Influence of Types of Media and Modes of Therapeutic Ultrasound on drug absorption in phonophoresis: A Comparative Experimental study on rabbits

Abstract

Although non-invasive transdermal application of various pharmaco-therapeutic drugs via phonophoresis (PH) is widely used in physical therapy, the influence of the type of medium in which the drug is prepared and mode of ultrasound on drug absorption is hardly explored. Hence, the same formed the aim of this study. In this study, serum concentration of diclofenac sodium (DS) was quantified and compared between gel and cream medium, using continuous mode (CTUS) and pulsed (PTUS) mode of Therapeutic Ultrasound (TUS) respectively. Study was conducted on eight healthy adult rabbits with 1% DS in gel and cream as topical application (TA) and PH using TUS of 1 MHz with 1 W/cm2 in CTUS and 20% PTUS respectively for 8 minutes during each session. Blood samples were analysed for drug concentration in serum by High performance liquid chromatography (HPLC) assay. Comparison of DS concentration in plasma showed a significant difference with cream than gel medium in both CTUS (p=<.001) and PTUS (p=.005) mode. For the modes of TUS, PTUS showed significance against TA in both gel (p= <.001) and cream (p=.001) and with CTUS better with TA in cream (p = 0.003) medium. The transdermal drug absorption was significantly higher in the cream than gel medium, having similar results between continuous and pulsed TUS. PH also confirmed significantly higher drug absorption than TA in both media and modes of TUS.