Novel method to improve transdermal drug delivery by atmospheric microplasma irradiation

Abstract

Application of atmospheric plasma could be used for wound healing, skin rejuvenation, and wrinkle treatment. The authors explored the feasibility of atmospheric microplasma irradiation (AMI) for enhancement of percutaneous absorption of drugs as an alternative to hypodermic needles. Pig skin was used as a biological sample exposed to AMI and analyzed by attenuated total reflection-Fourier transform infrared spectroscopy. A tape-stripping test (an evaluation method for skin-barrier performance) was also conducted to compare with AMI. Transepidermal water loss was also measured and compared with and without AMI. Results showed that surface modification of the stratum corneum (outermost skin layer) was observed upon AMI. Small pores on sample skin were observed with plasma jet irradiation due to the collision of charged particles. Percutaneous absorption was confirmed without damage upon microplasma irradiation. Our data suggested that dye pathways through skin samples could be related to the dynamic behavior of intercellular lipid bilayers, suggesting that AMI could enhance percutaneous absorption.

Enhancement of Percutaneous Absorption on Skin by Plasma Drug Delivery Method

“…After 30 s of atmospheric plasma jet irradiation, most of the stratum corneum layer was removed, as shown in (c). In the microplasma case, even after 5 min irradiation (d), the stratum corneum layer remained similar to the control sample, as shown in (a) [23]. Little difference in physical appearance was observed between the control pig skin sample and after microplasma irradiation.…”

“…When the effect of plasma jet was tested on PEN film, after 10 s of plasma jet irradiation, the surface potential increased to about 10% of the driven voltage. After long-term operation, it reached almost the same value as the driven voltage [23]. A similar problem could happen in electroporation but it uses very short operation times in the range of microseconds or milliseconds.…”

“…This is also confirmed by TEWL (Figure 13), which also shows the same values. On the other hand, TEWL after 5 min of microplasma irradiation of the pig skin sample, TEWL increased to almost double its original value, suggesting that the barrier properties were decreased through atmospheric microplasma irradiation but it is less effective than plasma jet [23]. …”

“…Another version of DBD is surface DBD used in Shimizu et al [23,69]. Both electrodes were in contact with isolator layer.…”

“…The exposure time was usually between 1 and 5 min (Figure 7). Experimental set-up with microplasma electrode [23].…”