There are four different single-use supplies in Mass Effect 3 multiplayer, the Cobra Missile launcher, Medi-Gel, Ops Survival Pack and the Thermal Clip Pack:
Until now I've just been hoarding them, but I wonder if there is some maximum limit of those supplies I can stash? Can I collect as many as I want of the supplies, or am I wasting the new supplies I get from packs at some point, because my inventory is full?