Automated remote dispensing of pharmaceutical tablets or pills demands great reliability. Dispensing failures and double dispensing can be dangerous. The ideal remote tablet dispenser will be compact and robust, it will select, singulate and dispense without failure from a bulk bin and be able to verify that it has done so.

This work briefly reviews the patent literature and reduces the major devices on offer to an archetypal mechanism. The designer has several variables to consider and some to manipulate. Key tablet variables are diameter, height and cap convexity. Key dispenser variables include hole diameter, hole height and degree of asymmetry.

This work discerns several potential jamming mechanisms and analyses these. Jams may occur if:
(a) a tablet's longest dimension exceeds the hole's shortest dimension, or if
(b) a second tablet partially enters an occupied hole thus preventing the hole-bearing platen from advancing or the occupying tablet from discharging

The work discerns multiple geometries which may give rise to jams. Combinations of tablet and dispenser variable are described mathematically where probability of a jam is likely to be elevated. A route to general design rules for reliable dispenser design is suggested.