尖端载药气泡可溶性微针的制备与透皮效果分析

Preparation and transdermal effect of a tip-loaded bubble-soluble microneedle

摘要:

气泡微针作为一种新型的经皮递药技术，可以实现无痛精确给药，引起了研究者极大的关注。为了提高微针携带药物的利用率，本文提出了一种尖端载药气泡可溶性微针的制备方法。在微针成型过程中将气泡形成于针体内，药物集中到微针顶端。重点研究了气泡微针的制备优化工艺，并探究了起泡剂浓度、干燥温度、溶液黏度对气泡微针成型效果的影响，同时对其透皮效果进行了分析。实验结果表明，气泡微针成型工艺稳定，成型率在90%以上，同时将成型周期缩短至4 h左右。药物主要集中在微针针尖，高度在180 μm，气泡的高度在250 μm，且该微针阵列能够在小鼠皮肤上打出微通道，微针的针体能够在5 min内迅速溶解。透皮扩散实验表明，气泡微针能够在1 min内迅速释放约48%的药物，5 min内共释放约91%的药物。微针阵列的气泡微结构能够阻碍药物向基底的扩散，有效提高了药物的利用率，为微针透皮给药的实际应用提供了一定技术依据。

Abstract:

As a new transdermal drug delivery technology, bubble microneedle could achieve painless and precise drug delivery, which has attracted great attention from researchers. In order to improve the utilization rate of the drug carried by microneedle, we proposed a method for preparing a tip-loaded bubble-soluble microneedle. During the molding process of the microneedle, air bubbles were formed in the needle body, and the drug was concentrated on the needle tip. The preparation process of the bubble microneedle was optimized. The effects of foaming agent concentration, drying temperature, and solution viscosity on the forming of bubble microneedles were explored. Furthermore, the transdermal effect of the product was analyzed. The experimental results showed that the bubble microneedle forming process was stable, with the forming rate above 90% and the forming cycle shortened to about 4 h. The drug was mainly concentrated on the tip of the microneedle, with a length of 180 μm, and the length of the bubble was 250 μm. Moreover, the microneedle array can create microchannels on the mouse skin, and the needle bodies can be rapidly dissolved within 5 min. The bubble microneedle could rapidly release about 48% of the drug within 1 min and about 91% of the drug within 5 min. The bubble microstructure of the microneedle array hindered the diffusion of the drug to the substrate, which improves the utilization rate of the drug. This study provides a technical basis for the practical application of microneedle for transdermal drug delivery.