Party with yob carrying drug to distribute (4,3)
I believe the answer is:
dole out
'to distribute' is the definition.
('dole out' can be a synonym of 'distribute')
'party with yob carrying drug' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'with' is a charade indicator (letters next to each other).
'yob' becomes 'lout' (I've seen this before).
'carrying' is an insertion indicator.
'drug' becomes 'e' (E is another name for ecstasy).
'lout' going around 'e' is 'leout'.
'do'+'leout'='DOLE OUT'
(Another definition for dole out that I've seen is " Apportion".)