A practical use of low frequency ultrasound for rapid and reproducible transdermal delivery of insulin

We have previously shown that the use of low-frequency ultrasound (20kHz) was effective in increasing transdermal delivery of insulin across hairless rat skin in vivo, a phenomenon referred to as sonophoresis. The aim of this work was to further investigate the potential of sonophoresis as a method of insulin administration to improve care for the insulin-dependent diabetes. Experiments were conducted on hairless rats and on a more relevant animal model regarding human skin structure and insulin metabolism i.e. pig. Insulin and 20kHz ultrasound (pulsed mode, 15 min) were applied on the animal skin. Animal blood samples were taken to monitor blood glucose levels during and after ultrasound exposure, and exposed skins were taken to observe any structural changes using electron microscopy. These results demonstrate that sonophoresis provides rapid, reproducible and reversible transdermal delivery of insulin suggesting that this method could be a painless alternatives to improve comfort and convenience of diabetic patients.