Assessing the Dermal Penetration Efficacy of Chemical Compounds with the Ex-Vivo Porcine Ear Model

Keck, Cornelia M.; Abdelkader, Ayat; Pelikh, Olga; Wiemann, Sabrina; Kaushik, Vasudha; Specht, David; Eckert, Ralph W.; Alnemari, Reem M.; Dietrich, H.; Brüßler, Jana

doi:10.3390/pharmaceutics14030678

Cited by 20 publications

(17 citation statements)

References 82 publications

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“…Additionally, room temperature is a more favourable condition for bacterial growth compared to cold storage [ 51 ], and tape stripping is one of the proposed approaches for collecting skin flora for bacterial analysis [ 52 ]. The second reason for the elevated iAOC during storage is the production of lactic acid as a part of postmortem changes that occur in the ears about 4–6 h after porcine slaughtering [ 40 ]. Lactic acid has been proven to have a concentration-dependent AOC [ 53 ], and its production in the skin increases at room temperature due to the increased skin decomposition under such conditions.…”

Section: Discussionmentioning

confidence: 99%

“…The use of the ex vivo porcine ear model allows the use of skin that is still connected to the cartilage. Hence, the skin is in its physiological tension and condition, and no artifacts, i.e., disrupted skin barrier, squeezed skin with water on the skin surface, etc., are created during the preparation [ 39 , 40 ]. Thus, those methods were used and combined, and a specific term was applied to describe the ability of porcine skin’s antioxidant system to scavenge free radicals: intrinsic antioxidant capacity (iAOC).…”

Section: Introductionmentioning

confidence: 99%

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Assessing the Oxidative State of the Skin by Combining Classical Tape Stripping with ORAC Assay

2022

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The antioxidant barrier system of the skin acts as the main defence against environmental pro-oxidants. Impaired skin oxidative state is linked to unhealthy conditions such as skin autoimmune diseases and cancer. Thus, the evaluation of the overall oxidative state of the skin plays a key role in further understanding and prevention of these disorders. This study aims to present a novel ex vivo model to evaluate the skin oxidative state by the measurement of its antioxidant capacity (AOC). For this the ORAC assay was combined with classical tape stripping and infrared densitometry to evaluate the oxidative state of the stratum corneum (SC). Outcomes implied the suitability of the used model to determine the intrinsic antioxidant capacity (iAOC) of the skin. The average iAOC of untreated skin was determined as 140 ± 7.4 µM TE. Skin exposure to UV light for 1 h reduced the iAOC by about 17%, and exposure for 2 h decreased the iAOC by about 30%. Treatment with ascorbic acid (AA) increased the iAOC in a dose-dependent manner and reached an almost two-fold iAOC when 20% AA solution was applied on the skin. The application of coenzyme Q10 resulted in an increase in the iAOC at low doses but decreased the iAOC when doses > 1% were applied on the skin. The results show that the combination of classical tape stripping and ORAC assay is a cost-effective and versatile method to evaluate the skin oxidative state and the pro-oxidate and antioxidative effects of topical skin treatments on the iAOC of the skin. Therefore, the model can be considered to be a valuable tool in skin research.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Assessing the Oxidative State of the Skin by Combining Classical Tape Stripping with ORAC Assay

2022

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“…The influence of the particles on the dermal penetration efficacy was investigated by using the ex vivo pig ear model [ 10 , 11 ]. Fresh pig ears were obtained from a local slaughterhouse from pigs that were slaughtered for food industry.…”

Section: Methodsmentioning

confidence: 99%

“…It was dissolved in the water phase of the particle dispersions and served as a surrogate for a hydrophilic AI. The different formulations were prepared and characterized, and the dermal penetration efficacy of the AI surrogate from the different particle-containing formulations was determined with the ex vivo porcine ear model [ 10 , 11 ]. The results obtained were compared to the dermal penetration of the AI surrogate from formulations with identical dispersion media without particles.…”

Section: Introductionmentioning

confidence: 99%

Particle-Assisted Dermal Penetration—A Simple Formulation Strategy to Foster the Dermal Penetration Efficacy

Wiemann

Keck

2022

Pharmaceutics

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(1) Background: The study systematically investigated the influence of dispersed particles within a topical formulation on the dermal penetration efficacy of active compounds that are dissolved in the water phase of this formulation. The aim was to prove or disprove if particle-assisted dermal penetration can be used for improved dermal drug delivery. (2) Methods: Fluorescein was used as a surrogate for a hydrophilic active ingredient (AI). It was dissolved in the water phase of different formulations with and without particles. Two different types of particles (titanium dioxide and nanostructured lipid carriers (NLC)) were used. The influence of particle size and number of particles and the influence of skin hydrating excipients was also investigated. (3) Results demonstrate that the addition of particles can strongly increase the dermal penetration efficacy of AI. The effect depends on the size of the particles and the number of particles in the formulation, where smaller sizes and higher numbers resulted in higher penetration parameters. Formulations with NLC that contained 20% w/w or 40% w/w particles resulted in an about 2-fold higher amount of penetrated AI and increased the penetration depth about 2.5-fold. The penetration-enhancing effect was highly significant (p < 0.001) and allowed for an efficient delivery of the AI in the viable dermis. In contrast, the penetration-enhancing effect of excipients that increase the skin hydration was found to be very limited and not significant (≤5%, p > 0.05). (4) Conclusions: Based on the results, it can be concluded that particle-assisted dermal penetration can be considered to be a simple but highly efficient and industrially feasible formulation principle for improved and tailor-made dermal drug delivery of active compounds.

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“…To our knowledge, no such attempt has previously been reported. Having confirmed satisfying physicochemical stability, the skin permeation of ginsenosides Rg1 and Rb1 was investigated in an ex vivo setup using the porcine ear model [ 34 , 35 ]. As vehicles, fluid oil-in-water submicron emulsions (termed “nanoemulsions”, NEs) as multiphase systems and hydroalcoholic gels as monophase systems were chosen for incorporation of KRG extract at 2% w / w .…”

Section: Introductionmentioning

confidence: 99%

Dermal Delivery of Korean Red Ginseng Extract: Impact on Storage Stability of Different Carrier Systems and Evaluation of Rg1 and Rb1 Skin Permeation Ex Vivo

Klang

Schweiger²,

Strohmaier³

et al. 2022

Pharmaceutics

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The root extract of Panax ginseng C.A. Meyer (Korean red ginseng/KRG extract) is a traditional Asian remedy introduced to dermal products for its antioxidative potential. However, little is known about technological aspects or skin penetration of main ginsenosides. Thus, stable oil-in-water nanoemulsions (NEs) and hydrogels for dermal delivery of KRG extract were developed and characterised using light scattering methods, analysis of flow properties and pH measurements. In addition, Rg1 and Rb1 contents were monitored by UHPLC/MS. Different surfactants (phosphatidylcholine, monoacylphosphatidylcholine and polysorbate 80) and polymers (polyacrylic acid and hydroxyethylcellulose) were tested and compared for their compatibility with KRG extract. The results showed that incorporation of KRG extract led to a significantly reduced formulation pH in hydroxyethylcellulose gels (−22%), NEs (−15%) and carbomer gels (−4–5%). The dynamic viscosity was in the range of 24–28 Pas at 10 s−1 for carbomer gels. The highest storage stability and skin permeation were observed for a hydroalcoholic gel with carbomer 50,000 and TRIS buffer (each of 1% w/w), containing ethanol (20% w/w) and KRG extract (2% w/w). Ex vivo diffusion cell studies confirmed skin permeation of the moderately lipophilic Rg1, but not the more hydrophilic Rb1 with a larger molecular weight.

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Assessing the Dermal Penetration Efficacy of Chemical Compounds with the Ex-Vivo Porcine Ear Model

Cited by 20 publications

References 82 publications

Assessing the Oxidative State of the Skin by Combining Classical Tape Stripping with ORAC Assay

Assessing the Oxidative State of the Skin by Combining Classical Tape Stripping with ORAC Assay

Particle-Assisted Dermal Penetration—A Simple Formulation Strategy to Foster the Dermal Penetration Efficacy

Dermal Delivery of Korean Red Ginseng Extract: Impact on Storage Stability of Different Carrier Systems and Evaluation of Rg1 and Rb1 Skin Permeation Ex Vivo

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