title: Topical drug delivery in humans with a single photomechanical wave.
abstract: OBJECTIVE
  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 ruby laser. In vivo fluorescence spectroscopy was used as an elegant non-invasive 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 vivo may be modulated by a single (110 nsec) photomechanical compression wave without adversely affecting the viability and structure of the epidermis and dermis. Furthermore, the stratum corneum barrier always recovers within minutes following a photomechanical wave. The application of the photomechanical wave did not cause any pain. The dose delivered across the stratum corneum depends on the peak pressure and has a threshold at approximately 350 bar. A 30% increase in peak pressure, produced a 680% increase in the amount delivered.
  
  
  CONCLUSIONS
  Photomechanical waves may have important implications for transcutaneous drug delivery.
authors.affiliation: Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, Boston 02114, USA. lee@helix.mgh.harvard.edu
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: N
authors.initials: N
authors.lastname: Kollias
authors.forename: D J
authors.initials: DJ
authors.lastname: McAuliffe
authors.forename: T J
authors.initials: TJ
authors.lastname: Flotte
authors.forename: A G
authors.initials: AG
authors.lastname: Doukas
mesh_terms: D000279:Administration, Cutaneous; D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000009:adverse effects; D016503:Drug Delivery Systems / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007834:Lasers; D008854:Microscopy, Electron; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D000622:Aminolevulinic Acid