[MarkBroussard]

@Margreat:

You can use either Propylene Glycol (1,2 Propanediol), 1-3 Propanediol or Diproplyene Glycol … they are pretty much interchangeable for this purpose.  Nix Sorbitol.

You can use either the hand mixer or the stick blender.  Be mindful that a stick blender may introduce lots of entrained bubbles into your batch unless you are making a relatively large volume.

[MarkBroussard]

Margreat:

I might suggest that you make a simple Vitamin C serum, unless you really, really, really want to make a cream.  The problem with Vitamin C is that is easily oxidizes rendering it biologically inactive, so it is always a good idea, if for personal use, to only make as much as you will use over a two week period.  Storing in the fridge will help as will storing your product in either an amber glass dropper bottle or opaque container.

You had previously inquired about Ferulic Acid and Hyaluronic Acid, both of which I use in formulations.  You can include either ingredient or leave them out.

Water - QS

Sodium Lactate - 3%

Panthenol - 1%

Glycerin - 1%

Ferulic Acid - 0.5%

Hyaluronic Acid - 0.2% (Regular Molecular Weight)

1,3-Propanediol - 30%

Ascorbic Acid - 20%

Preservative - QS

(1)  Add Sodium Lactate, Panthenol to water.

(2)  Add Glycerin to Ferulic Acid and mix to form a slurry.  Drizzle the slurry into the Water and heat to 80C to dissolve the Ferulic Acid 

(Note:  Ferulic Acid is a very fluffy powder than is very difficult to wet … it simply floats on the water.  Making a slurry solves this problem)

(3)  Cool down to 40C and add the Hyaluronic Acid through a sifter while stirring the water.  You can either let it sit for 3 hours to hydrate or mix it in with a homogenizer.  The regular weight Hyaluronic Acid with thicken the serum besides providing a moisture film-barrier.

(4)  Add individually and in sequence while stirring:  1-3 Propanediol, Ascorbic Acid, Preservative.

(Note:  This formulation yields a native pH of 3.5 without having to add Citric Acid or other pH adjuster.)

[MarkBroussard]

Yes, Belassi … you might try Clary Sage Oil.  While it will not mask the odor of Tea Tree Oil, the combination of Tea Tree and Clary Sage yields a nice woodsy, earthy aroma (my clients love it) and the Clary Sage will provide some benefits.

[MarkBroussard]

I think the culprit is Hydrolysed Wheat Protein … anyone ever have issues with Hydrolysed Wheat Proteins precipitation out at low pH?

I did a knock-out experiment eliminating the Hydrolysed Wheat Protein and that seems to have done the trick.

[MarkBroussard]

@Zink:

I agree with you.  You bring up a very interesting question as I saw in one published paper wherein the results showed that Lauric Acid reduced the P. Acnes population by 15X compared to Benzoyl Peroxide.

Unfortunately, there is scant published evidence on human studies regarding comedogenicity … I suspect that is because it is quite pricey to do those studies.

Since the FDA Acne OTC monograph only allows the 4 approved ingredients for one to be able to make acne product claims, it might be interesting to combine Lauric Acid or Monolaurin with a touch of Salicylic Acid in an acne formulation.

Assuming you are in the US?

[MarkBroussard]

There is really only one definitive way to know:  Formulate a product with either Lauric Acid or Glyceryl Laurate and test it on humans who have acne-prone skin.

[MarkBroussard]

No offense, but Acne.org and Wiki are not exactly what I would call reliable reference sources.

So, what is the point you’re trying to make … that the commonly used comedogenicity index is useless?  Or that comedogenicity does not matter?

[MarkBroussard]

Yes, I suspect it is indeed a pH issue as I get more precipitate with one formulation at pH 3.5 than I get in a second formulation at pH 4.0.

[MarkBroussard]

I am homogenizing at 15,000 RPM for 10 minutes, stirring for 30 minutes, and homogenizing at 15,000 RPM for another 10 minutes.  The solution is relatively clear.  But, in doing stability testing, I am getting some settling of a “gel” after 2 to 3 weeks and/or a floating haze, with a very clear layer at the top.

I’m going to do a run without the gums to see and a separate run with the gums to make sure that the precipitate is the gums or not.

[MarkBroussard]

Daniel,

To get an SPF of 30+ you’re going to need at least 7.5% TiO and 5% ZnO.

If you’re oil is separating out, you likely do not have enough emulsifiers in your formulation.  Have you done an HLB calculation on your oils and emulsifiers?

[MarkBroussard]

@belassi:

P Acnes is an oxygen-tolerant anaerobic, gram+, rod that is a natural flora organism on human skin.  All human beings have P. Acnes resident on their skin.  It lives in the hair follicles and on the surface of the skin and feeds on sebum.  So, yes, every human has P. Acnes on their skin.

Coconut-derivatives are generally not good for people with acne to put on their face due to comdogenicity, which traps the bacteria in the hair follicle where the population explodes creating a pimple.

The interesting thing about Lauric Acid / Glyceryl Laurate (Monolaurin) is the strong antibacterial properties against P. Acnes.

[MarkBroussard]

@Zink:

Avene is using Glyceryl Laurate in acne topicals in Europe.

Here’s an interesting point regarding Lauric Acid or Glyceryl Laurate:  

Since these ingredients have effective antibacterial properties against P. Acnes, is comedogenicity even an issue?  

What I mean by that is if these ingredients plug hair follicles, do their antibacterial properties prevent P. Acnes bacteria from growing beneath the plug, in which case, yes, they may plug hair follicle, but you do not have acne outbreaks as a result due to the antibacterial properties. 

[MarkBroussard]

Since P. Acnes resides on the surface of the skin, yes, a plate test would be indicative of or mimic a topical application.  It would also be very easy to do a topical comparison of the two regarding reduction of P. Acnes.  The advantage of the plate test is you don’t need human volunteers … it’s simple.

On the comedogenicity issue, you’re making the assumption that a 2% percent concentration will yield different results from a 10% concentration regarding acne breakouts.  Granted, it stands to reason that 10% will result in more pimples than 2%, but you cannot conclude from that that 2% will not be problematic.  

The great majority of consumers have no clue as to how the test to determine the comedogenicity index was conducted … what they do know is that if they have acne, an ingredient with a comedogenicity index of 4 is not good.

[MarkBroussard]

Well, one problem you’re going to have right off the bat is using Guar or Xanthan as “foam boosters”?

[MarkBroussard]

The first thing a person notices when testing a cosmetic product are (1) the scent and (2) the feel on the skin. These are extremely important product attributes.

Hand someone a test sample, the tester, especially women, will first immediately sniff the product before applying on their skin.

[MarkBroussard]

Or, just do a micro plate test on P. Acnes with Monolaurin versus Lauric Acid to see how they perform relative to one another.  You would know the results within a week.  Structurally, Glyceryl Laurate and Lauric Acid are very similar and I would suspect have similar antibacterial properties.

The question would then be if Glyceryl Laurate is as comedogenic as Lauric Acid?

[MarkBroussard]

Well, Eternity is not really a good name for a shampoo anyhow.

[MarkBroussard]

It depends on whether or not the term “Eternity” is trademarked by Calvin Klein and what the trademark covers.  Probably not an issue since you’re marketing a shampoo and not a perfume, but you should be able to check the trademark specifics on-line.

[MarkBroussard]

Yes, it’s quite a fascinating multifunctional ingredient.  I’m going to make some formulations using it and will post results.

[MarkBroussard]

This particular company is not a supplier of monolaurin as an ingredient for cosmetics use.  They were promoting it as an oral antibacterial supplement of sorts and making claims that it had an antibacterial effect in the gut.

Lonza sells it as a cosmetic emulsifier.

[MarkBroussard]

Thanks @Belassi.  That does not mean that there is a problem with the ingredient, the letter was issued regarding statements and claims the company was making on its website.

This is very cool … a surfactant/emulsifier/preservative booster multifunctional.  I’ll work it into some of my products.  

[MarkBroussard]

What do you mean, FDA doesn’t approve?  Sorry, I don’t have time yet to do the research on my own.  Is there a problem with using it as an ingredients in a cream in the US? 

[MarkBroussard]

Very interesting @Belassi … have you tried Lauricidin in topicals?

[MarkBroussard]

Anna:

Try increasing the Alkyl Benzoate to 5%.  Olivem 1000 simply soaps a bit under any circumstances.  It is an excellent natural emulsifier, but you are going to have to accept a bit of soaping, but not so much soaping that it is problematic.

Nasrins and Sarah posted a couple of other alternatives.  You might also look into jojoba esters or ethylhexyl palmitate.

Lastly, cut down on the Olivem to 3%.

[MarkBroussard]

There is really no benefit to adding Green Tea Powder to a cleanser.  You won’t get extraction of any of the catechins and polyphenols from the powder into the cleanser.  

Zink is interested in a marketing schtick … Green Tea … Green colored cleanser … get it?  This is not about benefits, it’s all about the color.  Zink also stated the he/she was separately adding Green Tea Extract as the source of catechins/polyphenols.

This really isn’t a big deal.  If you’re adding Green Tea Powder, as Microformulation said, the coloring from the powder is just a function of adding Green Tea Powder.  You are perfectly free to add approved ingredients to your formulation that do absolutely nothing and you don’t have to justify their presence.