Use of Physical Approaches for Systemic Drug Delivery

Physical methods of drug delivery involve application of physical forces to deliver drugs using different approaches. These approaches combine forces (such as magnetic, thermal, ballistic, and electrical forces) with novel formulation techniques, for example, those in targeted drug delivery. The important approaches include iontophoresis, low-frequency ultrasound, electrophoresis, magnetic drug delivery, and the use of microneedles. Physical methods have been used for the treatment of various tumors, targeted delivery of drugs and genes, magnetic resonance imaging, cell purification, and hyperthermia. In this chapter, we will provide an overview of the strategies employed in physical methods of drug delivery. The working principles underlying ultrasound-, photo-, magnetic-, and electrical-based delivery methods, as well as the possible use of microneedles to control drug release, will be presented. Clinical applications relevant to these methods will also be discussed.