|What is it?||Crothix™ Liquid is a 45% solution of solid CROTHIX™ (PEG-150 Pentaerythrityl Tetrastearate). Both versions of Crothix™ are made by Croda Inc. and are only available under the Crothix™ name.
We use Crothix™ Liquid to thicken liquid surfactant products, and it does this beautifully. Products thickened with Crothix™ Liquid have a really gorgeous professional, glossy, high-end consistency. Crothix™ Liquid also reduces irritation and improves skin feel on rinse-off.
|INCI||PEG-150 Pentaerythrityl Tetrastearate (and) PEG-6 Caprylic/Capric Glycerides (and) Water|
|Appearance||Clear viscous liquid|
|Texture||Smooth, viscous liquid.|
|Scent||Faintly detergent-y; does not come through in finished products.|
|Approximate Melting Point||Liquid at room temperature|
|Solubility||Crothix™ Liquid is water-soluble|
|Why do we use it in formulations?||Crothix™ Liquid thickens liquid surfactant products beautifully and easily.|
|Do you need it?||I highly recommend having some Crothix™ Liquid on hand if you create liquid surfactant-based cleansing products (shampoos, hand washes, body washes, face washes, etc.)|
|Refined or unrefined?||Crothix™ Liquid only exists as a refined product.|
|Strengths||Crothix™ Liquid is an excellent and very easy to use thickener for liquid surfactant products. In addition to contributing gorgeous, silky, glossy thickening it also makes formulations milder and improves their skin-feel on rinse-off.|
|Weaknesses||Crothix™ Liquid is not globally available.|
|Alternatives & Substitutions||This will depend on the formulation; as Crothix™ Liquid is included to thicken surfactant formulations, you’ll need a different way to thicken the formulation.
If you can purchase solid CROTHIX™ (PEG-150 Pentaerythrityl Tetrastearate), that can be a good alternative. You’ll only need 45% of the liquid amount, but it does need to be melted into the formulation, so you can’t easily add it at the end. I’d try including 1% solid CROTHIX™ in the heated phase of your formulation and adjusting from there as needed.
Some surfactant formulations will thicken well with salt, which is a very inexpensive option. This typically works best with formulations that have a decent anionic surfactant concentration.
You can also try using a gum or other gelling agent (like carbomer). There are a lot of possibilities and variations in this category, so it’s very important to know your ingredients and understand your formulation so you know what works well together and what provides results you will enjoy.
Alternatively, if the formulation is water-thin without any thickener, you can package it in a bottle with a foamer top and skip the thickener altogether!
|How to Work with It||Crothix™ Liquid is pretty flexible when it comes to incorporating it into our formulations.
Crothix™ Liquid can be added at the very end of the making process, adding approximately 1% at a time and stirring gently between additions until the desired final consistency has been reached. Croda recommends heating Crothix™ Liquid to above 50°C and adding it to a room-temperature formulation, but I’ve never found this to be necessary.
Crothix™ Liquid can also be included in formulations right from the start and can be hot or cold processed.
I like to make a formulation once without including the Crothix™ Liquid, and then add it at the end as needed, documenting how much was added. I’ll then remove that amount from the distilled water in the formulation, add the Crothix™ Liquid to the formulation, and make it again to ensure the final consistency was correct. For example: say I added 3g Crothix™ Liquid to a 100g (3.5oz) of body wash to get the desired end consistency. For my next batch, I would reduce the water by 3% (3g added onto a 100g batch makes that 3g 2.91%, which I’d round up to 3% for simplicity’s sake), add 3% Crothix™ Liquid, and then make it again to ensure the final consistency is what I’m looking for, adjusting as needed.
Keep in mind that the amount of Crothix™ liquid required to thicken a formulation can vary with the essential oil and/or fragrance oil used.
The product’s final pH should be in the 5–9 range.
|Storage & Shelf Life||Stored somewhere cool, dark, and dry, Crothix™ Liquid should last at least 2 years.|
|Tips, Tricks, and Quirks|
|Recommended starter amount||30g (1.06oz), more if you create a lot of surfactant products.|
|Where to Buy it||Buy it from an online DIY ingredient supplier.|