Methods are provided for enhancing the permeability of skin or mucosal tissue to topical or transdermal application of pharmacologically or cosmeceutically active agents. The methods entail the use of a base in order to increase the flux of the active agent through a body surface while minimizing the likelihood of skin damage, irritation or sensitization. The permeation enhancer can be an inorganic or organic base. Compositions and transdermal systems are also described.