Ethanol as preservative - Chemists Corner

Formulating

Ethanol as preservative

Posted by padech on February 8, 2016 at 5:02 am

Hi everyone.

I’ve tried to formulate the insects repellent spray which have essential oil as active ingredient, polysorbate 20, PEG-40 Hydrogenated Castor Oil and Ethanol as solubilizer. I’ve wonder, how much ethanol in the formulation that can act as the preservative in the product? So we could skip to use other preservative.

Thank in advance for every comments.

Padech.

belassi replied 8 years, 3 months ago 3 Members · 2 Replies
2 Replies

Bobzchemist

Member
February 8, 2016 at 3:29 pm

To be safe, you should be testing PET (USP 51). Start at 15% Ethanol and adjust based on your test results.
belassi

Member
February 8, 2016 at 3:46 pm

The essential oil may itself be an adequate preservative. Check the MIC levels for inhibition of fungal and bacterial. Many are in the range of 0.1-0.2% only. Then do a challenge test.

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