Historically, ligand-binding assays for pharmacokinetic samples employed duplicate rather than singlet-based analysis. Herein, the Translational and absorption, distribution, metabolism and excretion (ADME) Sciences Leadership Group of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) presents a study aiming to determine the value of duplicate versus singlet-based testing. Based on analysis of data collected from eight organizations for 20 drug candidates representing seven molecular types and four analytical platforms, statistical comparisons of validation and in-study quality controls and study unknown samples demonstrated good agreement across duplicate sets. Simulation models were also used to assess the impact of sample duplicate characteristics on bioequivalence outcomes. Results show that testing in singlet is acceptable for assays with % CV ≤15% between duplicates. Singlet-based approach is proposed as the default for ligand-binding assays while a duplicate-based approach is needed where imprecision and/or inaccuracy impede the validation of the assay.

The COVID-19 pandemic challenged pharmaceutical and bioanalytical communities at large, in the development of vaccines and therapeutics as well as supporting ongoing drug development efforts. Existing processes were challenged to manage loss of staffing at facilities along with added workloads for COVID related study support including conducting preclinical testing, initiating clinical trials, conducting bioanalysis and interactions with regulatory agencies, all in an ultra-rapid timeframes. A key factor of success was creative rethinking of processes and removing barriers – some of which hitherto had been considered immovable. This article describes how bioanalysis was crippled at the onset of the pandemic but how innovative and highly collaborative efforts across teams within and outside of both pharma, bioanalytical labs and regulatory agencies worked together remarkably well.

A rapid, competitive particle concentration fluorescence immunoassay (PCFIA) for the determination of tylosin (Tylan) concentrations in extracts of pre-mix, feeds (cattle, chicken, and swine), and liquid feed supplement is described. Tylosin-β-phyco-erythrin conjugate, tylosin standard or diluted sample extracts, and rabbit anti-tylosin antibody are incubated for 15 min in PCFIA plates. Rabbit anti-tylosin antibody is then captured, during a 15 min incubation, with goat anti-rabbit antibody that is attached to latex beads. Assay plates are washed to remove unbound tylosin-(β-phyco-erythrin and unbound, free tylosin. Fluorescence is measured with a fluorimeter. Tylosin concentration is inversely proportional to the β-phycoerythrin fluorescence signal. The method, evaluated and validated with an IDEXX Screen Machine, shows high specificity with regard to compounds expected to be found in the presence of tylosin, and results correlate well with traditional turbidimetric assay results. Hydrolysis of TUA (tylosin-urea ad-duct), necessary with microbiological methods, and cleanup of extracts beyond filtration are unnecessary with the PCFIA for tylosin.