Study of the permeation-promoting effect and mechanism of solid microneedles on different properties of drugs

Abstract

In transdermal drug delivery systems, the physicochemical properties of the drug affect its percutaneous permeability. However, whether the physicochemical properties of drugs change their transdermal permeability in the presence of pores in the presence of solid microneedles (MNs) has been less studied in this area. In this project, cinnamaldehyde, curcumin, ferulic acid and geniposide were selected as model drugs for the study of their transdermal permeability under the action of MNs, and a combination of classical experiments and visualization means such as scanning electron microscopy and laser confocal was used to investigate the permeation-promoting mechanism of MNs. The results showed that the MNs had significant permeation-promoting effects on different properties of drugs, with the permeation-promoting effects on cinnamaldehyde, curcumin, ferulic acid and geniposide being 6.36, 17.43, 29.54 and 8.91 times, respectively, and the permeation-promoting effects were more pronounced for lipid-soluble and amphiphilic drugs. Using scanning electron microscopy, transmission electron microscopy and other means to confirm that MNs can promote the penetration by acting on the skin to produce pores, and their effect on skin structure is greater than that of drugs. In addition, the existence of pores increases the amount of drug transdermal, which may enhance the diffusion of drug on the skin, and has no effect on lipid exchange and transdermal route. Through the research, it has been found that MNs is equivalent to direct peeling of the stratum corneum (SC), but it is simpler and safer for the patient.

Keywords:

• Solid microneedles
• different properties of drugs
• promoting permeation
• mechanism

Acknowledgments

We would like to thank everyone who contributed to this article. We would also like to thank the reviewers for their valuable comments.

Author contributions

Investigation, Data Curation and Writing-Original Draft (Huahua Li); Formal Analysis (Ziwei Peng, Yang Song, Minhang Dou and Xinying Lu); Methodology (Minghui Li, Xiaofeng Zhai, Yan Gu, Rexidanmu·Mamujiang); Funding Acquisition (Shouying Du and Jie Bai); Writing-Review and Editing (Jie Bai).

Data availability

Data will be made available on request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethics of experimentation

All animal studies were performed under the Guidelines for the Care and Use of Laboratory Animals, and experimental protocols were approved by the institutional animal experimentation committee of Beijing University of Chinese Medicine.

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities [grant number 2020-JYB-ZDGG-031].