Home Cosmetic Science Talk Formulating How should I thin out a thick shampoo in production?

  • How should I thin out a thick shampoo in production?

    Posted by laeury on April 17, 2014 at 3:14 pm

    This was a basic cold process shampoo that the formulation chemist before me had where 0.5% sodium chloride, 0.10% citric acid, and 0.10% sodium hydroxide  was to be added.  This turned the shampoo into a thick gel with a pH of 10.8.  I have brought the pH down with citric acid to a 7 but need to get it thinner.  Any suggestions?  Water doesn’t seem to be helping.  

    oldperry replied 9 years, 7 months ago 6 Members · 9 Replies
  • 9 Replies
  • laeury

    April 17, 2014 at 3:31 pm
    DI Water 73.99
    jeechem Shampoo Conc# 8CL 25.00
    Tetrasodium EDTA 0.10
    Sodium Chloride 0.50
    Polyquaternium-10 0.01
    Fragrance 0.20
    Quaternium-15 0.0010
    Citric Acid 0.10
    Sodium Hydroxide 0.10
  • laeury

    April 17, 2014 at 3:32 pm


  • DavidW

    April 17, 2014 at 5:09 pm

    Take a sample in a beaker and try adding polysorbate 20 to it.  See how much it takes to thin it out.

  • bill_toge

    April 17, 2014 at 6:40 pm

    hexylene glycol (IUPAC: 2-methyl-2,4-pentanediol, CAS # 107-41-5) is a very effective thinner too

  • oldperry

    April 17, 2014 at 8:14 pm

    since you only have 0.5% salt in you could probably add more salt to get to the other side of the salt curve and it will start to thin out.  Take a sample in the lab and slowly add more salt (in an aqueous solution).  That should do it.

  • chemist77

    April 18, 2014 at 3:30 am

    Guess Perry’s proposal is applicable in terms of cost, hexylene glycol is a costly affair but no harm in trying. Next time though he should be careful with his conc mix because PEG 150 stearate makes it viscous like jell-o.

  • laeury

    April 18, 2014 at 7:57 am

    Thanks so much for the advice guys!  I ended up adding salt until it thinned back out.  His other two baby products I had carefully watched as they were produced for the first time in manufacturing.  They went well so I thought this one wouldn’t need my careful watch.  Boy was I wrong when they called me to come look at it!  He never wrote anything down that he did in the lab…just his formula.  So it makes me wonder if this happened to him in the lab.  Oh well.  Again, thanks so very much!

  • Bobzchemist

    April 18, 2014 at 10:54 pm

    Less salt would have worked too. Just sayin…

  • oldperry

    April 22, 2014 at 12:59 am

    I was assuming he was trying to save a batch but you are correct, adding less salt would work (and would be the preferred method).

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