Home Cosmetic Science Talk Formulating Advanced Questions Are glycols like pentylene glycol soluble in oil?

  • Are glycols like pentylene glycol soluble in oil?

    Posted by formulatorN00b on December 19, 2021 at 5:27 am

    So The Ordinary released a new product, the Salicylic Acid 2% Anhydrous Solution.  The ingredients are as follows: 

    Squalane, Caprylic/Capric Triglyceride, Pentylene Glycol, Salicylic Acid, Oleic/Linoleic/Linolenic Polyglycerides, 4-t-Butylcyclohexanol, Hydroxymethoxyphenyl Decanone, Phenoxyethanol, Chlorphenesin

    I’m intrigued by how this product seems to be oil-based but includes Pentylene Glycol.  Is the pentylene glycol oil-soluble or is it kept stable in the formulation by some other ingredient?  Also, if it is, is this property similar to other glycols, like glycerin, propylene glycol, or 1,3 propanediol?  I was under the impression these are all only water-soluble ingredients.  I tried to Google & couldn’t find much on this. 

    formulatorN00b replied 2 years, 10 months ago 2 Members · 2 Replies
  • 2 Replies
  • Pharma

    Member
    December 19, 2021 at 9:44 am
    Lipophilic glycols are oil soluble/miscible. Pentylene glycol is just in between water and oil soluble. Shorter chain ones, like the others you mentioned, are only alcohol andwater soluble. These may be incorporated using emulsifiers/co-emulsifiers.
    This Ordinary product likely contains pentylene glycol as part of SymSitive (+ 4-t-butylcyclohexanol) and therefore, the amount should be in the low % range which is likely low enough for full dissolution in the oil base.
  • formulatorN00b

    Member
    December 19, 2021 at 5:13 pm

    Pharma said:

    Lipophilic glycols are oil soluble/miscible. Pentylene glycol is just in between water and oil soluble. Shorter chain ones, like the others you mentioned, are only alcohol andwater soluble. These may be incorporated using emulsifiers/co-emulsifiers.
    This Ordinary product likely contains pentylene glycol as part of SymSitive (+ 4-t-butylcyclohexanol) and therefore, the amount should be in the low % range which is likely low enough for full dissolution in the oil base.

    Thank you so much for this answer! That makes sense to me.  

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