

vitalys
Forum Replies Created
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@Perry Epidermis and especially dermis contain water, i.e., water solution of electrolytes, etc. It means that pH is measurable. I must say even more - pH is a key factor to make multiple enzymes work, which is important for instance for such physiological processes as proper keratinization or lipid formation in keratinocytes. Skin even contains the special proteins for the water transportation - aquaporins.
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@natiyo123
I have worked with this compound. Certainly, it cannot be considered as “natural”. Its properties are very similar to ethylhexylglycerin as well as obviously, they are completely comparable from the chemical standpoint. Comparable but… but they cannot replace each other. EHG outperforms MHG. However, MHG has nicer emollient properties and leaves velvety smooth not tacky finish on skin. MHG works as EHG in deo formulations, but its deodorizing efficacy is lower. We also compared two combinations EHG+Phenoxyethanol and MHG+Phenoxyethanol. While EHG+phenoxy works as a preservative in some formulations, MHG and phenoxy showed insufficient activity and required additional components. However, the combination of EHG+MHG+Phenethyl alc. was highly efficient against all potential microbial agents, including Aspergilus n., Pseudomonas, S.aureus and yeasts. We also found that MHG was efficient as antidandruff preparations as the only active ingredient at 2.2%. -
@chemicalmatt @Graillotion Thank you for the kind words, dear colleagues. It is just a small part of the skin knowledge, which is always useful in cosmetic formulating work.
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@natiyo123
You may download or order additional information right here:
Lexgard® MHG Natural MB - INOLEX -
@Abdullah
The questions you ask deserve the whole article or books.
You will find all the answers here: -
vitalys
MemberMay 10, 2022 at 5:37 pm in reply to: Sign up for the free cosmetic regulation webinar@Perry Thank you! It was great webinar!
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vitalys
MemberJanuary 30, 2022 at 2:57 pm in reply to: Montanov 202 and additional behenyl alcohol…. What is logical?@Graillotion My pleasure
It is an interesting and exciting journey!
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vitalys
MemberJanuary 26, 2022 at 2:36 pm in reply to: Does Vitamin C really work? Or it just stains the skin?@toketsu
I don’t believe that topical Ascorbic acid works the way the marketing campaigns declare. All the possible effects that we can observe are very similar to the effects of AHA. When studies don’t show or explain any compelling data or conclusions regarding this acid, I tend to explain the possible activity and effects of the topical Vit C by the fact that Ascorbic acid is still an acid, which also explains why the pure form of it works better vs the salts or esters. So, the topical Vit C is a form of the mild peeling, which is comparable to let’s say Lactic acid or Mandelic acid at 5-7% or some other acids like this. (If we add some Niacin to the mixture, the results would be even more positively pronounced for the shorter period of time)
As for the “orange stains” you may find it interesting to read here
Vitamin C Degradation Products and Pathways in the Human Lens (nih.gov)It doesn’t related directly to the topic we discuss, but it explains the degradation of Vit C and why the skin turns tanned.
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@Microformulation, Yes, the problem is getting to be significant every day with almost all classes of ingredients, especially those from overseas. Silicones, silicone emulsifiers, some preservatives, some fragrant compounds. Sometimes even the simplest compounds like Urea becomes an issue. I would add the shortage of packaging to paint the complete picture.
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vitalys
MemberJanuary 9, 2022 at 1:45 pm in reply to: Please help me understand what makes this commercial product SO effective for redness reduction@Abdullah It can be used up to 100%
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vitalys
MemberJanuary 9, 2022 at 1:44 pm in reply to: Please help me understand what makes this commercial product SO effective for redness reduction@emma1985 As @Perry said the active ingredient here is Dimethicone. I just would add that is how the right occlusive formulation work. This product is also w/o (w/Si) formulation (Cetyl Peg/Ppg-10/1 silicone emulsifier here), which also effectively
enhances the positive effect of this combination and allows to include the greater amount of Dimethicone. They use Hydrogenated Polyisobutene, which plays a role as a nice substitution for mineral oil (for better haptics). -
TEWL cannot be a reason, it is a result and one of the functional indicators. There are three pools/reserves of water in the skin - blood supply, dermal water, epidermal water. All of them are associated and dependent on each other.
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vitalys
MemberDecember 23, 2021 at 4:06 pm in reply to: Lactic acid solution at pH below 3. Safety and preservative needThere are plenty of peeling products that contain 50- 70% of the acid for home use. But… There is one trick the manufacturers use - they almost completely neutralize the acid making the product almost inactive. In fact, they sell Sodium lactate or Potassium Lactate, etc. The concentrations they claim is used for marketing. Another story with the preparations for professional use by cosmetologists/dermatologists who use various concentrations from 10 to 70. Those preparations always have highly informative descriptions and TDS almost like descriptions for medications ( in fact, professional peels are medical devices). TDS for those professional use products always declare the % of free acid, pH ( sometimes along with pKa), the recommended neutralizing agent or product, the method of use, etc.
All those peels for home use can only ensure the moisturizing effect and very mild, almost elusive exfoliation to avoid any complications among users. That is why the range of concentrations in peels for home use rarely exceeds 10% (if we talk about LA). Effective concentrations in skin peeling are always equal to ability to cause the controlled injury and inflammation, which in turn lead to desirable and visible long term skin improvements. -
vitalys
MemberDecember 22, 2021 at 6:08 pm in reply to: Lactic acid solution at pH below 3. Safety and preservative needIf 10% solution is 1/2 neutralized - means that active acid is 5% which is the same with 5% LA solution of free acid. However, this weak solution won’t show the pronounced exfoliating power (if any) but efficient moisturizing effect. You need higher% to get some efficient exfoliation or effect. Otherwise you need to use 5% solution for a very long period of time.
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in case I’m missing something important.
I am sorry, @Mayday indeed, you are missing something important…
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vitalys
MemberDecember 22, 2021 at 2:54 am in reply to: Lactic acid solution at pH below 3. Safety and preservative needIt depends on a formulation of the pretreatment product and how much of the free acid has been neutralized, which in turn is defined by the skin types including the determination according to Fitzpatrick system by a dermatologist. They are not the same. Are we discussing free acid or neutralized/partially neutralized acid in the product?
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@Mayday What do you mean by saying this: “I’m working within a tight osmolarity range, and hope that using HCl will give me more room for my humectant while reducing the buffering capacity of my formulation…”
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@Mayday According to your conclusions regarding using HCL, you may also give it a try to HNO3 or let’s say H2SO4… Could you explain why HCL?
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@Mayday I doubt that either citrate or lactate at the concentrations you have mentioned above can cause any sensitivity simply because they are a significant part of multiple bichemical reactions in a human body.
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vitalys
MemberDecember 21, 2021 at 2:14 pm in reply to: Lactic acid solution at pH below 3. Safety and preservative need1. It is safe to use 5-6%. 10% is used as a pretreatment before stronger skin peels.
2. It needs a preservative due to high water content.
3. The neutralization step is not required at concentrations you use. The skin has its own ability to recover pH here. Re: moisturizer. 5% Lactic acid has excellent moisturizing properties. You may formulate the moisturizing lotion with 5% LA. -
vitalys
MemberDecember 20, 2021 at 3:50 pm in reply to: Best online resource describing individual preservatives and efficacy? -
vitalys
MemberDecember 20, 2021 at 3:18 pm in reply to: Best online resource describing individual preservatives and efficacy?No, I have got a book