Maker-up of medicine pressed in preparation (9)

I believe the answer is:

dispenser

I'm a little stuck... Click here to teach me more about this clue!

'maker-up of medicine' is the definition.
I can't judge whether this defines the answer.

'pressed in preparation' is the wordplay.
'preparation' is an anagram indicator.
'pressed'+'in'='pressedin'
'pressedin' anagrammed gives 'DISPENSER'.

Can you help me to learn more?

(Other definitions for dispenser that I've seen before include "One filling prescription" , "Container releasing its contents in prescribed amounts" , "Pharmacist" , "Chemist" , "ATM" .)

I've seen this clue in The Irish Independent.

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