Evaluation of Glass Dissolution Vessel Dimensions and Irregularities

Used in the private or public USP Performance test, dissolution testing plays an important role in both product development and quality assurance for nonsolution oral dosage forms. The dissolution procedure itself,as described in USP General Chapter Dissolution , is sensitive and specific but requires special care in execution. Results of a recent USP collaborative study of new Lot P Prednisone Reference Standard Tablets indicate much higher reproducibility (interlaboratory variance) than repeatability (intralaboratory variance) (1,2). To improve reproducibility,the USP Biopharmaceutics Expert Committee recommends careful IQ,OQ,and PQ (mechanical calibration),as well as a Performance Verification Test (PVT); the latter two typically are performed at six-month intervals. Several variables such as shaft rotation speed,shaft and vessel alignment,basket/paddle height,and bath levelness have been cited as factors that contribute to high variability of the dissolution procedure. Missing from this list are factors relating to vessel dimension and irregularities,which are the subject of this report.