5,12-dihydro-2,9-dimethylquino[2,3-b]acridine-7,14-dione

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: no GLP compliance, low recovery

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Objective of study:

other: test for bioavailability

Principles of method if other than guideline:

analysis of test item in liver and blood samples obtained from male and female rats subjected to a 90-day oral toxicity study using HPLC

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

5,12-dihydro-2,9-dimethylquino[2,3-b]acridine-7,14-dione

EC Number:

213-561-3

EC Name:

5,12-dihydro-2,9-dimethylquino[2,3-b]acridine-7,14-dione

Cas Number:

980-26-7

Molecular formula:

C22H16N2O2

IUPAC Name:

2,9-dimethyl-5,7,12,14-tetrahydro-5,12-diazapentacene-7,14-dione

Test material form:

solid: nanoform

Radiolabelling:

no

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5% (w/v) carboxymethylcellulose in distilled water

Duration and frequency of treatment / exposure:

13 weeks + 4 weeks recovery

Doses / concentrations

Remarks:

Doses / Concentrations:
0 (control), 50, 200, 1000 mg/kg bw

No. of animals per sex per dose / concentration:

10 males and 10 females
The high dose group and the control group included 5 additional animals per sex sacrificed after 4 weeks of recovery

Control animals:

yes, concurrent vehicle

Details on dosing and sampling:

- samples were collected at the end of the 90-day exposure period
- liver samples of 4 males and 5 females of the control group and 5 males and 4 females of the 1000 mg/kg bw group were analysed
- blood plasma samples of 2 males and 1 female of the control group and 3 males and 2 females of the 1000 mg/kg bw group were analysed

- liver samples were thawed and freeze dried, dried liver samples were pulverized and mixed with N-methylpyrrolidone (NMP), sonificated for 30 minutes and then filtered using 0.2 µm membrane filters; resulting clear solutions were analysed for the content of Pigment Red 122 by HPLC

- frozen blood plasma was thawed and freeze dried, dried samples were pulverized and mixed with N-methylpyrrolidone; mixtures were stirred at 100°C for 3 hours and then filtered using 0.2 µm membrane filters; resulting clear solutions were analysed for the content of Pigment Red 122 by HPLC

- limit of detection:
- about 1.5 ppm test item in liver
- about 0.4 ppm for male rats (10 ml NMP extraction volume) and about 0.6 ppm for female rats (15 ml NMP extraction volume)

Results and discussion

Any other information on results incl. tables

- recovery rates from liver were between 43% and 59% with tendency to increase with the amount of test item used for spiking the liver samples

- no test item was identified in the chromatograms of the samples from the control animals

- no test item was identified in the chromatograms of the samples from the animals that had received 1000 mg/kg bw for 90 days, i.e. the concentration of the test item in dried liver was below the limit of detection of 1.5 µg/g

- recovery rates from blood plasma were between 20% and 39% with tendency to increase with the amount of test item used for spiking the plasma samples

- no test item was identified in the chromatograms of the samples from the control animals

- there was a shoulder in the background peaks that resulted from extracted blood plasma constitutents that interfered with the test item peak leading to some uncertainty in quantification, the estimated concentration of the test item in dried blood plasma was always below 1 µg/g

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): other: test item is not bioavailable
Test item concentrations in liver and blood plasma samples of male and female rats that had received Pigment Red 122 at 1000 mg/kg/day during a 90-day subchronic oral toxicity study (total administered dose 90000 mg/kg) were below quantifiable limit concentrations of 1.5 ug/g dried liver and 0.4 / 0.6 ppm dried blood plasma.

Executive summary:

The study aimed at generating data on the bioavailability of Pigment Red 122 after oral administration. To this end, liver and blood plasma samples were analysed that were obtained from male and female rats subjected to a 90-day subchronic oral toxicity study with Pigment Red 122. The organ samples were extracted and analysed with high-performance liquid chromatography (HPLC) for the presence of Pigment Red 122.

The recovery rates were between 43 % and 59 % for liver samples and between 20 % and 39 % for blood plasma samples. In both cases there was a tendency of the recovery rate to increase with the amount of Pigment Red 122 used for spiking the samples. Attempts to increase the recovery by altering the extraction time or temperature were not successful. Given the extremely low solubility of Pigment Red 122 in water and most organic solvents, the obtained recovery rates were considered acceptable. The limits of detection were estimated at about 1.5 ppm for dried liver and 0.4 / 0.6 ppm for dried blood plasma.

Analysis of organ samples from animals of the high dose group that had received 1000 mg Pigment Red 122/kg/day for consecutive 90 days revealed no concentrations of Pigment Red 122 above the detection limits. For both organs, in chromatogram region of the Pigment Red 122 peak at 16.9 minutes, there was a shoulder in the chromatogram caused by extracted blood plasma or liver constituents. This led to some variability in the peak area in this region between the samples. In some samples, a shoulder in the region of the Pigment Red 122 peak was visible. However, the estimated concentration of Pigment Red 122 in dried blood plasma was always below 1 µg/g. No Pigment Red 122 peak was visible in the chromatograms of the extracts of liver samples of the rats that had received 1000 mg Pigment Red 122/kg/day for 90 consecutive days.