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Researchers Initiate Automation of Skin Model Production

Instead of just a single layer skin model of a single cell type, the researchers have access to a patent-protected skin model that consists of two layers with different cell types. The researchers liken this model to a perfect copy of human skin and are in the process of developing the first fully-automated process chain for manufacturing two-layer skin models.

DNA: Hard Evidence of Cosmeceutical Claims

To support finished product or raw material claims these two in vitro methods—the Affymetrix microarray and the Taqman Real Time Polymerase Chain Reaction (PCR)—measure the up-regulation or down-regulation of genes.

In vivo Quantification of Corneocyte Lipids by Image Analysis

In a new method described here by the authors, fluorescence emitted from samples and captured by image analysis is used to quantify the number of lipids present in the cornified cell envelope. This in vivo approach is fast and noninvasive and could be used to screen molecules for potential moisturizing and restructuring effects.

In Vitro Model for Decontamination of Human Skin

The present study utilized an in vitro model to compare the decontamination capacity of three model decontaminant solutions: tap water, isotonic saline and hypertonic saline. Human cadaver skin samples were dosed with radio-labeled [14C]-formaldehyde and the surface skin of each sample was washed after each exposure with one of the three model decontaminant solutions.

Evaluating ACD Frequency After Reducing Exposure to Sensitizers

The economic burden of contact dermatitis is extensive due to work hours lost and physician visits. In the workplace, for example, contact dermatitis (irritant and allergic) accounts for 40% of all occupational illnesses (excluding injury) and 25% of time lost from work. Common sensitizers leading to allergic contact dermatitis (ACD) include metals, plants, cosmetics, rubber compounds and medicines.

Dermal Absorption Guidelines for Cosmetic Ingredients: An In Vitro Method

Ex vivo skin absorption studies measure the penetration and permeation of a compound to assess its safety, and can assist the formulator in increasing product efficacy and reducing toxicity. This review analyzes the currently available guidelines published by four major regulatory organizations to clarify important milestones in study design, data analysis and interpretation.

Measuring Antioxidant Capacity of Cosmetics with Emitted Light

Knight Scientific Ltd. offers a kit to manufacturers to measure the antioxidant capacity of their finished nutraceuticals and cosmetics to justify claims, produce technical documents, confirm batch uniformity and more.

Much Ado About Nothing: Cosmetics Testing with a Placebo

In this column, the author investigates the source of the placebo effect. In addition, he asks the question: Must cosmetics testing always incorporate tests against a placebo?

Using Skin Models to Assess the Effects of a Skin Care Emulsion on Skin Barrier Function

This study utilizes a 3D skin model to investigate barrier repair after damage with SDS and application of a skin care emulsion; it also demonstrates the suitability of using 3D skin models to study barrier repair.

Evaluating Antipruritics

Pruritus or itching is an unpleasant sensation that provokes a desire to scratch. Many factors such as chemical, mechanical, thermal and electrical stimuli can elicit the itch sensation. Mediators of itch presumably directly act on nerve fibers or lead to a nerve stimulation cascade whose final common pathway is interpreted in the central nervous system as itching. Putative receptors for itching are C-fibers with exceptionally low conduction velocities and insensitivity to mechanical stimuli. Histamine, the proto-typical chemical mediator of itch, which is released during mast cell degranulation and mediates its effects in the skin via H1 receptor, is the best-known experimental pruritogen.

In Vivo Quantitative Evaluation of Gloss

A real time polarization analysis technique is described that differentiates components of scattered light in video images and enables in vivo quantitative evaluation of gloss from hair and skin during quality control and claims substantiation.

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Evaluating Shampoo Foam

There is probably no personal care category that is more competitive than shampoos. With this in mind, formulators of shampoos are asked by marketing to develop products to both appeal to consumers and perform (whatever “perform” means).

Liquid Crystals in O/W Emulsions with Urea: Development and Testing

Using a ternary phase diagram, the authors developed systems based on nonionic surfactants, light paraffin oil, water, and (optionally) urea. Systems in which lamellar liquid crystals formed and in which urea was an ingredient showed higher occlusive power and lower TEWL in in vitro tests.

Testing for Penetration of the Skin Barrier

The skin barrier is described, after which tests and case studies illustrate how to show if actives and other ingredients have or have not penetrated the skin barrier.

Advanced Methods Measure Skin Penetrants at the Parts-Per-Billion Level

Healthy and intact skin was formerly considered an impermeable barrier designed to shield the living organism from all types of environmental injury, and certainly offering protection from all things chemical. Now skin is recognized as a semi-permeable membrane. Microorganisms cannot penetrate it, but it is pervious to chemicals, selectively allowing molecular passage in and out of the skin.

Advanced Methods Measure Skin Penetrants at the Parts-Per-Billion Level: Part II

Part I of this Dermatologic View column appeared in the January issue of C&T magazine and described advanced methods to measure skin penetration such as Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Atomic Absorption Spectrophotometry (AAS). Here, the authors continue this investigation of advanced methods to measure skin penetration.

Torsional Behavior of Human Hair by Single Fiber Torsion Pendulum Method

Torsional properties are described by the author as a method to distinguish between the surface and the bulk effects of actives in hair formulations.

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Ceramides in Skin Stress: Ultraviolet, Tape Stripping, and Crowding

Stress induces changes in the ceramide content of the skin, and may lead to compromised barrier function or skin diseases. Skin has ways of responding to these stresses, as we review here in the case of skin stressed by tape stripping, organic solvents, overcrowding, and ultraviolet (UV) irradiation.