One's own little drug store (5)
I believe the answer is:
stash
'drug store' is the definition.
(I've seen this before)
'one's own little' is the wordplay.
I cannot really understand how this works, but
'one's' could be 'as' (a thing is one thing) and 'as' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stash that I've seen before include "Hide (something) away" , "Treasure trove" , "Squirrel away" , "Secret store of valuables" , "Secret store (colloq.)" .)