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Preservative help
Hi everyone,
I’m working on two formulations—a leave-in conditioner and a deep conditioning mask, both with a pH of 4.5—and I’m having some trouble selecting a stable, broad-spectrum preservative that meets the demands of my target market (no parabens or formaldehyde donors). This change is primarily driven by <strong data-start=”466″ data-end=”483″ style=”font-family: inherit; font-size: inherit;”>market demand, rather than scientific concerns.
I’ve run several trials, and I’d love some guidance from those with more experience in this area.
What I’ve Tried So Far:
Liquid Germall Plus worked well in both formulas, but I’m trying to move away from it due to market preferences (consumers often avoid parabens and formaldehyde donors, even without fully understanding the science).
Euxyl K712 + Saliguard CGZ (booster): Caused a significant drop in viscosity in the deep mask immediately upon addition. It recovered somewhat after 2 days, but the texture was still inferior compared to Germall Plus.
Geogard 221 ans Saliguard CGZ as booster in the leave-in: Separated after 2 hours. The formula was previously stable, so the preservative seems to be the issue. Only other change was adding sodium phytate in. (0.1%)
Euxyl K940 in the mask: Good initial viscosity, but during 38°C incubator testing, the emulsion darkened slightly (texture and scent stayed stable). It’s now been 6 months in real-time with no issues.
Nipaguard SCE in the leave-in: Passed freeze-thaw and real-time testing, but separated in the incubator after a month. I later learned it’s not fully broad-spectrum, despite what my supplier claimed.
Euxyl PE9010 in the leave-in: Separated within a week.
What I’m Planning:
I’ve ordered Dermosoft OMP (do I need a booster, it says broad spectrum) and EDTA (to replace sodium phytate). Hoping these might help stabilize the system. They arrive Friday, so I’ll be testing them soon. I am now doubting the dermosoft OMP is suitable for these products (don’t ask me why ;).)
What I’m Looking For:
A fully broad-spectrum preservative system
Free of parabens and formaldehyde donors
Preferably mild and more “naturally positioned”, though I’m open to phenoxyethanol-based systems
Compatible with high-water formulations (like my leave-in)
Won’t cause viscosity loss or emulsion instability
I did study with IPCS and graduated last year, but we didn’t go deep into preservative systems, so I’m still learning. Every time I think I’ve found the right one, I run into issues like separation or thickening failure.
Any advice, recommendations, or experience you can share would be really appreciated!
Thanks in advance!
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3 Replies
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Perhaps the issues are a result of concentrations and unnecessary complexity that distinguishes these commercial systems.
keep phenoxy at or less than 5000 ppm (perhaps EHG but 9010 separated), organic acid - esp. benzoate 3000 ppm (or try benzyl alcohol), EDTA.
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ok, thank you for the reply.
Is there a preservative system that you can recommend for the type of products I am talking about.
I am using Aminosensyl ultras MB as my cationic emulsifier. I have checked compatibility with everything I am using in the formula, but I am just having a hard time deciding on a preservative.
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Think you’ve got yo work through an experimental process - 1st phase achieving a stable formula. next need establish preservative efficacy. I’m surprised the stability is such as issue with your formulas.
I wish folks could use single preservative chemicals but those are commodities with low margin commodity pricing so not as av in small quantities.. Proprietary blends warrant specialty pricing and are marketed in part for that but tossing in so much stuff risks stability problems and rarely are these actually “broad spectrum” through a wide pH range.
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