Re: Microfine Zinc Oxide or Avobenzone Supplier?

[Guest guest]

In a message dated 6/29/2004 12:40:56 PM Eastern Daylight Time,

maurice@... writes:

> Regular zinc oxide will work as a sunscreen but you get that white pasty

> look. Not a very aesthetic appearance. Microfine Zinc Oxide is essentially

> transparent when applied in a properly formulated vehicle.

Hi Maurice and All,

We've been looking at the microfine zinc oxide options for several months

now. We will more than likely be bringing this in very soon. There are two

types--one is hydrophilic and the other is hydrophobic. I'm leaning towards the

hydrophobic one since theoretically it's easier to use in formulating. Both of

these products are a bit pricey though---a lot more expensive than the

regular zinc oxide USP. I don't find the regular zinc oxide usp to be

problematic

in sunscreen products and it doesn't have that much more color to it than the

micronized. Any of the zinc oxides when used at 10% or higher will give skin

that pearlescent look But the microfine versions are the nicest for making

an elegant emulsion.

Angie

The Herbarie

www.theherbarie.com

[Guest guest]

>Does anyone know any supplier that sells Microfine Zinc Oxide (or

>avobenzone) in small quantities?

Because of it's photoinstability, I don't think avobenzone is a good sunscreen

for the average homecrafter.

Sunscreen Photostability

http://home.earthlink.net/~jstanfield/myweb/#Sunscreen%20Photostability

Avobenzone is a new UVA absorbing ingredient recently approved in the US for use

in OTC sunscreen products. The stability during sun exposure of sunscreen

products containing Avobenzone is rapidly

becoming an important issue for sunscreen manufacturers, dermatologists and the

consumer.

It is well-known that Avobenzone and other sunscreen ingredients may degrade in

sunlight, potentially reducing the protection factor of the sunscreen

product1,2,3. At the same time, it is known that sunscreen

products are tested in panels of 20 human volunteers, according to the FDA

Sunscreen Monograph4 to measure the sun protection factor (SPF). In the SPF

test, sunscreen products on the skin receive doses of

ultraviolet (UV) energy simulating sun exposure. For a product to be labeled as

SPF 30, it must prevent sunburn until a UV dose equivalent to 30 times the

minimal erythema dose (MED) is received. This is

approximately equivalent to a full day of summer sun exposure.

I've seen many websites that sell Zinc Oxide to homecrafter but I've never seen

any that sell microfine Zinc Oxide to homecrafters.

Regular zinc oxide will work as a sunscreen but you get that white pasty look.

Not a very aesthetic appearance. Microfine Zinc Oxide is essentially

transparent when applied in a properly formulated vehicle.

For homecrafters not familiar with the difference between microfine Zinc Oxide,

here's a quoting from a file in the CosmeticInfo files area

http://health.groups.yahoo.com/group/Cosmeticinfo/files/Ingredients/Sunscreen_Pr\

imer_w_Zinc_Oxide_Emphasis.pdf

" Zinc oxide has an unparalleled 300 year history of safe use on all types of

skin, first as a component of Calamine and then on its own in various

preparations. In fact, zinc oxide is the only sunscreen active that is

also an FDA recognized Skin Protectant.

Today, zinc oxide is still widely used as a topical therapeutic. It may be the

most commonly used topically applied compound of all time. An estimated

5,000,000 pounds per year are used on people in the US alone

without incident.14 Prior to the invention of the microfine form, zinc oxide was

produced with particle sizes ranging from 1 micron to several hundred microns.

Referred to as pigmentary grade, this zinc oxide is

rough in texture and tends to thicken formulations. As can be seen from figure

7, pigmentary zinc oxide scatters light very efficiently making it very white

and unsuitable for daily wear products such as sunscreens,

moisturizers, and makeup. Thus, pigmentary zinc oxide has received relatively

little use because of its aesthetic limitations. In addition, larger particle

zinc oxide is an inefficient UVR block compared to the microfine

form.

Microfine zinc oxide has an average particle size of less than 200 nm. Because

of this, it scatters light poorly (figure 7). It is inherently " transparent "

when applied to the skin, yet it is an excellent ultraviolet (UVA,

UVB and UVC) block. This allows its incorporation into virtually all topically

applied products including sunscreens and other daily wear formulations.

Microfine zinc oxide can be used alone or in combination with

other sunscreens.

The public health benefits of microfine zinc oxide are substantial. Consumers

can now apply a UVA (I & II) and UVB block that is both safe and cosmetically

elegant. As noted above, UVA regulatory guidelines are

not yet published. Until they are, consumers will need to read the ingredient

list to make sure they are getting the protection they need. If microfine zinc

oxide is listed, they know they are getting safe, transparent

and true broad spectrum protection. "

Maurice

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Maurice O. Hevey

Convergent Cosmetics, Inc.

http://www.ConvergentCosmetics.com

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[Guest guest]

> Any of the zinc oxides when used at 10% or higher will give skin

>that pearlescent look

Never went that high.

Maurice

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Maurice O. Hevey

Convergent Cosmetics, Inc.

http://www.ConvergentCosmetics.com

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