Thursday, February 24, 2011
Learning to formulate: Making more changes to a lotion...
NOT SO MUCH A SIX INGREDIENT LOTION ANY MORE WITH SHEA, SOY BEAN, AND SESAME OIL
HEATED WATER PHASE
20% aloe vera
2% hydrolyzed oat protein
2.5% sodium PCA
HEATED OIL PHASE
5% refined shea butter
7.5% soy bean oil
7.5% sesame oil
2% IPM or IPP
3% cetyl alcohol
COOL DOWN PHASE
1% Vitamin E
0.5% powdered chamomile extract
0.5% liquid Germall Plus
1% fragrance oil (Clementine Cupcake)
I originally create this recipe to help my husband with his itchy, winter skin. I chose my oils because they were high in phytosterols and linoleic acid. But what can we do to change this lotion?
What if I want to make this more occlusive? I turn to three things - dimethicone, allantoin, and cocoa butter, all of which are approved by the FDA as barrier ingredients. So if I wanted to make this more occlusive, I could switch the shea butter for cocoa butter and have a really occlusive lotion. It will make it thicker, but not a lot more greasy as shea butter is kind of greasy anyway.
What if I wanted to make this less greasy? I'm already using BTMS-50 and I've included IPM, but you could choose mango butter instead of shea butter and less greasy oils like hazelnut, macadamia nut, camellia seed oil, and avocado oil in place of the oils in the product. I could substitute my oils for some esters - I'd go with cetearyl ethylhexanoate and C12-15 alkyl benzoate or ethylhexyl palmitate - and make a lighter, less greasy product. Or you could add more IPM or IPP, up to 5%.
What if I want this to be more greasy? Remove the IPM or IPP, use Polawax or another emulsifier instead of BTMS-50, and choose greasier oils and butters (although shea butter is pretty much the greasiest you can find out of our standard butters).
What if I wanted this to be a lighter product? Replace the butter with oils. Remove the thickener or use less. Use lighter oils (since I'm already using soy bean and sesame seed oil, you could do something like use fractionated coconut oil in their place).
What if I wanted to turn this into a body milk like or sprayable product? Start with another recipe as the tweaking for this would take all day. But a quick summary would be to remove the butter, remove the thickener, use Polawax instead of BTMS-50 (as it will make a slightly thinner product), increase the water amount, decrease the oil amount, and recalculate it all. Or you could use something like Sucragel, which makes quite thin lotions even with 25% oils and butters.
What if I wanted to make this for sunburned skin? I could increase the aloe vera to 30% or higher (don't use all aloe vera as it can make a lotion feel sticky), and choose an extract and hydrosol good for that purpose. Lavender hydrosol is always nice and chamomile hydrosol and extract are good at soothing burned skin. So I could use 10% lavender hydrosol and 10% chamomile hydrosol or use 0.5% chamomile extract (which I've already done, but I'm trying to make a point here). I'd probably remove the butter as I don't want it to be too occlusive. And I could include up to 1% lavender essential oil as this is good for soothing as well.
What if I wanted to turn this into a body butter without messing with the emulsifier? I'd increase the butter to 15% to 20% and reduce the oils accordingly (so 0% to 5% oils).
What if I wanted to turn this into a foot cream without messing with the emulsifier? I'd increase the butter to 10% or so, use heavier oils, and use stearic acid as my thickener. I'd include some foot friendly essential oils - spearmint, peppermint, camphor, and eucalyptus in equal parts - at 3% and reduce one of the oils by 2% (because I already have 1% fragrance oil in the recipe).
What if I hate silicones? Remove them and use oil in the same amount in the right phase. Or use a silicone alternative.
What if I want to leave out the preservative? Don't.
Join me tomorrow for more fun learning how to formulate!