So I’m not 100% how I would use this for IV drug use as I never have although I’ve made steroids for years and compounded other injectibles (made some inject CBD yesterday using one actually) regularly.
The only thing I’m really not sure about is using a carrier or not but I’m assuming most compounds would be water soluble.
In this case you would heat your compound in a beaker along with your carrier (and solvents/preseevative) at the desired concentration until fully dissolved. Then wait for it to cool to around 100 degrees or less. Suck it up from the beaker in a large lure lock syringe then attach the sterile filter to the syringe and put an 18g needle on the other end of the filter.
At this point your set to put the 18g into a sterile vile (don’t forget to vent it) and filter directly into the vile.
Fairly easy and took me about 30min to make and filter 40ml of CBD in miglyol 840 carrier.