# US 9,518,979 B2 · Assay to evaluate drug metabolism

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- Number: US 9,518,979 B2
- Document ID: US9518979B2
- Status: Granted
- Kind: B2
- Application number: 14/615,233
- Filed: 2015-02-05
- Published: 2016-08-11
- Granted: 2016-12-13
- Earliest claimed: 2015-02-05
- Applicants: Albert P Li
- Inventors: Albert P Li
- Web page: https://patentgrep.com/patent/US9518979B2

## CPC

- G01N 33/5038: {involving detection of metabolites per se}
- G01N 33/5067: {Liver cells}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

A novel assay using plated (cultured) human hepatocytes is disclosed. In this assay, cryopreserved human hepatocytes are thawed and cultured for 4 hours to allow attachment, followed by incubation with compounds for 24 hours. After the 24 hour incubation, aliquots can be collected for quantification of the remaining parent compounds. The remaining incubated media are transferred to freshly thawed and cultured cryopreserved hepatocyte and incubated for another 24 hour period. The process can be repeated daily resulting in accumulated incubation durations of multiple days. The innovation is the use of a new culture on each day, thereby overcoming the known decrease in metabolic activity of hepatocytes with time in culture.

## Claims

### Claim 1

A method of evaluating metabolism of a test compound via cultured hepatocytes, the method comprising:
adding a medium with a test compound to be metabolized to a first multi-well plate each having cultured hepatocytes for a first time period;
pooling the medium with the test compound into a first container;
distributing the pooled medium in the first container into a second multi-well plate each having cultured hepatocytes for a second time period;
pooling the medium with the test compound into a second container; and
distributing the pooled medium in the second container into a third multi-well plate having cultured hepatocytes for a third time period.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
culturing cryopreserved hepatocytes in each plate of the first multi-well plate prior to the first time period.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
culturing cryopreserved hepatocytes in each plate of the second multi-well plate between the first and second time period.

### Claim 4 (depends on 1)

The method of claim 1, further comprising:
culturing cryopreserved hepatocytes in each plate of the third multi-well plate between the second and third time period.

### Claim 5 (depends on 1)

The method of claim 1, where the first, second and third time period each comprise 24 hours.

### Claim 6 (depends on 1)

The method of claim 1, wherein the test compound comprises a chemical compound.

### Claim 7 (depends on 1)

The method of claim 1, wherein the test compound comprises a drug.

### Claim 8 (depends on 1)

The method of claim 1, further comprising:
adding the test compound to be metabolized to the medium.

### Claim 9 (depends on 1)

The method of claim 1, wherein the test compound to be metabolized is added to hepatocyte cultures prepared on each day of the experiment.

### Claim 10 (depends on 1)

The method of claim 1, wherein:
the first multi-well plate includes more than one row and more than one column of wells;
pooling the medium includes pooling the medium from each row of wells;
distributing the pooled medium includes distributing the pooled medium to wells of a corresponding row of the second multi-well plate;
pooling the medium with the test compound into a second container; and
distributing the pooled medium in the second container into a third multi-well plate having cultured hepatocytes for a third time period.

### Claim 11 (depends on 1)

The method of claim 1, further comprising:
removing a portion of the medium from the first container for analysis or other treatment.

### Claim 12 (depends on 1)

The method of claim 1, further comprising:
removing a portion of the medium from the second container for analysis or other treatment.

### Claim 13

A method of evaluating metabolization of a drug via cultured hepatocytes during a multi-day experiment, the method comprising:
culturing cryopreserved hepatocytes in each plate of a first multi-well plate on a first day of the experiment;
adding a medium with the drug to be metabolized to the first multi-well plate for the first day of the experiment;
culturing cryopreserved hepatocytes in each plate of a second multi-well plate on a second day of the experiment;
pooling the medium into a first container on the second day of the experiment;
removing a portion of the medium from the first container for analysis or other treatment;
distributing the pooled medium in the first container into the second multi-well plate for the second day of the experiment;
culturing cryopreserved hepatocytes in each plate of a third multi-well plate on a third day of the experiment;
pooling the medium into a second container on the third day of the experiment;
removing a portion of the medium from the second container for analysis or other treatment; and
distributing the pooled medium in the second container into the third multi-well plate for the third day of the experiment.