Hardly care about opening of capsule in secret (8)
I believe the answer is:
scarcely
'hardly' is the definition.
(I know that hardly can be written as scarcely)
'care about opening of capsule in secret' is the wordplay.
'about' indicates anagramming the letters.
'opening of' suggests taking the first letters.
'in' is an insertion indicator.
'secret' becomes 'sly' (I've seen this in other clues).
The first letter of 'capsule' is 'c'.
'care' anagrammed with 'c' can make 'carce'.
'carce' going inside 'sly' is 'SCARCELY'.
(Other definitions for scarcely that I've seen before include "Not quite" , "Barely, hardly" , "Almost not" , "Only just or hardly even" , "Surely not" .)