Dear Valerie: Have you ever worked with Ethyl Lauroyl Arginate HCl as a primary preservative? I’ve seen some chatter about it online but am not aware of its use in the industry. —PRESERVATION SOCIETY

Dear Preservation:
For sake of ease, let’s just call this little molecule LAE because it’s a lot to type out! While I have not personally worked with this preservative, I am aware of its nominal use in the cosmetics industry. I was first introduced to LAE by Sharon, whose early range of Sharomix Amplify partially used this material, in a blend. It doesn’t seem to be available anymore; however, Sino Lion offers this preservative in a few different options.

Although it was new to me at the time, LAE has been used in the food industry for quite some time. In fact, it was granted Generally Recognized As Safe (GRAS) status in the early 2000s, at a maximum level of 200 ppm. It’s touted to have a low MIC and is said to be quite effective against quite a broad variety of organisms, including both gram-positive and gram-negative bacteria, yeast and mold. LAE has a considerable amount of in vitro and in vivo data regarding its toxicity and is considered to be low toxic.

Its mechanism of action is due to its cationic surfactant structure, which binds to phospholipid groups in the cell membrane. This depolarizes the cell membrane, causing cell death. One could also argue it imparts smooth feel to skin or conditioning to hair, but since the recommended use level starts at 0.25% and goes up to 2% for the most basic LAE blend (20% LAE in glycerin), I doubt you’re getting much conditioning activity.

LAE does appear in Annex V (the EU’s list of ingredients allowed to be used as preservatives) and can be used up to 0.4% active material for the intent of preserving products. Because it has GRAS status, it can also be used in oral care. One may also find it in anti-dandruff shampoos, as it has demonstrated efficacy against Malassezia furfur. It is not monographed in the US or Canada for this purpose, so you may have to leave North America to find these products.

I’m not sure why LAE is not more widely used in cosmetics, but it seems like a viable option to explore if you’re looking for alternate microbial solutions. However, maybe there is a good reason, and a microbial expert with more insight than me could explain why it’s not more ubiquitous in cosmetic products. 

Happi’s Dear Valerie column appears in Happi’s print magazine. Check out her October 2023 column.