title: Assessing parallelism prior to determining relative potency.
abstract: In the course of preparing a revision to Chapter (111) of the U.S. Pharmacopeia, the revision committee came to a unanimous agreement that the method for assessing parallelism that is currently presented in (111) and in the European Pharmacopeia's Chapter 5.3 is flawed and should be replaced. The symptoms are that perfectly acceptable assay results may fail due to good precision and that obviously faulty assay results may pass due to poor precision. The flaw is that the wrong statistical technique has been used. We propose an alternative approach based on the equivalence testing paradigm that does not have these shortcomings. Equivalence testing requires the establishment of equivalence limits. Specific approaches for establishing equivalence limits are discussed.
authors.affiliation: Biostatistics Section, Thomas Jefferson University, 211 S. Ninth St., #602, Philadelphia, PA 19107, USA. whauck@mail.jci.tju.edu
authors.forename: Walter W
authors.initials: WW
authors.lastname: Hauck
authors.forename: Robert C
authors.initials: RC
authors.lastname: Capen
authors.forename: Janice D
authors.initials: JD
authors.lastname: Callahan
authors.forename: James E
authors.initials: JE
authors.lastname: De Muth
authors.forename: Henry
authors.initials: H
authors.lastname: Hsu
authors.forename: David
authors.initials: D
authors.lastname: Lansky
authors.forename: Nancy C
authors.initials: NC
authors.lastname: Sajjadi
authors.forename: Sally S
authors.initials: SS
authors.lastname: Seaver
authors.forename: Robert R
authors.initials: RR
authors.lastname: Singer
authors.forename: Doris
authors.initials: D
authors.lastname: Weisman
mesh_terms: D003627:Data Interpretation, Statistical; D004364:Pharmaceutical Preparations / Q000378:metabolism; D010602:Pharmacopoeias as Topic / Q000592:standards*; D015203:Reproducibility of Results; D013678:Technology, Pharmaceutical / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D013810:Therapeutic Equivalency
chemical_list: D004364:Pharmaceutical Preparations