Saturday, February 12, 2011

Learning to formulate: Modifying a basic lotion

There are so many different ways to reach the goals I set out for yesterday's recipe, and it all depends on your preferred and available ingredients and your preferred skin feel. Let's consider our question about goals again, but tweak it a little for a different skin feel...

What kind of product do I want to make? Is it a moisturizer, body milk, lotion, cream, or butter? For which body part is this intended? What kind of skin feel do I want? Do I have a specific outcome in mind? For what skin type am I making this?

I think I'd like to make a lighter feeling body lotion for the upcoming spring months with some occlusive ingredients to protect me from the elements and some nice humectants. I would like a light to medium skin feel with some glide. I hate greasiness in my lotions, and I have dry skin. 

If you have dry skin, you might want to consider increasing the humectants in your heated water phase. Although glycerin is nice, adding a second humectant to the mix will increase the moisture that is drawn to your skin from the atmosphere. So let's say you like sodium lactate. We'll want to use at it 2.5% to avoid sun sensitivity, so let's add that to the water phase. Just remove 2.5% from the water amount to compensate for the increase in sodium lactate.  

And let's say you hate aloe vera but love hydrosols in your product. Consider using lavender or another hydrosol in place of the aloe vera. No need to compensate if you're leaving it at 10%. But what if you like aloe vera and lavender hydrosol, then remove 10% from the water amount to make up for the new addition. 

Oh, and what about something like hydrolyzed silk protein? It's great for dry skin and offers film forming and moisturizing. I think I'll use 2% in the heated water phase, so I need to decrease the water amount by another 2%. 

So what about the heated oil phase? Well, you'll want to choose less greasy oils and butters. Mango butter is a nice, less greasy butter, so it's a good choice, or you could substitute something like babassu oil, which feels less greasy as well. And you'll want to choose less greasy oils. Again, hazelnut (light), macadamia nut (light to medium), avocado oil (medium to heavy), and camellia seed oil (light) are good choices with long shelf lives. Consider grapeseed oil only if you're adding an anti-oxidant and plan to use it within 3 months or less! (Click here for your emollient choices and charts.) I think I'll go with hazelnut oil as it's light and has some nice levels of Vitamin E and phytostersols as well as a little linoleic acid. I'll leave the cetyl alcohol as I want some thickening in there and I'll leave the IPM because I'm going for a drier lotion. (If you want to leave out the IPM, increase the oils or butters by 2%). 

For the emulsifier, when I want less greasy I go with BTMS-50 instead of Polawax. It isn't subject to the 25% rule, but I'm going to leave it at the 6% emulsifier amount because it will offer nice conditioning and thickening to the product. Your product will be thicker if you use BTMS-50 over Polawax or e-wax. And if you use another emulsifier, you'll get a different skin feel. 

For the cool down phase, I want to include the panthenol, preservative, and fragrance or essential oil. What about the extract? I could keep it the same, leave it out, or choose another one. I think I'm going to leave out the extract as I don't have many around the house specifically for dry skin. So I'll increase my water amount by 0.5% to compensate for the loss of the extract. 

39.5% water (reduced by 2.5% for the sodium lactate, 10% for the lavender hydrosol, 2% for the silk; increased by 0.5% to compensate for the removal of the extract)
10% aloe vera
10% lavender hydrosol
2.5% sodium lactate
3% glycerin
2% hydrolyzed silk protein
0.5% allantoin

13% hazelnut oil
2% IPM
5% mango butter or babassu oil
3% cetyl alcohol
6% BTMS-50

1% fragrance oil
0.5% preservative
2% panthenol

That wasn't so hard, was it? As you can see, any changes in your lotion will come out of the amount we've allotted for water. If we increase the cool down phase, decrease the water amount. If we decrease the cool down phase, increase your water amount. And if we increase or decrease the heated oil phase, we decrease the water amount...with a few other tweaks. Join me tomorrow for fun increasing our heated oil phase and emulsifiers! 


MzJaxine said...

So this is a silly question but forgive me I'm new to the art of lotion making.I have hydrolyzed oats and silk amino acid ( I'm assuming that's that same as hydrolyzed silk, from what I read).is it safe to put them both in a lotion?

Susan Barclay-Nichols said...

Hi MzJaxine! Yes! What are you worried about in mixing the two?