Stop drug, nothing injected (7)
I believe the answer is:
station
'stop' is the definition.
(eg a stop on a train journey)
'drug nothing injected' is the wordplay.
I cannot really understand how this works, but
'nothing' could be 'o' (O resembles 0) and 'o' is present in the answer.
'drug' could be 'statin' (type of drug) and 'statin' is present in the remaining letters.
No letters remain.
This explanation may well be incorrect...
(Other definitions for station that I've seen before include "HQ - stopping place - post" , "Military base; rail stop" , "eg Temple Meads" , "Small military base" , "Place - railway stop - HQ - standing" .)