Design and evaluation of a rotating filter-stationary basket in vitro dissolution test apparatus. I. Fixed fluid volume system.

The apparatus described in this report provides a reliable and convenient means for determining in vitro dissolution characteristics of tablets, capsules, powders, suspensions, and most other solid drug dosage forms. Basic components of the apparatus are a perforated stationary sample basket, a rotating filter‐stirrer assembly, and a closed jacketed dissolution fluid container. Among major advantages of the apparatus are: (a) precision‐controlled variable intensity of mild laminar liquid agitation; (b) continuous or intermittent filtration of representative dissolution fluid samples through a nonclogging, microporous, in situ filter for automated or manual dissolution rate determinations; (c) convenient means for introducing solid samples in a stationary basket and positioning at a set level in the fluid medium; (d) minimal mechanical impacts, abrasion, and wear of the solid sample, with the retainment of its microenvironment during the dissolution process; and (e) simultaneous determinations of disintegration‐dissolution rates of tablets and capsules. Studies performed using this apparatus are described to demonstrate its reproducibility, reliability, and application versatility as a research, development, and quality control test apparatus. Dissolution rates of five different tablet lots of an antidiabetic drug evaluated by this apparatus correlated with their in vivo activity. A multiple‐test system for the simultaneous automated determination of six dissolution rates is described.