Here's what I did the last time:
I'm using 5.5 ml of water.
I turned the HCG vial upside down and inserted the syringe. The idea of upside down was that I would not be squirting right on the HCG.
The vial had vacuum and without me having to push on the plunger, about half of the water squirted in anyway.
I had to push the plunger to get the rest of the water in there. I knew that I had now pressurized the vial.
I turned the vial right side up. Now the water is at the bottom with the HCG and the syringe is in air.
I then withdrew the plunger from the syringe entirely, leaving the syringe needle in the bottle. The pressure inside/outside is now equalized. An easier way to do this would be to disconnect the needle from the syringe.
Result: No squirting from the vial this time.
