Rich man angry about drug going round university (7)
I believe the answer is:
croesus
'rich man' is the definition.
(famously rich ancient king)
'angry about drug going round university' is the wordplay.
'angry' becomes 'cross' (cross can mean annoyed or angry).
'about' indicates putting letters inside.
'drug going' becomes 'e' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'round' indicates putting letters inside.
'university' becomes 'u' (abbreviation for university).
'cross' enclosing 'e' is 'croess'.
'croess' placed around 'u' is 'CROESUS'.
(Other definitions for croesus that I've seen before include "Fat cat" , "King of fabulous wealth" , "King, a byword for wealth" , "Ancient king renowned for his wealth" , "One famously loaded" .)