In vivo

Researchers Dig Deeper Into Relationship Between Bacteria and Atopic Dermatitis

Mar 4, 2014

Researchers from the Drexel University College of Medicine have established a clearer relationship between Staphylococci bacteria and the conditions atopic dermatitis (AD) and eczema.

The Effect of Glycerol on the Water-holding Capacity of Chemically Irritated Skin*

Jan 13, 2014Howard I. Maibach, MD, University of California School of Medicine; and Nicolas Atrux-Tallau, PhD, ESPCI ParisTech

Glycerol is one humectant commonly employed due to its high hygroscopic and hyperosmotic properties. It is used in cosmetics as a moisturizer and in pharmaceutical formulations as an active compound. Being naturally present in the skin, glycerol was quickly identified for its role in skin hydration, similar to natural moisturizing factors (NMF).

Comparison of Age Determination by Three Evaluation Methods: Self-assessment, Expert Grader and Naïve Grader

Jun 1, 2013Rosanna Mootoo, Nima Gohil, Cristina Stroever and Christian Oresajo, L’Oréal USA Research & Innovation

This exploratory study investigates how consumers perceive age, using objective and subjective approaches. Results of this study suggest that when a subjective approach is implemented for age determination, subjects affix their emotions to the evaluation. The reverse logic was applicable for the expert and naïve grader methods, as grader results appeared more neutral than the self-assessment.

A High Throughput Method to Predict Skin Penetration and Screen Topical Formulations

Mar 1, 2013Konstantin Tsinman, PhD, Pion Inc.; B:aacute;lint Sinkó, PhD, SinkoLAB Scientific Bt

This work studies the applicability of a 96-well-based skin-mimetic artificial membrane permeability model to differentiate between topical pharmaceutical and cosmetic formulations. Results are compared with data obtained from in vitro Franz cell permeability measurements and reveal the applicability of this method to assess cosmetic formulation permeation and speed the discovery process.

Scalp Irritation From Hair Care Chemicals

Jan 1, 2013Hongbo Zhai, MD; Howard I. Maibach, MD; and Heidi P. Chan, MD; University of California San Franciso, Department of Dermatology

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.

Determining Korean Consumers’ Degree of Exposure to Lipstick and Face Creams

Nov 1, 2012

This study describes methods used in a Korean study to calculate consumer exposure to lipstick and face creams. The average amount applied daily was estimated and compared with data collected by weighing containers before and after use. The data collected was 1.8 to 1.6 times greater than the estimate, so although the survey represented real use patterns, the actual data was more accurate.

Designing Mild Personal Care Products: A Case Study

Oct 1, 2012Paul Cornwell, PhD, and Jeremy Goodwin, PhD, Z Cussons (UK) Ltd.

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.

Fluid Skin Imaging for Better Resolution

Apr 1, 2011Katie Schaefer, Cosmetics & Toiletries magazine

Noninvasive subcutaneous skin imaging is a tool sought for use by the medical, pharmaceutical and personal care industries, but techniques have been lacking due to resolution and speed constraints.

Evaluating 1,3-Propanediol for Potential Skin Effects

May 1, 2010Leigh A. Belcher, Carl F. Muska, PhD, and Joseph W. DeSalvo, DuPont

In the present article, the authors assess the skin irritation and sensitization potential of 1,3-propanediol (INCI: Propanediol). Results in animals and humans by acute or repeat exposure support a low potential of skin reactivity for the material. In addition, the skin reactivity potential in humans was found to be lower with 1,3-propanediol than 1,2-propanediol (INCI: Propylene Glycol).

Predicting the Percutaneous Penetration of Cosmetic Ingredients*

Apr 1, 2010Sara Farahmand, PhD, University of Cincinnati College of Pharmacy; and Howard I. Maibach, MD, PhD, University of California School of Medicine

While previous algorithms for predicting the skin absorption of permeants was based on in vitro data, the present article proposes a quantitative structure-activity relationship (QSAR) model based on in vivo human data. Here, a set of human in vivo data is described that provides entry into predicting the penetration of cosmetic ingredients.

Mechanisms of Tape Stripping and Protein Quantification*

Mar 1, 2010Ali Alikhan, MD, and Howard I. Maibach, MD

In this article, several methods to quantify the protein collected by tape stripping are described, including traditional gravimetric methods as well as novel colorimetric and visible spectroscopic techniques. Further, one colorimetric method is described to effectively determine the keratolytic efficacy of various materials in vivo, suggesting additional roles for this method.

Tape Stripping Method in Humans: Comparison of Evaporimetric Methods

Feb 1, 2009Hongbo Zhai, MD, and Howard I. Maibach, MD, University of California School of Medicine

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.

The Air Up There: Skin VOCs

Nov 1, 2008Katie Schaefer, C&T magazine

In 2001, Japanese researchers reported that after the age of 40, some individuals develop a malodor known as “aging odor,” attributed to the presence of unsaturated C9, 2-nonenal. George Preti, PhD, a member of Monell Chemical Senses Center and an adjunct professor of dermatology at the University of Pennsylvania School of Medicine, was interested by this report and began to conduct research of his own.