ATR-FTIR Spectroscopy and the Skin Barrier: Evaluation of Penetration-Enhancement Effects

SmartLipids are the latest generation of dermal lipid nanoparticles with solid particle matrix. Their characteristic properties resulting from the “chaotic” and disordered particle matrix structure are reviewed. These properties are high loading and firm inclusion of active agents, physical stability of the particle matrix lipid modification (primarily α, β′), and related to these three properties the improved chemical stabilization of labile active agents. Exemplarily data for these effects are shown and underlying mechanisms are discussed. Further, general properties of lipid nanoparticles, which are also exhibited by the SmartLipids, are reviewed. These include the restauration of the protective lipid skin barrier (anti-pollution effect), penetration enhancement by occlusion (invisible patch effect) and the option to control the release of active agents for optimized biological effect and reduction of side effects (e.g., skin irritation through sensitizing active agents), which improves the skin tolerability. Regulatory aspects, such as submicron particle status, excipients, and certifications, are also discussed.

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Recent Advances in Physical Approaches for Transdermal Penetration Enhancement

Current Drug Therapy ◽

10.2174/157488512803988030 ◽

2012 ◽

Vol 7 (3) ◽

pp. 184-197 ◽

Cited By ~ 2

Author(s):

HJessy Shaji ◽

Dhanila Varkey

Keyword(s):

Transdermal Delivery ◽

Fluorescent Dyes ◽

Skin Barrier ◽

Penetration Enhancement ◽

Transport Barrier ◽

Novel Technologies ◽

Combination Strategies ◽

Recent Advances ◽

Transdermal Drug Delivery Systems ◽

Transdermal Penetration

Transdermal delivery offers opportunities for inventive, challenging and valuable research with patient benefits. However, the prominent challenge in designing transdermal drug delivery systems is to overcome the natural transport barrier of the skin, the stratum corneum. Several physical and chemical enhancement techniques have been investigated in the last decade to breach the skin barrier and assist the transport of macromolecules across skin. Recent technological advances in this field include novel combination strategies of penetration enhancement techniques, microneedle array designs, needle-free technologies, nanocarriers, metered dose and microstructured transdermal systems. The present review reports on recent advances in physical approaches towards enhanced transdermal penetration. Enhancement strategies comprehensively covered in this review emphasize the significant achievements gained through successful transdermal delivery of hydrophilic macromolecules, vaccines, proteins, peptides, oligonucleotides, fluorescent dyes and plasmid delivery. Some commercially available technologies for transdermal delivery have also been covered. These novel technologies hold immense potential to advance further into clinical practice and enable better therapeutic applications and prophylactic interventions for various diseases.

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Changes in corneocyte element concentrations occur in skin inner stratum corneum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134326 ◽

1990 ◽

Vol 48 (2) ◽

pp. 146-147

Author(s):

R. R. Warner

Keyword(s):

Stratum Corneum ◽

Human Skin ◽

Element Concentration ◽

Skin Barrier ◽

Barrier Properties ◽

Brick Wall ◽

Inorganic Elements ◽

Dry Skin ◽

Skin Biopsies ◽

Intercellular Lipid

Keratinocytes undergo maturation during their transit through the viable layers of skin, and then abruptly transform into flattened, anuclear corneocytes that constitute the cellular component of the skin barrier, the stratum corneum (SC). The SC is generally considered to be homogeneous in its structure and barrier properties, and is often shown schematically as a featureless brick wall, the “bricks” being the corneocytes, the “mortar” being intercellular lipid. Previously we showed the outer SC was not homogeneous in its composition, but contained steep gradients of the physiological inorganic elements Na, K and Cl, likely originating from sweat salts. Here we show the innermost corneocytes in human skin are also heterogeneous in composition, undergoing systematic changes in intracellular element concentration during transit into the interior of the SC.Human skin biopsies were taken from the lower leg of individuals with both “good” and “dry” skin and plunge-frozen in a stirred, cooled isopentane/propane mixture.

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