Chemical enhancement of percutaneous absorption in relation to stratum corneum structural alterations

• Published in: Journal of controlled release Vol. 59; no. 2; pp. 149 - 161
• Main Authors: Marjukka Suhonen, T, A. Bouwstra, Joke, Urtti, Arto
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 20.05.1999; Elsevier
• Subjects: Animals; Biological and medical sciences; Epidermis - anatomy & histology; Epidermis - chemistry; Ethanol - chemistry; General pharmacology; Humans; Lipid layers; Lipids - chemistry; Medical sciences; Penetration enhancers; Permeability; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Proteins - metabolism; Skin; Skin Absorption - drug effects; Spectrum Analysis; Stratum corneum; Water - chemistry; Lipid layers; Skin; Stratum corneum; Permeability; Penetration enhancers; Pharmaceutical technology; Permeation; Molecular interaction; Lipids; X ray diffraction; Fluorescence spectrometry; Infrared spectrometry; Absorption; Absorption enhancer; Mechanism of action
• ISSN: 0168-3659; 1873-4995
• DOI: 10.1016/S0168-3659(98)00187-4

The outermost layer of the skin, stratum corneum (SC), provides an outstanding barrier against the external environment and is also responsible for skin impermeability toward most solutes. The barrier function is related to the unique composition of the SC lipids and their complex structural arrangement. The lipoidal matrix of the SC, therefore, is a target of penetration enhancer action. The literature on the skin barrier structure and function and on the mechanisms of action of some well established permeation promoters, with a focus on their impact on SC structural alterations, is reviewed. Data obtained from infrared, thermal, and fluorescence spectroscopic examinations of the SC and its components imply enhancer improved permeation of solutes through the SC is associated with alterations involving the hydrocarbon chains of the SC lipid components. Data obtained from electron microscopy and X-ray diffraction reveals that the disordering of the lamellar packing is also an important mechanism for increased permeation of drugs induced by penetration enhancers.