sodium chloride is saline. if it's sterile (not contact lens stuff) then it's ok to inject.
I assume you mean the water is in a 10ml syringe?
Equigen is 210IU not 270IU. The IU is the concentration of the drug, not the volume. IU is like mg not ml/cc Meaning there are 210IU in the equigen vial if you mix 1ml, 2ml or 10ml of water. Just the concentration per ml will vary.
depends how stong iu per ml you want it. If you mix 4.2ml of saline you will have a concentration of 1IU of GH for every 2IU marking on th einsulin pin. Basically, that means that if you measure on the insulin pin 2IU (one line) that equals 1IU of gh.
When you worry is when it DOESN'T have foam on top! Both the Equigen and "regular" gh will foam a little when you mix it if its real. That's one quick way to tell fake gh. It doesn't always foam a lot, but it should foam at least a little.