[cosmochem]

Hi,

The formula got SPF 60+ because of combination of UV booster (technically they are sunscreens by the structure, not approved by FDA). 

Regarding Alumina, it is typically as a coating of TiO2 because it helps in better dispersing the pigment and keeps the pigment itself stable.

Hope it helps!!!

[cosmochem]

Hey Arismac,

You can contact me at cosmoscientist1@gmail.com.

I am Senior Scientist in Cosmetic Industry based in USA so will try to help my best.

Thanks

[cosmochem]

Hi Priya,

I would suggest changing it to water in oil emulsion to get the full use of a Diaper Rash Cream. If in any case you have to stick with oil in water emulsion type, then it is better to use a thickener/suspending agent in aqueous phase like dehydroxanthan gum, amigel, or veegum.

It is better to avoid carbomer if you can because carbomer is incompatible with ZnO.

Hope it helps!!!!

[cosmochem]

Hi Eli,

You can try the photostabilizers from Hallstar. For example you can use Solastay S1 (INCI: Ethylhexyl Methoxycrylene), Solastay P1 (INCI: Polyester 25), Polycrylene (INCI: Polyester , and Hallbrite PSF (INCI: Undecylcrylene dimethicone).

Hope this helps!!!!!!!!!!!!!!!!!

[cosmochem]

I do agree with David that you need to put a Drug Facts only when you claim an SPF value on it. Claiming SPF turns cosmetic into drug.

[cosmochem]

What are you using it for? If it is for Acne, may be you can try Benzoyl peroxide.

[cosmochem]

You can use Styrene/Acrylate co-polymer also as an Opacifying agent.

[cosmochem]

If you are using a powder ZnO, your oil (liquids) phase better be twice as much as ZnO% you have. These need to be your carrier oils (like emollients). Ex. 10% carrier oils for 5% ZnO. But it can change from formulation to formulation. This will ensure that there is sufficient carrier for ZnO to suspend.

Innospec sells Polyhydroxystearic acid.You can put it in while adding ZnO to oil phase under fast homomixing to ensure a better suspension of ZnO. 

Yield value is much more important than Viscosity to control sedimentation of solids. If you want a thick product with ZnO, you can try using different gums individually or in combination. Typical gums that go well with ZnO are Xanthan gum, Dehydroxanthan gum, Sclerotium gum, Hydroxymethyl cellulose, etc..

Better to stay away from Carbomer or pemulen, if possible. If not make sure carbomer/pemulen are completely neutralized before they come into contact with ZnO.

[cosmochem]

I worked on different dosage forms with DHA. Also combined with ingredients that support DHA in tanning process. Let me know if I can be of help.

[cosmochem]

Hi,

I like the Ganex V-220 (VP/Eicosene co-polymer) for water resistance but as Bob said it it not natural.

But you can try Meristant series from Essential ingredients. These are Hydrogenated Pine Alkaloids and they market them as Green Chemistry, so you can try them as alternatives for Ganex to provide water resistance. In addition to these some emulsifiers like Potassium Cetyl Phosphate also contribute to water resistance.

Hope this helps!!!!!!

[cosmochem]

Hi Zink,

If you are using a pre-dispersion of Zinc Oxide, it might be easier to work with. But if you are using a ZnO powder then for sure you need a suspending agent like polyhydroxy stearic acid to keep ZnO suspended in your oil phase. You need a suspending agent because it is a low viscosity emulsion and needs to be sprayed.

I like to use Carbomer / Pemulen but both of them are incompatible with ZnO and will result in a cottage cheese like product. The incompatibility is due to the charges.

Regarding emulsifiers I would recommend using potassium cetyl phosphate in combination with low HLB emulsifiers like Sorbitan stearate, Glyceryl Stearate, etc..

I Hope this helps!!!