579 replies to this topic

[Eva Victoria]

I forgot to mention that the TiO2 (ans ZnO) in this formulation is not coated. In the case of TiO2 is not good news at all.

Dr. Mercola here in the US, now offers a formulation of 6% Titanium Dioxide and 22% ZnO in a base of water, green tea, Vitamin E and various oils - it is labelled as SPF50.

Can you give us your thoughts on this product? Thank you!

http://products.merc...r-survival-kit/

6% TiO2 and 22% ZnO seems as a good sunscreen. Though I really don't understand how they got SPF 50 out of this (without the SPF/PF increasers). Unless of course the particle size of the ZnO is smaller which is not good news for UVA protection though.
The formulation is not great. It is very important to get the right formula that can form an even film on the skin. It should also be pleasant for the user to encourage usage. What is a potential irritant doing in this sunscreen (Eucalyptus oil)?

I have to say that the website did not encourage trust.
UVB-biased sunscreens (heavy UVB protection, not-so good or non-existent UVA protection) pose a problem when it comes to protection and Vitamin D production. Many US sunscreens lack modern, state-of-the-art sunscreen ingredients. They are often formulated for great UVB protection but very little UVA protection (and often none in the UVA I region).

The aim for all sunscreens should be providing uniform UVR protection. Like being in the shade. Evenly minimizing UVB and UVA II and I rays, not only some of the rays and letting "the full heat" on on others. (Like it was with sunscreens in the past).

It is very difficult to achieve uniform protection for any sunscreen. There are very few sunscreen agents that are uniformly filter the UV spectrum. ZnO is one of them. It is of course a weak UV-absorber and needs to be used in a high amount to get adequate protection through the UVB, UVAII, UVAI. It will not give a high SPF sunscreen nor a high PPD sunscreen alone. To achieve good UVA protection one needs to have the particle size about 200 nm. It will be whitening on the skin esp. if a higher amount is used.
ZnO is an approved UV filter in the US and most places in the word. (It is also practically non-irritant, mild and highly suitable for children and people with sensitive skin.)

Then you have AVO: that is inherently unstable. It needs to be used with other chemicals to stabilize it. It does not provide uniform protection through out the UVR spectrum either. But it is world-wide approved.

Then you have to truly uniform protection provider (even at low concentrations): Tinosorb S and Tinosorb M. None of them are approved in the US.
There are of course Mexoryl SX (but it is the property of L'Oreal (so no other manufacturer can use it -nor Mexoryl XL), secondly Mexoryl SX is not an approved UV filter in the US, but products containing it and individually registered at the FDA are allowed for sale in the US since July 2006.

The EU versions of the UV products from L'Oreal (many also contain Tinosorb S, Mexoryl XL and other UV filters that are not approved in the US) provide a much more uniform UVR protection than most sunscreen products based on organic (and particulate with organic filters) filters in the world. (L'Oreal brands include: La Roche-Posay, Vichy, Garnier, Lancôme, Helena Rubinstein, Biotherm etc).

Uniform UVR protection means less UVR reaching our skin throughout the UVB-UVAI spectrum. Just like (or almost like) being in the shade. It is also proven that Vitamin D production is much higher when using sunscreens that uniformly filter the UVR spectrum than UVB-biased sunscreens (that suppress almost 100% of the production of Vitamin D).

I recommend you to read more on this subject from Brian Diffey, Emeritus Professor at Dermatological Sciences Institute of Cellular Medicine at the University of Newcastle and from Uli Osterwalder Ciba Speciality Chemicals (now part of BASF).

Sun Protection Facts and Fiction
http://www.nrp50.ch/...FP50_080901.pdf

Sun protection factors: world wide confusion
http://www.ncbi.nlm....pubmed/19775352

[happy lemon]

So glad you like this sunscreen.
Though if it is not whitening at all at 20% ZnO then either you don't apply the required amount or the particles are nano-size.

I asked the manufacturer and they said that the ZnO was coated and its particle size was under 100 naometers.

[Eva Victoria]

So glad you like this sunscreen.
Though if it is not whitening at all at 20% ZnO then either you don't apply the required amount or the particles are nano-size.

I asked the manufacturer and they said that the ZnO was coated and its particle size was under 100 naometers.

Indeed. I can see it from the INCI that the particles are coated. (My comment was for VesperLynd about the coating of the TiO2).
And the particle size under 100 nm mean also that it is nano-size ZnO. That is not such a good news when it comes to UVA protection though.

[happy lemon]

......And the particle size under 100 nm mean also that it is nano-size ZnO. That is not such a good news when it comes to UVA protection though.

Eva, from your previous posts, you mentioned that Z-Cote were about 60nm &I believe that the Zno used in the sunscreen are Z-Cote.

What are you comments of Z-Cote? Safe? UV protection?

[Eva Victoria]

......And the particle size under 100 nm mean also that it is nano-size ZnO. That is not such a good news when it comes to UVA protection though.

Eva, from your previous posts, you mentioned that Z-Cote were about 60nm &I believe that the Zno used in the sunscreen are Z-Cote.

What are you comments of Z-Cote? Safe? UV protection?

Z-Cote is a very fine, high qulity, ZnO produced in Japan and world-wide-distributed by BASF. There are two versions one that is uncoated, and the other one that is coated with Triethoxycaprylylsilane (Z-Cote HP1). There was a third version Z-Cote Max (Zinc Oxide, Dimethoxydiphenylsilane/Triethoxycaprylylsilane Crosspolymer) for formulations with Carbomer, but BASF don't seem to carry it anymore.
The dispersion of Z-Cote HP1 (among others used by Kobo) have a particle size of 290nm.
It is very important how ZnO (generally) is dispersed and what the final particle size is in the final product.

This is the product you have:
Active Ingredients: Ethylhexyl Methoxycinnamate 7.49 W/W%, Phenylbenzimidazole Sulfonic Acid 2.50 W/W%, Zinc Oxide 19.97 W/W%
CYCLOMETHICONE‧ZINC OXIDE ‧WATER (AQUA)‧ETHYLHEXYL METHOXYCINNAMATE‧CETYL DIMETHICONE‧ALCOHOL‧DIMETHICONE‧CETYL ETHYLHEXANOATE‧POLYMETHYLSILSESQUIOXANE‧PHENYLBENZIMIDAZOLE SULFONIC ACID‧ASCORBYL GLUCOSIDE‧MINERAL OIL (PARAFFINUM LIQUIDUM)‧PEG-9 POLYDIMETHYLSILOXYETHYL DIMETHICONE‧TRIETHANOLAMINE‧SORBITAN SESQUIISOSTEARATE‧ANGELICA ACUTILOBA ROOT EXTRACT‧COIX LACRYMA-JOBI MA-YUEN SEED EXTRACT‧MELOTHRIA HETEROPHYLLA ROOT EXTRACT‧SASA VEITCHII LEAF EXTRACT‧TOCOPHEROL‧TOCOPHERYL ACETATE‧BHT‧CITRIC ACID‧DISODIUM EDTA‧DISODIUM PHOSPHATE‧HYDROGEN DIMETHICONE‧POLYHYDROXYSTEARIC ACID‧SODIUM HYDROXIDE‧TALC‧METHYLPARABEN‧FRAGRANCE (PARFUM)‧

It can be that the uncoated Z-Cote they use in this formulation.
I can also see that they use POLYHYDROXYSTEARIC ACID for the dispersion of ZnO.
There are countless manufacturers (like Kobo and Croda) that offer ready-made dispersions of ZnO (and TiO2) so it is very difficult to say what ZnO they use unless the manufacturer lets you know.
But the general rule is that the larger the particle size of particulate filters (in the finished product) is the more whitening it gets on the skin since it gets visible on the skin. The good news is that it means also that it has protective properties in the UVA I range as well.

[happy lemon]

Eva,

Are there 2 particles sizes of Z-Cote?

One is 60 nm and another one is 290 nm.

http://www.longecity...ndpost&p=398544

http://www.longecity...ndpost&p=393293

[Eva Victoria]

Eva,

Are there 2 particles sizes of Z-Cote?

One is 60 nm and another one is 290 nm.

http://www.longecity...ndpost&p=398544

http://www.longecity...ndpost&p=393293

The original particle size is 60 nm. But in dispersions the particle size of ZnO (or TiO2) is different depending how it is dispersed. Kobo has a dispersiion of Z-Cote HP1 (original particle size 60 nm) but in the final dispersion it has a particle size of 290.

When I disperse Z-Cote HP1 I achieve particle sizes between 200 and 350 nm depending on the ester and disperser/homogenizer I have used.

I forgot to mention than all particle filters have to be dispersed before incorporation into the oil-phase. Dispersion of the particles also contribute to more even distribution on the skin hence higher (better) UVB and UVA protection.

Edited by Eva Victoria, 22 July 2011 - 07:31 PM.

[happy lemon]

The original particle size is 60 nm. But in dispersions the particle size of ZnO (or TiO2) is different depending how it is dispersed. Kobo has a dispersiion of Z-Cote HP1 (original particle size 60 nm) but in the final dispersion it has a particle size of 290.

When I disperse Z-Cote HP1 I achieve particle sizes between 200 and 350 nm depending on the ester and disperser/homogenizer I have used.

I forgot to mention than all particle filters have to be dispersed before incorporation into the oil-phase. Dispersion of the particles also contribute to more even distribution on the skin hence higher (better) UVB and UVA protection.

Eva, am I correct saying that if the final particle size of ZnO is over 200 nm after dispersion, then they are not nano ZnO?

[Eva Victoria]

The original particle size is 60 nm. But in dispersions the particle size of ZnO (or TiO2) is different depending how it is dispersed. Kobo has a dispersiion of Z-Cote HP1 (original particle size 60 nm) but in the final dispersion it has a particle size of 290.

When I disperse Z-Cote HP1 I achieve particle sizes between 200 and 350 nm depending on the ester and disperser/homogenizer I have used.

I forgot to mention than all particle filters have to be dispersed before incorporation into the oil-phase. Dispersion of the particles also contribute to more even distribution on the skin hence higher (better) UVB and UVA protection.

Eva, am I correct saying that if the final particle size of ZnO is over 200 nm after dispersion, then they are not nano ZnO?

That I cannot say. Because I do not know the particle size of ZnO in the final product. you will have to ask the producer of the sunscreen about the final particle size in the finished product. But it is not sure they will want to disclose this info.

[happy lemon]

Eva,

Ths for shedding light on the subject of the particle size.

[VesperLynd]

Eva,

The links you provided a few pages back were *very* helpful.

Thank you for shedding so much light on a cloudy subject (pun intended!)

VL

[Eva Victoria]

Eva,

The links you provided a few pages back were *very* helpful.

Thank you for shedding so much light on a cloudy subject (pun intended!)

VL

Thank you, Vesper!
I attach the protection curves of different UV filters available. This is from the book: Clinical Guide to Sunscreens and Photoprotection.

Attached Files

•  UV filter Protection Curves.JPG   106.84KB   82 downloads

[VesperLynd]

Eva,

Once again, thank you for sharing your knowledge.

I am based in the U.S. I understand your recommendation that the percentage of zinc in zinc based sunscreens
should be at least 15% of the formulation, in order to be moderately - or highly effective?

Also, with respect to particle size, are some size of zinc particles more effective at blocking? If so, are those sizes considered nano or micro?

What about coated particles? Is it important that they be coated? If so, what types of coatings?

I have read reference hear before to Zinclear? What type of sunscreen is that? and is it often recommended?

Thank you, again! VL

[Eva Victoria]

ZnO has 100% photo-stable UV protection. Fully effective in the UVB (thogh it is best to combine with an UVB filter, like TiO2, OMC or P-15), UVA II and UVA I ranges. It is not absorbed by the skin, cannot do any systemic damage. Has soothing properties, antibacterial,. Approved for children and as an anti-inflammatory agent.
One can formulate cosmetically more elegant sunscreens than with organic filters. (Needs skills to do this but the matteness it provides to the skin is more natural and elegant than the oiliness of organic filters.)
Protection of ZnO is dependent on particle size. The smaller the size the better UVB protector it is and will provide weaker UVA protection.
Micronized ZnO can provide protection up to 380 nm. (Should be combined with UVB-filter).
The smaller the particle size the more ZnO shifts to absorber of UVR. Originally it is more of an UVR reflector and less absorber. This is valid for TiO2 as well.

Coating of the particles will provide better stability in formulations. Coating is dependent on formulation type. But silicone coating is commonly used (since ZnO is often formulated in silicone containing formulations for more elegant finish). It can also be coated with Silica.

Zinclear is a nano-size ZnO that is very effective UVB blocker in its own. Needs much less ZnO in the formulation than conventional ZnO. It is invisible on the skin and making it possible to formulate very elegant sunscreen formulations. It provides weak UVA protection (similar to TiO2).

15% ZnO (micronized) will provide adequate UVA protection (beetween 375-380 nm), but it should be combined with a UVB filter. In the US OMC (3-7.5%) (or TiO2) is a common choice to combine ZnO with.

Eva,

Once again, thank you for sharing your knowledge.

I am based in the U.S. I understand your recommendation that the percentage of zinc in zinc based sunscreens
should be at least 15% of the formulation, in order to be moderately - or highly effective?

Also, with respect to particle size, are some size of zinc particles more effective at blocking? If so, are those sizes considered nano or micro?

What about coated particles? Is it important that they be coated? If so, what types of coatings?

I have read reference hear before to Zinclear? What type of sunscreen is that? and is it often recommended?

Thank you, again! VL

[happy lemon]

Eva,

You're quoted in other forum; great!

http://www.skincaret...html#post472444

http://www.skincaret...final-word.html

http://www.skincaret...html#post149916

maybe some more...

[ViolettVol]

Hi, I've read this thread and feel a bit confused:( What I've been doing right now is using the burnout sun zinc oxide 18% sunscreen, and i sometimes apply skinceuticalc vit c under it in my eye area for aded benefit. however, ido find that after two hours of re- application, it coalesces on my face and I end up with lots of whiteness. I dont mind it on the beach, but in the city it can be an issue. Am i doint things right> I read any titanium dioxide sunscreeen can be very harmful because they invite free radicals. Can a carotenoid supplement orallyadditionally help protect me from the vs that somehow get through the sunscreeen? I already live a life of mostly sun avidance. I'd install uv prof windows but i travl so much it seems like waste of monye - will really thick courtains do the trick?

[happy lemon]

Burnout also leaves my skin white even at the first application.

I believe carotenoid supplement does help & am taking astaxanthin daily.

Edited by happy lemon, 27 October 2011 - 01:38 PM.

[niner]

Hi, I've read this thread and feel a bit confused:( What I've been doing right now is using the burnout sun zinc oxide 18% sunscreen, and i sometimes apply skinceuticalc vit c under it in my eye area for aded benefit. however, ido find that after two hours of re- application, it coalesces on my face and I end up with lots of whiteness.

If you are re-applying the zinc oxide every 2 hours, you don't need to do that. Metal oxide sunscreens are photostable and don't get absorbed, so there shouldn't be any need to reapply unless you wash or rub it off.

[happy lemon]

Eva,

This sunscreen only contains 5% zinc oxide (Z-COTE) & 6% titanium dioxide but the PPD is 21.

Is it possible?

http://www.skinceuti...ense-SPF-50.htm

[Eva Victoria]

Eva,

This sunscreen only contains 5% zinc oxide (Z-COTE) & 6% titanium dioxide but the PPD is 21.

Is it possible?

http://www.skinceuti...ense-SPF-50.htm

Hi Happy Lemon,

This sunscreen is identical to LRP Anthelios Mineral SPF 50 PPD 21 but LRP Mineral has 11% TiO2 while Scinceuticals has 5% ZnO and 6% TiO2 (11% altogether). Both companies are owned by L'Oreal.
L'Oreal say that they use different particle size of TiO2 to achieve high PPD rating. But the higher the particle size the lower the SPF boosting effect of TiO2 (and ZnO) becomes.
Even though they use dispersant and silicones to formulate both sunscreens it is very hard to believe that you could achieve SPF 50 and PPD 21 with so few percentage of TiO2 (and ZnO).

I have not got hold of any of these sunscreens (since they are marketed in the US) but even taken it into consideration that both contain silicone, dispersant and SPF-booster that can increase UV-filter performance I would guess the formula with 5% ZnO and 6% TiO2 has (at the very most) about PPD 10. However if the SPF is not 50 but much less than I could go for PPD 15 at the top.
The final SPF and PPD is always formulation dependent but it would be a miracle if 5% ZnO and 6% TiO2 could give PPD 2/ percent active and about SPF 5/ percent active. even the smallest particle size of TiO2 with the best formulation will achieve about SPF 5/ percent active. But the protection will be only against UVB since the smaller the particle size the weaker the TiO2 becomes after about 320nm (and there is not much protection left after 330 nm).

The Clarins UV Plus protection fluid contains very small particle size of TiO2 (290-330 nm), labeled SPF 40 PPD about 8 and contains 8.1% TiO2. It is also based on silicones.

Ingredients:

LRP Anthelios SPF 50 Mineral Ultra Light Sunscreen Fluid (2011 US)

Titanium Dioxide 11%. Water, Isododecane, C12-15 Alkyl Benzoate, Dimethicone, Undecane, Triethylhexanoin, Isohexadecane, Styrene/acrylates Copolymer, Nylon-12, Caprylyl Methicone, Butyloctyl Salicylate, Phenethyl Benzoate, Silica, Tridecane, Dicaprylyl Carbonate, Dicaprylyl Ether, Talc, Dimethicone/PEG-10/15 Crosspolymer, Aluminum Stearate, Pentylene Glycol, PEG-9 Polydimethylsiloxyethyl Dimethicone, Alumina, Polyhydroxystearic Acid, Phenoxyethanol, Magnesium Sulfate, Propylene Glycol, Caprylyl Glycol, Aluminum Hydroxide, PEG-8 Laurate, Stearic Acid, Disteardimonium Hectorite, Diethylhexyl Syringylidenemalonate, Tocopherol, Propylene Carbonate, Cassia Alata Leaf Extract, Maltodextrin, Benzoic Acid, PEG-9.

Sheer Physical UV Defense SPF 50 (2010)

Active Ingredients: Titanium Dioxide 6%, Zinc Oxide 5%.
Inactive Ingredients: Water, Dimethicone, Isododecane, C12-15 Alkyl Benzoate, Undecane, Triethylhexanoin, Isohexadecane, Nylon-12, Caprylyl Methicone, Butyloctyl Salicylate, Phenethyl Benzoate, Styrene/Acrylates Copolymer, Silica, Tridecane, Dicaprylyl Carbonate, Dicaprylyl Ether, Talc, Dimethicone/PEG-10/15 Crosspolymer, Aluminum Stearate, Pentylene Glycol, PEG-9 Polydimethylsiloxyethyl Dimethicone, Alumina, Polyhydroxystearic Acid, Phenoxyethanol, Magnesium Sulfate, Caprylyl Glycol, PEG-8 Laurate, Disteardimonium Hectorite, Tocopherol, Propylene Carbonate, Artemia Extract, Benzoic Acid, PEG-9

[ymc]

Eva,

The links you provided a few pages back were *very* helpful.

Thank you for shedding so much light on a cloudy subject (pun intended!)

VL

Thank you, Vesper!
I attach the protection curves of different UV filters available. This is from the book: Clinical Guide to Sunscreens and Photoprotection.

Hi Eva

By looking at these graphs, it looks like a blend of EHT or DBT (aka Univul T 150 or Uvasorb HEB), BEMT (aka Tinosorb S) and BMDBM (aka avobenzone) should provide the best UV protection. Does such sunscreen exist? If not, what's the catch here?

Edited by ymc, 20 March 2012 - 07:46 AM.

[Eva Victoria]

Eva,

The links you provided a few pages back were *very* helpful.

Thank you for shedding so much light on a cloudy subject (pun intended!)

VL

Thank you, Vesper!
I attach the protection curves of different UV filters available. This is from the book: Clinical Guide to Sunscreens and Photoprotection.

Hi Eva

By looking at these graphs, it looks like a blend of EHT or DBT (aka Univul T 150 or Uvasorb HEB), BEMT (aka Tinosorb S) and BMDBM (aka avobenzone) should provide the best UV protection. Does such sunscreen exist? If not, what's the catch here?

It is very possible that a sunscreen like this exists. Nivea (Europe) have their sunscreens with these ingredients with the exception of Uvasorb HEB (they use Octocrylene or sometimes OMC).
But in my opinion, generally AVO should be replaced either by Uvinul A or/and Tinosorb M for better photostability. ZnO is a very good option as well of course.

[treonsverdery]

What do you think of this youthifying sunscreen approach

There is a potentially valuable new sunscreen ingredient spermidine http://en.wikipedia....wiki/Spermidine US Patent application 10/566,411 http://www.google.co...rmidine&f=false

the ingredient is shown to improve elasticity as well as skin hydration either orally or topically.

Very thrilling spermidine doubles the lifespan of mice as 3 mg.kg (LKM512 at the Journal PLoS one) http://www.longecity...__fromsearch__1 The oral version that improves appearance is just .5mg per human,

now viewing spermidine it is a polyamine NH2\/\/\/nh\/\/\/NH2 that looks a lot like a retinoid, The partial saturation (c-c=c) links cause bright colors so it is possible there is a UV absorbing particular length like NH2-c=c-c=c-c-c-NH-c-c=c-c=c-c=c-NH2 with c=c between the c-c, at the right length that chemical would absorb UV while also youthifying skin.

also what do you think of linking the part of the henna molecule to a sunscreen moecule to create a sunscreen that attaches directly to keratin to last days or months while being transparent http://www.halfbaker...onger_20lasting

Edited by treonsverdery, 26 March 2012 - 08:25 PM.

[treonsverdery]

here are some more sunscreen ideas what do you think
http://www.ncbi.nlm..../pubmed/8304784 says that the food oil EPA reduces inflammation from UVB, thus reduce reaction to UV redness

This paper says DHA Docosahexaenoic acid the brain nutrient oil reduces harm from UVB http://www.ncbi.nlm....pubmed/22140508

also regarding liposomes some people make those with spermidine, or dha, so they could be used at a liposomal sunscreen

Also I do not know what they are actually called yet there are chemicals that do not directly absorb UV that function as free radical quenchers or elecron glommers to the main ingredients, they are photostabilizers that make them last hours longer. the helioplex combo is like that yet there are others, possibly magnesium sulfate. What is a good "free radical cycle" quencher to use at sunscreens

Edited by treonsverdery, 26 March 2012 - 08:48 PM.

[Hope47]

What do you recommend for under eye dark lines.

[Eva Victoria]

What do you think of this youthifying sunscreen approach

There is a potentially valuable new sunscreen ingredient spermidine http://en.wikipedia....wiki/Spermidine US Patent application 10/566,411 http://www.google.co...rmidine&f=false

the ingredient is shown to improve elasticity as well as skin hydration either orally or topically.

Very thrilling spermidine doubles the lifespan of mice as 3 mg.kg (LKM512 at the Journal PLoS one) http://www.longecity...__fromsearch__1 The oral version that improves appearance is just .5mg per human,

now viewing spermidine it is a polyamine NH2\/\/\/nh\/\/\/NH2 that looks a lot like a retinoid, The partial saturation (c-c=c) links cause bright colors so it is possible there is a UV absorbing particular length like NH2-c=c-c=c-c-c-NH-c-c=c-c=c-c=c-NH2 with c=c between the c-c, at the right length that chemical would absorb UV while also youthifying skin.

also what do you think of linking the part of the henna molecule to a sunscreen moecule to create a sunscreen that attaches directly to keratin to last days or months while being transparent http://www.halfbaker...onger_20lasting

I don't have enough knowledge about spermidine to comment.
I still believe that the best way to protect your skin and preserve your youth is using sunscreens that have approved UVB- and UVA II and UVA I filters. the additional ingredients (like anti-oxidants or anything that claims protection against UVR but not approved as a UV-protecting agent) are a bonus.

Anything that will colour the keratinocytes will provide partial protection against UVB (like DHA). But there should be some questions of how good it is for your skin cells to have sunscreen in them without being able to remove it? How well does the sunscreen protects after a certain amount of time?

[Eva Victoria]

What do you recommend for under eye dark lines.

Dark circles and wrinkles can be caused by lack of sleep, allergy, too much UVR.
The first step is to find the reason and eliminate it.
Anyway using a well-formulated broad-spectrum sunscreen around the eyes (and face) is generally a good investment for your future health and looks.

[treonsverdery]

um actually I meant decahexanoic acid, food oil DHA that is neurobeneficial rather than sunless tanning dha dihydoxyacetone
decahexanoic acid is published as reducing UV inflammation



the henna approach at the link is actually transparent, it uses the michael reaction to attach a long lasting molecule to keratin I also wonder about how long it would function so am thinking about helioplexish or magnesium sulphateoid kinds of chemicals that make sunscreens function longer, is there some other molecule that could do a micheal reaction to creat transparent henna sunscreen with longer duration of activity


as a kind of amusing thing, what do you think of windshield coating that block UV. I heard vehicle windows only block some UV so this could be a stay younger looking longer option at cars

[happy lemon]

Hi Eva,

Before your sunscreen is launched, I would like to mix these sunscreen together for daily use. The zinc oxide of the first one is under 100 nanometer and the second one is of particle size of 1000 nanometer.

1. 16.23% ZnO + 9% OMC + 1% UAP

Ingredient list: Cyclomethicone, zinc oxide, water, ethylhexyl methoxycinnamate, alcohol, polymethylsilsesquioxane, methyl trimethicone, triethoxycaprylylsilane, trifluoropropyldimethyl/trimethylsiloxysilicate, butylene glycol, dimethicone, dimethicone/vinyl dimethicone crosspolymer, diethylamino hydroxybenzoyl hexyl benzoate, octyldodecyl myristate, PEG-8 trifluoropropyl dimethicone copolymer, trifluoropropyl dimethiconol, trifluoropropyl dimethylsiloxane/trimethylsilyl silsesquioxane, hydrogenated polyisobutene, dimethicone/PEg-10/15 crosspolymer, nylon-12, dipentaerythrityl tri-polyhydroxystearate, sodium citrate, polyglyceryl-10 diisostearate, sodium hyaluronate, BHT

2. Zinc Oxide 18.6%.

Other Ingredients: Deionized Water, Capric/Caprylic Triglycerides, Vegetable Glycerin, Sorbitol, Imperata Cylindrica (Root) Extract, Caprylyl Glycol, Lecithin, Arabidopsis Extract, Plankton Extract, Aloe Vera, Vitamin C, Vitamin E, Citric Acid.

Is it a good idea of mixing them together?

The reason why I don't like the second one is because it leaves white cast on my skin and the texture is not cosmetically elegant. While I worry that the first one cannot deliver me a good UVA protection.

[Eva Victoria]

Hi Happy Lemon,

The first sunscreen is a W/O formulation while the second one is (most likely since there is no stated emulsifier) O/W. You can mix them just before applying but I would not premix them for storing for a longer period of time. It will not give a stable formulation which will also effect the stability of the sunscreen ingredients.
I think the best would be if you added coated ZnO (that has higher particle size) directly to formulation one in 3-5%. It would make the formulation a bit drier and matter that you could compensate with an additional moisturizer if /where needed. Coated ZnO you can obtain from websites like makingcosmetics.com They sell BASF Z-Cote HP that is silicone coated.

I can see why you might not like the second sunscreen. It mst be rather sticky and not very flattering for the face. Although it has excellent anti-oxidants! The first one should at least have Vit. E combined with Vit. C. Is it Allie SPF 50+?

Hi Eva,

Before your sunscreen is launched, I would like to mix these sunscreen together for daily use. The zinc oxide of the first one is under 100 nanometer and the second one is of particle size of 1000 nanometer.

1. 16.23% ZnO + 9% OMC + 1% UAP

Ingredient list: Cyclomethicone, zinc oxide, water, ethylhexyl methoxycinnamate, alcohol, polymethylsilsesquioxane, methyl trimethicone, triethoxycaprylylsilane, trifluoropropyldimethyl/trimethylsiloxysilicate, butylene glycol, dimethicone, dimethicone/vinyl dimethicone crosspolymer, diethylamino hydroxybenzoyl hexyl benzoate, octyldodecyl myristate, PEG-8 trifluoropropyl dimethicone copolymer, trifluoropropyl dimethiconol, trifluoropropyl dimethylsiloxane/trimethylsilyl silsesquioxane, hydrogenated polyisobutene, dimethicone/PEg-10/15 crosspolymer, nylon-12, dipentaerythrityl tri-polyhydroxystearate, sodium citrate, polyglyceryl-10 diisostearate, sodium hyaluronate, BHT

2. Zinc Oxide 18.6%.

Other Ingredients: Deionized Water, Capric/Caprylic Triglycerides, Vegetable Glycerin, Sorbitol, Imperata Cylindrica (Root) Extract, Caprylyl Glycol, Lecithin, Arabidopsis Extract, Plankton Extract, Aloe Vera, Vitamin C, Vitamin E, Citric Acid.

Is it a good idea of mixing them together?

The reason why I don't like the second one is because it leaves white cast on my skin and the texture is not cosmetically elegant. While I worry that the first one cannot deliver me a good UVA protection.