What is the Origin of Dermal Absorption?

The term combines 'dermal,' referring to the skin, with 'absorption,' indicating the uptake of a substance. The scientific and pharmaceutical focus on this delivery method accelerated with the development of patches and topical creams for systemic drug delivery in the mid-to-late 20th century. It represents a specialized area within pharmacokinetics and toxicology, studying the skin as a drug delivery interface.

What is the Mechanism of Dermal Absorption?

The stratum corneum, the outermost layer of the skin, acts as the primary barrier to absorption. Substances must partition into this lipid-rich layer and then diffuse through the viable epidermis and dermis to reach the capillaries. The rate of absorption is influenced by the molecule's lipophilicity, molecular weight, the vehicle formulation, and the integrity of the skin barrier. For hormonal therapies, this mechanism offers a stable plasma concentration profile, minimizing the sharp peaks and troughs seen with other routes.

Dermal Absorption ∞ Area

Dermal Absorption

Meaning

Dermal absorption is the process by which a substance applied to the skin’s surface passes through the epidermal and dermal layers to enter the systemic circulation or local tissue. This route of administration is clinically significant for transdermal drug delivery systems, allowing for the sustained, non-invasive delivery of hormones and other lipophilic therapeutic agents. Efficient dermal absorption bypasses the gastrointestinal tract and first-pass hepatic metabolism.