Stomach's in order when given a pharmaceutical compound (6)
I believe the answer is:
omasal
'a pharmaceutical compound' is the definition.
The definition suggests an adjective which matches the answer.
'stomach's in order when given' is the wordplay.
'stomach's in' becomes 'al' (I can't justify this - if you can you should give a lot more credence to this answer).
'order' becomes 'om' (Order of Merit).
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'given' means one lot of letters go next to another.
'om'+'as'='omas'
'al' put after 'omas' is 'OMASAL'.
Can you help me to learn more?
(Other definitions for omasal that I've seen before include "Concerning beastly insides" , "Connected with stomach" .)