Canadian Journal of Pure & Applied Sciences

Abstract: The aim of this study was to investigate combination treatments of chemical enhancers and 20 kHz ultrasound across porcine skin in order to identify possible synergistic and/or additive effects. For this purpose, three different classes of permeation enhancers were selected. These were: terpenes, fatty acids and sodium lauryl sulphate (a surfactant). Terpenes were chosen as their low cutaneous irritancy makes them attractive for clinical use. Fatty acids were chosen due to their general potency, widespread historical use and established status as dermal enhancers. Sodium lauryl sulphate was chosen as it has already been proven to act synergistically with low frequency ultrasound. Throughout, hydrocortisone was used as a model drug screen the selected ultrasound application with various chemical enhancer pretreatments. The 300s concurrently-applied beam, at a 10% duty cycle was used as an application protocol for the study. Synergism with menthone and sodium lauryl sulphate occurred. More interesting was the fact that ultrasound exposure following 1% SLS treatment caused a highly significant synergistic 8.8-fold increase in hydrocortisone delivery. Treatment with 0.25% SLS and ultrasound caused a significant additive effect. A simultaneous administration of all three treatments could be more effective and probably simpler to apply to hydrocortisone compared with passive transdermal delivery.