Theoretical and Experimental Study of the Water-Based Drug Delivery under the Nail Plate by Er-Laser Radiation

Double-stage active laser drug delivery (DSLADD) of an aqueous solution of methylene blue using Er:YLF laser radiation experimentally was investigated. Model for describe of the delivery of local drugs under a microporated nail plate taking into account the peculiarities of laser radiation exposure, capillary effects in microholes and diffusion in the nail plate was developed. The phenomenon of spreading of the drug consisting in the fact that after laser action drug is distributed in the nail bed not only in the area of the nail bed located directly under the microhole, but also along the border of the nail plate and the nail bed around the microhole was observed for the first time. Calculations performed within the framework of the developed model showed that, taking into account spreading phenomenon, the density of filling the nail area with microholes can be significantly reduced, which can proportionally increase the productivity of laser delivery in general.