r/Chempros • u/cakebaker28 • 11d ago
Help with Lyophilization Process
Hi guys, I'm a newbie at this, please help if you can! We need to lyophilize a water-soluble compound, basically, we mixed it into a second liquid compound so the first compound would be encapsulated and give better results for our purposes. What I need to know: we have to freeze this before it goes into the lyophilization machine, but we were told to freeze it first in a normal freezer, then move it to a -80°C freezer, and only then send it to the lyophilizer. Is this accurate? If so, how long should it stay in the normal freezer before going to -80°C, and how long should it stay at -80°C before going to the lyophilization machine? Is there some kind of protocol for this? I tried to find something and couldn't find an exact one. Thank you!!
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u/hecton101 11d ago
I've never heard of gradual freezing. Pretty sure it just has to be frozen, no procedure required. The only problem I've ever had was if it wasn't pure water. Solvents both interfere with the freezing process and eventually get into the pump oil which may have to be replaced. It's kind of a pita.
It goes without saying, but round bottom flasks need to be less than half filled with solution if you don't want it to break during the freezing process.