Home Cosmetic Science Talk Formulating Unstable liquid lipstick

  • Unstable liquid lipstick

    Posted by PeiHoong on December 14, 2017 at 12:54 pm

    Hi all, 

    Recently I’m doing some liquid lipstick projects. I’m making one anhydrous and the other emulsion. However, I’m facing stability problem, the liquid lipsticks are having separation problem even I used 10% of bentone +3% silica to suspend my system. Therefore, I would like to ask for your kind advice on my formula. Is that any idea to make a less viscous yet stable liquid lipstick? 

    Thank you in advance. 

    PeiHoong replied 6 years, 9 months ago 2 Members · 5 Replies
  • 5 Replies
  • Bobzchemist

    Member
    December 16, 2017 at 12:12 am

    Did you use enough shear to fully develop the bentonite? Have you considered using pre-made gels?
    Did you use fumed silica?
    Are you using any waxes?

  • PeiHoong

    Member
    December 18, 2017 at 8:09 am

    @Bobzchemist  yes, i’m using both bentonite and fumed silica under high shear but not waxes as i would like to make it cold process. However, there is still some oil(?) leaked out…

  • Bobzchemist

    Member
    December 19, 2017 at 2:44 am

    It is not possible to avoid oil leakage using only bentonite and fumed silica, even if you use organically modified clays, high shear, and the correct activating agent. Some leakage will always be present unless you can add some way of re-forming the suspension matrix after it’s disrupted. Using waxes to gel the solvents is the typical way of doing this. Finding a way to make a cold-process formula as stable as a hot-process formula will be a significant challenge.

  • PeiHoong

    Member
    December 22, 2017 at 12:58 am

    @Bobzchemist I see, thank you very much for your advice. I will try with hot process then. Thank you! 

  • PeiHoong

    Member
    January 2, 2018 at 7:15 am

    I have tried to use beeswax to stabilize the system but there is still some oil leakage….

    Btw, I found out that there are some products which actually use cold process in liquid lipstick, for example: Bourjois Rouge Edition Velvet (which is my benchmark). The link attached shows it’s LOI
    http://www.cosdna.com/eng/cosmetic_95ea135260.html

    Just wonder if the factors below influence the stability of liquid lipstick:
    1. Viscosity of dimethicone used. Is it better for me to use higher viscosity (~350cst) dimethicone? 
    2. Grade of Fumed silica? For silicone sytem, should i used hydrophilic grade or hydrophobic grade? (Theoritically should be hydrophilic grade as silicone is non polar, am I right?)

Log in to reply.

Chemists Corner