[MakingSkincare]

You’re very welcome. So glad it worked out.

[MakingSkincare]

CosChemFan - thank you, glad you found the HLB calculator http://www.makingskincare.com/hlb-calculator/) useful.

Cetyl alcohol, unlike myristyl myristate and cetyl palmitate, helps build up the emulsion structure.  It’s a surfactant, as the alcohol group is hydrophilic and the rest of the molecule is hydrophobic.  As it’s near the oil/water interface, this makes the interface more rigid/solid. However, cetyl alcohol, is such a weak emulsifier that when you are using the HLB system it is considered an oil.

Myristyl myristate I find: rich, good absorption, lowers playtime, matt, waxy, dry, gives some viscosity but not as much as cetyl palmitate.

Cetyl palmitate gives a better skin feel than MM - less dry, glossy, more viscous than MM but less than cetyl alcohol. 

Behenyl gives a bouncy feel.

Cetearyl alcohol is a combo of cetyl alcohol and stearyl alcohol.  Stearyl alcohol can be quite waxy.

So if you would like your emulsion to be more viscous and more stable, I’d add more cetyl alcohol. For further, stability I find a combo of 0.2% xanthan gum and 0.35% carbomer work well with the cetyl.

For a sprayable lotion, I’d use Pemulen TR2 (sold by the personalformulator) instead, however it has it’s own quirks.

[MakingSkincare]

Many chemists use the hlb system, using a low HLB (w/o) emulsifier paired up with a high HLB (o/w) emulsifier to create an emulsification system eg o/w.  (You can read more about this and download a calculator here - http://www.makingskincare.com/hlb-calculator/ )

When the product is applied to the skin there is much shear force applied which will re-emulsify the product.  The water level in the emulsion will drop so the emulsion turns an O/W emulsion to a W/O emulsion.  Then it will leave an oily film as the water evaporates further. 

[MakingSkincare]

Yes the BASF calculator is indeed a useful tool for a very rough guide. The actual spf (ascertained from testing) will be influenced by a number of factors - emulsion type (w/o is preferred although doesn’t feel the best!), synergy between the filters, photostability, choice of emulsifier, rheology modifiers, emollients, particle size distribution to control film formation of the dispersed oil phase etc. You can also use spf boosters like sunsphere powder etc.

[MakingSkincare]

yep I agree, Iaskedbetter.  I’ve already answered a few questions that don’t meet those guidelines in the last couple of days!

Is there anyway to “pin”/”stick” this thread to the top of the forum so it’s more visible?

[MakingSkincare]

Hi Mark

I know a good one in the UK, where are you based?

[MakingSkincare]

What temp was the oven you refer to?  50c is approaching the melting point of some fatty acids - this will give you a yes answer but not always a no answer. 

What % of D5 do you have?  Silicones can be more challenging to emulsify.  Sepigel 305 does a nice job here but if you’d like to keep the pH low try simulgel NS.

Have you tried using the HLB system?  Downloadable self-explanatory calculator here: - http://www.makingskincare.com/hlb-calculator/

Lastly, try adding carbomer - gives good high temp stability.

[MakingSkincare]

Try pemulen TR2 - it’s a powerful emulsifier and stabiliser, doesn’t give much viscosity and you only need to use at a very low level.

[MakingSkincare]

Lanolin has emulsification properties.  Perhaps triethanolamine has been omitted from the ingredients list and it is reacting with the stearic acid creating TEA stearate, an anionic emulsifier. (Ditto with sodium borate reacting with the beeswax). 

If this “emulsion” is very viscous then due to stokes law it will take longer to separate than a thinner emulsion. 

[MakingSkincare]

NuSil sell a range of Caresil ES encapsulated silicones - elastomer gels encapsulated into hydrophilic gels.  You’ll need to mach the refractive index to get transparency but they can guide you on that.

Message me if you’d like me to send you the suppliers details.

[MakingSkincare]

As Belassi said, if all ingredients are liquid at room temperature then there is no need to heat.

Cold process emulsifiers vary greatly and many have formulation restrictions so it’s advisable to research.  I’d recommend the Seppic range - the simulgels, sepigels, sepiplus etc.  They are sensitive to electrolytes.

If you are a diy homecrafter you can buy these in small amounts: Sepigel 305 (personalformulator), Sepiplus (lotioncrafter), simulgel INS 100 (chemistrystore renamed it: body cream & lotion creator) or Simulgel EG (makingcosmetics renamed it: gelmaker emu).

[MakingSkincare]

Margreat, so you can work out the HLB, here’s a handy calculator http://www.makingskincare.com/hlb-calculator/ 

The pH seems quite low and that could be contributing to instability so I would aim for the pH to be somewhere between 5 and 6. 

Caprylyl Glycol can also cause instability issues - see this webpage for tips on how to deal with this - http://www.makingskincare.com/preservatives/

Hydrosols and aloe vera can be challenging to preserve so I would drastically reduce these - see the link above for more info.

I would increase your % of cetyl alcohol - it’s a great thickener and stabiliser.  Also add 0.3% xanthan gum to stabilise.

The vitamin C you are using, is that l’ascorbic acid? If so, it’s highly unstable and I would remove it and replace with an oil soluble more stable form instead.

btw I’d stick to buying the glyceryl stearate for now rather than trying to create it at home. 

[MakingSkincare]

Neither carbomer nor sorbitol are emulsifiers.  Sorbitol is not a thickener.

It might help to learn the basics of lotionmaking first - http://www.makingskincare.com/how-to-make-a-lotioncream-part-1-equipment-and-ingredients/

Swiftcraftymonkey also has some great info.

[MakingSkincare]

Try sepigel 305.

[MakingSkincare]

cossci21 those two organic acids will likely not be sufficient and sodium benzoate has failed some patch tests we carried out.  There’s far more to preservation than just adding a preservative. You need a strategy.  Handy checklist and reviews of 27 preservatives here -

http://www.makingskincare.com/preservatives/

[MakingSkincare]

IGisele - I’ve written reviews of the IKA and Caframo and recommended alternatives in this post - https://chemistscorner.com/cosmeticsciencetalk/discussion/95/industrial-mixer-for-small-scale-manufacturer-emulsions

[MakingSkincare]

Andy, I’m also from the UK.  You can purchase those esters in very small amounts from DIY craft suppliers in Europe:-

dicaprylyl carbonate:-

http://translate.google.co.uk/translate?hl=en&sl=fr&u=http://www.aroma-zone.com/fiche-technique/emollient-dicaprylyl-carbonate-aroma-zone&prev=search

phoenixproducts.co.uk sells the ethylhexyl palmitate

Regarding the cetiol PGL, I think you can get away without using it.

Please send me a PM as I might be able to help more.

[MakingSkincare]

Yes EWG, Skin Deep etc etc etc, there’s a LOT of scaremongering around.

If you have concerns braveheart you can look it up: http://www.cir-safety.org which provides unbiased, scientific, expert advice on cosmetic ingredients and, the European Scientific Committee for Consumer Safety is a politically and commercially impartial panel of doctors and toxicologists, whose job it is to review safety data for materials - http://ec.europa.eu/health/scientific_committees/consumer_safety/opinions/index_en.htm

[MakingSkincare]

Unfortunately, many “natural” chelators are not very effective.  You can see more info on this in this discussion forum: https://www.facebook.com/groups/makingskincare/ :

Here are the links to the relevant posts:-

sodium citrate - https://www.facebook.com/groups/makingskincare/permalink/501195716672924/?stream_ref=2

sodium gluconate - https://www.facebook.com/groups/makingskincare/permalink/492641234195039/?stream_ref=2

sodium phytate - https://www.facebook.com/groups/makingskincare/permalink/521621747963654/

[MakingSkincare]

You could try swapping out 10-20% of the butter for captex SBE

[MakingSkincare]

http://www.ctpa.org.uk/content.aspx?pageid=428

[MakingSkincare]

braveheart, you could try http://www.donlab.co.uk/ tel 01243 783487

[MakingSkincare]

Margreat, not sure if you are aware, but sunscreen is classed as a drug by the FDA.  

Also, without a homogenizer how will you properly disperse the zinc?  Zinc molecules are chemically inclined to clump together - visually you won’t see the clumping but you do not get an even spread of protection. The clumping leaves empty pockets and these “empty” pockets actually attract UV rays like a beacon risking skin damage - see: http://realizebeauty.wordpress.com/2012/12/30/the-trouble-with-making-your-own-sunscreen/

[MakingSkincare]

Thank you Perry for all your hard work running this Discussion Forum - it’s an invaluable resource to many.  

Looking forward to plenty of interesting discussions in 2015. 

[MakingSkincare]

braveheart, yongnn30, nasrins, There is a LOT more to preserving a product than just adding a preservative. In this post I set out the checklist below https://chemistscorner.com/cosmeticsciencetalk/discussion/598/experiences-with-leucidal-liquid-as-a-natural-preservative-in-creams-and-lotions/p1 

(The checklist which was originally taken from http://www.makingskincare.com/preservatives/ which Mark also refers to above)

1. Minimise sources of energy for microbial growth (aka “bug food”) - eg fruit, botanicals, tea, lecithin, mineral water, milk of any kind, honey, hydrosols, floral waters, aloe vera, extracts, protein, clay, powders, starches etc - reduce these to a tiny % (eg 0.1%). This is very important. 

2. Double check against the webpage above whether your preservative is truly broad spectrum.  If your preservative isn’t one of the 27 reviewed on this webpage check for it here - https://www.facebook.com/groups/makingskincare/permalink/529462787179550/ (If you can’t access this second link do first join the Making Skincare facebook group here - https://www.facebook.com/groups/makingskincare/)

3. Add glycerin and other polyols

4. Add 0.2% disodium EDTA into the heated water phase

5. Switch to packaging which the customer can’t contaminate easily - jars are the worst for contamination. 

6. Reduce the pH to between 4 and 5 if possible.

7. Sanitise your equipment with 70% IPA

8. Use distilled, deionised or purified water, not tap/faucet or mineral water

9. If your water isn’t micro checked, heat and hold your water phase at 75c/167f for 20 minutes - this will kill some of the non-endospore forming bacteria. (If your preservative can withstand heat put it in the heated water phase rather than the heated oil phase. This improves preservative contact with the water phase so that it is not partitioned in the water-oil interface).

10. If possible micro test all of your raw materials.

11. Use good GMP - http://www.mariegale.com/good-manufacturing-practices/gmp-basics.html

12. Don’t rely on sight, smell - one can put 100,000 bacteria into a milliliter of water and the water will appear to the naked eye to be crystal clear and usually won’t smell bad. Most cosmetics tested have counts ranging into the tens of thousands or millions of cells per milliliter have subtle or no aesthetic differences from sterile samples. The only way to know if your preservative system is working is to get it tested.