Pharmacokinetics of Drug Permeation through Human Skin

Mathematical modeling of transdermal drug delivery.

“…They have made great efforts to understand the penetration of drugs through the skin. The permeation data, however, were frequently analyzed on simplistic assumptions such as a single layer skin, a constant diffusivity, a steady-state condition, a simplified boundary condition, a compartment model of skin, etc>l- 3,6,8,9,[12][13][14]18,21,23,37,43,44) A mQre^^^_ proach is needed, at this stage of transdermal drug delivery studies, to elucidate the mechanism of percutaneous absorption.…”

Pharmacokinetic Interpretation of the Plasma Levels of Clonidine Following Transdermal Delivery

“…( a + p) = kz + k3 + k,; = k2k4 F = kl + k , ( w + p ) = k' + k, + k,; w p = k'kl Cg = Ako/Vdk4 (8) Using the values of A, ko, V d , and k4 quoted above (5 cm' , 1.6 pg/cm2/h, 147 L, and 0.08 h-', respectively), eq. 8 predicts C y = 0.68 ng/mL, i.e., a value in complete agreement with the actual observations and indicative that the in vitro determined ko is operating in vivo.…”

A study of the ageing of the gel structure in a nonionic O/W cream by X-ray diffraction, differential scanning calorimetry and spin-lattice relaxation measurements

“…Frequently, the colloidal systems used as vehicles for intradermal or transdermal drug delivery are hydrophilic creams. Being among the oldest dosage forms presently used, primarily for topical administration, hydrophilic creams nowadays are recognized to compete with recently developed dosage forms, such as the transdermal delivery systems based on self-adhesive polymer patches, which draw widespread attention [1,2].…”