I am not into the figures, but the Apothecary has that strange looking device on his back. What is it?
Apothecary pics? What is that machine on his back?
It's never explained in detail but one can assume it's full of medical equipment. It obviously has a floodlight and diagnostics sensors, and on the back of the miniature you can see the structure is different from normal bacpacks, and it includes some vials and even a small mechadendrite or small mechanical appendage.
In game terms you can assume that it's this that allows the apothecary to synthesize the poisons and also provides the necessary materials for patching up wounds.