When combining multiple vials through filtration a single unit works well enough. In my experience I merge two reta vials into one sterile vial using just that one unit. I also keep in mind the possible breakdown for Tirz since it apparently loses some quality over 60 to 115 days.
Curious what the maximum is for running triz vials through a single 13mm filter. Got a few I want to reconstitute together at the same time. Might it work better if I grab a fresh one for each vial instead?