Safety Study

In vitro hepatotoxcity evaluation

1Bile Acid-Dependent Hepatotoxicity Study
When the drug candidate inhibits the transport of the bile salt excretion, the bile salt can be accumulated within the cell which is known to cause the cholestasis. Using the sandwich-cultured primary human hepatocytes, we evaluate the potential of this risk.
2Mitochondrial Toxicity Assay
Mitochondrial toxicity is seen in about 80% of the boxed warning compounds reported by the FDA. We can evaluate the toxicity using HepG2 cells and its Crabtree effect.
3Reactive Metabolite Identification
1. 1Cysteine Trapping Assay
  Since some reactive metabolites are unstable, we use 35S cysteine as a trapping reagent to quantify the amount of reactive metabolites.
2. 2KCN Trapping Assay
  By using K¹⁴CN, we can trap and quantify the reactive metabolites cannot be measured by ³⁵S cysteine.
3. 3Identification of acylglucuronic conjugates
  Acylglucuronic conjugates are highly reactive and also known to contribute to the liver injury. We can evaluate the formation of 1-O-β-glucuronic conjugates to isomers and its rate.
4. 4Covalent binding styudy
  We can determine the amount of radiolabeled compound and its metabolites that covalently bind to protein using human hepatocytes or liver microsome for in vitro evaluation. For the in vivo evaluation, rats are subjected to the induction of liver metabolic enzymes followed by administration of the radiolabeled compound. The liver is then removed at a specified time and the radioactivity in plasma and the liver will be measured to calculate the covalent binding of the radiolabeled compound.

Toxicokinetics Study

Biological samples collected from safety studies will be measured with the validated analytical methods under OECD-GLP standards.

Drug Concentration Determination

Gene Expression Analysis

We conduct a wide variety of studies ranging from comprehensive gene analysis through gene expression analysis focusing on toxicity, to the quantitative evaluation of target genes of toxicity markers to meet the customers' needs.

Measurement of Biomarkers

We establish analysis systems for an assigned biomarker using the immunological and gene analysis methods, as well as perform measurements of samples in compliance with the GLP standards.

Samples can be measured by multiplex method using bead-based suspension array, high-sensitivity digital ELISA or ECL.
Biomarker gene will be measured using real-time PCR (RT-PCR), bead-based suspension array or PALSAR^®.