Sterilization of glassware and product pre-dispense

Hi guys,

Firstly I am new to this community and industry. I love every topic, suggestion and comments. They are so helpful. Resources and leads I find here are most valuable to me.

I must add I am working in a lab in Canada and I have to play by the books 100%. I have two part sterilization question.

  1. I clean my glassware with solvent at first >> Alconox >> dry >> spray with EtOH again before using, however, I want to add a sterilization step, maybe some time in the vacuum oven post Alconox. Is anyone doing this and has a suggestion on the time and temp for it?
  2. After rotovaping, homogenizing oil with MCT, how can we be sure of the sterility of the product? Is there a step or test that I can do to assure the product is sterile and safe to be dispensed?

Like I mentioned, I really need to make this process as clean as possible. I would appreciate any thoughts on the topic.


Uvc light box?

I make these for growers to assist in pm/mold spore remediation. Hospitals use them to kill airborne viruses and such. I also have one in my hvac system.

Be very cautious with uvc exposure. It can and will cause cancer, blindness, and cataracts.

But is great for disrupting the DNA of living things.

Or a heated oven.


Hey thank you so much for your reply. My first thought was UV as well. I have the same health concerns as you addressed. I am curious to know if UV causes any undesired effects or alterations to the product in the long run?

Heated oven, I don’t want to introduce heat and lose any cannabinoids. However, surely thinking about oven to sterilize glassware.

You said cleaning glass. My post pertains to only sterilizing glassware, not cananaboids. . If needing to treat cananaboids, there are SOP for pesticide remediation and the like on here. It may be in the GLG area.


Sorry I wasn’t clear, my second question was for sterilizing the end product. How can I be sure the homogenized MCT and cannabis oil is sterile? This maybe a very trivial question :disappointed_relieved:

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Is this a regulation you are trying to satisfy?

I’ve never seen any microbial growth on cannabis oil or MCT oil. Both oxidize, but always pass microbial testing, even if the weed failed.


I filter to 1um. or 0.2um if I’m concerned there might be fungal contamination. getting cannabinods in mct through a 0.2um filter is not trivial. you can get 1um sock filters which will make much faster work of it. not sure what your regulators are going to want to see. you might be able to find 0.2um socks. or you might be able to add a filter aid (perlite??)

edit: at what concentration. I was at 33mg/ml. it probably won’t work if you’re making carts.

  1. Isn’t alcohol itself a sterilizing agent?
  2. If in an enclosed system, you ought to be able to simply raise the temperature of the mix to whatever pasteurization temp satisfies the regulators. It won’t hurt the Cannabinoids.

Yes it is a regulation we are trying to satisfy. Health Canada regulations make me overthink the safety and sterility standard of our work flow. Because at this point, we have to try to make our products pharmaceutical grade. It is complicated :disappointed_relieved:

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Our conc is different depending on the customer, 15 - 20 mg/ml. Regulations dictate we cannot go over 30mg/ml at the moment. Thanks for the filtering suggestion, I am going to look into it. Our batch size may be too big but it could work! Maybe we can test it before and after to verify for microbes? Would be intersting to know.

Yup. Alcohol is sterilizing, but once ethanol is recovered, it is just oils, it needs to maintain sterility (or we gotta prove it is still sterile). I know this sounds obsessive but playing by these rules is! :confused: It is intense!

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Spores can survive in alcohol, but they can be filtered out. Mycotoxins are a bigger concern than sterility though I would think.


I would look into heat-based treatment. The typical times and temps used for pasteurization are well below points where cannabinoids degrade.


Years ago mid 90s we irradiated our phyto raw material for drug standards for Health Canada/HPB, that’s how we did our microbial control to meet drug grade we used a company in Whitby called Isomedixs?. We also did QC work to determine the gamma loading so we didn’t fry our actives. We got an NRC/Irap grant to do all the work.


As for as sterilization of glass I clean with ethanol with micro fiber food/lab grade cloths and put into vac oven at 100+ F to evaporate out the rest of the ethanol.

Thank you for your reply. That is the process I am leaning towards, expect I might rinse with Alconox before the Oven. How long do you put the glassware in the oven at 100F?

I wash with a acetone and thn water to remove any acetone residue, then iso to remove any etho. Ive used this prior do dont a tested clean baych and wantedto make sure there was no cross contamination and when rhe clean batch was tested it cane back clean

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The solution is likely not as elaborate as you may expect. Its simply procedural and there’s really no set way to do it. Every chemist is going to give you different procedure and it’s really dependent on your problems faced and your style.
I would say for cannabis your #1 concern should be pesticides because they will fail a batch with even the smallest contamination.
Your best friends will be solvent, an autoclave, fume hoods and cell culture hoods. Lot’s of bags and aluminum foil also :wink: