Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Predicting skin permeability of neutral species and ionic species
The skin forms an extremely efficient barrier between internal organs and the external environ-ment, but also provides an attractive administration route. Skin permeability (as log Kp) is a critical parameter for estimating transdermal delivery of chemicals in contact with the skin in pharma-ceutics and cosmetics. Given the fact that measurement of log Kp is quite time-consuming and laborious, various mathematical models based on understanding of the fundamental mechanisms underlying skin permeation have been proposed to estimate the otherwise unavailable log Kp. However, there has been no model up to now for prediction of log Kp of ionic species. In order to solve this problem, we proposed and investigated two potential solutions in this study: one is the Potts-Guy model on the basis of partition parameters in liposome-water systems and molecular volume (MV), and the other is the extended linear free-energy relationship (LFER), which can be used to predict biological membrane permeability of ionic species. In this study, the compounds with a broad structural diversity were selected and their reten-tion factors were measured in liposome electrokinetic chromatography (LEKC), where cerasomes composed mainly of the stratum corneum (SC) lipids and liposomes (POPC80/PS20) were used as the pseudo-stationary phases, respectively. These two negatively charged membrane systems and a neutral immobilized artificial membrane (IAM) system from literature as a surrogate for neutral liposome-water partition were compared with various organic solvent-water partitioning systems using LFERs. It was observed that liposomes display a greatly different chemical environment from those of organic solvents, and no organic solvent can thus provide a general model for lipo-somes in partition processes. What is more, the correlation between the skin-water partition and organic solvent/liposome-water partitions was also investigated. The results show that cerasome exhibits a better chemical similarity with the skin as compared to ...
Predicting skin permeability of neutral species and ionic species
The skin forms an extremely efficient barrier between internal organs and the external environ-ment, but also provides an attractive administration route. Skin permeability (as log Kp) is a critical parameter for estimating transdermal delivery of chemicals in contact with the skin in pharma-ceutics and cosmetics. Given the fact that measurement of log Kp is quite time-consuming and laborious, various mathematical models based on understanding of the fundamental mechanisms underlying skin permeation have been proposed to estimate the otherwise unavailable log Kp. However, there has been no model up to now for prediction of log Kp of ionic species. In order to solve this problem, we proposed and investigated two potential solutions in this study: one is the Potts-Guy model on the basis of partition parameters in liposome-water systems and molecular volume (MV), and the other is the extended linear free-energy relationship (LFER), which can be used to predict biological membrane permeability of ionic species. In this study, the compounds with a broad structural diversity were selected and their reten-tion factors were measured in liposome electrokinetic chromatography (LEKC), where cerasomes composed mainly of the stratum corneum (SC) lipids and liposomes (POPC80/PS20) were used as the pseudo-stationary phases, respectively. These two negatively charged membrane systems and a neutral immobilized artificial membrane (IAM) system from literature as a surrogate for neutral liposome-water partition were compared with various organic solvent-water partitioning systems using LFERs. It was observed that liposomes display a greatly different chemical environment from those of organic solvents, and no organic solvent can thus provide a general model for lipo-somes in partition processes. What is more, the correlation between the skin-water partition and organic solvent/liposome-water partitions was also investigated. The results show that cerasome exhibits a better chemical similarity with the skin as compared to ...
Predicting skin permeability of neutral species and ionic species
Zhang, Keda (Autor:in)
10.04.2013
Hochschulschrift
Elektronische Ressource
Englisch
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