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Guar Gum (Cationic) with nonionic surfactants and anionic emulsifier
Hi,
I am working on a dog shampoo and used guar gum at 0.3% for its conditioning benefits as well as thickening. The primary and secondary surfactants are nonionic and amphoteric, but I am usesing 2.5% Glyceryl Stearate Citract at 2.5%. The water phase was sufficiently fhick, but after the emulsion and add the surfactants, the formula lost viscosity. Here is the basic formula:
**D. I WATER 43.95% GUAR GUM 0.30% PANTHENOL 0.05% GLYCERIN 4.00% ALOE VERA JUICE 0.50% 0.00% AVOCADO OIL 1.00% ARGAN OIL 0.10% COCONUT OIL 0.80% GLYCERYL STEARATE CITRATE 2.50% CETYL ALCOHOL 1.00% Lauryl Glucoside 3.00% Decyl Glucoside 25.00% COCOMIDOPROPYL BETAINE 12.00% PROBIOTICS 3.00% ROSEMARY EXTRACT 0.10% HONEYSUCKLE (UAG 15029/00) 0.00% LINATURAL ULTRA 3 2.00% potassium
hydroxide0.70% Any ideas or suggestions?
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6 Replies
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Gura hydroxypropyltrimonium chloride is in theory incompatible with glyceryl stearate citrate. The latter though is composed of mostly glyceryl stearate plus some % (theoretically anionic) glyceryl stearate citrate. Depending on the degree of modification of guar gum and the % of real GSC, adding some guar can increase stability and viscosity or it might kill either of which completely. To determine this, you could either use a zetasizer or do a trial and error panel using different proportions.Alternatively, replace GSC with a nonionic, amphoteric, or even better a cationic surfactant if you think that you really need GSC. After all, you already have a bunch of emulsifiers/surfactants in there. For increased oil phase viscosity, try pure glyceryl stearate. I wouldn’t know why GSC should add any benefit to your formula stability-wise.Out of curiosity, what is in your formula that makes it so acidic that you have to add 0.7% KOH and what final pH do you get? Being in an acidic pH renders GSC fairly nonionic-like and your guar should (again in theory) increase stability whereas a high pH renders it very anionic and small amounts of quaternised guar should still be okay. On the other hand, it is possible that said combination leads to an increase in stability but produces smaller oil droplets and that’s where loss of viscosity comes from. Without a zetasizer you won’t be able to really tell what’s going on. Although, a good microscope might give strong indications too
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I kinda zapped that you don’t have a standard emulsion but a shampoo… that might change everything. Did you try thickening with salt? Might work.
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Try replacing the Decyl Glucoside with Cocamidopropyl Hydroxysultaine or Sodium Cocoyl Isethionate. The Glucosides are notoriously difficult to thicken.
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Hi, Thank you for your comments and suggestions. The pH was low, I believe because of the Aloe Vera Juice, although, I can’t be certain. The pH needs to be above 7 for the client. I will replace the GSC with something else, perhaps Ceteareth-20 and play around with some of the other surfactant suggestions. The client wants as natural and mild as possible. Thanks so much!
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oh, for clarification the KOH is an 18% SOLN.
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Glucosides notoriously crash guar gum and cationic guar. Change out those surfactants as Mark suggests and you’ll see better stability.
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