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Transdermal absorption of Zn, in urine, blood
http://www.ncbi.nlm.nih.gov/pubmed/22316633
As observed in a larger outdoor trial following this pilot study but with a different formulation and with UV exposure: values of (68)Zn in blood continued to increase beyond the 5 day application phase with the highest measurement at 14 days after the first application; variable amounts of the (68)Zn tracer were observed in urine; and the amounts of extra Zn added to blood were small and indicate very low levels of absorption (minimal estimate <0.01% of the applied dose) through the skin
Sharing swatches of the sunscreen. It’s a very good colour. a shade too dark for me but you guys can consider it. Very cosmetically elegant. Good to layer makeup over it. Not too greasy either.
Have shared the Light and Medium shades.tempted to check out their day moisturiser.ps: i bought the SPF50+ Face & Body Sunscreen with 25% zinc oxide. will comment on the white cast.Zinc Oxide has a higher change of skin absorption, but if it is absorbed it is believed it will break down to Zn ions, which is naturally in your blood anyway. Absorption of Titanium Dioxide is lower, but if it gets absorbed it has more health concerns. It is believed after all research that nano zinc oxide and nano titanium dioxide are not absorbed, most particles are found in the top most layer of skin. But as you can see applying it for longer periods may show different results, good studies where they apply nano physical filters for weeks on impaired facial skin 2 or 3 times each day don’t exist, and that’s is a thing which worries me. That’s why I didn’t give zinc oxide and titanium dioxide the highest rating in my list of sunscreen actives. In the end “chemical” or physical, both types of sunscreen actives have there advantages and disadvantages, I believe Dr Lens also mentioned that.btw according the 500 dalton rule, actives greater than 500 dalton are not absorbed by skin. Actives smaller than 500 Dalton can be absorbed by skin, most skin allergens are no surprise smaller than 500 Dalton. Titanium Dioxide and Zinc Oxide are about 80 dalton. Tinosorb S is 692 Dalton, Polysilicone-15 is about 1500 Dalton, normal non cleaves Hyaluronic Acid is about 15000 Dalton, so impossible to to anything for skin.@Peter Dr Lens said he doesn’t even wear sunscreen everyday. His main reasons for preferring chemical sunscreen on his child is how uncomfortable the white goop is. His other concern is zinc oxide is bad for marines, something i will confirm. Australia is very protective of the reefs especially at the beautiful great barrier reef, i would imagine this is something the authorities will bring up.
I’m happy to trust the TGA stance that Zinc Oxide is safe. There has been many cases, each time choice does a sunscreen review 300 people tests it. After so many years and reviewing nano particles since 1996, i believe if something is bad. It should come up. Even the men here are diligent with sunscreen, those who work under the sun too. It’s something many individuals are using daily, everyday few times a day reapply their sunscreens.Especially from many years of personal experience myself of applying it multiple times.Zinc oxide reflects… doesn’t burn my face like the chemical sunscreens.Well at least, my own dermatologist recommends mineral sunscreens.
Agree to disagree on this. The sun here is baaaaaaaad. I think your Netherlands Summer is milder than Australia’s winter (it gets sunny too, lucky us). Plus there is a hole in the ozone layer above us, another story for another day why.@Peter You have converted me on Uvinul and Tinorsob, 4 chemical sunscreen ingredients i would consider now (not during summer)thanks for sharing the Dalton rule. I learn something new today! i was looking that one up.@Peter that is a very good vitamin C derivative! It is usually recommended at 2% or less. Wow 5% is heaps! Another name for that vitamin C derivative is Tetra-C. It is fat soluble and is able to penetrate the skin well, care to share what brand/product it is? I am using this vitamin C as well currently.
I have studied /researched Vitamin C derivatives & you can read more about the 10 vitamin C derivatives. The beauty brains had a post on it that is Super well writtened! http://thebeautybrains.com/2014/05/which-kind-of-vitamin-c-is-best-for-skin-the-beauty-brains-show-episode-31/
Oke, I thought you needed something like 15% vitamin C. The vitamin C moisturizer is from the same brand, Uncover Skincare, I know I’m a bit obsessed by this brand at the moment, although it’s not cheap. They store the moisturizer refrigerated to keep the vitamin c stable and use airless pump packaging. Although maybe I want a vitamin C serum with a higher percentage of Vitamin C.Uncover Skincare Vitamin C moisturizer (airless packaging)Aqua, Cyclopentasiloxane, 5% Ascorbyl Tetraisopalmitate, 5% Niacinamide, Sodium PCA, Glycerin, Propylheptyl Caprylate, 2% Dipotassium Glycyrrhizate, Glyceryl Stearate, Cetyl Alcohol, Butylene Glycol, Cetearyl Alcohol, 1% Tocopherol, Caprylyl Glycol, Evodia Rutaecarpa Fruit Extract, Ergothioneine, Sodium Hyaluronate, PEG-75 Stearate, p-Anisic Acid, Ceteth-20, Steareth-20, Xanthan Gum, Lactic Acid.Uncover Skincare Salicylic Acid 1% Gel (airless packaging)Aqua, Glycerin, Pentylene Glycol, PEG-40 Hydrogenated Castor Oil, Citric Acid, Salicylic Acid, Methyl Gluceth-20, Dipotassium Glycyrrhizate, Hydroxyethylcellulose, Evodia Rutaecarpa Fruit Extract, Allantoin, Sodium Hydroxide, Ethylhexylglycerin, Butylene Glycol, Disodium EDTA.Aqua, Pentylene Glycol, Glycerin, Niacinamide, PEG-40 Hydrogenated Castor Oil, Butylene Glycol, Methyl Gluceth-20, Dipotassium Glycyrrhizate, Evodia Rutaecarpa Fruit Extract, Allantoin, Ethylhexylglycerin, PEG/PPG-20/6 Dimethicone, Tetrasodium EDTA.Uncover Skincare Suncare SPF30-UVA22 (airless packaging)Aqua, C12-15 Alkyl Benzoate, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, Methylpropanediol, Dipropylene Glycol Dibenzoate, Niacinamide, Cyclopentasiloxane, Potassium Cetyl Phosphate, Polymethyl Methacrylate, Cetyl Alcohol, Cyclohexasiloxane, Caffeine, Hydrogenated Dimer Dilinoleyl/Dimethylcarbonate Copolymer, Lecithin, Tocopheryl Acetate, Decyl Glucoside, Camellia Sinensis Leaf Extract, Tocopherol, Helianthus Annuus Seed Oil, Glycerin, PPG-15 Stearyl Ether Benzoate, Caprylyl Glycol, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Phenylpropanol, Tetrasodium Glutamate Diacetate, Propylene Glycol, Xanthan Gum.@Peter 15% Vitamin C is the maximum the skin can absorb and it refers ONLY to L Ascorbic acid. (LAA)
Each variant has a different recommended %. For Tetra C, the guidelines are 0.5-2% some say up to 10%
Many times the LAA serums eg 20% are there to account for degradation. the skin can only absorb MAXimum 15%. Minimum of 10% of LAA is required for collagen benefitsCall me greedy.. but i would use a water soluble and a fat soluble Vitamin C at the same time. Tetra C is THE ONLY fat soluble vitamin C i would consider.@Peter Uncover looks amazing. i seriously want to check it out too. Your enthusiasm is truly infectious. Could you take more photos of their amazing packaging to share? I am kind of a packaging nut. hehe
I was using Skin Actives which i like but i don’t think they use enough preservatives or the right packaging… they do sell it at a good price point. At the tail end of my cream/serum/ it has gone bad despite storing in the refrigerator.i am surprised Uncover Skincare Suncare SPF30-UVA22 contains Tocopheryl Acetate a synthetic version. Perhaps the reason is because it is more stable than the natural. When i DIY, i always use natural Vitamin E because it is better for the skin!
Peter,
I went to my local Sephora to check out some sunscreens and came across this:Ultimate Sun Protection Lotion WetForce for Sensitive Skin and ChildrenBroad Spectrum SPF 50+I wanted to let you know because it’s a mineral sunscreen. I can’t seem to find the full list of ingredients on the Internet and I didn’t take a screenshot of the box (since I didn’t buy it I was a little shy…), but IIRC, it’s 19% ZnO and a small % of TiO2. It went on pretty white on the back of my hand and I was disappointed but after a minute or two, I realised that the white cast had disappeared! I was so shocked. The texture was great, not chalky, smooth and easy to spread/smooth out on skin.The English site doesn’t say much, but if you look at the Japanese site:It is PA++++. At near CAD45 per bottle, it’s pricer than most sunscreens but it’s 100 mL too. If I have to pay CAD20 for an Innisfree 50mL sunscreen (physical filters % not listed at all), then CAD45 for 100mL doesn’t sound too bad at all. You might want to check this out.Okay, I found the ingredients:what a good share! i think the price is ok because it is such a large bottle.Is it meant for the face? Do you think it would be cosmetically elegant to layer makeup over?did you reference the ingredients? didn’t see it.A perfect sunscreen has to fulfill the following requirements:
- It should block a broad spectrum of UV light (UVA and UVB) almost completely.
- It should be nonirritating, noncomedogenic, non-toxic, without any hormonal or other unwanted biological effects.
- It should be stable and neither degrade nor react with other ingredients under normal conditions and when exposed to sunlight.
- It should not absorb into the skin or at least not absorb into systemic circulation. If it does absorb, it should be proven to be very safe pharmacologically.
- It should dissolve and/or mix well with various skin care vehicles, including oil-based and water-based ones.
- After an application, it should stick well to the skin and not come off, rub off, dissipate or wash off (if swimming/sweating is expected) easily.
- It should be backed by sufficient scientific and clinical evidence convincingly demonstrating that the above criteria have indeed been met
now i am spoilt for choice. which sunscreen.
also the Invisible Zin tinted sunscreen, i tried on my hand and it was too dark, but after i walked home, i compared it to my other hand and it was the same colour after… wow. it is easily to layer makeup over it too.@Peter my derm’s products are packaged in this airless container that closes shut and the pump part goes down flow.
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