ALS formula thickening problems again!

Hello there!

I have had a bit of trouble with thickening my ALS/CAPB formula... it is all nice and thick up until i add my essential oil blend in. (it is meant to be a simple handwash with a citrusy EO blend)

I have tried adding salt, adding more CAPB, adding more ALS and adding carbopol (though i am trying to avoid this) to no avail..

Any other suggestions? I am at a loss :(


  • PerryPerry Administrator, Professional Chemist
    Add less oil.  Also, consider using some solubilizer nonionic surfactant like Polysorbate.

    What benefit are you trying to provide by including the oils?  

    You are running into a simple fact of surfactants, they are really good at removing oils.  So trying to put oils in the formula or even getting it to deliver to the surface is extremely difficult.  

    If it is just for marketing reasons, cut the level down to 0.1%.  That should stop the negative viscosity effect.
  • DavidWDavidW Member, PCF student
    How much oil (%) are you trying to put in?  Perry is correct.  You can also try premixing your oils (at a low percent) into the ALS.  Some oils will go in and some won't. 
  • Hi @perry and @davidW thank you for your responses. I am trying to add in 0.65% of an EO blend that is high in citrus oils... 

    I also have an alcoholic extract in the formula, albeit at a low percentage.. is alcohol known to be incompatible with such surfactant formulas?
  • hi guys, I tried adding 1:1 polysorbate 20 premixed with the EO blend, but it didn't work! Also, reducing the pH from 7.5 to ~6.5 also drastically reduced the viscosity!

    should i be using more polysorbate? or a combination of polysorbate 20 and Cremophor? 
  • this extra information might help...

    it is a ALS, Cocoamindopropyl Betaine and Cocoamide DEA system. its not my formula, i have merely been using this as a template/base. is this template even worth working off?
  • DavidWDavidW Member, PCF student
    IF you are using polysorbate, you need to start at 3 parts poly to each 1 part oil.  However, the polysorbate will reduce viscosity most likely and then you have to ry thickening it back up.
  • AylaAyla Member

    I think 0.65% of EO is a bit high.

    You could try Solubilisant LRI from Sensient. It worked well for me.

  • PerryPerry Administrator, Professional Chemist
    7.5 pH?  That seems pretty high.

    I think if you could list your entire formula and % you might get better suggestions.
  • aqua - 48%
    glycerine - 5%
    ALS - 20%

    Adjust to pH 4.5

    Cocoamide DEA - 15%

    Phenoxyethanol - 0.55
    Fragrance - 0.65%
    alcoholic  extracts - q.s.

    Cocoamidopropyl betaine - 11%

  • PerryPerry Administrator, Professional Chemist
    edited April 2015
    Wow, that's a lot of amide and betaine in the formula!

    More typical would be...

    ALS = 15% (on an actives basis)
    Cocamidopropyl betaine = 5% (on an actives basis)

    Most companies avoid DEA containing ingredients because they have to be listed as carcinogens on California's Prop 65 list.  In this formula you wouldn't really need it.
  • So i should remove DEA completely and thicken with salt?
  • ozgirlozgirl Member, PCF student
    I have never seen Cocamide DEA used at more than about 2% in this type of formula. You can replace Cocamide DEA with Cocamide MEA.
  • I well go with Sepigel 305 without changing the initial formula. It's going to help with thickening as well as with the emulsifying the oils. I we'll start with 0.50 %. You'll see if you need higher viscosity you can increments 0.25% up to desired viscosity. You can go as high as 1.50-3.00 % or more if needed.
  • PerryPerry Administrator, Professional Chemist
    You don't need the Cocamide DEA.  You can get plenty of thickening with the ALS / Betaine blend plus salt.  No other thickening system required.
  • Chemist77Chemist77 Member, PCF student
    Agree with @Perry, Cocamide DEA just modifies the salt curve rather than being a thickener itself. You can avoid it altogether and either go Perry's way or @Venera's, though I would be interested to know the final performance with Sepigel 305. 
  • @Perry You mentioned that the CAPB should be formulated at a 5% "active base". Most CAPB I've come across is only 30% active. So assuming that @cawarra has CAPB that is only 30% on an active basis he/she will only have 3.3% active material in the formula. And assuming he/she has a CAPB that is 50% active, 11% CAPB is 5.5% active material in the formula. Am I confused about how that works? I'm still a little fuzzy on this topic. 

  • @CosChemFan I understood it as the latter: i would have to use 10% of my 50% CAPB to get an overall 5% CAPB activity in the final formulation? is this correct? 

  • i did a formulation as below

    water - qs
    glycerine - 5
    ALS (26%) - 58

    Adjust to pH 4.5

    alcoholic extracts - 2
    phenoxyethanol - 0.5

    cocoamidopropyl betaine - 10
    EO Blend 1

    The EO is at 1% because clients wanted it to have a strong fragrance... Viscosity is beautiful when i add CAPB in and give like 3 stirs, but with subsequent stirring, the viscosity crashes out.. is there a reason for this/is this normal??
  • It is. Your formula is no compatible with the fragrance formula.

    You may have another way around. Get in touch with the fragrance house and ask them to adjust the fragrance formula to your formula. Most of them are very helpful. You can provide them with approximately 1kg base without fragrance, so they can have same material to work with.

    Out of curiosity, have you tried Sepigel 305


  • PerryPerry Administrator, Professional Chemist
    You've got it.  11% of a 50% active ingredient is 5.5%
  • CosChemFanCosChemFan Member
    edited April 2015
    Thank you for responding! So @Perry I guess I'm looking for further clarification as to why you said cawarra's formula had too much CAPB? Or were you making a general statement that the DEA + CAPB was too much? I just want to be sure I'm not over/under doing things over here in my formulas  :)).

  • PerryPerry Administrator, Professional Chemist
    Hello @CosChemFan - Sorry, I didn't consider the % activity when I was answering.  I believe the CAPB we worked with at Alberto was 100%.  Although I could be remembering it wrong.
  • Thank you @Perry!
  • @venera Thank you for that... unfortunately, ihave developed the fragerance ourselves based on the aroma alone and i have no expertise in fragrance compounds! :( i am not sure what i will do now. I have yet to use sepigel 305 as i am waiting for it to come in.

    I tried thickening the above with salt but it seems the sample with the most ideal viscosity was the control (no salt) because i didn't stir it much(the more i stir it, the thinner it gets, so when i try to dissolve the salt in by stirring, the product goes super thin)! i assume this high viscositywill crash out over time? 
  • Bill_TogeBill_Toge Member, Professional Chemist
    edited April 2015
    this is the chemical structure of CAPB

    at pH 4.5, the carboxylic acid group on the end is protonated, and no longer carries a negative charge, so the overall charge on the molecule is positive

    the sudden increase in viscosity is because the positive charge on the CAPB is attracted to the negative charge on the ALS, and the two come together to form a transient insoluble "gel", which breaks down when the CAPB is fully dispersed

    try adding it at pH 7 instead of pH 4.5 and see if you get the same effect; I'll bet you won't
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • and the two come together to form a transient insoluble "gel"
    Thanks for that, Bill. That explains an early experiment when I was trying to learn about surfactants; I accidentally created a big clear rubbery ball that bounced around the table.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • I used the proper amount of ALS and CAPB and its all good now! thanks everyone! will also be trying ANTIL® Soft SC . will update..

    @venera: i got some of spigel in.. i didnt use it on an ALS formula, but i used it on a laponite cream and it thickened beautifully!!
  • hello guys.. 

    my ALS and CAPB forumla has been great so far but its not great in 40C stability (it goes a little thin)... and pointers??
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