Develop a drug with revolutionary fix for cell (9)
I believe the answer is:
guardroom
'cell' is the definition.
(guardroom is a kind of cell)
'develop a drug with revolutionary fix' is the wordplay.
'develop' indicates an anagram.
'with' means one lot of letters go next to another.
'revolutionary' shows that the letters should be reversed in order.
'fix' becomes 'moor' (mooring is a kind of fixing**).
'moor' reversed gives 'room'.
'a'+'drug'='adrug'
'adrug' is an anagram of 'guard'.
'guard'+'room'='GUARDROOM'
'for' is the link.
(Other definitions for guardroom that I've seen before include "Security centre on military camp" , "Disciplinary centre in military unit" .)