Anti-wrinkle ointment mostly succeeded before tins sat abandoned (6-9)

'anti-wrinkle' is the definition.

'ointment mostly succeeded before tins sat abandoned' is the wordplay.
'ointment' becomes 'cream' ('cream' can be a synonym of 'ointment').
'mostly' means to remove the last letter.
'succeeded before' becomes 'sere' (I can't justify this - if you can you should give a lot more credence to this answer).
'abandoned' indicates an anagram.
'cream' with its last letter taken away is 'crea'.
'tins'+'sat'='tinssat'
'tinssat' with letters rearranged gives 'sistant'.
'crea'+'sere'+'sistant'='CREASE-RESISTANT'