3ml Pen Injector Pre-Purged Vial: Thoughts?

I tried filling after pre-purging and it saved the venting step, but I stopped and went back to venting the cartridge myself. Since I already filter and work hard to stay sterile it feels risky to fill into a cartridge that has sat open to air, so I avoid that approach now.

I just ordered some v4 pens and was thinking through the steps. It does use up a lot of supplies: one luer lock for reconstitution, a filter, another luer lock and syringe for venting and transfer, plus a pen needle to purge air. When loading two new cartridges can any of those items be reused safely?

I'm about to order needles and syringes for making up cartridges. Which sizes do you use?

Appreciate the details, that's precisely what I needed. Filling the pen cartridges has been tricky lately, and I'm wondering if it's because the vent needle is too small to release air properly or if the 13mm PES .22 filter might be getting blocked somehow. Planning to switch to bigger needles for venting but unsure of the right size. Any ideas would be great.

That sort of cart doesn't appeal to me personally at all.

Back a few weeks ago I saw this recording of a guy filling one of those ready-to-go cartridges but now when I want to see it again it's gone. He inserted the needle directly into the packaging that protected it during shipping without removing the wrapper first, added the contents, and stripped it off only after it was full so he could load it into the device. The reason seemed to be minimizing contact while the internal plug descended.

Not really sure either way. Went ahead and placed an order for a few anyway. The air inside my place probably isn’t full of germs or anything, or at least that’s what I’m hoping. Still, I’m pretty comfortable taking chances like that.

I learned that with the compact three milliliter cartridges the narrow inner space forces you to pick needles with extra care. Sizes around twenty three or twenty five work best. The thicker option handles pressure changes right away when you move liquid in or out fast. The thinner one protects the small seal the most by limiting how much it shifts so it stays sealed tight later in the device. For length either half an inch or a full inch can fit. The shorter one tends to suit better since the barrel stays tight and brief so it passes the stopper without dipping into the fluid. The longer version works if you watch how far it goes stopping once the opening just gets past the inner side of the stopper by only a couple millimeters. Keep the tip up in the empty space above the liquid or else fluid pushes out instead of air. Hit the middle of the rubber disc to slide through cleanly without hitting the metal edge. Steer clear of anything twenty gauge or bigger because those tear or widen the little seal too much and then leaks start once pressure builds inside the unit.