Monday, March 29, 2010

Formulating for your skin type: Body butter

Our facial skin type is not always the same as our body skin type. I have oily-sensitive (rosacea)-non-pigmented-wrinkled skin on my face, but my body skin is fairly normal (except my back), fairly resistant, non-pigmented with some signs of aging. Take a look at the skin types again to see if your facial skin type differs from your body skin type!

What do we want in a body butter? We want maximum moisturizing through the use of emollients, occlusives, and humectants. For the most part, we can keep the general recipe the same by switching oils for other oils, humectants for other humectants, and so on.

I know, I know, this sounds surreal, right? There are probably a thousand recipes for different skin types out there - and probably a hundred thousand products - but the ingredients between them really don't differ that much. A dry skin lotion might contain more butters and humectants; an oily one might go for more astringent oils and fewer butters. Add a little Vitamin E and advertise that this one is for aging skin; add a little aloe vera and claim it's good for dry skin.

Here's the basic formulation from which I'll be working today...(Click here for the original body butter recipe with rationales for these percentages).

60% water
2% sodium lactate or glycerin

10% oils
15% shea butter
6% emulsifier
3% cetyl alcohol

0.5 to 1% preservative
1% fragrance or essential oil blend

Pretty basic, right? Let's take a look at our goals for each skin type...

Dry skin: Humectants and emollients galore, with an emphasis on using oils high in linoleic acid or GLA to help repair possible skin barrier damage. Occlusion can be achieved by using butters and heavier oils, as well as dimethicone.

Oily skin: Humectants galore, with an emphasis on lighter, possibly astringent oils, and a possible switch to using BTMS as the emulsifier for a drier feeling. We want to use more astringent extracts. Occlusion can be achieved by using allantoin and dimethicone with fewer butters.

Sensitive skin, acne prone: Probably not the product for you as it's kinda hard to formulate a body butter without a ton of oils and butters. A silicone based product might be the best choice for you.

Sensitive skin, rosacea prone: Lovely anti-inflammatories for your redness is always a good idea, so extracts, phytosterols, and soothing ingredients are your friend.

Pigmented skin: You might want to include some of those skin lightening ingredients like liquorice or strawberry extract, and use sunscreen on top of a body butter to prevent further sun damage.

Wrinkled skin: You want lots of humectants and emollients to help with skin's plasticity and elasticity, along with some anti-oxidants and inflammation reducers.

We want humectants galore in our dry skin lotions, to attract water from the atmosphere to keep our skin hydrated. We want occlusive ingredients to trap water in and keep the world out! We have a ton of ingredients to choose from as occlusive ingredients - butters and oils, extracts, dimethicone, and allantoin - so we have something for every type of formulating. And we want emollient ingredients, which soothe and moisturize our skin. This includes not only butters and oils but aloe vera, hydrosols, extracts, and conditioning agents.

Let's take a look at how to create a body butter or lotion to reduce trans-epidermal water loss. We want to formulate something that is very occlusive to trap in the water, and we know that a thick cream is more effective than a light lotion, so our goal is to create a thick cream with lots of humectants, occlusives, and emollients. Studies have shown that glycerin is great for increasing the hydration in dry skin, so this will be our primary humectant, but I'll throw in another one just to make sure we're good and hydrated. Lotions high in GLA or linoleic acid will help greatly with restoring skin's barrier mechanisms, so we definitely want some of those oils in there. We also want to choose oils high in ß-sitosterol, as it reduces itching, moisturizes, and reduces TEWL. We want something to occlude, so we can use some hydrosols or extracts as well as oils.

Join me tomorrow to put all these concepts together for a dry skin body butter!

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