Allantoin

What is it? Allantoin is a naturally occurring compound that is soothing, anti-irritating, and an FDA recognized skin protectant.
INCI Allantoin
Appearance Fine white crystalline powder
Usage rate “The Food and Drug Administration (FDA) has reviewed the safety of Allantoin and permits its use as an active ingredient in Over-The-Counter (OTC) skin protectant drug products at concentrations of 0.5 to 2%.” (Source)

You don’t need a minimum of 0.5% to get the benefits of allantoin, though! Modern Cosmetics lists the usage range for cosmetics as 0.1–0.5% and I’ve found that to be more than enough as well as being much easier to work with.
Scent None
pH 7
Solubility Water-soluble to just over 0.5%
Why do we use it in formulations? It helps boost healing by increasing skin cell turnover. It is moisturizing, soothing, anti-irritating, and stimulates healthy tissue production.
Do you need it? No
Strengths Effective skin protectant and general good-skin-health promoting ingredient at low concentrations.
Weaknesses It can crystallize into uncomfortable shards.
Alternatives & Substitutions You could try a water-based comfrey root extract or infusion, though you’d want to use more than called for amount of allantoin as the comfrey root will not contain nearly as much allantoin. Comfrey root can contain 0.6–4.7% allantoin (source), and with levels that low you won’t be able to achieve the same concentration of allantoin in your finished product. If the allantoin content is on the lower end your product would have to be pure comfrey! I’d probably go with the maximum recommend amount from your supplier, removing the additional amount from the distilled water in the formula.
How to Work with It Thoroughly blend allantoin into the cool-down phase (below 50°C). While it is heat stable, I prefer to incorporate it into the cool down phase so it does not have the opportunity to dissolve at higher temperatures and re-crystallize as the mixture cools, creating uncomfortable shards (I learned this from Lotion Crafter). While this isn’t as necessary if you are using low percentages of allantoin, it’s a small enough amount that it doesn’t take up much room in the cool down phase and it seems an easy enough change to make to prevent possible shardy-ness that would negatively impact the formulation.

In order to ensure the allantoin fully dissolves, I like to calculate its usage based on its solubility and the water content in a formulation. For instance, if a formulation contains 60% water, multiply that by 0.5% (the water solubility of allantoin) to get 0.3% allantoin content for the overall formulation. I’ve never had issues with allantoin feeling “shardy” when I calculate the concentration of it this way. You certainly can use more than this, but it will increase solubility challenges.
Storage & Shelf Life Stored somewhere cool, dark, and dry, allantoin should last two years. It is hygroscophic (it will absorb moisture from the air), so you might want to consider double-bagging it if you live somewhere humid.
Tips, Tricks, and Quirks Apparently it’s pronounced “uh-lan-toyn”.
Recommended starter amount 30g (1oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Allantoin

Skills

Posted on

November 29, 2018