In Vivo Skin Performance of a Cationic Emulsion Base in Comparison with an Anionic System

Cosmetic science is a science-based, but fashion-led discipline. It covers a wide range of intersecting subjects, including biological sciences, dermatology, applied chemistry and physics.

New raw materials for cosmetics and toiletries are continuously introduced into the competitive ingredients market. It is important that independent researchers perform strict, unbiased studies in order to assess their respective performance in the final products. This paper deals with a specific example of a relatively new class of emulsifying materials, the positively charged (cationic) emulsifiers. There are very few data regarding in-vivo skin performance of cationic emulsions against well-established non-ionic emulsifying systems, and no data regarding anionic/cationic comparison.

The aim of this study was to perform a comparative assessment of the skin hydration potential of two emulsion creams: a cationic emulsion, based on distearyl dimethyl ammonium chloride, and an anionic emulsion, based on commonly used modified acrylic acid polymer. In addition, creams containing 5% herbal extracts (chamomile flower and blackthorn fruit, respectively) in each of the emulsion bases were also evaluated. A randomised in-vivo study was performed at the London College of Fashion, while the partners from the University of Belgrade have provided purposefully made and standardised plant extracts.

The results showed significantly higher skin hydration obtained by the tested cationic emulsion, especially in the initial stages of the 3-hour trial. This finding backs-up the theoretical assumption of increased skin efficacy of cationic emulsions, because of their conditioning effect.

The study is a part of the body of work concerning the ingredient/product relationship in topically applied products. Published work includes: the assessment of cream ageing (Proceedings from the IFSCC Conference, 2001), the assessment of the moisturising potential of some commercial vitamin-enriched creams (Euro Cosmetics, Vol. 10, issue 10, 2002) and the production of vitamin E nanoparticles (British Pharmaceutical Conference, 2006).