Ultrasound for controlled delivery of therapeutics.

Release of substances from polymeric drug delivery systems can be repeatedly modulated at will through ultrasound. Nondegradable-diffusion controlled and degradable-erosion controlled polymeric delivery systems have both been shown to have enhanced kinetics of release when exposed to ultrasonic energy. The effect of ultrasound was also evaluated on skin and synthetic membranes permeability. The main factors contributing to this effect included mixing, temperature, cavitation, acoustic streaming and polymer morphological changes. These phenomena have appealing therapeutic and commercial possibilities, as many drugs may benefit from subtle delivery pattern under temporal control to obtain optimal therapeutic effects.