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Alpha-Arbutin and dark spots
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quote: our skin doesn’t absorb water? Only oils with small molecular weight can
be absorbed through our skin? Because Most active ingredients are water
soluble, therefore we need to choose oils(easy absorbed) and
emulsifiers with small molecular weight => cream is easy to absorb to
our skin?It does absorb water in a way, just stay in the bath tub long enough and you’ll notice. Small molecular weight oils will absorb into the outer layer of the skin and will then get stuck. Small compounds follow certain rules (Lipinski’s rule of five) which aren’t a scientific fact but based on observation and originally made for orally available pharmaceutical drugs. Skin penetration is more regulated and hence, it’s rather a rule of three and/or a higher required lipophily. Though, too lipophilic (i.e. triglycerides) will have the molecule get stuck in the lipid layers of the skin because they completely lack water solubility and there’s quite a lot of water in our bodies. On the other hand, some molecules like heparin contradict all rules and still show transdermal bioavailability.As mentioned by @ngarayeva001, some small molecules such as DMSO, laurocapram, urea, medium chain fatty acids, or isopropyl myristate may serve as resorption enhancers, rendering a cosmetic product into a pharmaceutical drug.Furthermore, most creams aren’t absorbed but adsorbed. Although leaving a dry afterfeel, lipids stay on the skin often in a way like water in a sponge.Which enhancer you want to use depends on the active ingredient. Too good a solvent will make the active stay in the solvent rather than going into the skin. Another consideration is that resorption enhancers aren’t necessarily solvents but usually show additional effects and may be chaotropic substances, cause swelling of the stratum corneum, and/or alter the lipid layer or intercellular protein organisation. All these effects reduce the skin’s protective function and make transcutaneous flux easier (some literature as example: CLICK ME). Again, it all depends on the compound you wanted to get through the skin. -
@Pharma, apologies a bit offtopic, I read (not very reliable source) that water in oil emulsions are better at delivering actives. I wonder if there’s any scientific backing for such a claim.. Maybe this claim comes from the fact that most topical drugs come in form of ointments?
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It depends on the used drug. Ointments show better occlusion and that’s about the only real difference. Because cutaneous resorption is usually only possible for lipophilic molecules, some oil as solvent may be advantageous. Also, many dermal preparations are meant to treat injured skin and that one often lacks it’s barrier function, an ointment is hence better suited than a light cream.A different story would for example be salicylic acid or lidocaine: Both can be dissolved in water in their salt form but skin penetration of charged molecules (salts) is poor. Dissolving them in a polar oil seems logical but shows less effect/penetration than suspending them in mineral oil. The trick here is that oil-dissolved salicylic acid and lidocaine love being dissolved and hence stay in the solvent/oil rather than being pushed into the skin as it happens when using occlusive vaseline.Besides, ointment isn’t usually used as scientific nomenclature and there’s a lot of mumbo-jumbo and marketing involved. An ointment might come as light cream, high internal phase oil in water emulsion, or as tough zinc oxide containing anhydrous salve. The pharmaceutical terms which describe the physical state and composition of the preparations aren’t usually what customer think it is.
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I also thought they must be just more occlusive and that’s the ‘magic’. Thank you!
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Here after 4 days, apply cream before going to bed.
cream with only alpha arbutin: nothing improved
cream with alpha arbutin + ethyl ascorbic acid: skin tone brighten and more even + fading dark spots about 20%. -
What tools did you use to take the
measurements? -
Just vision check on the picture before applying the cream and after 4 days (taking pictures)
next times checking is 8th day. -
Molecular weight of alpha arbutin is around 272 g/mol = 272 da
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Molecular weight of ethyl ascorbic acid is 204 da
So both of them have molecular weight less than 500 da -
@ngarayeva001, do you know any tools to measure? I just do by vision
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After research, I found that
when applying cream to the skin, there are three possible ways:
1) if the ingredients < 500 daltons , they are absorbed through skin.
2) if the ingredients > 500 daltons, they may be absorbed through the glance
3) if the ingredients > 500 daltons, they may be absorbed between the cells
most of extra oils will be staying on the surface of the skin to perform occlusive.
it takes about 30 minutes for absorption -
Unfortunately it’s not as easy as being below 500 daltons. There are many other factors. Having said that I am in a doubt you can see any result in 4 days. Skin renewal cycle takes 28 days in average. Apha arbutin doesn’t make skin lighter it prevents it from getting darker after sun exposure. Not sure how ethyl ascorbic acid works, but LAA also takes some time to demonstrate any visible result. The only skincare that gives visible result overnight are AHA peels. And even that isn’t measurable.
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Or bleaching products such as benzoyl peroxide
.Ascorbic acid may in fact cause bleaching but I don’t know how many % would have to be used to do the trick and I’m not sure if it also works on dark spots or just stains. I did manage to remove stains I got from handling colours and chemicals with the aid of ascorbyl palmitate but it took a lot and didn’t work as well as intended. Also, said spots were susceptible to decoloration by antioxidants. -
You’re not going to see any noticeable results from using Alpha Arubtin within a 2 to 3 months, at best. So, any improvement you are seeing after only 4 days is an optical illusion … we all like to self-delude that our skin care products make more difference than they really do when we look in the mirror.
If you want something to work faster than that, I would recommend applying a Trichloroacetic Acid peel once weekly, combined with serum containing a cocktail of melanin inhibitors: Alpha Arbutin, Kojic Acid, Daisy Extract, Niacinamide, Bearberry Extract, Mulberry, Licorice Root + 8% Glycolic Acid
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TCA and Glycolic in the same routine sounds a bit drying.
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Not at all … it greatly accelerates cell turnover. Nothing “drying” about it as you are rapidly replacing new skin cells.
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@MarkBroussard, thanks.
there Is problem with glycolic acid that for maximum effect of glycolic acid, the pH must be around 3.8 and fda allows < 10% concentration and its side effect on exposing to sun light or hot temperatures. -
Another is usually stirring glycolic with NaOH
i tried to dilute glycolic but the pH is changing little. -
The results are surprised
even skin tone
dark spots reduced but not evenly
several small fading spots in dark spot have same color as normal color skinso they look not nice
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You’re going to have to use a base (20% NaOH solution) to increase the pH of the Glycolic Acid mixture to get the pH to the proper level. It’s a process … as I said before, it will take a couple of months of daily use to fade the spots.
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The results;
even skin tone : nice
dark spots: 80%
overall: nice
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