A stopped-flow microdialysis sampling-flow injection system for automated multivessel high resolution drug dissolution testing

A simple and robust flow injection on-line microdialysis system for multivessel drug dissolution testing is described. Microdialysis probes were used for sampling from the dissolution media. A stopped-flow dialysis mode with a 50-s stopped-flow period followed by 10-s injection at a perfusion rate of 2.8 ml min(-1) for each probe was used to achieve high resolution of dissolution events using relatively simple equipment and operation. The precisions obtained for simultaneous monitoring of dissolution profiles for six tablets were all better than 0.9% (RSD n = 80) and the overall sampling frequency of the system was 360 and 60 h(-1) for each test vessel. The dissolution profiles of isoniazid fast-release tablet from three sources were determined to demonstrate the performance of the system. (C) 1999 Elsevier Science B.V. All rights reserved.