What is the Origin of Transdermal Absorption Kinetics?

This is a highly specialized sub-discipline of pharmacokinetics, specifically developed to model and predict the unique behavior of drugs delivered via the skin. The distinct nature of the skin barrier necessitates specialized mathematical models to accurately account for the slow, continuous absorption profile, which differs significantly from oral or intravenous kinetics. Clinical monitoring and dose adjustments rely heavily on these kinetic models to interpret plasma hormone levels.

What is the Mechanism of Transdermal Absorption Kinetics?

The typical transdermal absorption profile is characterized by a slow onset, followed by the establishment of a sustained, zero-order plateau phase, and a slow decline upon removal of the dosage form. The kinetics are primarily governed by the drug's effective permeability coefficient across the stratum corneum and the constant concentration gradient established by the formulation. The desired zero-order kinetics, representing a constant absorption rate, are the ideal outcome for long-acting hormonal delivery systems.

Transdermal Absorption Kinetics ∞ Area

Transdermal Absorption Kinetics

Meaning

The quantitative study and mathematical modeling of the rate and total extent to which a therapeutic compound, such as a steroid hormone, is absorbed from the skin surface into the systemic circulation over a defined period. These kinetics describe the entire dynamic process, encompassing initial partitioning, stratum corneum penetration, dermal diffusion, and final vascular uptake. Understanding these precise parameters is essential for establishing appropriate dosing intervals and achieving reliable, sustained therapeutic effects in clinical practice.