Simplified Method to Determine the Efflux Ratio on P-Glycoprotein Substrates Using Three-Compartment Model Analysis for Caco-2 Cell Assay Data

• Published in: Pharmaceutical research 2020-01, Vol.37 (1), p.13-12, Article 13
• Main Authors: Nagayasu, Miho, Ozeki, Kazuhisa, Sakurai, Yuuji, Tsutsui, Haruka, Onoue, Satomi
• Format: Article
• Language: English
• Subjects: Analysis; ATP Binding Cassette Transporter, Subfamily B, Member 1 - chemistry; ATP Binding Cassette Transporter, Subfamily B, Member 1 - metabolism; Biochemistry; Biological Transport; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biosensing Techniques - methods; Caco-2 Cells; Communications equipment; Cyclosporine; Cyclosporins; Drug discovery; Drug Interactions - physiology; Glycoproteins; Humans; Medical Law; Methods; Models, Biological; P-Glycoprotein; Permeability; Pharmacology/Toxicology; Pharmacy; Protein Binding; Research Paper; Sampling; Substrates; Time Factors; Transcytosis
• ISSN: 0724-8741; 1573-904X
• DOI: 10.1007/s11095-019-2729-x

Purpose Multiple time-point sampling is required in transcellular transport studies to accurately calculate the appropriate efflux ratio (ER). Our study sought to develop a simplified method to determine the ER in Caco-2 cells. Methods The equation for the ER was derived from a three-compartment model of apical to basal and basal to apical transport. Transcellular transport studies were conducted with 10 non-P-glycoprotein (P-gp) and 6 P-gp substrates in Caco-2 cells, and the ER was calculated using this equation. Results The equation for the ER used the concentration ratio in the receiver compartment at the same time-point; therefore, the ER can theoretically be calculated using only a single point. The ER of all non-P-gp substrates tested was close to 1 at all sampling times. The ERs of cyclosporine A calculated from the concentration ratio at 30, 60, 90, and 120 min incubation were 2.93, 6.43, 7.12, and 9.57, respectively, and the ER at 120 min was almost identical to the theoretical value (9.62) calculated using three-compartment model analysis. The other 5 P-gp substrates showed a similar tendency. Single-point sampling can be used to accurately calculate ER at 120 min. Conclusions Single-point sampling is a promising approach for calculating appropriate ERs in the drug discovery stage.