Making ones own bulk bacteriostatic water for IM injection

[.:Holy::Toast:.]

I was wondering if it was possible to buy a litre of saline with an irrigation spout attached, and buy my own benzyl alcohol to 0.9% concentration and add it to the saline.

Would this keep itself bacteriostatic despite open to the air, even if only slightly.
Because the 30ml reusable ampules are incredibly expensive so if i could just spray out 3ml every time into a sterilized graduated cylinder it should be much easier.

 

[ObieWan]

You can also buy saline or sterile water from the drugstore. I don't think you need an RX. Maybe for the liters though.

Me I use tap water, well it's well water but it's clean enough for me.