TB-500 Being Sent Out Pre-Mixed?

Hello. I found a local Dr. who has prescribed me thymosin beta-4 (TB-500). It is being sourced from a local pharmacy who makes it. They are sending it to me overnight (cant pick it up for some reason) and the vials come premixed. I believe they are 15mg vials. I am assuming that they will be sent with dry ice to keep cold. I plan on taking 2.5mg twice per week as i am recovering from tendon surgery. I am concerned about this as i have heard conflicted things as to how long this peptide lasts once its mixed. The pharmacy said their product is good for 30 days once the vial is punctured. Has anyone heard of TB-500 being sent out pre-mixed like this? Im spending a fair amount so want to make sure it will be effective. Thanks for any help.

I’ve received other peptides pre mixed. As long as it’s kept cold it should be fine.