[MarkBroussard]

In that case, stay away from Potassium Sorbate which can cause a flushing reaction in some people.  It’s the only preservative that I’ve ever had a reaction to.

What preservatives are you considering using?

[MarkBroussard]

@Ruben:

If you have any doubts about the reliability of the test strips, dip your finger into an unpreserved sample and into a preserved sample; also test a preserved sample into which you have not dipped your finger.  Run the 3 test strips side by side.  You’ll get growth on the finger-dipped, unpreserved sample.  If your preservative is working, you should not see any growth on the two preserved samples.  

[MarkBroussard]

@Belassi & @Ruben:

If you buy them direct from Schuelke, they’re about half the price.  Plus, if you use any Schuelke Preservative or Preservative Booster in your formulation, Schuelke will perform a 6-week KOKO challenge test on any samples you send them for free, you only need pay the shipping to their labs in Germany.

[MarkBroussard]

@Belassi:

Here you go:

http://www.schuelke.com/int/en/default/48159.php

I’m sure there is a Schuelke distributor covering Mexico.  If you can’t find one, let me know and I’ll give you a couple of contacts.

[MarkBroussard]

@Ruben:

The test strips are quite reliable.  One side supports the growth of bacteria and the other yeasts/mold using different types of agar.

Yes, the preservative inhibits the growth of microorganisms on the strips … that’s the whole idea.  If your preservative is working, you won’t get any growth at all.

[MarkBroussard]

Second Belassi’s comments.

First, make sure the preservative(s) you use don’t have any incompatibilities with any ingredients in your formulation or with the packaging you intend to use.  And, make sure you have a preservative combination that gives you broad spectrum coverage.  I generally combine two different preservative blends.  For instance, Gluconolactone/Sodium Benzoate with Benzyl Alcohol/Dehydroacetic Acid.

Second, make a batch at the High (maximum permitted level) and mid-range of the manufacturer’s recommended level to bracket your concentrations.

Test your batches with Schuelke & Mayr Mikrocount Combi test strips.  If you get a pass with the test strips, then it’s off to the lab for Preservative Challenge Test.

[MarkBroussard]

Benzyl Alcohol, Sorbic Acid and Salicylic Acid all have antimicrobial effects.

If you want to make your own preservative alternative to this you might try:

Benzyl Alchol, Ethylhexylglycerin, Willow Bark Extract and Sodium Levulinate in 1,3-Propanediol.

But, why take a chance making you’re own unproven preservative combination to begin with? …. scratching head.

[MarkBroussard]

That’s a relatively high percentage of Potassium Sorbate which can be a skin irritant and cause a flushing reaction in some people.  I would recommend that you make a batch at 1% and test it on yourself and few people.  

[MarkBroussard]

@Galina:

Yes, it is also known as Amorphophallus Konjac Root Powder or Glucommanan.  If you use it around 1.0% it will form a nice, crystal clear gel, much like Carbomer.  At lower percentages (0.2%) it will thicken like a serum and at 0.5% will form a thick gelatinous liquid.  

Better than Carbomer in my opinion since it has moisturizing and film forming properties and is stable over a wide pH range … 2 to 10 and quite tolerant of acids/bases, electrolytes.

Pay no attention to the weight loss applications … it is also used as an ingredient in food products.  Try to find 95% Konjac Root Powder.

[MarkBroussard]

Yes, Omega 3/6 imbalance is a major cause of systemic inflammation.  Most people get, in their diet, approximately 10X more Omega 6 relative to Omega 3, than is optimal, especially in “Western” diets.  The imbalance can manifest itself as a contributing factor to many skin conditions.

[MarkBroussard]

Agreed.  At that pH, I would not use a Carbopol.  Lubrizol does have one that gels at pH 4.0, but I forgot the name of it.

At the pH level you want to work with, I would go with Konjac Root Powder as the gelling agent.

[MarkBroussard]

Depends on the format of the water you’re using.  If you’re buying distilled/deionized jugs that you’re going to use quickly once opened, no need to check for anything.

If you are going to be storing the water in a large vessel, but will not use all of it fairly quickly, or if you are setting up your own RO system, then you’ll want to check for dissolved solids and a micro check.

[MarkBroussard]

Certainly.  Ultrasound gel is really nothing more than water, carbomer and preservative.  No problem adding functional ingredients to it.

[MarkBroussard]

Why don’t you just use Sodium Lactate, which is a great moisturizer, and eliminate the whole nitrosamines issue altogether.

[MarkBroussard]

Well, the optimal pH is between 4.0 and 5.5, but in some cases the stability of a key ingredient may be in the pH range of 6.0 to 7.0.  As you mentioned, Niacinamide has optimal stability at pH 6.0, Sodium Ascorbyl Phosphate is most stable at pH 7.0.  If these are the key functional ingredient in your formulation, then you’ll want to shoot for the best pH range for that key ingredient or come as close to it as possible to keep your formulation in balance.

A product with a pH of 6.0 would not be “detrimental”.

As @pma noted, you really have to get to the extremes of pH to be concerned.

@pma:  I recall seeing a study investigating the use of high pH products and recall that higher pH products have a negative impact on the acid mantle barrier that can take some time for the skin to rebalance.  A disrupted acid mantle barrier can result in a host of complications including infections.  

[MarkBroussard]

@Margreat:

Since you have Sodium Lactate in your base formula, no need to then add Triethanolamine to increase your pH … just add more Sodium Lactate.

[MarkBroussard]

@Margreat:

It’s not because scientists are introverted … Debates amongst scientists can get quite raucous! It’s that TV is looking for personalities that can excite their audiences to draw advertising dollars. And, this is most often accomplished by fantastical claims with no real scientific basis or pseudoscience … hence, Dr. Oz and his weight loss and skin care “wonder” products, Dr. Phil, Paula Beroun The Cosmetic Cop.  The problem is more that people want to drink that Cool-Aid.

Curious, Perry did you debate the other female guest one-on-one in the segment, or we’re you kept separate?

[MarkBroussard]

Nice job Perry!

Yes, Dr. Oz could use a science advisor! His testimony when he got hauled before Congress was enlightening … Just another huckster on television.

[MarkBroussard]

@Braveheart:

What I am saying is that the US OTC Monograph specifically states “Salicylic Acid” at up to 2.0% as the drug active ingredient in acne OTC products.  Since George stated he was using Salicylic Acid at 2.0% that falls right in light with the OTC Monograph.  So, it would seem very easy for the FDA to conclude that his product was both a drug and a cosmetic even if he is not making acne claims.

Perhaps less so with a natural base of mixed salicylates.

[MarkBroussard]

@george:

(1)  Cosmetic don’t have “Active Ingredients” like OTC drug products.  So, no, you should not list BHA as an active ingredient if you are not making acne claims.

You’re treading on water where your product could be considered both a cosmetic and a drug due to the BHA at 2%.

Perhaps you should consider a natural source of salicylates such as Wintergreen or White Willow instead a straight up Salicylic Acid.

[MarkBroussard]

It’s the panthenol, the tocopherols and the glycerin … All are sticky.  You can cut the panthenol down to 1% and the tocopherols of 0.5%.  Also, you can eliminate the glycerin if you want to .  That will cut down on the stickiness quite a bit.

[MarkBroussard]

@Belassi:

Yep … the main constituents in urine are urea, creatinine and ions.

[MarkBroussard]

@braveheart:

Keep laughing!  This is nothing more than a kook trend and it will blow over as fast as it blew in.  Really, how many people do you think actually piss in their cosmetics?  

Madonna … Madonna … have you seen her face?  She needs better piss!  Next thing you know she be rubbing shit on face.

@Belassi:

I only eat raw and organic, so my Marpissic Acid is as pure as you can get.

[MarkBroussard]

@braveheart:

With Ferulic, just make a slurry with Panthenol, add to water phase and heat to 80C.  It readily goes into solution.

HA … it does not form a slurry with anything that I have tried … you just have to sprinkle it onto water with rapid stirring and wait.

[MarkBroussard]

@braveheart:

If you aren’t aware, one trick to incorporating gums into formulations is to first prehydrate the gums by making a slurry.   Add glycerin to the gums and and mix with a spatula.  Then drizzle the slurry into the water phase while either stirring vigorously or under high shear if you have a homogenizer.