Home Cosmetic Science Talk Formulating Best solvent for terpenes (terpinen-4-ol and nerolidol)

  • Best solvent for terpenes (terpinen-4-ol and nerolidol)

    Posted by JbeanRaz on August 30, 2019 at 9:26 am

    Hello Chemistry Experts!

    Please share with me what you think would be the best/optimal solvent for a hair serum that includes terpinen-4-ol and nerolidol.

    I have tried different solvents and so far Ethylhexyl Stearate seems to work best although it is too thin and needs thickening.

    I’ve also tried fractionated coconut oil with mixed results (didn’t seem to be as potent and found that some of the serum started to solidify).

    For regulations purposes here n Canada, I cannot use solvents already classified as “drugs” i.e. dimethicone, isopropyl myristate.

    The purpose of the serum is to kill lice. When tested on live bugs, it has immediate effect in the ethylhexyl stearate however when applied to hair of infected people, it runs down the hair shaft and thus the head lice are not sufficiently immersed and escape neutralization.

    If you can suggest a better solvent and substance that would thicken to more of a gel like substance, please tell me!

    Or, if the Ethylhexyl Stearate is the best solvent, how to thicken to a gel like product to trap the bugs in the hair?

    Thank you for your time and suggestions ☺️

    bill_toge replied 4 years ago 4 Members · 7 Replies
  • 7 Replies
  • MarkBroussard

    August 30, 2019 at 4:44 pm


    You can thicken your Ethylhexyl Stearate mixture with Phytol.

  • JbeanRaz

    August 31, 2019 at 9:51 am

    Actually, we did try usIng phytol as a thickener with the fractionated coconut oil and it had no effect at all. 

  • MarkBroussard

    August 31, 2019 at 10:47 am

    Yes, but did you try it with the Ethylhexyl Stearate?

  • pharma

    August 31, 2019 at 11:27 am

    Is there a reason why you didn’t try adding a standard oil thickener/gellant?

  • JbeanRaz

    September 4, 2019 at 5:54 pm

    No we didn’t try it with the ethylhexyl stearate. We can certainly give it a go and see what happens. 

    After sampling different solutions on peoples’ hair, I’m leaning more towards a stronger hold gel like substance to trap the bugs and eggs in the solution rather than a more liquid gel like substance that seems to run down the hair and off the parasites.

    Do you think the phytol will work better on the ethylhexyl stearate?

  • JbeanRaz

    September 4, 2019 at 5:59 pm

    We’re not at all averse to trying a standard thickener / gellant - just wondered if there is any in particular that is more effective. What is most important is to use the best solvent for the terpenes and then the best thickener for the mixture.

    Ideally a stronger hold gel like substance rather than a liquid gel that runs away from the scalp and down the hair shaft.

  • bill_toge

    September 5, 2019 at 9:28 pm

    for thickening, try some combination of hydroxystearic acid / hydrogenated castor oil / trihydroxystearin, they’re reliable thickeners in this kind of solvent

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