Multi-coated dragee cores - production in a series of alternating and rotating coating vessels and lock chambers

摘要

The known process for coating dragee cores with successive coatings of solid material, in which the dragee core is introduced into a vessel rotating round an inclined axis, the coating material is added and distributed over the dragee cores and deported as a solid layer, after which the coated dragees are dried, and if required coated with further layers of solid, is improved when (a) the dragee cores or dragees are divided into successive batches containing approximately equal numbers; (b) a first batch is coated with a first layer of solid in a first vessel and is transferred to a first lock chamber, from which it is supplied to a second vessel, while a further batch of dragee cores is introduced into the first vessel and is coated with a first layer of solid at the same time as the already coated first batch is coated with a second layer of solid; (c) alternately complete batches of dragees are simultaneously advanced into a further vessel, coated with a further layer of solid and subsequently discharged into a lock chamber; (d) simultaneously with the introduction of a number of dragee cores, the withdrawal of approximately the same number of finished dragees takes place. Provides a rational process for continuous production of multi-coated dragees.