Acceptable, equivalent, or better: Approaches for alternatives to official compendia! procedures

The General Notices in the US Pharmacopeia (USP) permit analysts to use acceptable (suitable) alternatives to an official procedure. In a revision that will be effective May 1, 2009, the General Notices will require that the alternative procedure be demonstrated to give results that are equivalent to or better than those obtained by the official procedure. This Stimuli article discusses approaches for determining equivalent or better procedures. The concepts and tests discussed in this paper may become one or more USP General Chapters. The preceding Stimuli article speaks to approaches that determine an acceptable procedure without requiring a study to document equivalent or better.