Topical drug delivery in humans with a single photomechanical wave

Purpose. Assess the feasibility of in vivo topical drug delivery in humans with a single photomechanical wave. Methods. Photomechanical waves were generated with a 23 nsec Q-switched rub y laser. In vive fluorescence spectroscopy was used as an elegant non-invas ive assay of transport of 5-aminolevulinic acid into the skin following the application of a single photomechanical wave. Results. The barrier function of the human stratum corneum in vive may be m odulated by a single (110 nsec) photomechanical compression wave without ad versely affecting the viability and structure of the epidermis and dermis. Furthermore, the stratum corneum barrier always recovers within minutes fol lowing a photomechanical wave. The application of the photomechanical wave did not cause any pain. The dose delivered across the stratum corneum depen ds on the peak pressure and has a threshold at similar to 350 bar. A 30% in crease in peak pressure, produced a 680% increase in the amount delivered. Conclusions. Photomechanical waves may have important implications for tran scutaneous drug delivery.