Comparison of physical enhancement technologies in the skin permeation of methyl amino levulinic acid (mALA)

[Display omitted] Physical drug delivery enhancement in skin has been shown to enhance cosmeceutical actives efficacy. Among the physical drug delivery enhancement technologies, microneedle is the most commercially successful technology. However, there are pros and cons like other physical enhancement technologies including variabilities in penetration depth and lack of efficacy. In this study, three physical topical dug delivery enhancements, elongated microparticles, microneedles and dermaroller, were applied to ex vivo pig skin and compared. The model topical drug that was used is 5-Aminolevulinic acid, the most commonly used photosensitiser prodrug. The skin was pre-treated before mounting on to Franz cell diffusion apparatus. Transdermal epidermal water loss was measured, and receptor fluids were collected at 7 time points for HPLC analysis. The results show that all three technologies disrupted the skin surface. All microporation pre-treatments significantly enhanced mALA cumulative permeation over 8 h (p elongated microparticles. In conclusion, physical enhancement tools such as microneedles, dermarollers and elongated microparticles demonstrated significant penetration and retention of mALA through/into piglet skin. Further study is needed to determine the cost, dose and patient compliance.