Synthesis and Enhancing Effect of Transkarbam 12 on the Transdermal Delivery of Theophylline, Clotrimazole, Flobufen, and Griseofulvin
作者:Alexandr Hrabálek、Pavel Doležal、Kateřina Vávrová、Jarmila Zbytovská、Tomáš Holas、Jana Klimentová、Jakub Novotný
DOI:10.1007/s11095-006-9782-y
日期:2006.5
Dodecyl-6-aminohexanoate (DDEAC) is a transdermal permeation enhancer with excellent activity, low toxicity, and no dermal irritation. We hypothesized that DDEAC reacts with air CO2 to form a two-chain ammonium carbamate—Transkarbam 12 (T12)—which is responsible for the enhancing effect. DDEAC and T12 were synthesized, their structures were confirmed by spectral methods, and their enhancing activity was studied using the Franz diffusion cell and human skin. A high-performance liquid chromatography method was developed for determination of T12, and its biodegradability was evaluated using porcine esterase. Only the carbamate salt T12 was responsible for the high enhancing activity; DDEAC tested under argon to avoid reaction with CO2 was inactive. T12 enhanced transdermal permeation of drugs covering a wide range of physicochemical properties, including theophylline (enhancement ratio up to 55.6), clotrimazole (7.7), flobufen (5.0), and griseofulvin (24). The activity was pH-dependent, further confirming the importance of the carbamate structure. The metabolization of T12 followed a second-order kinetics with t 1/2 = 31 min. Our results indicate that T12 is a promising biodegradable permeation enhancer for a wide range of drugs, and the structurally novel group of carbamate enhancers warrants further investigation.
十二烷基-6-氨基己酸酯(DDEAC)是一种具有优良活性、低毒性且无皮肤刺激的经皮渗透增强剂。我们假设DDEAC与空气中的二氧化碳发生反应,形成一种双链铵盐氨基甲酸酯——Transkarbam 12(T12),这是其增强效果的原因。我们合成了DDEAC和T12,并通过光谱方法确认了它们的结构;同时,利用Franz扩散池和人皮肤研究了它们的增强活性。我们开发了一种高效液相色谱法来测定T12的含量,并使用猪酯酶评估其生物降解性。只有氨基甲酸盐T12对高增强活性负责;在氩气环境下测试DDEAC以避免与二氧化碳反应时,其活性无效。T12能够增强多种药物的经皮渗透,涵盖了广泛的物理化学特性,包括茶碱(增强比率高达55.6)、克霉唑(7.7)、氟必利(5.0)和灰黄霉素(24)。其活性依赖于pH值,进一步确认了氨基甲酸酯结构的重要性。T12的代谢遵循二级动力学,半衰期为31分钟。这些结果表明,T12是一个有前景的生物可降解渗透增强剂,适用于多种药物,而这种结构新颖的氨基甲酸酯增强剂值得进一步研究。