If i'm not too mistaken fina is made to be put inside a cows skin anyway. You're just making it able to be injected right? And in this case you really wouldn't want to make a huge batch and mix it together since it will seperate and you won't be sure how much of the drug you will be drawing up per shot. So keep it all in one syringe makes sence to me. I'm way newb when it comes to Home brew but it's verry interesting to me. Just make sure I know I'm being a dumbass if I don't get it, Sometimes I think i'm smarter than I am.