Laser treatments on skin enhancing and controlling transdermal delivery of 5-fluorouracil

• Published in: Lasers in surgery and medicine 2008-01, Vol.40 (1), p.6-12
• Main Authors: Gómez, Clara, Costela, Ángel, García-Moreno, Inmaculada, Llanes, Felipe, Teijón, José M., Blanco, Dolores
• Format: Article
• Language: English
• Subjects: 5-Fu; Administration, Cutaneous; Animals; Ear; Fluorouracil - administration & dosage; Fluorouracil - pharmacokinetics; In Vitro Techniques; Laser Therapy; Lasers; Nd:YAG laser; Rabbits; Skin - drug effects; Skin - metabolism; Skin - radiation effects; Skin Absorption; stratum corneum; transdermal delivery
• ISSN: 0196-8092; 1096-9101
• DOI: 10.1002/lsm.20590

Background and Objective Laser ablation of stratum corneum (SC) enhances transdermal delivery of hydrophilic drugs. The influence of the infrared (IR) (λ = 1,064 nm), visible (λ = 532 nm), and ultraviolet (UV) (λ = 355 nm) radiations of a Nd:YAG laser on transdermal delivery of 5‐Fluorouracil (5‐Fu) across skin was studied in vitro. Materials and Methods Pinna skin of the inner side of rabbit ear, was used for the skin permeation. The light source for laser treatment was a Q‐switched Nd:YAG laser (Lotis TII SL‐2132). Ablation thresholds were estimated by using a photoacoustic technique. In addition, permeation study, and morphological and structural skin examination by histology and differential scanning calorimetry (DSC) were carried out. Results A significant increase in the permeation of 5‐Fu across skin pre‐treatment with the three different wavelengths studied was obtained. Since irradiation at 1,064 nm allows deep penetration of the radiation, collagen fibers were affected [7.7 J/cm2 (15 Hz)]. Visible radiation of Nd:YAG laser showed the wider range of fluences (3–8.4 J/cm2 at 15 Hz) to enhance skin delivery of 5‐Fu, without risk of skin lesion. UV radiation required minor energy contribution to produce the same effects within a narrower range of fluences [0.3 J/cm2 (5 Hz)–1.5 J/cm2 (15 Hz)] so the process is less controlled and this radiation shows greater impact on the lipidic structure than visible and IR radiations. Conclusions Use of the visible radiation of a Nd:YAG laser is a good method for improving the efficacy of topical chemotherapy of 5‐Fu. Lesers Surg. Med. 40:6–12, 2008. © 2008 Wiley‐Liss, Inc.