Percutaneous absorption in diseased skin: an overview

Abstract

The stratum corneum's (SC) functions include protection from external hazardous environments, prevention of water loss and regulation of body temperature. While intact skin absorption studies are abundant, studies on compromised skin permeability are less common, although products are often used to treat affected skin. We reviewed literature on percutaneous absorption through abnormal skin models. Tape stripping is used to disrupt water barrier function. Studies demonstrated that physicochemical properties influence the stripping effect: water-soluble drugs are more affected. Abrasion did not affect absorption as much. Freezing is commonly used to preserve skin. It does not seem to modify water absorption, but still increases the penetration of compounds. Comparatively, heating the skin consistently increased percutaneous absorption. Removing SC lipids may increase percutaneous absorption of drugs. Many organic solvents are employed to delipidize. Delipidization with chloroform-methanol increased hydrophilic compound permeability, but not lipophilic. Acetone pre-treatment enhanced hydrophilic compound penetration. More data is needed to determine influence on highly lipophilic compound penetration. Sodium lauryl sulfate (SLS) induces irritant dermatitis and is frequently used as a model. Studies revealed that SLS increases hydrophilic compound absorption, but not lipophilic. However, skin irritation with other chemicals increases lipophilic penetration as much as hydrophilic. Animal studies show that UV exposure increases percutaneous absorption whereas human studies do not. Human studies show increased penetration in psoriatic and atopic dermatitis skin. The data summarized here begin to characterize flux alteration associated with damaged skin. Understanding the degree of alteration requires interpretation of involved conditions and the enlarging of our database to a more complete physicochemical spectrum.

Evaluation of 3D-human skin equivalents for assessment of human dermal absorption of some brominated flame retardants

“…Many organic solvents (e.g. chloroform and methanol) are employed to delipidize the skin, which increases the permeability of hydrophilic-but not lipophilic-compounds (Chiang et al, 2012).…”

Permeation of Hydrophilic Molecules across Glycated Skin Is Differentially Regulated by the Stratum Corneum and Epidermis–Dermis

“…4) Despite many percutaneously applied cosmetics and drugs being used to treat damaged skin or diseases that affect skin condition, few reports have shown a difference in penetration and permeation between normal and damaged skin. [5][6][7] Advanced glycation end products (AGEs), which are linked to both aging and hyperglycemia, cause marked functional and structural alterations in human skin. 8,9) AGEs are generated via the non-enzymatic Maillard reaction between reducing sugars and proteins, lipids or nucleic acids.…”

Impact of structural differences in hyperbranched polyglycerol–polyethylene glycol nanoparticles on dermal drug delivery and biocompatibility

“…Additionally, we studied the toxicity and biocompatibility of non-loaded PG-PEG particles employing different in vitro setups. Knowledge about the toxicity of locally applied carrier systems is of great importance, particularly in diseased or barrier impaired skin, because the nanoparticles can penetrate into deeper dermal layers and be taken up into the systemic circulation [14,18]. In contrast to CMS nanotransporters, PG-PEG particles are less structurally defined and the alkyl and PEG chains are randomly attached to the dendritic PG core without a multishell formation [22].…”

“…Here, the carrier system can easily come into contact with cells of the viable epidermis which particularly requires low toxicity [14]. It is still highly debated if nanoparticles are able to overcome the outermost layer of intact human skin, the stratum corneum (SC), and penetrate into deeper dermal layers.…”