I've heard that freezing it in preloaded syringes after mixed is fine. I believe Austinite said he used this method. I've done it before with preloaded syringes, and never had any problems. I'd like to hear more thoughts on this though.

I mix, draw up in syringes, wrap in a freezer bag, put in a Tupperware, and toss it in the freezer, but never refreeze.

I hope that's a good protocol