Poly(oxy-1,2-ethanediyl), α-[2-(dide- cylmethylammonio)ethyl]- .omega.- hydroxy-, propanoate (salt) (Bardap 26)

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The substance did not induce mutations in the bacterial reverse mutation assay, did not cause chromosomal damage or polyploidy in human lymphocyte cultures, did not induce mutations in mouse lymphoma cells.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

The substance did not induce chromosome damage in bone marrow cells in vivo. The substance is not considered to be genotoxic.

Link to relevant study records

Reference

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August to October 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)

Deviations:

no

Principles of method if other than guideline:

Not applicable.

GLP compliance:

yes

Type of assay:

chromosome aberration assay

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

The test animals were male and female Sprague-Dawley rats obtained from Charles River (UK) Ltd. At the start of the main study the males weighed 307-365 g and the females 200-235 g, and were approximately 8-10 weeks old. The rats were acclimatised for a minimum of 5 days, prior to random selection into test groups. They were housed in same-sex groups of up to 5 in solid floor polypropylene cages with woodflake bedding. The were provided with food (Rat and Mouse Expanded Diet No. 1., SDS Ltd., UK.) and mains water ad libitum. Food was removed overnight prior to dosing, and returned approximately 2 hours after dosing. The animal room was maintained at a temperature of 19-23°C, and relative humidity of 53-58%. There were approximately 15 air changes per hour and a 12 hour light/dark cycle.

Route of administration:

oral: gavage

Vehicle:

Arachis oil B.P.

Details on exposure:

The test substance was administered orally by gavage in arachis oil B.P. to rats fasted overnight. Dosing solutions were freshly prepared as required. The dose volume in all cases was 10 ml/kg bw.

Duration of treatment / exposure:

Single gavage dose

Frequency of treatment:

Single gavage dose

Post exposure period:

6, 24 or 48 hours post-dosing

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Remarks:

actual ingested

No. of animals per sex per dose:

5 males and 5 females

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide monohydrate (20 mg/kg bw). The positive control group was sacrificed 24 hours aafter treatment.

Tissues and cell types examined:

Bone marrow

Details of tissue and slide preparation:

Animals were injected i.p. with colchicine at 4 mg/kg bw up to 2 hours prior to bone marrow harvest. Animals were killed at the scheduled time (6, 24 or 48 hours post-dosing), and both femurs were extracted. The bone marrow was aspirated into 5 ml of HBSS and centrifuged. The supernatant was removed and the cell pellet resuspended in 0.075 M KCl at room temperature for 15 minutes. The cells were centrifuged and all but 1 ml of the supernatant removed. After resuspension, the cells were fixed by the addition of freshly prepared fixative (methanol/glacial acetic acid, 3:1). The fixative was changed several times and the cells stored at 4°C for at least 4 hours. After storage the cell suspensions were recentrifuged and the fixative removed to leave a sufficient amount of suspension. Several drops of the suspension were dropped onto clean wet slides and dried on a hot plate at ~40°C. When completely dry and cooled, the slides were stained in 5% Giemsa for 10 minutes and rinsed in tap water and distilled water. The slides were mounted in DPX once dry.

Slides were scored blind. Fifty metaphase spreads per rat were examined for chromosomal aberrations. If the cell had 42 or more chromosomes, any gaps, breaks or rearrangements were noted according to the simplified system of Savage (1976).

Evaluation criteria:

Cytotoxicity: Reduction in mean mitotic index.
Genotoxicity: Increase in chromosome aberration frequency, increase in polyploidy.

Statistics:

Chi-squared test; Exact test

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

There were no reductions in mean mitotic index, however the observation of clinical signs indicates that systemic absorption of the test material had occurred. There were no statistically significant increases in chromosome aberrations or polyploidy.

No clinical signs were observed 1 hour post dosing. There was one premature death in the 24 hour 1000 mg/kg bw test group; this was considered to be due to a technical error and not due to the test material. In the animals sacrificed 6 hours after test substance administration hunched posture, decreased respiratory rate and laboured respiration were observed. In the animals sacrificed 24 and 48 hours after test substance administration the following clinical signs were observed: hunched posture, lethargy, pilo-erection, tiptoe gait, diuresis, decreased respiratory rate, laboured respiration, gasping respiration, noisy respiration, dehydration, diarrhoea, stains around snout, stains around mouth, emaciation and ataxia.

Conclusions:

There was no significant increase in chromosome aberration frequency or in polyploidy, therefore the test substance is not considered to be clastogenic.

Executive summary:

The potential for Bardap 26 (N,N-Didecyl-N-methyl-poly(oxyethyl)ammonium Propionate in aqueous/alcohol solution) to induce chromosome damage in bone marrow cells was evaluated in vivo according to OECD 475. Male and female Sprague-Dawley rats were administered a single oral gavage dose of 1000 mg/kg bw test substance (controls were dosed with the vehicle, Arachis oil B.P. only). Bone marrow smears were taken, 6, 24 and 48 hours post-dosing. Fifty metaphases per rat were examined for chromosomal aberrations.

Administration of the test substance at 1000 mg/kg resulted in clinical signs of toxicity in the test animals, indicating systemic absorption of the test material had occurred. Bone marrow cells showed no evidence of toxicity. There was no significant increase in chromosome aberration frequency or in polyploidy at any of the three time points, therefore the test substance is not considered to be clastogenic to bone marrow cells in vivo.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vivo:

In Vitro

Bardap 26 (N,N-Didecyl-N-methyl-poly(oxyethyl)ammonium Propionate in aqueous/alcohol solution) was toxic at all concentrations used in most of the bacteria strains used in the Ames test. No evidence of mutagenicity was observed in either the presence or absence of metabolic activation (Jung and Weigand, 1986).

Bardap 26 was exposed to cultured human lymphocytes for 4 hours or mouse lymphoma cells for 3 hours, with and without metabolic activation, or for 24 hours without metabolic activation. The short exposure period resulted in a 50% reduction in the mitotic index in the human lymphocytes and a dose related reduction in the index for the longer exposure time. Toxicity was also observed in the lymphoma cells in the presence or absence of metabolic activation. However, the toxicity of the test substance to the human lymphocytes was not followed by any chromosomal damage or polyploidy, and no toxicologically significant increase in mutant frequency in the mouse lymphoma cells (Wright, 2002; Wright & Nolan, 2001).

In vivo

Bardap 26 did not induce cytotoxicity or chromosome damage in rat bone marrow cells, although clinical signs observed in the animals post-dosing indicated that systemic absorption of the test material had occurred. There was no increase in chromosome aberration frequency or polyploidy (Durward, 1994), and the test substance was considered to be non-clastogenic.

Justification for selection of genetic toxicity endpoint
All studies in vitro and in vivo were negative; the selected study is a higher tier in vivo study.

Justification for classification or non-classification

The substance did not induce mutations in the bacterial reverse mutation assay, did not cause chromosomal damage or polyploidy in human lymphocyte cultures, did not induce mutations in mouse lymphoma cells, and did not induce chromosome damage in bone marrow cells in vivo, therefore no classification for genetic toxicity is required according to CLP criteria.