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Ready-to-use assay systems for DMPK and ADMET studies

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TRANSILXL High Sensitivity Binding kit

A novel plasma protein binding assay for “sticky” and tightly bound compounds.

This assay accurately predicts the free fraction of drugs in plasma, even if the fraction is below 0.1%. It is designed to accurately determine the free fraction of highly lypophilic drugs or any other compounds that tend to bind tightly to the dialysis systems. Moreover, most difficult to solubilize drugs can be handled well in the TRANSIL High Sensitivity Binding assay kit.

  • Ready-to-use silanized glass vials pre-filled with buffer and membrane beads, designed to conveniently assess plasma protein binding of compounds through competitive binding to cell membrane on the beads.
  • Includes spreadsheet, facilitating manipulation of statistical parameters and calculation of final results.
  • Accurate detection of very low free fractions (<0.1% or less) as well as free fractions in the “normal” range of 20% or less.
  • Successfully applied to assess plasma protein binding of peptide drugs.
  • High recovery even with very “sticky” compounds.
  • Versatile assay that can be used with plasma from any species.
  • User friendly, easy handling system.
  • Rapid, only 30 minutes assay incubation time reduces potential biases through metabolic instability.
Background and Technical Information

Several methods exist for assessing the unbound fraction of a drug in plasma. Standard methods include dialysis, ultrafiltration, centrifugation and rapid dialysis with immobilized plasma proteins such as TRANSILXL HSA and TRANSILXL AGP Binding kit. Once the unbound fraction of the drugs become very low and comprises only 1% the total drug in plasma or even less, then all the mentioned methods become inaccurate mainly because of analytical problems such as detection limits, non-linear responses (LC-MS/MS), or limited compound purity (scintillation counting). To overcome these limitations as well as common issues with low recovery or limited solubility we offer the TRANSILXL High Sensitivity Binding kit.

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