The “Most Searched Products” section in Innovadex’s New Trend Tuesday e-newsletter highlights several ingredients each week that are popular with users of the search engine. One that you may have noticed in the recent past is SEPIGEL™ 305 (Polyacrylamide, CI3-14 Isoparafin, Laureth-7-Seppic), a liquid dispersion polymer (LDP) used to thicken oil in water emulsions and gels. I’ve designed the following overview as a research reference for formulators on this commonly used ingredient.
Launched around 1990 by SEPPIC, SEPIGEL™ 305 was one of the first LDPs on the market and represented a significant improvement over Carbomers in terms of formulating ease and low PH tolerance. SEPIGEL™ 305 is produced by crosslinking polymerized 2-Acrylamido-2-methylpropane sulfonic acid (AMPs) with a difunctional acrylamide monomer like N,N’-Methylenebisacrylamide. The low PH thickening ability of SEPIGEL™ 305 is due to the low PKa of the sulfonic acid group compared to the carboxyl group of acrylate based polymers.
LDPs are common thickeners used in personal care products and have displaced powdered Carbomers in popularity. They are produced by polymerizing monomers in a water-in-oil emulsion and the water is then removed. A hydrophilic surfactant is added to facilitate hydration when added to water.
- Extremely easy to process, hot or cold
- PH stable 3-12
- Can formulate excellent low PH self-tanning products or Salicylic acid products
- Excellent skin feel with good pickup
- Can make stable emulsions without using additional emulsifiers
- May be cheaper on an active basis then powdered Carbomers and acrylates
- Compatible with insoluble salts like iron oxides or zinc oxide (>PH7). Carbomers are not compatible
- The polymer in LDPs can settle out over time
- Can’t make clear gels
- Very salt sensitive
- 7% active polymer 59.5K cps, .6% Sodium Chloride
- 2% active polymer 60K cps, 0% Sodium Chloride
The views, opinions and technical analyses presented here are those of the author or advertiser, and are not necessarily those of ULProspector.com or UL. The appearance of this content in the UL Prospector Knowledge Center does not constitute an endorsement by UL or its affiliates.
All content is subject to copyright and may not be reproduced without prior authorization from UL or the content author.
The content has been made available for informational and educational purposes only. While the editors of this site may verify the accuracy of its content from time to time, we assume no responsibility for errors made by the author, editorial staff or any other contributor.
UL does not make any representations or warranties with respect to the accuracy, applicability, fitness or completeness of the content. UL does not warrant the performance, effectiveness or applicability of sites listed or linked to in any content.
19 Responses to “Popular Ingredients – SEPIGEL™ 305”
Whenever I use a thickener (Sepigel, Aquagel or Simugel in my product it leaves an oily feel and look on the skin especially on the hands. Any suggestions ?
Julian Levine Dip. Pharm. D.Hom
Hi Julian, thanks for your question. Liquid dispersion polymer based thickeners like Sepigel 305 use oil based
emollients as carriers for the polymeric thickener. The carrier represents
around 50-60% of the dispersion. If you want no oily residue skin feel, you
need to use powdered thickeners like Carbopol Ultrez 21 (Lubrizol) or
Aristoflex AVC Clariant).
Alternatively try Dow Corning RM 2051 Thickening Agent which is similar chemistry of polymer and will mix in the same way but uses silicone instead of isoparaffin as the oil – this should give a nicer skin feel.
Dow Corning RM2051 is polyacrylate based. So, pH range is shorter than Seppic 305
May I ask a question?
As INCI suggests, I though SEPPIC 305 is polyacrylamide (-CONH2) and not AMP….but according to your text, I may be wrong…
Sepigel 305 is an AMPs based polymer crosslinked using Bis Acrylamide. The INCI listing for Sepigel 305 is incorrect.
¿puedo hacer una mezcla de RM 2051 3% y sepigel 305 2% en una crema facial-corporal?
If I understand the polyacrylamide component of Sepigel 305 correctly, it is a ‘crosslinked ingredient’ versus just ‘polyacrylamide with a specific molecular weight’. Can you please confirm that this is accurate and correct? Thank you.
Quick Follow Up Question: Based on your comments above, what is the correct INCI for Sepigel 305? Also, is there a UNII code for this product? If not, then can you please provide the full descriptive name and UNII Code for the polyacrylamide (i.e,, 1500 MW, resin modified, etc.)?
Sepigel 305 is a AMPs based polymer that has been crosslinked using bis acrylamide.
I have purchased Sepigel 305 to thicken a skin cream containing macadamia oil however it is not penetrating the skin please recommend a product that will give good penetration , would a propylene glycol or solvent help and how should it be added. Thanks
Your best best is to use some Lecithin in the formulation. Phospholipids in general are good penetration enhancers..
Can you use Sepigel 305 in a Rosacea Cream?
Is sepigel safe if ther is contacting with mouth?can i use it to make a food grade lotion?
This question would be best directed to the manufacturer. You can find their contact details in Prospector.
Thanks for your question!
UL Content Team
we use sepigel as thickener (2.5%) in cream base and pH value was 4. after a month the cream changed become solid like a tofu. what a factor involved to this problem? plz kindly give us alternative thickener suggestion.
The Sepigel may be crosslinked by something in the formulation. I can ‘t give any recommendations without knowing what else is in the formulation.
Thanks for reading,
Hi there, can sepigel 305 be used in a cleanser,
It will work only in an emollient based oil in water cleanser that doesn’t contain any salt. I won’t work in surfactant based cleansers.
Thanks for reading,