Diffusion modeling of percutaneous absorption kinetics. Predicting urinary excretion from in vitro skin permeation tests (IVPT) for an infinite dose was written by Liu, Xin;Yousef, Shereen;Anissimov, Yuri G.;van der Hoek, John;Tsakalozou, Eleftheria;Ni, Zhanglin;Grice, Jeffrey E.;Roberts, Michael S.. And the article was included in European Journal of Pharmaceutics and Biopharmaceutics in 2020.HPLC of Formula: 118-61-6 This article mentions the following:
In this work, we developed a number of generalised skin diffusion based pharmacokinetic models to relate published in vivo urinary excretion data to matching exptl. generated in vitro human skin permeation test (IVPT) data for a series of topically applied salicylate esters. A simplified linear in vivo model was found to inadequately describe the time course of urinary excretion over the entire sampling period. We represented the skin barrier as both a one layer (stratum corneum) and a two-layer (stratum corneum with viable epidermis) diffusion model and convoluted their Laplace solutions with that for a single exponential disposition phase to describe the urinary excretion profiles in the Laplace domain. We also derived asymptotic approximations for the model and estimated the conditions under which they could be used. We then sought to develop in vitro – in vivo relationships (IVIVR) for topically applied Me, Et and glycol salicylates using our exptl. IVPT data and the literature urinary excretion data. Good linear IVIVRs for Et and glycol salicylates were obtained, but the IVIVR for Me salicylate was poor, perhaps because of topical stimulation of local skin blood flow by Me salicylate. The ratio of the hydrated to dehydrated skin permeation for all salicylate esters was the same in both the IVPT and in vivo studies. A diffusion based one compartment pharmacokinetic model was also developed to describe the urinary excretion of solutes after removal of topical products and to compare the Me salicylate skin permeation for five different body sites. The work presented here is consistent with the development of skin IVIVRs, but suggests that different skin conditions, application sites and local skin effects may affect model predictions. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6HPLC of Formula: 118-61-6).
Ethyl 2-hydroxybenzoate (cas: 118-61-6) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.HPLC of Formula: 118-61-6
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics