Home Cosmetic Science Talk Formulating need help with mineral sunscreen / pilling off when applying on skin

  • need help with mineral sunscreen / pilling off when applying on skin

    Posted by marimaster_3991 on September 13, 2022 at 12:45 pm

    Hi, there!

    I’m formulating a mineral sunscreen and i’ts been a nightmare lol 
    I’m using a combination of titanium dioxide and zinc oxide and a combinationg of hydroxyethylcellulose and xanthan gum to stabilize. Turns out it gets lumps all over the product after cooling down. Plus, when we apply it on the skin it seems to be pilling off, so frustrating! 

    I’m thinking it can be the gelling agents, but i’ve worked with both of them together before and had no problem; does anyone here ever had this kind of issue? or have any ideia of what can be causing this? 

    I appreciate any help/suggestions! Thanks :)

    marimaster_3991 replied 1 year, 9 months ago 3 Members · 4 Replies
  • 4 Replies
  • MarkBroussard

    Member
    September 13, 2022 at 12:55 pm

    @marimaster_3991

    You’ll have to post a full formula for anyone to be able to help you … just not enough info in your post to understand what might be causing the issue.  But one quick Q:  Are you adding ZnO and TiO2 powders and homogenizing or are you adding pre-mix ZnO and TiO2 in carrirer oils? 

  • marimaster_3991

    Member
    September 13, 2022 at 1:30 pm

    @MarkBroussard, hello! 

    I’m sorry, you’re right! This is the formula i’m referring to

    water —- qsp
    sodium gluconate — 0.15%
    magnesium sulfate — 0.5%
    propanediol — 2%
    hydroxyethylcellulose — 1%
    glycerin — 2%
    xanthan gum — 0,1%

    polyglyceryl-2 dipolyhydroxystearate — 3%
    sodium stearoyl glutamate — 0.5%
    glyceryl stearate — 2%
    caprylic/capric trigl — 5%
    c12-15 alkyl benzoate — 7%
    cetiol cc — 8%
    isopropyl palmitate — 5.5%
    polyhydroxystearic acid — 0.8%
    antaron v216 — 1%
    zinc oxide (coated triethoxycaprylylsilane_ — 13.5%
    TiO2 (coated hydrated silica, aluminum hydroxide, hydrogen dimethicone) — 9.5%

    preservative (pe + hg) — 0.8%
    tocopherol — 0.1%

    cyclopentasiloxane — 1.5%
    dimethicone — 1%
    belsil eg5 — 2%
    silica — 0,75%
    calcium starch octenylsuccinate — 2.5%

    And about your question, I’m adding both powders and homogenizing in the esters before emulsion. I do know it’s easier to handle these filters when they are pre dispersed but I have to work with what is available here :/ 

  • evchem2

    Member
    September 15, 2022 at 7:21 pm

    I don’t know what specific grades of xg and HEC you’re using but they could be contributing to pilling (esp in combination with the starch and silica), can I ask why you’re using all 4?  

  • marimaster_3991

    Member
    September 16, 2022 at 7:30 pm

    @evchem2 actually I wanted to formulate a fluid mineral sunscreen but couldn’t stabilize using only one gelling agent. The manager then decided to go for a more creamier formula. Since it is an w/o emulsion i had few options of gelling agents that are nonionic. Tbh I tried only xg yesterday and worked just fine, plus I didn’t feel the pilling effect anymore

    The starch and the silica actually gave a more dry touch feel. I’m not a fan of mineral sunscreen because of the white cast it leaves and the greasy feel, but at least using both powders kinds solved part of the problem

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