never keep gear in syringe. its been incontact with air outside the vial/amp , is likely contaminated and a matter of time for bacteria to thrive AND th solvents in the gear could eat away at the plunger in the syringe. not worth the risk and id never rec it unless to be used that day. buy sterile sealed vials and fill up a couple with your amps, dont forget to vent the top of vial as you fill it with a syringe tip.
many will say they preload their gear in syringes and keep it for days or weeks, but its still reckless and stupid IMO.
be safe.
btw our sponsor here has sterile sealed vials, that is how i would do it ( and have) with amps