There was question of where this came from. I just came across a version of it in the Star Trek: The Next Generation magazine, Vol. 7 pg. 35. But the one you posted has altered notations. The top vial is labeled: "Medicine Vial (Cartridge)". The piston extension on the bottom drawing has an arrow pointing to the parting line on the top drawing. And a legend that says:
1. Extend Handle
2. Place Nozzle Against Arm
3. Push to Collapse Handle (with Appropriate Sound FX)".
It accompanies a familiar drawing of the standard hypospray and has an annotation saying: "The Medical Hyposprayer is the 24th Century equivalent of today's injection needle. It is used by all medical personnel to administer vaccines and antidotes. The "shot" is given to a person in the carotid artery.
EDIT...dang, I need to read the whole thread first. I see you did find and post that info. But I'm not deleting it!