[Bill_Toge]

try washing them through with white spirit / light petroleum ether, then leaving them open for a little while, so the solvent can evaporate

[Bill_Toge]

personally I’d go with “Pyrus Malus fruit extract”

[Bill_Toge]

Perry said:

Propylene glycol is not a preservative.  You need to use a proper antimicrobial preservative like parabens, formaldehyde donors, phenoxyethanol, etc.

it can be, at a sufficiently high level (15% or higher) - 1,2-diols have antimicrobial effects and the MIC decreases as the chain length increases

[Bill_Toge]

you could also use benzophenone-4 to prevent discolouration, as it’s a radical trap - 0.1% works well for all but the most light-sensitive colours

[Bill_Toge]

try etidronic acid or one of its salts - it’s a chelator that also suppresses radical formation, and is used to stabilise hydrogen peroxide solutions

[Bill_Toge]

and in Europe, the only grades permitted for use in cosmetics/toiletries are pharmaceutical

if they’re fit for use in medicines, they’ll not be carcinogenic

[Bill_Toge]

petrolatum can be hugely variable between different suppliers; you could also try using lanolin wax in place of lanolin itself

[Bill_Toge]

+1 for slurries; glycerine works well as it has a relatively high viscosity and slows down the hydration

[Bill_Toge]

BHT and BHA work at very low levels (0.2% or less), and have zero odour

[Bill_Toge]

table salt has anti-caking additives, e.g. sodium ferrocyanide; if you want pure salt with no additives, your best bet is the Pure Dried Vacuum (PDV) type

[Bill_Toge]

sometimes it comes from the use of ingredients specifically designed for the under-eye area, but in my experience it’s mostly marketing

[Bill_Toge]

what’s your method of manufacture?

[Bill_Toge]

dthul1 said:

Bill_Toge said:

dthul1 said:

Any suggestion on the amount of cetaryl alcohol I should use? 

I’d suggest you start with 2% and work from there

also, xanthan gum is anionic, meaning it’s incompatible with the Honeyquat; chances are that’s not helping matters at all

Should I get rid of the honeyquat all together? I was utilizing it so the glycerin would t get to sticky on the skin. 
Thanks in advance. 

yes, chances are it’s knackering your xanthan gum

in my experience, glycerine in a cream doesn’t feel at all sticky at only 2%; the effects of the oil phase would counteract that

mind you, some people (namely, the type who buy things then do nothing but whinge about them) would find water sticky

[Bill_Toge]

EVchem said:

@Bill_Toge oh my- makes sense but very different from what we could achieve without extra equipment! we are based in Florida so it’s worst case scenario of nice warm temperatures. Even in a “controlled” room we still can get pretty hot.

sounds like you need more aggressive anti-microbial measures than just a UV lamp; chlorinating your water at a few ppm should help, and giving it a brief ‘blitz’ of 10,000-20,000 ppm every other month should help eliminate any resistant stragglers

[Bill_Toge]

EVchem said:

Any UV lamp recommendations? We have a similar system but our plate counts are still too high

what’s the typical temperature of your water?

depending on the time of year, ours is between 5 and 15 °C, so it’s far too cold to sustain significant microbial growth; if it’s between 25 and 40 °C, that’s the region where growth is fastest

Mary24 said:

perfect  :open_mouth: thank u Bill for ur help .. could u please till me about the conductivity of water from ur system ?? and what kind of products used for ?!! thanks a lot 

the measured resistivity varies between 1-8 MΩ.cm and we use it for face creams, cleansers, toners and serums; nothing exceptionally sensitive, but if we were to make more ion-sensitive products like mouthwash the quality would be more than sufficient

[Bill_Toge]

BTMS-50 is cationic, and not compatible with anionic surfactants (SCI, SLS, DLS); try again without the BTMS-50 and see how it turns out

[Bill_Toge]

KateCreates said:

Sigh.  I found the reason i didn’t use phenonip.  Phenoxyethanol….  Coconut derived.    Sorry for the excited positive post immediately followed by correction.  I still can incorporate the other advice though, so I can still improve the formula based on feedback.  Thanks

hang on, what? the vast majority of phenoxyethanol is synthetic and has never even been near any coconuts

[Bill_Toge]

dthul1 said:

Any suggestion on the amount of cetaryl alcohol I should use? 

I’d suggest you start with 2% and work from there

also, xanthan gum is anionic, meaning it’s incompatible with the Honeyquat; chances are that’s not helping matters at all

[Bill_Toge]

Sibech said:

@Dynamin Strictly speaking they are not selling it as cosmetics, and since it’s written as a chemical it does not fall under the cosmetic regulation but REACH and CLP (possibly others too) in the EU.

if anything, many of these products are unlicensed medicines, which would put their distributors even further up that infamous creek without a paddle if they were to get caught

[Bill_Toge]

Doreen said:

@Bill_Toge
So the temperature of around 38C has increased the rate of the hydrolysis reaction?
That must be the reason why I’ve never had this happen before with both allantoin and NaOH in a formula, I always alter the pH at the very end of the process, at room temperature.

absolutely: for relatively simple chemical reactions, the dependence of rate on temperature is exponential, so there’s a huge difference between 28 and 38 °C

[Bill_Toge]

the active ingredient, lawsone, is chemically very similar to a number of synthetic semi-permanent dyes, which is why it works the way it does

Indian Standard IS 11142:1984 describes a number of test methods for checking the purity, quality and lawsone content of henna powder; you may find it useful, as adulteration is a common practise even now

[Bill_Toge]

Doreen said:

@Bill_Toge
Thanks for your answer and explanation!

One more question if you don’t mind:

What if I add the allantoin (in solution) later on in the cool down and I need to adjust the pH just a bit more? 

I’d suggest putting the sodium ascorbyl phosphate and allantoin in first, then adjusting the pH at room temperature; not only will this reduce the probability of any hydrolysis reactions, SAP itself is very basic, so you’ll need less caustic soda to get the desired pH

or you could use something like TEA or AMP instead of caustic soda, as they are non-nucleophilic and can’t hydrolyse amides

[Bill_Toge]

Microformulation said:

DMSO is not generally used in Cosmetics. It is also not as innocuous as many believe.

and that’s why it’s been banned in European cosmetics since 1979

[Bill_Toge]

try adding cetearyl alcohol to your oil phase

[Bill_Toge]

most likely the allantoin; it’s got a terminal amide group (-C()-NH2), and if that’s hydrolysed, e.g. by a strong base, it’d release ammonia