Photomechanical transdermal delivery of insulin in vivo

Background and Objective Previous studies have shown that photomechanical waves transiently permeabilize the stratum corneum in vivo. The aim of the present work was to investigate the potential of photomechanical waves for systemic drug delivery. Study Design/Materials and Methods Photomechanical waves were generated by ablation of a polystyrene target by a Q-switched ruby laser. Systemic insulin delivery in a streptozotocin-diabetic rat model was monitored by measuring the blood glucose level. Results After photomechanical insulin delivery, the blood glucose decreased 80  ±  3% and remained below 200 mg/dl for more than 3 hours. Whereas in control experiments (for which insulin was applied without photomechanical waves), there was no dramatic change in the blood glucose (standard deviation of measurements over 4 hours was 7%). Conclusion The application of the photomechanical waves allowed ∼6-kDa protein molecules (insulin) to pass through the stratum corneum and into the systemic circulation. Lasers Surg. Med. 28:282–285, 2001. © 2001 Wiley-Liss, Inc.