Home Cosmetic Science Talk Formulating O/w or w/o emulsion ?

  • O/w or w/o emulsion ?

    Posted by Miassa on November 13, 2022 at 6:22 pm
    Hello , 
    I have a question about emulsifyers : 
    If i use both ceteareth-20 and glyceryl monostearate to prepare a cream the final result will be 
    O/w or w/o cream ??
    Is it real that if we use more than 3 emulsifyers , the sens of the emulsion follows the lowest hlb ?? 
    Regards
    gordof replied 2 years, 1 month ago 5 Members · 6 Replies
  • 6 Replies
  • OldPerry

    Member
    November 13, 2022 at 6:41 pm

    Probably Oil in Water but it depends on how much oil and water is in your system and how you make it.

  • Pharma

    Member
    November 13, 2022 at 9:12 pm

    Miassa said:

    …the sens of the emulsion follows the lowest hlb ??

    What do you mean by this?
    The type of emulsion is determined by all the emulsifiers and their ratios (as well as the oils used and the way you prepare the emulsion). The HLB system is also only applicable to a very narrow set of formulations. HLD would be more accurate but once you have lamellar structures, no system is currently able to accurately predict the outcome.
  • Miassa

    Member
    November 14, 2022 at 8:52 pm

    Thank you for your answers 
    So how can i know if my emulsion is w/o or o/w ??

  • Paprik

    Member
    November 14, 2022 at 10:39 pm

    You need to understand your emulsifiers - 
    Glycerol Monostearate - low HLB
    Ceteareth-20 - high HLB 

    Let’s say you use 10% lipids, 3% Ceteareth-20 and 0.5% GMS, you’d end up with O/W emulsion. If you would use more lipid (or lot more GMS) it would probably separate. 

    If you would use 75% lipids, 3% GMS and 0.5% Ceteareth-20 you will end up with W/O emulsion. 

    In other words, you need enough high HLB emulsifier to hold your lipid portion in O/W and low HLB emulsifier to hold you water portion in W/O emulsion. 

    Hope you got the idea? :) 

  • Pharma

    Member
    November 15, 2022 at 5:32 am

    Miassa said:

    Thank you for your answers 
    So how can i know if my emulsion is w/o or o/w ??

    You can try and calculate according to one of the systems or simply ‘measure’ the outcome. The most basic test is try and wash the cream of. A more advanced and visual one uses a water and an oil soluble colour. And you may also measure electrical resistivity.

  • gordof

    Member
    November 21, 2022 at 9:02 am

    As Pharma said just add some Water Soluble Colour and add a 1 % Water solution of it on top of the product if it is Oil in water the Product will be colored over time if it is Water in oil Colour will stay at the top. 

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