A NEW PROTOCOL FOR ANTIMICROBIAL TESTING OF OILS
This paper describes modifications of the Food and Drug Administration's 1991 proposed rule for topical antimicrobial drug products for over-the-counter human use, affecting first aid antiseptic drug product testing for recovery of test bacteria from tea tree oil. Because the FDA's proposed method provided for the testing of water soluble and/or miscible products, along with the use of a chemical neutralizer, Mitech Laboratories, Inc. developed a new method for testing of water insoluble oils using a non-toxic solvent. In a bactericidal assay, specific sterile diluting fluids are used as a non-toxic solvent followed by a rinse. The bacteriological retentative membrane filtration method, rather than chemical neutralization, is used for recovery of bacteria along with accurate organism counting. This new method provides a mechanism to enable general recognition of effectiveness for oil-based antiseptic drug products in compliance with the Federal Food, Drug, and Cosmetic Act.
Smith, Martha D. and Navilliat, P. L. (1996). A NEW PROTOCOL FOR ANTIMICROBIAL TESTING OF OILS. Acta Hortic. 426, 31-38