Home Cosmetic Science Talk Formulating NACL AND GLYCERIN IN WATER PHASE

  • NACL AND GLYCERIN IN WATER PHASE

    Posted by marytsiang on February 7, 2018 at 10:00 am

    What I cannot understand well, is, in which emulsions/lotions do I have to add in the water phase NACL, and when Ι dont have to.
    It has to be a stabization with ions,but I im not so sure about the chemistry that hides behind.
    I also would appreciate it if anyone could tell me the purpose of the glycerin in the water phase, apart from humecting.
    thank you in advance.

    chemicalmatt replied 6 years, 1 month ago 11 Members · 21 Replies
  • 21 Replies
  • das

    Member
    February 7, 2018 at 3:46 pm

    Depending on the rest of the formula sodium chloride can act as a thickener. If a buffer is what you need a salt like EDTA is more appropriate.

    Glycerin can be used as a solvent.

  • ozgirl

    Member
    February 7, 2018 at 11:21 pm

    It would be very unusual to add sodium chloride to a lotion at all.

    Sodium Chloride is used to thicken some surfactant systems (e.g. shampoos, body washes). It can also be used as an exfoliant in anhydrous scrubs.

  • duncan

    Member
    February 7, 2018 at 11:58 pm

    Electrolytes like Epsom salts (Mag Sulphate) are often seen in traditional formulations for water in Oil emulsions, but only at pretty low levels.
    Most emulsion systems are uncomfortable with high levels of electrolytes

  • oldperry

    Member
    February 8, 2018 at 12:09 am

    I’ve always found that NaCl in an emulsion leads to instability so avoided it.

  • belassi

    Member
    February 8, 2018 at 12:23 am

    Are you sure you’re not confusing shampoos with lotions?

  • marytsiang

    Member
    February 8, 2018 at 11:43 am

    I think I have NOT posed the question correct.I have been working a formula of foundation, W/Si, and one of my suppliers told me to stabilize the emulsion by adding 1% NACL in the aqua phase. This is why I talked for emulsions. I have also seen some formulas in creams/lotions which contain 1% of NACL. I was thinking that it must be an equilibrium between ions, for stabilizing reasons.. 

  • em88

    Member
    February 8, 2018 at 12:39 pm

    What is NACL?

  • marytsiang

    Member
    February 8, 2018 at 1:42 pm

    Sodium Chloride, NaCl.

  • belassi

    Member
    February 8, 2018 at 4:19 pm

    I would never use salt in a lotion. NEVER.

  • das

    Member
    February 8, 2018 at 5:47 pm

    Is not rare to see comercial formulas with cetyl alcohol and salt, but 0,1% maybe.

    I don’t see 1% salt in a formula other than a shampoo. Im curious, what’s on that water phase?.

  • ozgirl

    Member
    February 9, 2018 at 12:21 am

    The addition of salt for stabilisation seems to be limited to silicon and water emulsions.

    This article might be of interest
    https://pubs.acs.org/doi/abs/10.1021/ie401490c

  • belassi

    Member
    February 9, 2018 at 2:36 am

    about 0.05%

  • em88

    Member
    February 9, 2018 at 11:29 am

    Exactly as @DAS said, that is why I asked what was NACL. 

  • marytsiang

    Member
    February 9, 2018 at 3:10 pm

    Thank you all for the information. @DAS in the water phase there is just water, glycerin and sodium chloride..It seemed that for the moment it has been passing the stability test.as for the article @ozgirl thank you very much, very helpfull.  

  • bill_toge

    Member
    February 12, 2018 at 8:41 pm

    in W/O and W/Si emulsions, salt increases the surface tension of the water phase, allowing it to be emulsified (and stay emulsified) more easily

  • drbobverdient-biz

    Member
    February 13, 2018 at 12:10 am

    Actually salt lowers cmc of SAA which lowers the interfacial Tension:Unfortunately it can also cause a catotrophic phase transition leading to eventual Oswald Ripening followed by coalesce and instability!

  • marytsiang

    Member
    February 13, 2018 at 9:22 am

    thank you so much @Bill_Toge and @”DRBOB@VERDIENT.BIZ” your information is very helpful.

  • bill_toge

    Member
    February 13, 2018 at 9:31 am

    salt also brings you good luck if you throw a pinch of it over your left shoulder

  • drbobverdient-biz

    Member
    February 13, 2018 at 2:18 pm

    only if you are right-handed:lefties throw it over the right shoulder

  • doreen

    Member
    February 14, 2018 at 8:53 am

    :joy: :joy:

  • chemicalmatt

    Member
    February 15, 2018 at 5:32 pm

    Thanks again, Bill Toge, for livening this blog with both his science and his wit.  To enhance Bill’s insight: salts such as NaCl and Mg sulfate must be added to INVERSE PHASE emulsions (w/Si or w/o) to stabilize these just as Bill says, and also depending on the emulsifier type used.  Adding a salt to a standard o/w emulsion is a good way to DESTABILIZE it. I found that 2.0% salt in the water phase of the appropriate w/o or w/Si emulsion does the trick nicely, even though suppliers (Evonik,others) usually state 1.0% or less. Technical tidbit of the day: this is exactly how the trendy HIP emulsions are made. Word.

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