In Vitro ADME, Preclinical Pharmacokinetics and Prediction of Human Pharmacokinetics of RBx14255, a Novel Ketolide with Pharmacodynamics Against Multidrug-Resistant Bacterial Pathogens

Authors

  • Trdib Chaira Department of Drug Metabolism and Pharmacokinetics; New Drug Discovery Research, Ranbaxy Research Laboratories, R & D III, Gurgaon, India; Centre for Drug Design Discovery and Development (C4D), SRM University, Delhi-NCR, Sonepat, Haryana, India.
  • Tarani Barman Department of Microbiology, Daiichi Sankyo India Pharma Private Limited, Gurgaon, Haryana, India; New Drug Discovery Research, Ranbaxy Research Laboratories, R & D III, Gurgaon, India.
  • VETHAKKANI SAMUEL RAJ Department of Microbiology, Daiichi Sankyo India Pharma Private Limited, Gurgaon, Haryana, India; New Drug Discovery Research, Ranbaxy Research Laboratories, R & D III, Gurgaon, India; Centre for Drug Design Discovery and Development (C4D), SRM University, Delhi-NCR, Sonepat, Haryana, India.

DOI:

https://doi.org/10.18433/jpps30942

Abstract

Purpose: The preclinical pharmacokinetic and pharmacodynamic properties of a potent fluoroketolide RBx14255 against Streptococcus pneumoniae and Haemophilus influenzae was compared with telithromycin and human clinical dose was predicted for preclinical development. Methods: The in vitro pharmacokinetic characterization was performed for solubility, Caco-2 permeability, microsomal stability, CYP inhibition and plasma protein binding. In vivo pharmacokinetic studies were performed in Swiss albino mice, Sprague Dawley rats and Beagle dogs. The pharmacodynamic studies were carried out in mouse against S. pneumoniae in systemic infection and against S. pneumoniae and H. influenzae in rat lung infection models. Results: RBx14255 showed superior potency and efficacy in mouse and rat infection models. RBx14255 showed pH dependent solubility (0.41 mg/mL at pH 6.8 and >1 mg/mL at pH 1.2), moderate Caco-2 permeability (A to B: 12 nm/s) with high efflux ratio. It showed high plasma protein binding (>97%) in mouse and low binding (45-70%) in rat, dog and human. The compound is mainly metabolized through CYP3A4. Pharmacokinetic parameters and absolute bioavailability of both, RBx14255 and telithromycin are similar in mouse. Both the ketolides showed low plasma clearance (18% of the normal hepatic blood flow rate) in mouse, moderate to high clearance in rat and dog. Mean oral bioavailability was high in mouse (≥85%), moderate in rat (RBx14255: 15% and telithromycin: 51%) and high to moderate in dog (RBx14255: 98% and telithromycin: 56%). The predicted efficacious dose for a 70 kg man ranges from 124 mg BID to 226 mg BID. Conclusion: RBx14255 displayed significantly better pharmacodynamics which correlates with the pharmacokinetic properties against S. pneumoniae and H. influenzae as compared to telithromycin. The predicted human efficacious doses are in the range of 124-226 mg, making it amenable to oral dosage form drug in human. This could be a promising clinical candidate for future studies.

Downloads

Download data is not yet available.

Downloads

Published

2020-06-22

How to Cite

Chaira, T., Barman, T., & SAMUEL RAJ, V. (2020). In Vitro ADME, Preclinical Pharmacokinetics and Prediction of Human Pharmacokinetics of RBx14255, a Novel Ketolide with Pharmacodynamics Against Multidrug-Resistant Bacterial Pathogens. Journal of Pharmacy & Pharmaceutical Sciences, 23(1), 206-219. https://doi.org/10.18433/jpps30942

Issue

Section

Pharmaceutical Sciences; Original Research Articles