In October 2007, Sontra Medical Corporation was acquired by Echo Therapeutics. Sontra Medical Corporation engages in the development of transdermal diagnostic and drug delivery products based on its SonoPrep ultrasonic skin permeation technology. SonoPrep is a noninvasive ultrasonic skin permeation technology for medical and therapeutic applications, including transdermal diagnostics and the delivery of drugs through the skin. SonoPrep treatment creates imperceptible, reversible micro-channels through the stratum corneum thereby making the skin permeable to topically applied drugs. The company has developed the SonoPrep skin permeation device that makes the skin permeable for up to 24 hours by applying ultrasonic energy to the skin for approximately 15 seconds
