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 insu lin delivery in a streptozotocin-diabetic rat model was monitored by measur ing the blood glucose level. Results: After photomechanical insulin delivery, the blood glucose decrease d 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 deviati on of measurements over 4 hours was 7%). Conclusion: The application of the photomechanical waves allowed similar to 6-kDa protein molecules (insulin) to pass through the stratum corneum and i nto the systemic circulation. (C) 2001 Wiley-Liss, Inc.