Drug like it is containing animal’s skin (9)
I believe the answer is:
digitalis
'drug' is the definition.
(I've seen this before)
'like it is containing animal's skin' is the wordplay.
'like' becomes 'dig' (I've seen this in another clue).
'it is' becomes 'itis'.
'containing' means one lot of letters goes inside another.
'skin' says to hollow out the word (remove centre letters) (only the skin or outside of the word is used).
'animal' with its middle taken out is 'al'.
'itis' placed around 'al' is 'italis'.
'dig'+'italis'='DIGITALIS'
(Other definitions for digitalis that I've seen before include "Drug derived from foxglove leaves" , "Cardiac stimulant prepared from 11" , "plant making this drug?" , "Drug from foxgloves" , "medicinal drug" .)