IPM is an ester of isopropanol (the alcohol) and myristic acid (the carboxylic acid), so it's called an isopropyl ester. It has only one fatty acid chain - as compared to something like olive oil (a triglyceride), which has a glycerin backbone and three fatty acid chains. The length of the chains is an important feature with esters: The shorter chains, like IPM, feel drier and have less impact on foam in surfactant products. The longer chains (like glycol stearate or glycol distearate) tend to be greasier and have more impact on foam.
It is used as a light penetration enhancer, bringing your lovely ingredients deeper into the skin, and you'll find it in many medical applications for this reason. It reduces residue in things like anti-perspirant, so if you've got a lotion that just won't sink in or leaves behind a white mess, IPM at 2% is perfect for you!
So why would we use IPM in our creations?
- To impart a less greasy feel
- To act as a dry, astringent emollient
- To bring ingredients deeper into the skin
- To reduce residue from other ingredients
So I'm going to contradict myself here...I mentioned above I wouldn't use it at more than 5% or so because it imparts a dry feeling, but I want this in my anhydrous body oil. I was asked to make this as an after bath oil with ingredients that were non-staining and very emollient. I added a lot of IPM to reduce the greasy feeling of straight sesame and fractionated coconut oil because it was simply way too oily. And it's also non-staining, so it fit in well with my creation.
BODY OIL WITH IPM
66% sesame or fractionated coconut oil - I used 33% of each
1% fragrance or essential oil
Pour all the ingredients into a spray bottle. Shake well. You're done.
Join me tomorrow for more fun with esters - thickeners!