Tablet coating machine

Abstract

A tablet coating machine for applying a coating to a bed of tablets, the machine comprising a circular drum with frusto-conical ends which is rotated about its axis. The periphery of the drum is perforated to allow air to flow through the bed of tablets disposed in the drum under the action of a suction shoe. In order to be able to optimise the efficiency of the tablet coating process for different quantities of tablets, the volumetric capacity of the drum is adjustable to achieve a desired tablet depth for the quantity of tablets being processed. More particularly an axially adjustable wall portion is provided within the drum to adjust the length of the tablet containing portion of the drum. The wall portion is made up of segments which are dimensioned to fit through an opening into the drum by which tablets are introduced into the drum. In one embodiment a threaded rod is connected between the wall portion and an end wall of the drum to facilitate adjustment of the wall portion within the drum the area over which air is sucked from the drum by the suction shoe applied to the periphery therof, is adjustable to tailor it to the length of the table containing portion of the drum.