Development and validation of analytical method for microbiological quality control of cannabis oil solution

Introduction. As of January 22, 2021, the US FDA has approved Cannabidiol (CBD) and Tetrahydrocannabinol (THC) containing medications for therapeutic use. Exogenous cannabinoids, such as THC and CBD, and their effect on the endocannabinoid system are frequently discussed regarding their role in oncology related diseases.

Materials and methods. European Pharmacopoeia specifies reference criteria for microbiological quality control as "Special Ph. Eur. provisions for oral dosage forms containing raw materials of natural origin" with specified quality control parameters: Total Aerobic Microbial Count (TAMC), Total Combined Yeasts and Molds Count (TYMC), Total Bile-tolerant GN bacteria (TBTGN), as well as Absence of Staphylococcus aureus, Absence of Escherichia coli and Absence of Salmonella.

Results. The Recovery Percent results obtained from all quantitative challenge tests show that the tested Cannabis oil solution product doesn't demonstrate significant product matrix interference or antimicrobial properties against any reference microorganisms while using primary suspension of the product (1:10 dilution in TSB), thus resulting with readable plate count and Recovery factor values ≤2 for all testing microorganisms. The results obtained from qualitative challenge tests for Absence of Staphylococcus aureus/ml, Escherichia coli/ml and Salmonella/10ml, demonstrated positive recovery on all three testing iterations, with relative Recovery rate of 100% for all specified microorganisms while using primary suspension (1:10 dilution in TSB) of the product.

Conclusion. The Cannabis oil solution: THC 40 mg + CBD 40 mg/1 ml doesn't demonstrate product matrix or antimicrobial interference by 1:10 dilution in Tryptic Soy Broth, without the necessity for addition of any surface active agent, such as isopropyl myristate or polysorbate 80. The stabilization of the primary suspension of the product is achieved by temperature controlled dispersion.

Key messages.

1. Cannabis oil solution shows no antimicrobial interference in microbiological quality control tests.
2. The method allows reliable recovery of specified microorganisms from the product matrix.
3. Stabilization of the product suspension is achieved by temperature controlled dispersion without surfactants.