I've done a couple weeks of it at a time. Not the best idea though. It will actually dissolve the rubber in the syringe over time. That's why you also want to store vials upright
I wouldn't preload anything more than what you'll use within a couple days myself, due to sterility reasons. Besides that, it's not like it takes that long to draw up and prep a syringe
I preloaded the day before and I’m thinking that was a bad idea since the PIP is worse this time around. It was my 4th injection in glutes. Other 3 times it was a little sore like a charlie horse. This time is a little worse. The skin is not red but the muscle is very tight and there’s a little more pain when sleeping on that side.