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

LC‐MS in Drug Metabolism and Pharmacokinetics: A Pharmaceutical Industry Perspective

“…Therefore, urine bioanalytical assays tend to suffer from analyte losses more often than plasma assays. A variety of antiadsorptive agents including organic solvent, BSA, zwitterionic detergents such as CHAPS (3 -[(3 -Cholamidopropyl) dimethylammonio] -1 -propanesulfonate), sodium dodecyl benzene sulfonate, β -cyclodextrin, Tween 80 (polysorbate 80), and Tween 20 (polysorbate 20) can be used to block the adsorption of the compound to the surface of the container. Adsorption should always be evaluated for a urine assay prior to the urine collection so that a correct urine collection procedure can be incorporated into the study protocol.…”

Development of a quantitative LC–MS/MS analytical method coupled with turbulent flow chromatography for digoxin for the in vitro P-gp inhibition assay

“…This research was a follow-up from our earlier application of this analytical technique towards analysis of samples from Caco-2 cell based P-gp substrate assay [1].…”

“…P-gp, by its ubiquitous expression coupled with the capacity to interact with a wide-spectrum of substrates, is known to play a prominent role in dictating the pharmacokinetics and pharmacodynamics of several drugs. It is widely recognized to be a major determinant of absorption, distribution and elimination of a wide array of marketed drugs [1].…”

Development of a μ-turbulent flow chromatography focus mode method for drug quantitation in discovery bioanalysis

“…a time saving advantage over more labour intensive liquid-liquid extraction or solid phase extraction techniques. Several authors over the years have demonstrated successfully how such a reduced sample preparation time, coupled to a short turbulent flow chromatographic gradient can reduce the bottleneck of discovery sample throughput, particularly during quantification of in vitro [8,9] and in vivo samples [10][11][12]. Recently, TFC operating in a dual column (sample extraction and isocratic focusing) mode has utilised a monolithic column compatible with high flow rate and low backpressures [13], to reduce cycle times to shorter than 1.5 min.…”