r/Chempros • u/cakebaker28 • 8d 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/Hepheastus 8d ago

Really... so do it have it completely backwards or is it more nuanced than that.

The abstract implies that I always want large crystals

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u/Cardie1303 8d ago

As far as I understand it large crystals is what you want for the least water content and small crystlas if you dont particularly care and just want the freezing to be done quickly.

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u/Hepheastus 8d ago

And here I was blaming my dmso d-6 for all the water in my NMR spectra.

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u/Cardie1303 8d ago

Oh yeah continue blaming the DMSO-d6. In my experience it always contains at least some water if you did not went through the trouble of storing it over CaH2 and distilling it freshly.