ABSTRACT
Low-frequency ultrasound can increase the transdermal delivery of many drugs, including macromolecular drugs. The main mechanism is ultrasonic cavitation. Most researchers pointed out that it could change the form-structure of stratum corneum keratinocytes and, in this way, it can improve the permeability of skin. Low-frequency sonophoresis has been in use for in-vitro experiments and in-vivo animal experiments, and so far, both small-molecules transdermal delivery and macromolecules transdermal delivery have been successfully performed in many experiments. However, there are few reports about the real low-frequency sonophoresis for clinical treatment. A large number of clinical trials are necessary to confirm its safety and practicality. Once its safety is confirmed and the suitable low-frequency sonophoresis devices are developed successfully, Low-frequency Sonophoresis will come to be a safe, effective, controllable, and economic new delivery method.