Home Cosmetic Science Talk Formulating General required Hlb in emulsion seems more theoric science?

  • required Hlb in emulsion seems more theoric science?

    Posted by Fekher on February 11, 2019 at 9:27 am

     hello friends i want sharing my experiences in o/w emulsion .
    So as abstract such emulsion needs to calculate the required hlb of our oil phase hlb(oils) = hlb(oil1)* x(1)+…+hlb(oil n)*x(n)
    where x(n) =( % of oil(n) in oil phase /100)
    So to have good emulsion almost we need too emlsifiers where hlb (emulsifiers)= x(emulsifier 1)*hlb(emulsifier 1) +x (emulsifier 2)* hlb(emulsifier 2)  must be equal hlb(oils)
     Knowing that hlb(emulsifier 1) > hlb (oils) and hlb(emulsifier 2) < hlb (oils) .
    however according to my experiences
     I made very stable o/w emulsion petrolatum hlb=7 in water using cetearth 25 also texture of emulsion is  good. knowing that hlb(ceteareth 25) =15, 7  so it is clear that hlb(petrolatum) and hlb (ceteareth 25) are soo far same i did with white bee wax and emulsion is soo stable knowing hlb(beewax)=12 far from hlb(ceteareth 25) so how emulsion is stable however hlb are differents?
     hlb (olive oil)= hlb (petrolatum)=7
    using same level and same emulsifier ceteareth 25 emulsion with petrolatum is fine not case of olive oil where cream have bad texture and seperation phases exist .
    Note : even in industriel formulation i made verification and i find that the low of required hlb is not respected that means hlb ( emulsifiers) is not equal hlb(oils).
    Any one have explication?
    @Perry @Dirtnap1 @Chemist77 @ngarayeva001

    Fekher replied 5 years, 9 months ago 3 Members · 4 Replies
  • 4 Replies
  • NeilL

    Member
    February 11, 2019 at 11:07 am

    HLB is a good starting point when it comes to selecting emulsifiers. However this is not the only factor in making a stable emulsion. A stable emulsion is one where the continuous phase (in your example the water phase) has a large viscosity. This helps to stabilize the dispersed droplets of oil as it prevents coalescence of the droplets. Also if the density of the continuous and the dispersed are equivalent this also helps stability. HLB theory is exactly that a theory to help provide a starting point however there are many more factors to forming a stable emulsion.
    I hope this helps you :)

  • Fekher

    Member
    February 11, 2019 at 11:23 am

    Thanks @NeilL actually you argument is soo clear thanks for information.

  • ngarayeva001

    Member
    February 11, 2019 at 12:20 pm

    @Fekher, I had a lot of back and forth with HLB system. I used to calculate it before but many experts say it’s just a starting point, and if you have good emulsifiers blend such as glyceryl stearate/PEG100 stearate you don’t really need to calculate HLB.
    I don’t really see much difference when I do calculate and don’t calculate HLB (but I don’t do proper stability testing, what I mean by no difference is that I see no separation for 5-6 month in room temperature). Also HLB ignores thickeners that do not have emulsificaton properties but act as co-emulsifiers (cetearyl alcohol, cetyl alcohol etc).

  • Fekher

    Member
    February 11, 2019 at 12:45 pm

     Thanks a lot @ngarayeva001 for your interesting share.

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