The study is specifically being conducted to examine how such molecules affect the small portion of skin molecules that are in a liquid state, because these determine important skin properties such as elasticity and barrier function.
The researchers are using solid state Nuclear Magnetic Resonance (NMR) technology to help detect changes in the fluid skin molecules brought on by the interaction of various types of solvent molecules commonly found in topical creams and lotions.
Identifying how solvents impact skin molecules
Additionally, the research is also helping to identify how the addition of the solvent molecules impact and interact with the fluid skin molecules.
"These types of measurements have not been done before. Our results complement previous studies that have measured how molecules penetrate the skin under different conditions,” said Emma Sparr, professor at the Department of Chemistry at Lund University.
“Our contribution is that we have now increased our understanding of how molecules - both added components and skin molecules - are affected by each other.”
Solvents play a big part in skin care
Solvents are crucial part of skin care products because they are used to dissolve certain ingredients, helping to enhance functionality, texture and sensorial attributes.
A wide range of commonly used ingredients can be categorized as solvents, including water, vegetable or animal oils, silicones or alcohols.
Propylene glycol is one of the most commonly used solvents in cosmetics like skin lotions, moisturisers and liquid foundations as well as toothpaste and mouthwash, and in recent years has become increasingly popular with formulators.
Increased understanding of skin mechanisms
Moving forward, the research is expected to throw more light on how cosmetic and formulators can determine how solvents influence and alter skin properties.
The group of scientists behind the project, which as well as Professor Sparr also includes Professor Daniel Topgaard and doctoral student Quoc Dat Pham, is studying, testing and reviewing a wide range of topical products, which as well as skin care products also includes hygiene and pharmaceutical products.
"Through an increased understanding of molecular mechanisms we are able to more efficiently influence and regulate skin properties", said Sparr.