Some medication does work, containing silver (6)
I believe the answer is:
dosage
'some medication' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'does work containing silver' is the wordplay.
'work' is an anagram indicator.
'containing' means one lot of letters goes inside another.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'does' is an anagram of 'dose'.
'dose' going around 'ag' is 'DOSAGE'.
Can you help me to learn more?
(Other definitions for dosage that I've seen before include "Measured amount of medicine to be taken" , "Prescribed quantity of medicine" , "Giving of medicine in prescribed amount" , "The giving of medication in prescribed amount" , "Measured portion of medicine" .)