Influence of Ultrasound on the Percutaneous Absorption of Ketorolac Tromethamine In Vitro Across Rat Skin

Abstract

The influence of ultrasound on percutaneous absorption of ketorolac tromethamine was studied in vitro across rat skin. Sonication was carried out with a continuous mode, at an intensity of 1-3 W/cm2 and a frequency of 1 MHz for 30 min. A significant increase in permeation of ketorolac through rat skin was observed with the applied sonication at 3 W/cm2 when compared with permeation at 1 and 2 W/cm2. Enhanced ketorolac penetration at 3 W/cm2 can be explained by the mechanical and/or thermal action of ultrasound waves. The distance of the ultrasound probe from the skin surface did not influence the flux of the drug. Pretreatment of skin by 5% d-limonene in ethanol for 2 hr followed by sonication at 3 W/cm2 (30 min) significantly enhanced the permeation of ketorolac when compared with passive flux with or without enhancer pretreatment.

Permeation enhancer strategies in transdermal drug delivery

“…But this techinique has some limitations, i.e. formation of attenuation which is due to the fact that sound waves transforms to heat energy (Tiwari et al, 2004). The additional advantages, limitations and applications that the ultrasound technique comprises are summarized in Tables 5 and 6, respectively.…”

A combined approach of chemical enhancers and sonophoresis for the transdermal delivery of tizanidine hydrochloride

“…Although the combination of ultrasound and chemical enhancers has been reported for increasing transdermal flux, their simultaneous use has not been investigated. Rather, the skin is either pre-treated with ultrasound or chemical enhancer (Fang et al, 2001;Tiwari et al, 2004). In addition, it has also been proposed that sonophoresis is more effective for enhancing the permeation of hydrophilic molecules such as TIZ, as transfollicular pathways are more susceptible to ultrasonic enhancement than are transcellular processes (Meidan et al, 1995).…”

Therapeutic effects of nanogel containing triterpenoids isolated from Ganoderma lucidum (GLT) using therapeutic ultrasound (TUS) for frostbite in rats

“…The use of ultrasound for the transdermal delivery of drugs has been investigated extensively and its mechanisms of skin permeability enhancement may include cavitation (generation and oscillation of gas bubbles), thermal effects (temperature increase), induction of convective transport and mechanical effects (occurrence of stresses due to pressure variation induced by ultrasound) (Tiwari et al, 2004;Polat et al, 2011; Alexander et al, 2012). However, the mechanisms of skin permeabilization induced by ultrasound with different frequency are different.…”