Controllable coating of microneedles for transdermal drug delivery

Abstract

Coated microneedles have been paid much attention recently, and several coating strategies have been developed to address the problems during coating process. However, there are still some unresolved issues, such as, precise control requirements, microneedle substrate contamination and high processing temperature. The purpose of this study was to develop a simple and controllable method to make uniform coatings on microneedles at room temperature. This novel method avoids the contamination of microneedle substrate by providing both the adsorption force of thickener and micro-scale coating film produced by a newly design device. Thickeners were screened to enhance the mass of coatings. The parameters that influence the coatings were tested systematically, which made coating process controllable. Finally, three model drugs were coated onto microneedles to prove the method is applicable more broadly. In addition, insertion experiments were carried out to test the drug delivery feasibility of the coated microneedles. In conclusion, this study presents a simple and controllable method to coat microneedles with small molecular chemical drugs or large proteins for rapid skin drug delivery.

• Adsorption force
• coating device
• coating film
• coating microneedles
• coating solution
• transdermal drug delivery

Declaration of interest

This work was partially supported by the Science Foundation of the Chinese Academy of Sciences and the National Natural Science Foundation of China (Grant No. 31300763). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.