On 29 December 2011, the USP announced that the appropriate experts group of the USP had revised General Chapter <711> - Dissolution Testing. This revision will enter into force on 1st February 2012.
The background for the revision is the removal of Chlorpheniramine Maleate Extended-Release Tablets RS from the list of reference standards and from the Apparatus Suitability section.
The standard used until now had turned out and couldn't be replaced.
The USP is currently in the process of identifying replacement materials to be used in the Performance Verification Test for Apparatus 3.
The revised Chapter will be integrated in the second supplement of USP 35 - NF 30.
Further information is available in the Revision Bulletin - General Chapter <711> Dissolution as well as in the revised chapter.