Nov 19, 2014
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.
Feb 24, 2014
As an alternative to semi-invasive facial rejuvenation techniques, the authors developed an active ingredient to reactivate senescent fibroblasts by stimulating metabolic pathways for collagens I and III, and elastin. The biological activity of the resulting ingredient is investigated here using in vitro models, ex vivo explants and human volunteers.
Feb 21, 2014
Consumers have demonstrated a clear desire for hair that isn’t “dried out” while also demonstrating a clear distaste for the effects of high humidity on hair. To find the balance in creating products, it is necessary to have an accurate means of measuring hair’s water content. This article describes equipment used to perform this task while highlighting experimental variables that can produce suspect results and lead to incorrect conclusions.
Jan 13, 2014
The most common approach to determine ingredient deposition on hair is to analyze the treated tresses, but this poses several challenges. Instead, the authors describe a novel approach based on determining the amount of ingredient collected in the rinse water, and back-calculating the amount deposited on hair. Development and validation efforts discussed here use polydimethylsiloxane as a model compound.
Jun 1, 2013
This article reviews and assesses damage types caused to hair before and after artificial coloration, i.e., by bleaching, perming, heat treatment, UV exposure and shampooing, to compare how they impact color durability individually and combined. Formulation emerges as the key to designing shampoos that efficiently deliver actives to improve color protection against these and other damage types.
May 1, 2013
Here, the author compares two methods to determine the maturity of corneocytes based on their cross-linking that could be used to evaluate the anti-aging effects of molecular agents. The first utilizes microfluorometry, while the second involves F-D curves generated via contact mode AFM. Both methods successfully detected differences in mature or immature corneocytes with 95% confidence.
Nov 1, 2012
Particulate contamination and discoloration may occur in products due to foreign materials introduced via raw materials or during the manufacturing process. Agglomeration or reactions between ingredients and packaging components also are possible sources. The identification of contaminants and their origin, described here, is therefore critical so that future incidents can be prevented and safety or regulatory concerns can be addressed.
Sep 1, 2012
Endocrine disruptor chemicals (EDCs) are a class of chemicals that has raised alarm for being linked to a wide variety of detrimental effects on human and wildlife populations, e.g., cancers, precocious puberty and obesity. Thus, there is a need to test personal care products and supplements for EDCs, which can be accomplished using the validated bioassay described here.
Jul 1, 2012
Botanical ingredients are interesting for their unique and complementary chemical diversities yet they are criticized for these very traits, which make quality assurance, reproducibility and good phytochemical characterization—required for successful high throughput screening, difficult. This article discusses these challenges as well as the benefits of large-scale screenings of botanical extracts that are currently used or developed for cosmetic product development.
Mar 1, 2012
The present article describes a reproducible method for determining the photostability of sunscreen products. This method is based in part on the in vitro determination of the UVA protection factor as proposed by Colipa for the irradiation aspect, and on the spectroscopy of a sunscreen in dilute solution for the absorbance measurement aspect.
Jan 1, 2012
To evaluate the comprehensive effects of shine and color intensity in hair, a hair color vibrance factor has been developed to enable new claims for hair dye formulas and after-dye treatments. Experimental results described here show how varying the ingredients in shine spray and hair dye formulas affect this factor and correlate with subjective panelist assessments.
Nov 1, 2011
Today, product formulation goes hand in hand with efficacy testing, but nearly 40 years ago, when Sergio Nacht, PhD, started out in the personal care industry, it was a different story. Throughout his decades in personal care, Nacht has developed methodologies that have allowed the personal care industry to establish efficacy of a product and convey this to the consumer. He has also been instrumental in the increased efficacy of personal care products through sustained release.
Feb 1, 2011
Genomics assists product developers in understanding the expression of specific genes and their relationship to particular skin attributes. This article reviews commonly used testing techniques, such as DNA microarray, RT-PCR, SAGE, northern blot and RNA sequencing, and describes their application in testing the effects of cosmetic ingredients and products on skin.
Nov 1, 2010
The present study uses confocal laser scanning fluorescence microscopy to assess the penetration of protein hydrolyzates into hair. While higher amounts of protein were found in the cuticle, still significant quantities were observed in the cortical parts of hair, and this penetration was enhanced by longer incubation times.
Aug 1, 2010
Aging influences cutaneous parameters that give rise to progressive changes in three skin chromophores, altering the visual homogeneity of skin. To address these changes, the authors developed and examined the effects of a complex based on Siegesbeckia orientalis and Rabdosia rubescens using a novel skin imaging technique.
Jun 1, 2010
In the present work, the antioxidant capacities of three essential oils derived from basil and thyme were evaluated using a photochemiluminescence (PCL)-based assay. In addition, since the base formulation can affect the antioxidant activity of oils contained therein, ingredient interactions within final formulations were investigated.
Feb 1, 2010
New methodologies have recently been developed to determine antioxidant effects but they often require extensive training and are time-consuming to conduct. In the present article, however, the authors describe an in vitro method to detect the effects of antioxidant-containing formulations using photochemiluminescence to provide rapid, accurate and sensitive measurements.
Jul 1, 2009
The present study uses an evaporimeter to measure the degree of water loss from in vitro skin samples covered by occlusive and semi-occlusive wound dressings to serve as a model for determining the effectiveness of occlusive cosmetic formulations. The purpose of this work was to develop a model for determining the effectiveness of occlusive cosmetic formulations.
May 1, 2009
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.
Apr 1, 2009
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.