The Society of Cosmetic Chemists (SCC) returned this week to New York for an on-site (and online) Scientific Meeting and Showcase. From Dec. 13-15, 2021, attendees will: reflect on the SCC's 75 years; explore advances in natural, cleaner and milder formulations; focus on diversity in beauty; seek to advance makeup and hair care; learn new findings of cannabinoids (CBDs) and the skin microbiome; take a sustainability deep dive and more.
Bringing Personal Care to Environmental Care
In the cosmetic industry, a key sustainability objective is to provide consumers with improved personal care products that simultaneously reduce environmental impact while meeting current skin care needs, especially for cleansing and therapeutic benefits.
This presentation, presented by Brittany M. Pease MS; INOLEX, Inc., demonstrated formulation strategies that employ ingredients with improved sustainability profiles to deliver products that meet consumer expectations for mildness, efficacy and sensory experience.
According to Pease, polyesteramines (PEAs), e.g., polyester-11 and -37, exhibit lower environmental risk compared with traditional conditioning polymers due to their non-quaternary ammonium cationic groups and ready biodegradability. The use of polyesteramines in surfactant-based cleansers was shown to dramatically improve the skin mildness of relatively harsh commodity surfactants and provides the benefits of synergistic viscosity building and easy-rinsing skin conditioning.
"We can maintain the performance of our ingredients by thinking through [sustainable, green chemistry and life cycle thinking," "Sustainability with function goes beyond just the polyesteramines lipids [presented] today. You can change out your emollients to be more sustainable and functional; you can change out your preservation systems; you can change out your film-formers—so there's still plenty of opportunities beyond what is presented today."
Amino lipids, e.g., brassicyl valinate esylate (BVE), also demonstrated higher environmental profiles relative to conventional quaternary ammonium compounds such as distearyldimonium chloride, yet they deliver equivalent performance for formulating lamellar liquid crystalline emulsions for highly efficacious moisturizers.
Understanding the different ingredients that go into cleansing and therapeutic moisturizing formulations allows formulators to maintain the efficacy of the formula while making improvements in mildness and sustainability, all without compromising performance. Polyesteramines in cleansing formulas improve both mildness and sustainability in harsh commodity surfactant systems, and 100% bio-based amino lipids can be used for maintaining a desirable sensory profile in high emollient-high humectant lotion formulations, via LLC structure formation.
Qualitative and Quantitative Interactions of Cationic Surfactants
There is a belief that anionic species would systematically interact with cationic surfactants, thus inhibiting their efficiency and leading to some sort of automatic incompatibility. The present study, presented by Paul Salama, Ph.D., Sharon Laboratories, was aimed at revisiting this belief using scientific tools targeting the establishment of objective conclusions.
Isothermal titration calorimetry (ITC) is a technique in the biomolecular field that quantitatively determines the thermodynamic parameter of molecular interactions. Conductimetric methods have been used to characterize ionic surfactants behavior in solution.
The research purpose was to develop a methodology using physicochemical tools to determine the degree of interactions between cationic preservative species and anionic compounds, and to achieve a proper selection of cationic preservatives to a given cosmetic formulation in presence of anionic surfactants.
This study revealed that to be a systematic phenomenon, not all anionic species would interact with cationic surfactants but only a specific subgroup. The tools developed can be used to quickly assess and predict the interactions between any anionic and cationic species with reliability. This work opens more opportunities for ingredient selection based on the scientific understanding of molecular interactions.
Assessing Baby Cleanser Mildness
Since infant skin is different and still developing, it requires specially formulated with mild skin care products that should not disrupt the skin barrier. Certain surfactants in skin cleansers may be harsh and damage the infant skin barrier and lead to irritation. Thus, measuring the effectiveness of the infant skin barrier is important in assessing the mildness of products for use on infant skin. However, there are concerns with testing on infants that may preclude or limit the use of certain methods and/or the number of participants.
A method of assessing product mildness in adults was developed by comparing the amount of penetration of a topically applied marker before and after product treatment (patch) with non-invasive confocal Raman microspectroscopy. This method allows for consistent results with the exaggerated patch test method in adults.
Finally, a validated computational model of the infant epidermis can use adult data to predict the penetration of the marker in infant skin. Presented here by Georgios Stamatas of Johnson & Johnson Santé Beauté France, this process is applied for the first time to predict the mildness of cleanser products on infant skin, using clinical data of marker penetration in adults.
This method takes less time compared with other exaggerated tests, is non-invasive and reportedly shows a better dynamic range to distinguish among formulations, particularly mild formulations, compared with other accepted models. It also confers the ability to screen for effects of products on the skin that may not be apparent from the product ingredients.
Sustainable Smart Cosmetic Emulsions
The development of new formulations where traditional ingredients such as synthetic surfactants, polymers, silicone oils, etc. are being replaced by more sustainable alternatives such as biosurfactants, bio-based surfactants, biopolymers, natural oils. This replacement of traditional ingredients by more sustainable alternatives however is not trivial as re-building the performance of traditional ingredients can be challenging. This is specifically true of oil-in-water and water-in-oil-based emulsion systems, which constitute a large majority of cosmetic products. The stability, texture/rheology/sensory has to be re-engineered in these sustainable formulations. This re-engineering of the formulations however does additionally present opportunities to build in new performance attributes.
Presented by Samiul Amin from Manhattan College reported on the formulation design of two sustainable emulsion systems: a thermo-responsive whey protein/chitosan oil-in-water emulsion system and a glycolipid/silica particle water-in-oil emulsion system.
This study highlighted that that effective formulation design allows the engineering of stable oil-in-water and water in oil emulsion systems from sustainable ingredients where the rheology can be created to have acceptable non-Newtonian character and additionally (for whey protein/chitosan) have built-in smart (stimuli-responsive) effects.