Spot calcium used in cosmetic cream (8)
'spot' is the definition.
(I've seen this before)
'calcium used in cosmetic cream' is the wordplay.
'calcium' becomes 'Ca' (Ca is the chemical symbol for calcium).
'used in' indicates putting letters inside.
'cosmetic cream' becomes 'lotion' (I've seen this before).
'ca' going inside 'lotion' is 'LOCATION'.
(Other definitions for location that I've seen before include "Place, site", "Particular place", "Position,place", "Position or situation", "Whereabouts, position".)