Abstract
Ultrasound has been in use for the last three decades as a modality for diagnostic imaging in medicine. Recently, there have been numerous reports on the application of nonthermal ultrasound energy for targeting or controlling drug release. This new concept of therapeutic ultrasound combined with drugs has led to much excitement in various medical fields. Ultrasound energy can enhance the effects of thrombolytic agents such as urokinase. Therapeutic ultrasound catheters are currently being developed for treatment of cardiovascular diseases. Devices with ultrasound transducers implanted in transdermal drug patches are also being evaluated for possible delivery of insulin through the skin. Chemical activation of drugs by ultrasound energy for treatment of cancers is another new field recently termed "Sonodynamic Therapy". Various examples of ultrasound application are under investigation which could lead to revolutionary drug delivery systems in the future.