ketchito
Forum Replies Created
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Since you’re not using a big amount of silicone emulsion, the issue might not be to visible. Usually, a higher amount of silicone is used in conditioning shampoos. In one formula I had, with around 3-4% of a silicone emulsion (50% active), I saw creaming after 1 month at 40°C, so I had to add Carbopol to stabilize it.
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pH itself is not an issue, but the use of higlhy basic or acid substances, which are not present in your formula.
There’s nothing really obvious, but I’d advise to greatly reduce Glycerin (15% is too much, you could use around 5%). Also, Tocopheryl acetate is too high (it’s not active as antioxidant to protect your formula, and in your skin it still needs to be converted), I wouldn’t add more than 0.2%. Ceteareth-20 is also very high (you don’t need more than 0.5% depending on your oil phase, which in your case is not too high). And don’t forget to add a broad spectrum preservetion system, even if you’re still designing your formula.
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Can you try one sample without Potassium sorbate? If your formula is sensitive to electrolytes, adding potassium sorbate could bring your viscosity down (I add it during the cool down phase and with very low shear, to prevent viscosity loss). I’d be better though to use Sodium benzoate. Phenoxyethanol could also reduce your viscosity.
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Which type of dyes your’re using? If you’re using cationic dyes, that might be the reason.
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Anionics foam better at higher pH. It’d be weird that CAPB impairs color stability. Also, putting your sample in the fridge and taking it out does’t make much sense for color (that’s the freeze-thaw stability, but that’s usually done for emulsions). For color fade, you normally expose your product to UV light, that’s why I suggested to put it under sunlight.
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Amodimethicone is a cationic silicone. Your Cyclopentasiloxane (and) Dimethiconol will give you a different effect. If you are using some quat (like Behentrimonium chloride), you could i crease it a bit and replace Amodimethicone by Dimethicone (1000 cSt would be OK) at the same level.
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It might be the case that your emulsion is sensitive to low levels of electrolytes (when you react NaOH with EDTA, you form a salt).
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You might need to add more of your glycolipids.
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Can you make a sample without NaOH? Maybe it’s an issue with your manufacture method.
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You can place samples to direct sunlight, always with a benchmark on the side, as a reference of how much your color should last.
Now, a rapid change as you described doesn’t occurr under normal conditions, so check if something else could be affecting your product. Is there a sudden change in pH as well?
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Some high melting point material from your oil phase could solidify when in contact with water, especially if there’s not enough mixing, and if your water phase somehow cooled a bit. It’s just out of precaution.
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Did you see any difference in performance? In an emulsion, since they both have more or less similar melting point and chemical structure (with minor changes), I wouldn’t expect any significant difference in performance.
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It’s best to have your oil phase completely melted separately, so you make sure everything is alteady in a liquid state. Also, you usually add the oil phase slowly to the water phase, to allow for better mixing. And in practice, it’s always best that your water phase is a little bit higher in temperature than your oil phase.
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Hi! Could you describe what went wrong with your batch, and what you want it to look like?
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Try removing Sodium chloride, and increasing viscosity only with either Cocamide DEA or CAPB.
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Bring the pH closer to 8.5-9.0. It that doesn’t work, chances are your system is too sensitive to sodium chloride. You can reduce LABS and increase your SLES.
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No worries, it’s my pleasure. We are all here to help each other. Good luck!
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I agree with @luttie . In case of loss of foam, I’d check two things: turbidity (thic could mean that your SDBS after neutralization is interacting with your NaCl, and not liking it very much, I’ve seen that happening few times, and after some time, the turbity turns into a sedimento of part of your surfactant), or pH drift (anionics foam better at higher pH, being this more important in the case od SDBS).
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Propylene glycol will for sure reside in the water phase of your emulsion.
Regarding your emulsifiers, Glyceryl stearate SE has potassium (or sodium) stearate as emulsifier (Glyceryl stearate is a structuring agent) and that requires high pH to work as such, but your preservative system has two organic acids that require low pH to be in their active form, so you have a conflict there. Your lauric acid will probably be neutralized if you choose to use a high pH to favor your emulsifier, and might not work the way you expect.
Also, limonene is a known allergen, so be careful with it. Check again your oil phase, not all the ingredients you mentioned are part of the oil phase.
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If you’re preparing the two phases (oil and water phases) separately, and then mixing them together, you could melt your BTAC with the whole oil phase, so you don’t have problem having a homogenous mixture (BTAC has usually the highest melting point of thw waxes). Then, add slowly the oil phase into the water phase with high shear, and keep both temperature and shear for some time (I do that for at least 20 min). Then start cooling down with more or less half the speed you used for your emulsion.
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Some formulas can’t hold high amounts of electrolytes. Try one sample without the Mg ascorbyl phosphate. If that works, the add it in the cool phase, but I’d suggest to add less.
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Just out of curiosity, what’s your preservative system?
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I’d better replace your glucoside with a mild anionic surfactant. There you could see a synergy with CAPB.
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“I also note that preservative adequacy was tested independently of container design. As we are all aware, container design is a big factor in protecting consumer skin care products”.
There are few studies pointing about the negative effect of a bad chosen package (not only by removing some preservatives from the bulk, but also by allowing higher contact and transfer of microbe), so I wouldn’t say packaging is necessary a barrier to prevent contamination, at least not all the time.
Also, the point that @PhilGeis made constantly about in-use testing is very relevant, and is unfortunately something that only big companies do. GMP conditions are ideal and something that won’t happen once the consumer starts using the product.
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The capacity of PG to drag your hormone into the water phase will depend on your hormone’s partition coefficiente.
In the case of your emulsifiers, I’d choose a system that doesn’t require neutralization. I’ve seen Glycery stearate (and) PEG-100 stearate being used im topical creams, but you need to check which type of emulsifiers (or emulsions) are better to deliver your type of active (there are several papers on the matter).
About your nonanol, I’m kind of concern. The point is that on the papers you linked, the delivery system is different (none are emulsions). Chances are that your nonanol would rather go and form part of the interface of the emulsion, and not perform as penetration enhancer. Lauric acid could also behave the same way (like Stearic acid does when it’s used). Penetration enhancers that @chemicalmatt mentioned are the most used and in this case, might seem like a better choice, but you can still test your system and perhaps compare it to one with those others ????
@PhilGeis raised very good points. Also, how would you evaluate penetration of your actives? If I remember well, usually sections of skin or skin models are taken, and the active is extracted with solvents.