20 research outputs found
Generation and characterization of a novel multidrug resistance protein 2 humanized mouse line
Validation of In Vitro Cell-Based Human BloodâBrain Barrier Model Using Clinical Positron Emission Tomography Radioligands To Predict In Vivo Human Brain Penetration
Development of an on-line extraction turbulent flow chromatography tandem mass spectrometry method for cassette analysis of Caco-2 cell based bi-directional assay samples
P-gp Inhibition Potential in Cell-Based Models: Which âCalculationâ Method is the Most Accurate?
The objective was to directly compare the four different âcalculationâ methods of assessing P-gp inhibition potential using experimental data obtained from ~60 structurally diverse internal research and marketed compounds. Bidirectional studies for digoxin (probe for P-gp substrate) were performed with and without test compounds (at 10Â ÎŒM). Four different calculation methods were applied to the same dataset (raw bidirectional permeability values) to obtain the âpercent inhibition of P-gpâ for these compounds using the different methods. Significantly different inhibition potential was obtained with the âexactâ same experimental dataset depending on the calculation method used. Subsequently, entirely different conclusions regarding the âinhibition potentialâ of test compound was reached due to the different calculation methods. Based on the direct comparison of these methods, method no. 3 (i.e., inhibition of B to A permeability of digoxin) is recommended as the calculation method ideal during screening stages due to its high throughput amenability. The methodology is capable of rapidly screening compounds with adequate reliability for early stage drug discovery. Method no. 3 provides an abridged version of a bidirectional study that is fully capable of identifying all non-inhibitors (0â20%), moderate inhibitors (20â60%), and potent inhibitors (>60%) and demonstrates high correlation with method no. 1 (inhibition based on both A to B and B to A permeability of digoxin). Nevertheless, method no. 1 might be appropriate for more detailed mechanistic studies required in late stage discovery and development