A topical applicator of the propel/repel type includes a reservoir, an attachable applicator cap, and a metered dosing system. The reservoir is suitable for mixing a topical formulation of multiple constituents using an electronic mortar and pestle and is closed using the applicator cap. Alternatively, the reservoir may be prefilled with a ready-to-use cream and medicament formulation, then sealed with a removable seal. The topical applicator can include a fast purge feature that overrides the metered dosing system to facilitate removal of air from the reservoir. The topical applicator can also include a one-way ratcheting feature to prevent reverse movement (repel) of the metered dosing system. Metered doses can be dispensed through holes in the applicator cap by rotating a knob, which has detent positions that correspond to discrete doses, and which provides audible and tactile feedback.