A Microemulsion-Based System for the Dermal Delivery of Therapeutics

There has been a continuously increased interest during recent years in the use of topical vehicle systems that can enhance drug penetration through the skin barrier into the skin or the systemic circulation. In particular, transdermal drug delivery (TDD) is an attractive alternative to conventional oral and injectable dosage forms. Since its introduction about twenty years ago, TDD has generated much hype as a solution for drugs with short biological half-lives, narrow therapeutic windows and poor oral absorption. Transdermal ‘patches’ are currently available for motion sickness (scopolamine), cardiovascular diseases (clonidine and nitroglycerine), chronic pain (fentanyl, sulfentanil), hormone replacement (for example, estradiol, levonorgestrel), smoking cessation (nicotine), hypogonadism (testosterone) and overactive bladder (oxybutynin). Many more transdermal products for various diseases and disorders are at various stages of research and development.