Absorption

Spectral and mass characterization of kinetic conversion from retinoids to retinoic acid in an in vitro 3-D human skin equivalent model

To investigate the effect of retinoids, such as retinol (ROL), retinal (RAL), and retinyl palmitate (RP), on epidermal integrity, skin deposition, and bioconversion to retinoic acid (RA). 3-D human skin equivalent model (EpiDermFT™) was used. Epidermal cellular integrity measured by TEER values was significantly higher for a topical treatment of ROL and RAL than RP […]

Characterization of an air-liquid interface primary human vaginal epithelium to study Ebola virus infection and testing of antivirals

Ebola virus (EBOV) is the causative agent of the often-fatal Ebola virus disease (EVD) characterized by hemorrhagic fever in humans and non-human primates. Sexual transmission from male survivors has been at the origin of multiple outbreak flare-ups between 2015 and 2021. However, this route is still poorly understood and the resulting EVD from it is […]

In vitro prediction of the performance or equivalence, of different formulations of the same drug substance using a 3D reconstructed human intestinal tissue model: application to generics or drugs in development

“The BCS (Biopharmaceutics Classification System)-based biowaiver approach is intended to reduce the need for in vivo bioequivalence studies in Human, in order to lower costs of development, increase the market access for generic drugs and from an ethical point of view, avoid unnecessary exposure of healthy volunteers (Humans). These waivers are limited to Class I […]

In vitro models replicating the human intestinal epithelium for absorption and metabolism studies: A systematic review

Absorption, distribution, metabolism and excretion (ADME) studies represent a fundamental step in the early stages of drug discovery. In particular, the absorption of orally administered drugs, which occurs at the intestinal level, has gained attention since poor oral bioavailability often led to failures for new drug approval. In this context, several in vitro preclinical models […]

Dietary excess regulates absorption and surface of gut epithelium through intestinal PPARα

Intestinal surface changes in size and function, but what propels these alterations and what are their metabolic consequences is unknown. Here we report that the food amount is a positive determinant of the gut surface area contributing to an increased absorptive function, reversible by reducing daily food. While several upregulated intestinal energetic pathways are dispensable, […]

Evaluation of Inflammation by Cytokine Production Following Combined Exposure to Ultraviolet and Radiofrequency Radiation of Mobile Phones on 3D Reconstructed Human Skin In Vitro

The absorption of exposure to radiofrequency (RF) emitted by wireless devices leads to a high specific absorption rate in the skin. Ultraviolet (UV) radiation can induce several damages to the skin. The aim of this study was to examine whether combined, consecutive exposure to solar UV radiation and 1950 MHz RF exposure of third generation […]

Bypassing P-glycoprotein mediated efflux of afatinib by cyclodextrin complexation – Evaluation of intestinal absorption and anti-cancer activity

A cyclodextrin complex of afatinib, a FDA-approved pan–ErbB inhibitor and known P-gp substrate, was developed to enhance its bio-activity while also reducing p-glycoprotein (P-gp) efflux, thereby improving its transport across the intestinal membrane. A sulfobutyl ether derivative of β-cyclodextrin (SBE-β-CD, pharmaceutical grade) was selected based on preliminary phase solubility studies and molecular modeling to prepare […]

In Vitro Demonstration of Intestinal Absorption Mechanisms of Different Sugars Using 3D Organotypic Tissues in a Fluidic Device

Intestinal permeability is crucial in regulating the bioavailability and, consequently, the biological effects of drugs and compounds. However, systematic and quantitative studies of the absorption of molecules are quite limited due to a lack of reliable experimental models able to mimic human in vivo responses. In this work, we present an in vitro perfused model […]

A heat-stable microparticle platform for oral micronutrient delivery

Micronutrient deficiencies affect up to 2 billion people and are the leading cause of cognitive and physical disorders in the developing world. Food fortification is effective in treating micronutrient deficiencies; however, its global implementation has been limited by technical challenges in maintaining micronutrient stability during cooking and storage. We hypothesized that polymer-based encapsulation could address […]

Evaluation of Clay-Functionalized Wafers and Films for Nicotine Replacement Therapy via Buccal Mucosa

The functional physicochemical properties of nicotine (NIC)-loaded composite freeze-dried wafers and solvent-evaporated films comprising hydroxypropylmethylcellulose (HPMC) and sodium alginate (SA), stabilized with magnesium aluminium silicate (MAS), have been reported. The formulations were characterized for swelling capacity, mucoadhesion, in vitro drug dissolution properties in simulated saliva (SS) and PBS at pH 6.8, and ex vivo and […]

A series of in vitro and human studies of a novel lip cream formulation for protecting against environmental triggers of recurrent herpes labialis

Purpose: These studies describe the testing of a novel, daily-use lip cream designed for individuals with lips prone to recurrent herpes labialis (RHL) that protects against environmental triggers. Subjects and methods: In vitro occlusive and in vitro and in vivo photoprotection analyses, a characterization of normal vs dry lips, and a randomized, evaluator-blinded, clinical trial […]

Nintedanib-Cyclodextrin Complex to Improve Bio-Activity and Intestinal Permeability

Cyclodextrin complex of nintedanib was prepared aiming for increased bio-activity and improved transport across intestinal membrane with reduced p-glycoprotein (p-gp) efflux. Based on preliminary phase solubility studies and molecular modeling, sulfobutyl ether derivative of β-cyclodextrin (SBE-β-CD, Captisol®) was selected to prepare inclusion complex. Complexation was confirmed using FTIR, 1H NMR, DSC, and XRD. Bioactivity of […]

Hyperosmolal vaginal lubricants markedly reduce epithelial barrier properties in a three-dimensional vaginal epithelium model

Most of the widely used vaginal lubricants in the U.S. and Europe are strongly hyperosmolal, formulated with high concentrations of glycerol, propylene glycol, polyquaternary compounds or other ingredients that make these lubricants 4 to 30 times the osmolality of healthy vaginal fluid. Hyperosmolal formulations have been shown to cause marked toxicity to human colorectal epithelia in vivo, and […]

IL-22 Increases Permeability of Intestinal Epithelial Tight Junctions by Enhancing Claudin-2 Expression

Dysfunction of the epithelial barrier is a hallmark of inflammatory intestinal diseases. The intestinal epithelial barrier is maintained by expression of tight junctions that connect adjacent epithelial cells and seal the paracellular space. IL-22 is critical for the maintenance of intestinal barrier function through promoting antipathogen responses and regeneration of epithelial tissues in the gut. However, little is […]

Human 3D Gastrointestinal Microtissue Barrier Function As a Predictor of Drug-Induced Diarrhea

Drug-induced gastrointestinal toxicities (GITs) rank among the most common clinical side effects. Preclinical efforts to reduce incidence are limited by inadequate predictivity of in vitro assays. Recent breakthroughs in in vitro culture methods support intestinal stem cell maintenance and continual differentiation into the epithelial cell types resident in the intestine. These diverse cells self-assemble into microtissues with in […]

In Vitro Permeation of Latanoprost Eye Drop Formulations in a 3-Dimensional Normal Human Corneal Tissue Model

Permeation of topically applied ocular drugs occurs predominantly through the cornea and therefore absorption studies using corneal tissues play a critical role in ocular drug formulation. The purpose of the study was to evaluate the permeation of Latanoprost eye drops through in vitro reconstructed normal human corneal tissue model. Seven different formulations of Latanoprost eye […]

An in vitro Reconstructed Normal Human Corneal Tissue Model for Corneal Drug Delivery Studies of Ophthalmic Formulations

Purpose: Permeation of topically applied ocular drugs occurs predominantly through the cornea and therefore absorption studies using corneal tissues play a critical role in ocular drug formulation. Currently, most ocular absorption studies use in vivo or ex vivo animal tissues that have many disadvantages including poor standardization, species extrapolation, high cost, and ethical concerns. Methods: […]

Chip-based human liver–intestine and liver–skin co-cultures – A first step toward systemic repeated dose substance testing in vitro

Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called human-on-a-chip concepts are […]

SUPPRESSED PERMEATION OF LINOLEIC ACID IN A LIPOSOMAL FORMULATION THROUGH RECONSTRUCTED SKIN TISSUE.

This study by researchers at Okayama University Graduate School of Natural Science and Technology, SUNSTAR, Inc., and the University of Shizuoka School of Pharmaceutical Sciences demonstrated that Mattek’s MelanoDerm in vitro human skin tissue equivalent is an excellent in vitro model for testing the effectiveness of novel skin whitening agents in both damaged and undamaged […]

EVALUATION OF RECONSTRUCTED HUMAN EPIDERMIS KITS FOR THE IN VITRO ASSESSMENT OF COSMETIC SAFETY.

Reconstructed human epidermis is one of the most promising tools for in vitro evaluation of cosmetics. In recent years, their availability as kits offered to users practical models for the assessment of safety and efficacy of ingredients and finished products. However, the evaluation of their reproducibility, reliability and the relevance of the data obtained with […]

THE USE OF STANDARDIZED HUMAN SKIN MODELS FOR CUTANEOUS PHARMACOTOXICOLOGY STUDIES.

Reconstructed skin and epidermis models are finding increasingly numerous applications in cosmetology and dermatology. In particular, they are currently employed to assess the tolerability and efficacy of raw materials and formulations, in conditions approaching those of normal use. Importantly, the use of such models greatly reduces the need for animal testing. Various models of reconstructed […]

RECONSTRUCTED HUMAN EPIDERMIS EQUIVALENTS.

Special Section. (See Mattek TR’s 276 thru 283.)

DESIGN PRINCIPLES OF CHEMICAL PENETRATION ENHANCERS FOR TRANSDERMAL DRUG DELIVERY.

This study by researchers at the University of California at Santa Barbara demonstrated how Mattek’s EpiDerm human skin tissue equivalent can be used to measure the irritation potential of chemical penetration enhancers (CPEs) present in a large number of transdermal, dermatological, and cosmetic products. Chemical penetration enhancers (CPEs) are present in a large number of […]

INTRA- AND INTERLABORATORY REPRODUCIBILITY (ET-50) OF EPIDERM, AN IN VITRO MODEL FOR DERMAL IRRITANCY TESTING.

An in vitro model of the human epidermis, EpiDerm™, cultured from normal human epidermal keratinocytes (NHEK), was introduced by Mattek Corporation in April 1993. Using highly controlled tissue culture techniques, weekly batches of EpiDerm are produced for dermal irritancy testing, percutaneous absorption studies, and basic skin research. Histology, sterility, and the toxicological behavior are rigorously […]

LIPID AND ULTRASTRUCTURAL CHARACTERIZATION OF A NEW EPIDERMAL MODEL SHOWS GOOD CORRESPONDENCE TO NORMAL HUMAN EPIDERMIS.

A model of the human epidermis, EpiDerm, based on neonatal foreskin-derived normal human epidermal keratinocytes (NHEK), has recently been characterized by scientists at the University of Iowa College of Dentistry in terms of stratum corneum (SC) lipids and ultrastructure. Cultured using serum free media, the model allows determination of the effects of defined media additives […]

LIPID CHARACTERIZATION OF A NEW EPIDERMAL MODEL FOR SKIN IRRITANCY AND PENETRATION STUDIES.

A model of human epidermis, EpiDerm™, based on neonatal, foreskin-derived normal human epidermal keratinocytes (NHEK) has recently been characterized by scientists at the University of Iowa College of Dentistry in terms of stratum corneum lipids, ultrastructure, and barrier properties. Cultured using serum free media, the EpiDerm model allows determination of the effects of defined media […]

EVALUATION OF THE USEFULNESS OF 3-D MODELS OF RECONSTITUTED HUMAN SKIN AND EPIDERMIS IN APPLICATIONS OF REGULATORY SKIN TOXICOLOGY: PREVALIDATION, VALIDATION, CATCH-UP VALIDATION, AND REGULATORY ACCEPTANCE.

In 1991 we evaluated a model of full human skin (Skin2, ATS, La Jolla) for phototoxicity testing. The test developed showed promising results as an adjunct to a test performed with Balb/c 3T3 cells. While it detected acute phototoxins correctly, it classified those chemicals negative, that are known photoallergic in humans, but are not phototoxic […]

LONG TERM REPRODUCIBILITY OF EPIDERM, AN EPIDERMAL MODEL FOR DERMAL TESTING AND RESEARCH.

This technical reference summarizes Mattek’s 10-plus YEAR EpiDerm tissue reproducibility data. Long-term reproducibility is important not only to Mattek Customers, but also to European (ECVAM) and US (ICCVAM) regulators. Regulators constantly stress the need for superior reproducibility of in vitro tissue equivalents, not only during a specific validation program, but also long after the initial […]

THE Mattek STORY – HOW THE THREE Rs PRINCIPLES LED TO 3-D TISSUE SUCCESS!

FRAME, the UK-based Fund for the Replacement of Animals in Medical Experiments, asked Mattek to contribute an article to a special edition of ATLA, FRAME’s scientific journal, commemorating FRAME’s 40th anniversary. FRAME asked Mattek to focus the article on the successful development of our in vitro 3-D tissues, produced from normal (non-transformed) human cells, as […]

EFFECT OF LAUNDERING ON ABILITY OF GLOVE FABRICS TO DECREASE THE PENETRATION OF ORGANOPHOSPHATE INSECTICIDES THROUGH IN VITRO EPIDERMAL SYSTEMS.

Researchers at Virginia Tech University examined two knit glove fabrics, one of 100% cotton and one of 100% polypropylene, for their capability to decrease the penetration of the organo-phosphate insecticides (OPs), azinphos-methyl and paraoxon after 4 h at field concentrations (3000 and 15 ppm, respectively) through an in vitro epidermal system (Skin2, Advanced Tissue Systems, […]

DERMAL PENETRATION OF PESTICIDES AND POLYCHLORINATED BIPHENYLS FROM HOUSE DUST.

This study demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalents were the most in vivo-like for performing percutaneous penetration experiments in vitro. Indoor contamination has been rated as a high environmental risk, as people living in industrialized countries spend about 80-90% of their individual live time indoors. Several epidemiological studies showed a link […]

NALTREXONE ESTER PRODRUG BIOCONVERSION IN A HUMAN EPIDERMIS EQUIVALENT.

IMPROVEMENTS IN EPIDERM, A HIGHLY DIFFERENTIATED SKIN MODEL, FOR DRUG DELIVERY STUDIES.

The ability to produce skin in vitro with barrier properties equivalent to those of native epidermis remains a much sought after goal. This study by scientists in the Department of Pharmacology and Physiology, UMDNJ-NJMS and Mattek Corp. involves the use of a highly differentiated skin model, EpiDerm™, which has been shown to be useful in […]

PARTICLE SIZE AND BILAYER RIGIDITY EFFECTS ON SKIN DIFFUSION OF NANOSOMES.

BIOCONVERSION OF NALTREXONE AND ITS 3-O-ALKYL-ESTER PRODRUGS IN A HUMAN SKIN EQUIVALENT.

This study by scientists at the University of Kentucky College of Pharmacy and Mattek Corp. demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent can be used as an alternative experimental system to human skin for the prediction of topical/transdermal drug/prodrug bioconversion. The purpose of this study was to compare the percutaneous absorption and […]

IN VITRO SCREENING TECHNIQUES IN DERMATOLOGY.

To avoid skin irritation and allergies from cosmetic products, the raw materials should be screened during product development. In vivo screening techniques are best. The author describes two in vitro models (cell culture and living skin equivalent) and several in vitro tests (percutaneous absorption, toxicity, melanogenesis, wound healing, antiaging, and cell proliferation and differentiation).

IN VITRO PERCUTANEOUS ABSORPTION USING THE Mattek EPI-606X SKIN CONSTRUCT AND HUMAN SKIN.

The rates of absorption of chemicals in human skin can be modeled in the in vitro percutaneous absorption assay. Moreover, the impact of various vehicles on the permeation rates of chemicals can also be evaluated. The reference material, benzoic acid (BA), was prepared in two vehicles (acetone and petrolatum) and was tested in duplicate trials […]

ASSESSMENT OF HUMAN CADAVER AND RECONSTRUCTED SKIN MODELS TO PREDICT PHARMACOKINETICS OF TESTOSTERONE TRANSDERMAL DRUG DELIVERY PATCHES.0

Testosterone TDD patches were compared for in-vitro skin permeation characteristics and in the clinic for in-vivo pharmacokinetic parameters. In-vitro evaluations were conducted using both human cadaver and reconstructed skin models in order to determine a model predictive of in-vivo delivery. HCS was chosen at the model most predictive of testosterone in-vivo delivery. The preliminary IVIVC […]

INTERRELATION OF PERMEATION AND PENETRATION PARAMETERS OBTAINED FROM IN VITRO EXPERIMENTS WITH HUMAN SKIN AND SKIN EQUIVALENTS.

In a comparative study, two different in vitro cutaneous test systems were examined: (1) The Franz diffusion cell (FD-C), a test system to study drug permeation through the skin and to obtain data like steady state flux and lag time as well as permeability and diffusion coefficients. (2) The Saarbruecken penetration model (SB-M), a test […]

COMPARISON OF CUTANEOUS BIOAVAILABILIY OF COSMETIC PREPARATIONS CONTAINING CAFFEINE OR α-TOCOPHEROL APPLIED ON HUMAN SKIN MODELS OR HUMAN SKIN EX VIVO AT FINITE DOSES.

The use of human skin models for performing cutaneous bioavailability studies has been little investigated. For instance, only few studies have been reported on human skin models dealing with vehicle effects on percutaneous penetration. The present study aimed at evaluating the influence on caffeine’s and α-tocopherol’s cutaneous bioavailability of cosmetic vehicles such as a water-in-oil […]

TESTING AND IMPROVEMENT OF RECONSTRUCTED SKIN KITS IN ORDER TO ELABORATE EUROPEAN STANDARDS: FIRST RESULTS.

Cosmetics, safety testing, Cutaneous irritancy, Cutaneous irritation, Cutaneous metabolism, Cutaneous toxicity, Cytoplasmic enzymes, Dermal absorption, Dermal irritancy, Dermal irritancy testing, Dermal irritation, Dermal penetration, Dermal permeation, ECVAM, EpiDerm, EpiSkin, European standards, Glutamate-oxaloacetate transferase, Glutathione-S-transferase, IL-1a, Interleukin (IL), Lactate dehydrogenase, Lauric acid, MTT, MTT ET-50 tissue viability assay, MTT assay, Mannitol, Metabolism, NADPH quinone reductase, Penetration, […]

EFFECT OF SIZE AT THE NANOSCALE AND BILAYER RIGIDITY ON SKIN DIFFUSION OF LIPOSOMES.

This study by researchers at Drexel University’s School of Biomedical Engineering and the Dept. of Dermatology and Cutaneous Biology at Jefferson Medical College (Thomas Jefferson Univ.) demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent can be used to determine the permeation characteristics of liposomes by their particle size at the nanoscale level. This […]

PERCUTANEOUS PERMEATION OF ZINC FROM NON-WOVEN FABRICS IMPREGNATED WITH ZINC SULFATE MONOHYDRATE FORMULATIONS USING EPIDERM™.

Zinc sulfate monohydrate is a widely used agent in the pharmaceutical industry. It can be applied on the skin in the form of a solution, ointment, or lotion, and recently in the form of non-woven fabrics impregnated with zinc sulfate monohydrate formulations. Topical zinc preparations have been found to accelerate wound healing and relieve chronic […]

LIPID AND ULTRA-STRUCTURAL CHARACTERIZATION OF RECONSTRUCTED SKIN MODEL.

The study aimed at evaluating tissue architecture and quality of the permeability barrier in commercially available reconstructed human skin models; EpiDerm™, SkinEthic™ and Episkin™ in comparison to native tissue. For this purpose, tissue architecture was examined by electron microscopy and epidermal lipid composition was analyzed by HPTLC. Stratum corneum lipid organization was investigated by electron […]

RECONSTRUCTED EPIDERMAL MODELS AS A POSSIBLE ALTERNATIVE TO THE USE OF EXCISED HUMAN SKIN FOR ASSESSING IN VITRO PERCUTANEOUS ABSORPTION.

Until now there is no general guideline to study the penetration of foreign substances into the skin and there are several in vitro models to study topical dermatological dosage forms. Excised human skin has proven to be one of the most suitable models, but because of its limited availability and the high donor rariability it […]

VISUALIZATION OF IONTOPHORETIC TRANSPORT PATHS IN CULTURED AND ANIMAL SKIN MODELS.

Physiological structures associated with iontophoretic paths in hairless mouse skin and two cultured skin models (“EpiDerm” by Mattek, Corp., and “SKIN” by Advanced Tissue Sciences, Inc.) are reported. Visualization of ionic paths at current densities between 20 and 100 uA/cm2 is accomplished by the counterdirectional transport of Fe(CN)64- and Fe3+, resulting in the controlled precipitation […]

THE USE OF RECONSTRUCTED HUMAN EPIDERMIS FOR SKIN ABSORPTION TESTING: RESULTS OF THE VALIDATION STUDY.

This formal validation study by scientists at the Freie Universität Berlin, Across Barriers GmbH, Beiersdorf AG, BASF Aktiengesellschaft, Technische Universität Carolo-Wilhelmina zu Braunschweig, Stiftung Tierärztliche Hochschule Hannover, Ludwig-Maximilians-Universität München, Cognis Deutschland GmbH & Co. KG, Universität des Saarlandes and ZEBET demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent is an appropriate alternative to […]

LOCALIZATION OF β-GLUCOCEREBROSIDASE ACTIVITY IN MAMMALIAN EPIDERMIS BY IN SITU ZYMOGRAPHY.

A critical, late step in epidermal barrier formation is the transformation of secreted lamellar body contents into mature extracellular lamellar unit structures. Although previous studies have demonstrated a crucial role for the enzyme β-glucocerebrosidase (GlcCer’ase) in the final steps of membrane structural maturation, the precise in vivo localization of GCase activity and protein is not […]

ASSESSMENT OF SKIN ABSORPTION AND METABOLISM OF ARACHIDONIC ACID & GLYCERYL ARACHIDONATE USING IN VITRO DIFFUSION CELL TECHNIQUES.

Arachidonic acid (AA), has been used in cosmetics as a surfactant-cleansing and emulsifying agent. Glyceryl arachidonate (GA), a skin conditioning agent and emollient, may be partially metabolized by ester hydrolysis in skin to AA. Based on the Cosmetic Ingredient Review (CIR) Panel’s concern that there was a lack of dermal absorption data for AA, in […]

COMPARISON OF AN IN VITRO HUMAN SKIN EQUIVALENT MODEL TO NORMAL HUMAN SKIN FOR DERMATOLOGICAL RESEARCH.

EpiDerm, an in vitro human skin equivalent (HSE), was compared to normal human breast skin (NHS) to morphologically and biochemically assess its feasibility for dermatological research. Intralot and interlot variability was studied in day 0, 1, 2, and 3 in vitro cultures and in day 0, 3, 5, and 7 NHS. For NHS, light microscopy […]

RECONSTRUCTED HUMAN EPIDERMIS FOR SKIN ABSORPTION TESTING: RESULTS OF THE GERMAN PREVALIDATION STUDY.

This study by scientists at the Freie Universität Berlin, Across Barriers GmbH, BASF Aktiengesellschaft Experimental Toxicology and Ecology, the Institut für Pharmakologie, Ludwig-Maximilians-Universität München, Cognis Deutschland GmbH & Co. KG, Universität des Saarlandes, ZEBET (Berlin, Germany), and Henkel KGaA demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent can be used to predict the […]

INTRA- AND INTER-LOT VARIABILITY OF EPIDERM™, AN EPIDERMAL MODEL FOR DERMAL RESEARCH AND TESTING.

A model of the human epidermis, EpiDerm, cultured from neonatal, nor-mal human epidermal keratinocytes has been sold commercially by Mattek Cor-poration since April 1993. Using serum free media, weekly batches of EpiDerm are produced and shipped for dermal irritancy, product efficacy, percutaneous absorption, and basic skin research studies. For all applications, it is important to […]

RECONSTRUCTED SKIN EQUIVALENTS FOR ASSESSING PERCUTANEOUS DRUG ABSORPTION FROM PHARMACEUTICAL FORMULATIONS.

Excised human skin has so far been considered to be one of the most suitable in vitro methods to evaluate the penetration of dermatologically applied substances. The limited supply and the relatively high donor variability stimulated many research groups to use animal skin as a substitute for human skin. Since nowadays reconstructed skin equivalents are […]

RECONSTRUCTED EPIDERMIS AND FULL-THICKNESS SKIN FOR ABSORPTION TESTING: INFLUENCE OF THE VEHICLES USED ON STEROID PERMEATION.

This study by researchers at the Free University of Berlin demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent and EpiDermFT full-thickness in vitro human skin tissue equivalent can be used in the development of topical dermatics and for hazard analysis of toxic compounds and their formulations. A protocol for percutaneous absorption studies has […]

EVALUATION OF HUMAN BIO-ENGINEEREED SKIN EQUIVALENT FOR DRUG PERMEATION STUDIES.

PURPOSE: To test the barrier function of a bio-engineered human skin (BHS) using three model drugs (caffeine, hydrocortisone, and tamoxifen) in vitro. To investigate the lipid composition and microscopic structure of the BHS. METHODS: The human skin substitute was composed of both epidermal and dermal layers, the latter having a bovine collagen matrix. The permeability […]

NEW DRUG DELIVERY SYSTEMS: VALIDATION OF IN VITRO MODELS.

IN VITRO PERMEATION AND IRRITATION OF BENZOYL PEROXIDE – CONTAINING PRODUCTS.

Two in vitro models to measure release of benzoyl peroxide (BPO) from formulations were presented. Franz-type diffusion cells and acetonitrile/water receptor mediums were used in both models. The barrier in one model was silicone sheeting and in the other was cultured human epidermis. The similarity in release profiles, rates of permeation, and diffusion coefficients obtained […]

COMPARISON OF IN VITRO MODELS OF PERCUTANEOUS ABSORPTION.

As part of a Colgate-Palmolive sponsored program to validate an in vitro percutaneous absorption model, three reference materials with extensive in vivo human and in vitro (animal and human) data were evaluated in three in vitro models. The objective of this study was to determine if the results are consistent with data published in the […]

IMPROVEMENT OF THE EXPERIMENTAL SETUP TO ASSESS CUTANEOUS BIOAVAILABILITY ON HUMAN SKIN MODELS: DYNAMIC PROTOCOL.

Human skin models, such as EpiDerm® and Episkin® are not easily mounted into static or dynamic diffusion cells that are commonly used to perform bioavailability studies with human skin ex vivo. For various reasons, such as fragility, small sample size, and other morphological constraints, skin absorption studies with human skin models are often carried out […]

PERMEATION AND SKIN ABSORPTION: REPRODUCIBILITY OF VARIOUS INDUSTRIAL RECONSTRUCTED HUMAN SKIN MODELS.

Human reconstructed skin models could be very useful tools to quantify percutaneous permeation and absorption. Before using such models, the reproducibility in the same batch and/or various batches, i.e. the relevance of the results obtained, must be verified. The reproducibility of 3 industrial models – EpiDerm™, Episkin® and SkinEthic® – was tested regarding the permeation […]

THE INFLUENCE OF COSMETIC PRODUCTS ON THE STRATUM CORNEUM BY INFRARED AND RAMAN SPECTROSCOPY.

The stratum corneum is the outermost layer of the skin and as such represents the decisive barrier between the body and the environment. The combination of horny cells and lamellar lipid layers prevents water loss from the body and protects it against penetration by exogenous substances. For selective investigation of the thin outermost stratum corneum […]

APPLICATION OF A HUMAN SKIN TISSUE CULTURE MODEL IN DERMAL ABSORPTION STUDIES OF 3,3’,4,4-TETRACHLOROBIPHENYL (TCB).

TCB, one of the dioxin-like PCBs, demands much research and regulatory attention. To evaluate an in vitro generated human skin tissue culture model, cutaneous disposition of TCB under different exposure scenarios was investigated. Occlusive or non-occlusive doses of 14C-TCB were applied at 4 or 40 µg/cm2 in different vehicles including acetone, methylene chloride, a water-acetone […]