Design and evaluation of a rotating filter-magnetic basket apparatus: tablet and basket position

Abstract

The authors have designed a dissolution device which combines the properties of a rotating filter device developed by Shah and a magnetic basket designed by Shepard et al. The effects of stirring, tablet and basket placement were investigated. Visualization of flow and dissolution patterns was possible by testing non-disintegrating salicylic acid tablets containing 3% phenolphthalein in 0.1 N sodium hydroxide solution. Dissolution experiments were conducted on non-disintegrating salicylic acid in pH 7.4 U.S.P. phosphate buffer at 37°C. For the tablet placement experiments one tablet face and the tablet land was coated so that only a single tablet face was available for dissolution. The data for the same size tablets placed at the side of the bottom and at the center of the bottom of the dissolution fluid container indicated the importance of exact placement of a tablet in a dissolution fluid container. The differences in face position of the tablet either with or without a magnetic basket present indicates the importance of face position which must be accounted for especially in the testing of double-layer sustained release products. Through the dissolution data and the visualization studies the authors have characterized the hydrodynamics of this device.