The effect of processing variables on the compression properties of controlled release core-in-cup compressed tablets from a new adjustable punch

Abstract

A novel adjustable punch that can be adjusted to produce compressed cup-shape tablets of different depth has been evaluated. The resultant cups have been compressed together with core tablets to produce compression coated tablets that have the ability to release active drug at a zero-order rate. The influence of three independent variables (percentage carnauba wax in the cup tablet, the compressed hardness of the cup tablet, and depth of the cup tablet) on the friability of the cup tablet and splitting of the cup tablet in aqueous dissolution fluid was studied using a 3 3 factorial design. The friability of the cup tablets were influenced by all the factors as well as the second-order interaction effects. The splitting of the cup tablets were only significantly influenced by the depth of the cup tablet and the hardness of the cup tablets. Core-in-cup tablets containing 5% w/w HPMC K4M in ibuprofen as the core, 4 mm final cup depth, 15% carnauba wax in ethylcellulose as the cup, and compressed to a cup hardness of approx. 100 N/m 2 and final core-in-cup hardness of approx. 160 N/m 2, released ibuprofen at zero-order rate of release for up to 18 h.