Terpenes and Essential Oils as Skin Penetration Enhancers

Percutaneous drug delivery is beset with an outstanding and inevitable challenge in the form of the stratum corneum – a natural skin barrier which regulates the influx of foreign substances into the body. One of the classical approaches used to mitigate this barrier is the use of chemical penetration enhancers. Terpenes and essential oils are one of the most effective and safe class of chemical penetration enhancers and are classified under generally regarded as safe (GRAS) category by US full name (Food and Drug Administration). This chapter presents an overview of the research ventures dedicated to the application of terpenes and essential oils as sorption promoters in pursuit of improved and accentuated drug delivery via percutaneous route.