Recent in Testing (page 6 of 32)

Zeta Potential and Particle Size to Predict Emulsion Stability

Emulsions are popular vehicles in skin care due to their affinity for the skin; however, they are thermodynamically unstable systems. This study investigates zeta potential and particle size distribution as potential screening tools to predict instabilities in emulsion-based cosmetic products, to supplement regular accelerated stability testing.

Hair as a Test Substrate

Hair is a distinctly variable material, and the nature of this substrate can have a major impact on laboratory test results. This article discusses hair as a laboratory substrate to provide guidance on minimizing variability and creating optimal test conditions.

L'Oréal Obtains Business License to Market Chinese Episkin

L'Oréal was granted a Chinese business license for Shanghai Episkin Biotechnology Ltd., the company it created to market the Asian version of its reconstructed skin model Episkin.

Non-Invasive Measurement of Epidermal Proteins for Psoriasis and Skin Care*

Abnormal epidermal turnover in psoriatic skin impairs its barrier function and tissue repair capabilities. Therefore, studies of hyperkeratinization and hyperproliferation have been conducted to better understand the disease. Here, the administration of heavy water and a tape-stripping method are used to measure skin protein turnover in psoriatic skin and surrounding tissues. Results demonstrate benefits over other proliferation measurements.

Improving the UV Exposure of Sunscreen During In vitro Testing

In any sun protection evaluation method, an irradiation step is required to determine the photostability of the UV filters in a product. The aim of this study was to identify key parameters involved to improve this UV exposure. Here, the authors consider temperature at the substrate surface, air flow influence and beam uniformity during UV exposition.

Quantifying the Performance of Hair Styling Products—Part 2

A previous article discussed traditional measurements to assess the properties of hair spray products. However, the properties of polymer films deposited by these products are not constant and can be altered by both formulation means and environmental conditions. This article highlights additional useful measurement techniques for characterizing these film properties.

Testing and Developing a Sugar-derived Surfactant Blend for Delicate Skin

Vegetable-derived, mild and sustainable skin cleansing ingredients are in demand, and this has led to the development of new detergent structures. Described here is a combination of two mild surfactants that fulfils these requirements using the concept of “interrupted soap” to impart mildness. Studies to verify the functional, sensorial and mild characteristics of the new blend are detailed.

Quantifying the Performance of Hair Styling Products—Part 1

There are two general classifications of hair styling products—those that help with style creation and those that prolong the style. Both facilitating style creation and promoting hold longevity stem from the presence of water-soluble polymers in formulations. This paper discusses methods to evaluate these properties and quantify performance.

From the Archives … Flexabrasion: A Method for Evaluating Hair Strength

From the December 2001 issue of Cosmetics & Toiletries, this article describes how both bending and abrasion should be tested–along with extension–when evaluating hair strength, as the authors show here in tests of an active developed to increase the strength of bleached hair.

Octocrylene Concerns Flag Industry's Attention

The industry reacts to a new study published in Contact Dermatitis reviews reports of the UV absorber octocrylene for its potential to cause photo contact allergy.

Correlating Aging with Skin’s Mechanical and Optical Properties

The aim of this study was to monitor the evolution of biomechanical and optical properties of the skin with aging. Different biophysical parameters were measured, including skin: elasticity and firmness, color, brightness, fluorescence emission, sebum content, hydration and pH. A significant evolution of the evaluated parameters with aging was observed.

Proposed Method to Evaluate the Microbiological Stability of Cosmetics During Use

The authors propose an approach to assess the microbial stability of a product during use, referred to as the Microbiological Use Test (MUT), and apply this analysis in case studies to predict the microbiological risk of commercial products. The described test has been used successfully in the development of cosmetics.

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