Menthol in gel

I am trying to make a gel that contains 10% menthol crystals that is being requested by a customer, however at that high of a percent, menthol either will not mix in to the gel or it starts to look more like an emulsion.  I have used it with Carbopol 940, Ultrez 10 and Ultrez 20. I have tried using Polysorbate 20 to help solubilize some of the oil and it works decent when using 5% menthol, 5% tween 20 but I wasn't sure what the limitations on using tween were and if I would be able to take it up to 10%.  There is also 10% IPA in the formula which I normally dissolve the menthol crystals in first.

Anybody have any suggestions on how I might be able to get up to 10% menthol and still make a nice gel?  Thanks!

Comments

  • FekherFekher Member, Professional Chemist
    edited September 30
    @mhart123 try hot process may you will not need solubulizer .
  • @Fekher I've tried a few different ways with heat.. I've dispersed the carbopol 940 and heated to 50C until hydrated, added the menthol directly in, and then neutralized and also neutralized first and then added the menthol but either way once the carbopol 940 is neutralized the gel separates and the menthol does not go into solution. I've also heated the water first and added the menthol, and then added carbopol but same thing happens.
  • FekherFekher Member, Professional Chemist
    @mhart123 ; great job . So the second plan you can use 3:1 parts ( solubilizer: menthol ) it will almost work however you will use 30 %  solubilizer wich is too much or try high level of alcohol ( ethanol , ISP)  try differents level to find the minimum required level to solubilise 10 % of Menthol .
  • @Fekher Thanks I will try that out! 
  • Not sure what your entire formula requires but I recently made a hand-sanitizer type gel with menthol (not 10% though) using  ultrez 21 and 60% Denat. Alcohol.  

    I think you can take the tweens up as high as you want, but they start to get very sticky.
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