Piero Armenante, Ariel Baruch, Karl Box, Hector Bucaro, Ben Calvopina, Bryan Crist, Lee Dowden, Keith Hamman, Sandra Klein, Mark R. Liddell, Xujin Lu, Heather Mead, Tahseen Mirza, Ishai Nir, Ashvin Patel, Sanjaykumar Patel, Steve Prüfer, Alger Salt, Balint Sinkor, Sandip Tiwari, Maria Vertzoni, David Walker

Correspondence should be addressed to: Margareth R.C. Marques, Senior Principal Scientist, US Pharmacopeia, 12601 Twinbrook Parkway, Rockville, MD 20852-1790; email: mrm@usp.org.

Historically, classical dissolution testing of pharmaceutical formulations using USP Apparatus 1 and USP Apparatus 2 as described in general chapters Dissolution 〈711〉 and The Dissolution Procedure: Development and Validation 〈1092〉, as well as the majority of monographs referencing 〈711〉, primarily have recommended media volumes in the range of 500 to 1000 mL (with exceptions for special cases using 2-L vessels or pooling in 4-L vessels). However, new extrema in dosage form characteristics have led to interest in expanding the range of compendial dissolution testing volumes to those lower than 500 mL, and in some cases substantially lower. USP is referring to this new class of volumes as “reduced-volume” dissolution testing. Given the increased interest in using this new range of reduced-volume apparatuses for preliminary biorelevant methods and possibly even QC methods, industry needs definition and standardization from global regulatory bodies. This article proposes standardization criteria for reduced-volume apparatuses including vessel dimensions, agitation parameters, and scalability considerations.