Full in Vitro DDI Package, Improved Hepatocyte Assays and more News & Developments!

December 18, 2023


Full in Vitro DDI Package Now Available 

With the new addition of CYP450 reaction phenotyping services to our portfolio, SOLVO now offers a full regulatory in vitro drug-drug interaction (DDI) study package, including all required CYP450- and transporter assays. For compounds that are metabolized in human liver microsomes (HLMs) in a NADPH-dependent manner, CYP450 reaction phenotyping is conducted in two different assay systems:

  • CYP450 reaction phenotyping by chemical CYP450 inhibition in human liver microsomes.
  • Substrate clearance using recombinant CYP450 enzyme systems.

Using output from both experiments, CYP450 enzymes mainly catalyzing test compound metabolism can be identified. Identification of enzymes that contribute to >25% of a compound’s metabolic clearance is required by regulatory guidelines such as the FDA 2020 final and the ICH M12 2022 draft guidance documents. Click to learn more about the SOLVO metabolism portfolio.

Improved Biliary Clearance and Hepatic Uptake Assays

Bioavailability of new molecular entities is highly affected by hepatobiliary clearance processes, knowledge, and optimization of which is essential to achieve sufficient plasma exposure to modulate new targets effectively and safely. The B-Clear assay has been developed to measure the biliary secretion of compounds in vitro using sandwich-cultured hepatocytes (SCH). Our new Vectorial Efflux assay improves this approach, measuring uptake and efflux processes separately – this allows determination of the uptake, basolateral- and biliary efflux of compounds at once, in a single experiment in addition to biliary clearance evaluation. The Vectorial Efflux assay is validated with human and rat SCH, while for the “traditional” B-Clear assay, rat and dog SCH were also added to the SOLVO portfolio.

We also developed additional measurements to improve the performance and physiological relevance of our in vitro hepatocyte uptake assay. As it is well established, that human hepatocytes can better predict in vivo clearance in the presence of bovine or human serum albumin or human plasma, an assay for addressing hepatic uptake clearance in the presence of albumin in the medium was developed and validated. Uptake of OATP1B1, NTCP, OAT2 and OCT1 substrates with different protein-binding capacity was determined in HEK293 cell lines and in primary human hepatocyte cultures in the presence and absence of physiological quantities of human or bovine serum albumin. This method allows us to determine whether the presence of proteins affect a compound’s uptake clearance, or only alter the free drug concentration.

New Lysosomal Trapping Assay Using LC-MS/MS Readouts 

Lysosomal accumulation of a drug alters their intracellular distribution, limiting its access to target localized in the cytoplasm or nucleus as well as its availability for metabolic and transport processes. Beside identification of lysosomal interaction of a compound via an indirect approach such a HCI-based lysosomal dye-extrusion assay, information on the magnitude of lysosomal sequestration may also be necessary, especially for accurate hepatic Kp,uu determination.

For this purpose, we have complemented our lysosomal trapping assessment services by a new assay for detecting lysosomal trapping of compounds directly using LC-MS/MS in the presence and absence of a lysosomal function inhibitor, Bafilomycin A1. The assay was set up and optimized in Caco-2 cells and human hepatocytes.

Updates from Bioanalytics Team 

Our group’s efforts in 2023 focused largely on meeting expectations of drug development projects based on new modalities. As an expansion of our capabilities, quantification of therapeutic oligonucleotides by reverse phase (RP) on HT LC-MS/MS or hydrophilic interaction liquid chromatography (HILIC) is now available. Peptides are analyzed directly or by enzymatic digestion, depending on their physicochemical properties and structure.

We also improved throughput of bioanalytical services in support of screen-type assays run at SOLVO. Our high-throughput (HT), high-sensitivity analytical systems, now including the dual-arm ADDA and LS-1, each coupled to Sciex 6500+ triple quadrupole mass spectrometers, have demonstrated their exceptional performance. As part of an exemplary R&D transporter study, 26,680 samples were measured in just 2.25 days – 20-times faster than the “standard’ approach! The streamlined bioanalytical data workflow is supported by the custom-built laboratory information management software (LIMS), nicknamed BAMBI.

2023 Webinars and Publication Highlights 

As part of our Meet the Experts Webinar Series, the following three topics were presented by leading industry experts:

Click to browse the full SOLVO webinar library.
SOLVO also fully authored or contributed to 9 peer-reviewed publications this year, including the  below key papers on transporter assay applications:

Consult our full publication list here.

Meet the Experts Budapest 2024 - Transporters & ADME Symposium

It’s our pleasure to announce our next symposium held in Budapest, Hungary on May 8-10, 2024.  
Not only will this be the 10th anniversary of the Meet the Experts (MEEX) Transporter meetings, but it will also mark the first time the ADME and Transporters symposium is held as a Charles River event while continuing to integrate the quality and innovation that SOLVO is known for.

To learn more or register visit our webpage!

We wish you Happy Holidays and a successful New Year!

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