What is the Origin of Cutaneous Metabolism Influence?

This concept developed as pharmaceutical scientists moved beyond viewing the skin as a simple physical barrier, recognizing its complex biochemical role. Early drug absorption studies often produced inaccurate predictions because they failed to account for the skin's capacity for biotransformation. Understanding cutaneous metabolism became a necessary component for accurately modeling and predicting drug plasma concentrations.

What is the Mechanism of Cutaneous Metabolism Influence?

Enzymes located in the viable epidermis and dermis can catalyze Phase I oxidation and reduction reactions, as well as Phase II conjugation reactions on the drug molecule. For certain prodrugs, this localized metabolism is intentionally utilized for activation into the therapeutic hormone. Conversely, it can lead to the premature degradation and inactivation of an active hormone before it reaches the systemic circulation. This localized enzymatic activity determines the ultimate therapeutic fate of the applied dose.

Cutaneous Metabolism Influence ∞ Area

Cutaneous Metabolism Influence

Meaning

The physiological effect of endogenous enzymatic activity within the various layers of the skin on the chemical structure and pharmacological potency of an administered compound. The skin is not a passive barrier; it contains numerous metabolic enzymes, including various reductases and conjugating enzymes, capable of biotransforming hormonal agents. This influence directly dictates the systemic bioavailability and therapeutic efficacy of transdermally delivered hormones. It is a critical factor in determining the final active dose.