There has been a scientific survey which I reported to Franktalk back in May 2013. This is what I posted:
"There have been lots of posts concerning the life and effectiveness of the 3 main injection therapies - Bimix, Trimix and Alprostadil (PGE-1, Caverject and Edex) used by itself. I thought that I would do some research and see if this has been scientifically tested. I eventually came across a peer reviewed study by the Division of Pharmacy at the University of Texas. (
http://www.stabilis.org/FichesBiblio/1899-recherche)
This was a comprehensive study and, in summary, the principal findings were as follows:
Bimix, Trimix and Alprostadil can be frozen at -20degC for 6 months and then thawed to room temperature (23degC) with no loss greater than 5% of any of the drugs. They tested up to 4 freeze/thaw cycles with no adverse effects.
The least stable component of Trimix is Alprostadil (the only drug in Caverject and Edex) loses about 12.5% of its concentration at room temperature (23degC) after 7 days and 44% after one month. However, at normal domestic refrigerator temperature (4degC) there is only a 2% loss after 7 days and less than 6% after one month. Even better, if stored in a freezer at -20degC the loss was less than 3% after 6 months."
The figures for the other components of Trimix and the sole components of Bimix are 7 days at room temperature no significant degradation, the same as in a refrigerator or frozen. After 6 months frozen at -20DegC the loss was less than 5%.
So it would appear that those using Trimix could, when travelling, leave it unrefrigerated for 24 hours with, at worst, only a minor degradation in one component (Alprostadil). Clearly the temperature to which it is exposed is important and left in a hot car when parked it could be much more than 23degC and this might degrade the Alprostadil much faster.
This explains why many Franktalk members have found their Trimix to be only slightly less effective after even 12 months in a fridge (probably a small loss of Alprostadil). Bimix remains stable for long periods even at room temperature.
Finally, of course, it is always important that the contents of a vial remains sterile. If storing injection compounds for extended periods freezing will inhibit any bacteria growth and from the study it would appear that this is not harmful to the product even if frozen/thawed and refrozen up to 4 times."
So put simply - frozen it will remain fully effective for at least 6 months - 4 freeze/unfreeze cycles do not have adverse effects - in the fridge it will not have lost much effectiveness after a month. Simple solution is to transfer solution to single use syringes and freeze (leave a small airgap because it expands when you freeze) and take out a syringe and defrost when you need to use it.