Optoacoustic tomography is proposed and evaluated as a method for visualization and quantitative measurements of drugs, contrast agent and other substances penetration in skin and nails. Monitoring was made with the optoacoustic front surface transducer (OAFST) operating in backward mode. Denatured egg-white was used as a model for homogeneous porous tissue, and porcine skin in vitro was employed as a model for human skin. Experimental results demonstrated that transdermal penetration and penetration through egg- white have different mechanisms. Properties and behavior of percutaneous layers of porcine skin after application hydrophilic and lipophilic substances was different. An attempt to monitor drug delivery through a nail was made, however, no significant penetration of aqueous solutions in the nail was observed. The inner nail structure was visualized with optoacoustic tomography. We conclude that optoacoustic monitoring of tissue is feasible with spatial resolution limited only by duration of laser pulses. Axial in-depth resolution of 18 μm was achieved with 12-ns long laser pulses.

Date Published: 15 June 2001
PDF: 10 pages
Proc. SPIE 4256, Biomedical Optoacoustics II, (15 June 2001); doi: 10.1117/12.429322

Published in SPIE Proceedings Vol. 4256:
Biomedical Optoacoustics II
Alexander A. Oraevsky, Editor(s)