将含有3％MAP的）放入聚（二甲基硅氧烷）模具中，在真空下填充微通道，然后在干燥器中干燥。进行扫描电子显微镜以记录MN的尺寸。通过染料结合证明了皮肤微穿孔。组织学皮肤切片显示苏木精-曙红染色下的微通道形状。通过共聚焦显微镜研究了微通道的实际深度和药物分配途径。在Franz扩散细胞上进行体外渗透以确定药物进入皮肤和穿过皮肤的速率和程度。SEM从阵列中捕获了单个MN，每个MN的长度约为400μm。制备的10×10 MN阵列在处理2分钟后导致形成95至100个微通道。此外，组织学评估显示在皮肤中形成微通道，其形状与MN互补。通过共聚焦显微镜确定，形成的微通道的深度总计约125μm。当前MN技术的应用增强了MAP在皮肤中的递送（96.8±3.9μg/ cm²）与MAP的被动递送策略（44.9±16.3μg/ cm ²）相比。HA MN显着增强了MAP在皮肤内和跨皮肤的体外透皮递送。