Related Experiment Video
Updated: Sep 11, 2026

In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis
Published on: May 4, 2017
Novel direct curve comparison metrics for bioequivalence
1Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore 21201, USA. jpolli@rx.umaryland.edu
Purpose:
The object of this work was to devise four new direct curve comparison (DCC) metrics and examine each metric's distribution properties and performance characteristics.
Methods:
DCC metrics, Cmax, and AUCi were calculated from two bioequivalence studies of three sustained release carbamazepine formulations, where a range of profile similarity was observed. DCC metric values and their confidence intervals were compared to Cmax and AUCi.
Results:
The DCC metrics rho, rhom, deltaa, and deltas, exhibited more favorable distributions than Cmax and AUCi ratios, which were frequently skewed. The DCC metrics performed differently than Cmax and AUCi ratios in profile comparisons due to the nature of the DCC metrics. Unlike Cmax and AUCi, the DCC metrics utilize all data points to directly compare entire profiles. Each DCC metric appears to measure "exposure" in a single assessment. Possible bioequivalence acceptance criteria are: p < or =1.40, rhom, < or =0.35, deltaa, < or =0.27, and deltas < or =0.102.
Conclusions:
These DCC metrics, particularly rhom, are promising bioequivalence metrics for "exposure."
Related Concept Videos
Bioequivalence: Overview
Measurement of Bioavailability: Pharmacodynamic Methods
Equivalence: In Vitro and In Vivo Bioequivalence
Bioequivalence studies: Biowaivers
Bioequivalence Data: Statistical Interpretation
Dose Response Curve: Conventional Versus Nonmonotonic

