Recent in Testing (page 9 of 25)

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.

Designing Mild Personal Care Products: A Case Study

This article reviews the mechanisms underlying skin irritation and sensitization, and methods used in a case study to test cosmetic products for their potential to cause irritation. It also covers the main skin conditions that can influence susceptibility to irritation, as well as ingredients affecting the mildness of cosmetic products.

Tape Stripping Method in Humans: Comparison of Evaporimetric Methods

The current preliminary study compared the sensitivity and correlation of open chamber device and closed chamber device on a tape stripping human model. The amount of SC removed by tape stripping was also quantified with a protein assay method.

Scalp Irritation From Hair Care Chemicals

While scalp irritation also can be caused by contact with physical or biological agents, this column will discuss the irritation resulting from hair chemicals. The desire for a specific hairstyle or color can render the scalp exposed to different hair chemicals that may result to scalp irritation.

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