Effect of applying modes of the polymer microneedle-roller on the permeation of l-ascorbic acid in rats

Abstract

Despite the advantages of drug delivery through skin, transdermal drug delivery is only used with a small subset of drugs because most compounds cannot cross the skin at therapeutically useful rates. Recently, a new concept known as microneedle was introduced and could be used to pierce effectively to deliver drugs using micron-sized needles in a minimally invasive and painless manner. In this study, the polymer microneedle-roller was fabricated so that it can be applied into the permeation of l-ascorbic acid. Moreover, a recent publication suggested the possibility of ascorbic acid 2-phosphate as a hair restorer; hence, this study was carried out to check the effect of l-ascorbic acid itself on the hair growing rate in rats according to the presence of various application frequencies of the polymer microneedle-roller. When the polymer microneedle-roller was applied nine times with four directions into rat’s shaved skin, the permeation of l-ascorbic acid increased by 10.54-fold compared to that of the absence of the polymer microneedle-roller. The histological examination revealed that the skin pretreated with various application frequencies of the polymer microneedle-roller had more transport pathways. The faster hair growing phenomenon was observed in the presence of polymer microneedle-roller compared to the absence of the polymer microneedle-roller.

Keywords::

• l-ascorbic acid
• polymer microneedle-roller
• permeability
• hair restorer

Acknowledgments

The present study was supported by the Intelligent Microsystem Center (IMC; http://www.microsystem.re.kr), which carries out one of the twenty-first century’s Frontier R&D Projects sponsored by the Korea Ministry of Knowledge Economy and by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MEST) (No. R01-2008-000-20071-0).

Declaration of interest: The authors report no conflicts of interest.