I reuse film running in mixer (10)

I believe the answer is:

emulsifier

'mixer' is the definition.
(thesaurus)

'i reuse film running' is the wordplay.
'running' indicates an anagram.
'i'+'reuse'+'film'='ireusefilm'
'ireusefilm' with letters rearranged gives 'EMULSIFIER'.

'in' is the link.

(Another definition for emulsifier that I've seen is " Chemical agent".)

I've seen this clue in The Times.

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