D-panthenol is the alcoholic analogue of pantothenic acid, or Vitamin B5. (Remember, alcohol doesn't mean the stuff we drink, it's an organic chemistry functional group. Look at those OH or hydroxyl groups!) "Animals require pantothenic acid to synthesize coenzyme-A (CoA), as well as to synthesize and metabolize proteins, carbohydrates, and fats." (Wikipedia) What we purchase at our suppliers is D-panthenol or DL-panthenol (DL-panthenol tends to be what we see in powdered form). It is well absorbed by our skin and rapidly converted to Vitamin B5 in our body. Pantothenic acid "appears to be essential to normal epithelial function..." (page 428, this paper)
It is water and alcohol soluble, but practically insoluble in fats, so we will be using this in water based or emulsified products, and not in anhydrous products. The suggested usage is 1% to 5% and you'll be using it in the cool down phase (liquid) or heated water phase (powder). It is approved by the FDA at 2% to be in anti-itching and wound healing products, although you can't make that claim. It is considered atoxic, meaning there should be no side effects from using it as it is something our body produces. It is also considered a penetration enhancer.
What are the claims about D-panthenol?
- Improves stratum corneum hydration
- Reduces redness and inflammation
- Increases wound healing by stimulating skin epithelialization
- Improves skin barrier mechanism repair
- Mitigates itching and soothes irritation
- Behaves as a humectant
IMPROVING THE HYDRATION OF OUR STRATUM CORNEUM
Panthenol improves the hydration of our stratum corneum by behaving as a humectant (page 31, this paper, or p 428, this paper), so it draws water from the atmosophere to our skin. This increases skin's elasticity and softness. This means our skin will feel less dry and we'll see less cracking or flaking. One study reported that treatment with a panthenol ointment for 7 days improved the stratum corneum's hydration and reduced transepidermal water loss (page 679, this paper)
REDUCES REDNESS AND INFLAMMATION
Although an experiment using 4.2% panthenol ointment did not protect against inflammation and redness from sun exposure (p. 429, this paper), it has been demonstrated that it can be used in after sun formulations to relieve redness and inflammation (page 333, Barel Handbook of Cosmetic Science & Technology, 3rd edtion). It can be used to alleviate dry or inflamed skin caused by SLS induced irritation (in experiments) and for people who have to wash their hands very frequently, and it can be used in advance to reduce future irritation and reduce injury to skin's barrier mechanisms (p 430, this paper)
In our hair, as little as 2% in an aqueous solution has shown an increase of up to 10% in the diameter of our hair (Handbook, 3rd edition, page 113).
INCREASING THE SPEED OF WOUND HEALING BY EPITHELIALIZATION
Studies have shown that 2% to 5% panthenol ointment can increase the healing of wounds caused by skin transplants or scar treatment, diaper rash, and leg ulcers (page 429 to 430, this paper). Panthenol has been shown to activate fibroblast proliferation, which is a major part of wound healing. (It's suggested that we keep wounds moist!)
For more information on wound healing, click here for Anthony Dweck's paper on the topic.
IMPROVING SKIN'S BARRIER REPAIR MECHANISMS
"In sodium lauryl-sulphate-induced irritated skin, panthenol has been found to promote skin barrier repair and SC (stratum corneum) hydration." (page 678, this paper)
I feel satisfied seeing all the science behind these claims, but there's one small drawback. Most of these results have been found while using an ointment or water-in-oil product. We make oil-in-water products, so we aren't going to see the same results. One study showed a reduction in absorption of panthenol when it was administered to the skin in olive oil, which showed you that the type of product in which you add the panthenol is just as important as the panthenol itself. So you might want to consider using the higher amount of panthenol - 5% - rather than lower levels in oil-in-water emulsions or any other product (say a cleanser or toner).
Join me tomorrow as we take a look at some other benefits of using humectants!