Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 459 Wethington Bldg., 900 South Limestone Street, Lexington, Kentucky 40536-0082, USA.
Pharm Res. 2011 Jan;28(1):124-34. doi: 10.1007/s11095-010-0191-x. Epub 2010 Jun 25.
Transdermal delivery of drugs is often limited by formidable barrier properties of stratum corneum (SC). Microneedles (MN) enable creation of transient microchannels in the SC and bypass this barrier. Many reports have focused on the great effectiveness of MN in improving percutaneous flux values of a variety of drugs over a large molecular size spectrum. The objective of the present study is to evaluate the influence of formulation on MN-enhanced transdermal transport of naltrexone hydrochloride (NTX HCl).
A series of in vitro experiments employing binary mixtures of propylene glycol (PG) and water as vehicle were used with either MN-treated or untreated skin. A simple model taking into account two parallel flux values through intact skin and microchannels was used to analyze data.
Transdermal permeation of NTX HCl from different donor solutions indicated that PG-rich formulations greatly limited MN-enhanced transport but had a much smaller effect on transport through intact skin.
Diffusion through the microchannel pathway seems to be donor viscosity-related and follows the relationship predicted by the Stokes-Einstein equation as shown by linear dependence of flux on diffusivity of NTX in donor solutions.
药物的经皮传递常常受到角质层（SC）强大的屏障特性的限制。微针（MN）能够在 SC 中创建瞬时微通道并绕过该屏障。许多报告都集中在 MN 在提高各种大小分子药物的经皮通量值方面的巨大效果。本研究的目的是评估制剂对 MN 增强盐酸纳曲酮（NTX HCl）经皮传递的影响。
使用含有丙二醇（PG）和水的二元混合物作为载体，进行了一系列体外实验，分别使用 MN 处理和未处理的皮肤。采用考虑到完整皮肤和微通道两个平行通量值的简单模型来分析数据。
来自不同供体溶液的 NTX HCl 的经皮渗透表明，PG 丰富的制剂极大地限制了 MN 增强的传递，但对完整皮肤的传递影响要小得多。
通过微通道途径的扩散似乎与供体的粘度有关，并遵循由 Stokes-Einstein 方程预测的关系，正如在供体溶液中 NTX 的扩散率与通量的线性关系所表明的那样。
