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@Sam I’d suggest to check formulations on internet similar to the one you’re trying to make. The HLB system rather than telling you how much of emulsifier you need, it tells you is the nature of that emulsifier is suitable for the type of oils you want to emulsify. As a very general rule, you can consider a ratio emulsifier:oils of 1:4 or 1:5. It’s better if you count the Cetearyl alcohol as part of your oil phase. If it doesn’t work, you might consider changing the emulsifier (I don’t think you could calculate the HLB of your TEA-stearate since it’s an anionic emulsifier, and they have many limitations compared to non ionic emulsifiers).  

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@Padmavathi It’s ok that you mix both saponified oils with surfactants. My point is that you might not have used enough NaOH, so part of the fatty acids were not converted into soaps themselves, but rather stayed as fatty acids. So, when you mix them with your synthetic surfactants, you’d emulsify them, similar to when you mix cooking oil with water and detergent. Some companies actually leave part of the fatty acids unsaponified, since they give humectancy and there’s less free alkalinity in the system, but the product is of course not transluscent. 

By cooling rate I was thinking more about trying to cool the soaps rather fast to avoid tight packaging of surfactants (similar to when you make glass, which is cooled fast so it stays as an amorphous inner structure that lets light pass without scattering). 

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@pepe I’m also very familiar with Emulgade 165, but at least for the description, Emulgade SE seems like a very nice combo: one low HLB emulsifier, two high HLB emulsifiers, a fatty alcohol and a high melting point ester. The mixture of low and high HLB emulsifiers give a more stable emulsion (Emulgade 165 was designed under the same principle), while the incorporation of two waxes (a fatty alcohol and a high melting point ester) makes the crystalline network more rigid, resulting in higher viscosity (that’s why you add fatty alcohols in emulsions) and more stability. You could actually do this on your own, but I believe Emulgade SE has a very specific and synergistic ratio. At least, I’d try it. 

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@Padmavathi Perhaps your fatty acids or castor oil are not being completely neutralized, and either being emulsified by surfactants or just migrate to the center and crystalize due to cooling down. Also, cooling rate could have an effect on transparency.

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@Leo Citric acid in a liquid soap at a pH above 9 will be present as its salt (Citrate) rather than the acid form.

Regarding the need for a preservative, if your idea is not to include one, there are a couple of readings you might want to take a look at: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1468-2494.2009.00492.x, https://makingskincare.com/preservatives/.

So, pH as a sole strategy could be tricky, since being at least at a pH of 10 for shrinking the risk of microbial growth (I’ve seen products being contaminated at pH around 9), can also mean that you might have free alkalinity in your product. Of course this is more sensitive for leave on products, but for individuals with reactive skin (not to mention if the product reaches your eyes) and under repetitive use, that might cause some problems.  

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Hi @anani1:

1. I don’t think the list of ingredients is in order of dosage; also, polyquats can bind to water once deposited on hair, glycol distearate also works as non-occlusive humectant, and dimethicone works giving some occlusive humectancy  
 
2.  Sulfates are not the evil, they just need to be properly used in a formulation….and silicones are actually the best friends of curly girls

3. Sodium citrate could work in two ways in that formula: as a water softener (only a weak one), and as part of a buffer system.

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@Leo  If you have a liquid soap, you’d need to go very low on pH to prevent microbial growth, and as @Dr_Sara mentioned, it’ll impair foam and detergency, and it’d also increase the chance of instability (for instance, CAPB behaves as a cationic at low pH, which will interact with anionic surfactants forming a precipitate). It can be done, but you should be very careful with the ingredient selection…also, you’ll need a very good GMP system in place to guatantee that your water for instance is of very high quality, since low pH helps prevent microbial growth, but it won’t avoid your product being contamined from external sources.

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@ankitanks I know this question was not for me, but I remember I read an article about Ethylhexylglycerin and Panthenol being better humectants than Glycerin, since they don’t reduce alcohol’s potency.

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@shellyco I would leave some EDTA (0.05-0.1%), it actually reduces oxidation of the fatty part of your quat and fragrance. The amount of IPA is a bit high, unless your final product with 8% of Stepanquat GA 90 is too thick, although it might impair micelle formation at that level, so you can also reduce it.

You can also improve your softening performance by adding a silicone (preferable emulsified, so it doesn’t mess up with your viscosity). I’d also add a fatty alcohol ethoxylate (like laureth-9 or 7), to prevent formation of insoluble complexes between anionic (from detergent) and cationic (from softener) surfactants. 

Check if the thermal stability of your product is ok…usually, products with over 8% of quats tend to destabilize a bit, so a rheology modifiers could be useful. 

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@Nilesh May I ask which preservative are you using (and at which dose)?

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@Econatural Both Potassium sorbate and especially Sodium benzoate are not quite soluble in Ethanol, so you can make one sample without these materials to see if the problem is fixed…also, if you’re using more than 20% of Ethanol (which I believe is your case), chances are that you don’t need preservatives.  

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@ajw000 It’s ok to have a pH a bit higher than that of the skin…but just a bit. It helps anionic surfactants to perform better. 

You could use Sodium citrate as a chelator (just keep in mind that it’s actually a weak one), or use Citric acid and then add NaOH.

You don’t need to replace completely the Isethionate. Actually, I remember it’s stable in a pH range of 6-8, else it’d hydrolyze, and maybe that’s what’s happening, so you definitely need to raise you pH a bit.

Try this, and if the gain is not too much, you could replace a bit for another anionic that foams better, or even adding a zwitterionic like Cocamidopropylbetaine.  

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@Leo Usually bar soaps from saponification of either tallow or vegetable oils, are the ones that are basic (alkaline). If you have a liquid soap, you could actually have it at a pH closer to the skin (roughly around 4.5-5.5). If you want to stay at that pH range, isothiazolinones are very effective, same as formaldehyde-releasers (like DMDM hydantoin, Diazolidinyl urea, etc.), but that is if you’re ok with that type of preservatives. 

I do believe your liquid Castille soap needs since you need quite some watter to haved in a liquid form. 

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@AndrewSeel No, I meant that PQ-10 performs a bit better than CGuar at depositing oils/silicones. There’s a very nice Dow Corning study about that (http://www.nononsensecosmethic.org/wp-content/uploads/2015/05/silicones-deposition-on-hairs.pdf).

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AndrewSeel said:

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@ngarayeva001 Hi! Regarding your questions:

1) I believe it’s there to increase the ionic strenght of the water phase, precisely so that oil droplets (like those from cyclomethicone) don’t get trapped in the water phase…you could actually either increase the sodium chloride or add/replace it by magnesium chloride

2) all of those preservatives are actually fairly soluble in water…the parabens you see at the end are all part of a blend (phenoxyethanol, methyparaben,…), although even water phase is what you aim to preserve, being a biphasic product, it would be advisable to ad some oil soluble preservative to the oil phase as well

3)  you could actually reduce your Butylene glycol from your starting formula, since being a solubilizer, it’s the only thing there that makes the two phases combine brifely when shaking them…don’t ad a surfactant, since you’ll create an emulsion instead

I have tried increasing salt but it make the water phase turbid!

Then, you can try reducing the Butylene glycol a little.

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@AndrewSeel That’s tricky. Generally speaking, Polyquaternium-10 might have higher deposition than Cationic guar, but it all depends on the charge density. Nowadays, you have Cationic guars of different charge densities (the higher the charge density, the more deposition). Also, Cationic guar is a bit easier to remove from hair than Polyquaternium-10. Keep in mind that they also help oils to deposit (like silicones), and on that, again PQ-10 performs a bit better than Cationic guar. One strategy to reduce chances of buil-up is to use both polymers instead of only one.  

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@ngarayeva001 Hi! Regarding your questions:

1) I believe it’s there to increase the ionic strenght of the water phase, precisely so that oil droplets (like those from cyclomethicone) don’t get trapped in the water phase…you could actually either increase the sodium chloride or add/replace it by magnesium chloride

2) all of those preservatives are actually fairly soluble in water…the parabens you see at the end are all part of a blend (phenoxyethanol, methyparaben,…), although even water phase is what you aim to preserve, being a biphasic product, it would be advisable to ad some oil soluble preservative to the oil phase as well

3)  you could actually reduce your Butylene glycol from your starting formula, since being a solubilizer, it’s the only thing there that makes the two phases combine brifely when shaking them…don’t ad a surfactant, since you’ll create an emulsion instead

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Even though I love soaps and cosider them rather complex systems (I’ve seen many phase diagrams during my soap making years, whose phases depend not only on formulation but also on shear during extrussion, for instance, making some glycerol migrate from one phase to another only because of mechanical stress), I also believe that permeation of molecules like glycerol from soap through the skin is very difficult. Deposition of oils is more likely to happen. 

Penetrating enhancers would help glycerol if conditions like contact time are met. Also, even though there are some aquaporins that help water soluble substances to go through the skin (there is actually one for glycerol), there are still so many barriers to overcome, like: 1) solvation (glycerol as being so hydrophilic is highly solvated by water molecules), 2) mechanical solvent flux (water will mechanically move solution while bathing), 3) little contact time (because of solvent flux, reducing contact time), 4) osmolarity (high excess solvent outside the skin would not favor skin permeation), 5) detergency (this is more for added oils in soaps, which mostly will be solubilized inside detergent micelles, although some could actually reach and remain on the skin). Things are different when glycerol is used in a cream, serum or gel, frem where it can migrate and permeate more favourably.

The residues that deposit from soap are some oils that escaped from detergent micelles, but mainly, calcium and magnesium salts of soap fatty acids (like calcium stearate), which actually give a soft touch to the skin (that’s why some soap manufacturers use mixtures of free fatty acids in their formulas). But, if you use this as a shampoo, these calcium salts plus natural sebum will leave hair heavy, greasy and dull, and this is why soap (made from tallow) was replaced by synthetic detergents in shampoos. 

And in the case of shampoos, the residues are not meant to be unpleasant; for instance, cationic polymers deliver a thin flexible and soft film on the skin. Silicones on the other hand, when not properly formulated (especially non functionalized silicones), can give great conditioning at the start but build up on hair, making it heavy and non “natural”, but not dull as calcium fatty acids, since silicones have a high refractive index.     

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@Aanchal Pure Formaldehyde is banned in cosmetics. Its presence in household items actually depends on each country’s sanitary office: if they use for instance EU’s Cosing database, they will not give you a license for a product that contains Formaldehyde.

In my country, we have two different offices, one for cosmetics (which uses Cosing database as reference) and the other for household products (that doesn’t use Cosing since they consider it’s for cosmetics only), being the latter still permisive with the use of Formaldehyde as preservative. Nevertheless, doses of Formaldehyde are very low, and you’d still need lab equipment and reagents to identify its presence (unless they declare it in the label), or you could find that information in the product’s MSDS (if they posted it).   

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@ngarayeva001 you’re right! I’m familiar with formulas up to 10% of LAA, but I believe I was outdated with that info, since I found some studies with higher doses. Good to know, thanks 

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@Abdullah Sarcosinates foam very well even in the presence of oil. Amine oxides work synergistically with anionics to fight sebum more thoroughly. 

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@ajw000 You actually have a very high content of surfactants in there. I’d start to check for the pH (you might need to reduce your Apple Cider Vinegar quite some)…try it to be above 5 (some anionics foame better at higher pH). You can include a chelator, since the isethionate can be impaired by water hardness. Also, you definitely need to reduce your Glycerin, since it depress foam at some point, and being a very water soluble molecule, it’d tend to go away with water rather than doing anything to your skin/hain in a rinse-off system. If you want even more foam, I’d replace a couple of glucosides, but I think you can improve foam without doing that.

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@Abdullah You can check a couple of very nice books: “Liquid detergents” and “Handbook of detergents part E: formulation”. There are some sites where you can download them for free like Genesis library.

You can also find papers like this one: https://www.researchgate.net/publication/7756634_Mixed_Solutions_of_Anionic_and_Zwitterionic_Surfactant_Betaine_Surface-Tension_Isotherms_Adsorption_and_Relaxation_Kinetics. Seach for the terms “synergy” and “mixed surfactants”. 

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@Abdullah I understand, but every formula has specific needs, and the ingredients you are listing as preservatives are actually preservative boosters rather than preservatives. Companies nowadays sell them as green or natural preservatives, but most of them lack of activity against specific strains. In very simple formulas, they might work more or less combined, but if you have extracts, proteins, starches, not only you’ll need higher amounts of some of them, they might fail to protect against certain microbes (not to mention that adding them in the wrong way to an emulsion, when you have solubilizers or emulsfiers, could get them out of your water phase, which is the one you want to focus on), so again, it depends on your formulation needs. 

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@Blue_Lavander A chelator not only traps unwanted metal ions, but it also improves the performance of preservatives, so yes, I’d recommend adding one. I believe your vitamins are way too high, especially the ascorbic acid. Propylene glycol is also definitely high, considering also that it’s not only an penetration enhancerm but also a known allergen beyond 4-5%. Polysorbate is also high, and I’d check first what is it that’s causing the loss of clarity (maybe even the very low pH could contribute, and actually, it’s lower than the skin pH which is roughly in between 4.5-5.5…reducing the amount of Tocopherol could also help).