Implementation of parallelism testing for four-parameter logistic model in bioassays.

Parallelism is a prerequisite for the determination of relative potency in bioactivity assays. It involves the testing of similarity between a pair of dose-response curves of reference standard and test sample. The evaluation of parallelism is a requirement listed by both the United States Pharmacopeia (USP) and European Pharmacopeia (EP). The revised USP Chapters 〈1032〉 and 〈1034〉 suggest testing parallelism using an equivalence method. However, implementation of this method can be challenging for laboratories that lack experience in statistical analysis and software development. In this paper we present a customized assay analysis template that is developed based on a fully good manufacturing practice (GMP)-compliant software package. The template allows for automation of the USP-recommended equivalence parallelism testing method for 4PLmodel in bioassays. It makes the implementation of the USP guidance both practical and feasible. Use of the analysis template is illustrated through a practical example. LAY ABSTRACT: Parallelism is a prerequisite for the determination of relative potency in bioactivity assays. It involves the testing of similarity between a pair of dose-response curves of reference standard and test sample. The evaluation of parallelism is a requirement listed by both the United States Pharmacopeia (USP) and European Pharmacopeia (EP). The revised USP Chapters 〈1032〉 and 〈1034〉 suggest testing parallelism using an equivalence method. However, implementation of this method can be challenging for laboratories that lack experience in statistical analysis and software development. In this paper we present a customized assay analysis template that is developed based on a fully good manufacturing practice (GMP)-compliant software package. The template allows for automation of the USP-recommended equivalence parallelism testing method for 4-parameter logistic model in bioassays. It makes the implementation of the USP guidance both practical and feasible. Use of the analysis template is illustrated through a practical example.