6-[(p-tosyl)amino]hexanoic acid, compound with 2,2',2''-nitrilotriethanol (1:1)

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2012-2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study was conducted by a GLP accredited laboratory using OECD Testing Guideline 422. The study was conducted on 6-[(p-Tosyl)amino]hexanoic acid, which is the carboxylic acid component of the registered substance i.e. tosyl salt.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

Principles of method if other than guideline:

Daily administration by stomach tube for 54 days

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tosyl carboxylic acid

IUPAC Name:

Tosyl carboxylic acid

Constituent 2

Reference substance name:

6-[(p-Tosyl)amino]hexanoic acid

IUPAC Name:

6-[(p-Tosyl)amino]hexanoic acid

Constituent 3

Reference substance name:

6-[[(4-methylphenyl)sulphonyl]amino]hexanoic acid

EC Number:

278-934-5

EC Name:

6-[[(4-methylphenyl)sulphonyl]amino]hexanoic acid

Cas Number:

78521-39-8

Molecular formula:

C13H19NO4S

Test material form:

solid: crystalline

Details on test material:

- Physical state: solid, white crystalline powder
- Batch No.: 110526S
- Expiry date: 26.05.2013
- Purity: 99.24% (taken as 100%)
- Instructions for storage: Room temperature, tighly closed container, cool, dry, only in original container
- Colour: white
- Odour: odourless

Test animals

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Germany, D-97633 Sulzfeld
- Age at purchase: 11 weeks
- weight rage at time of grouping: males, 175-200 g
- Fasting period before study: no
- Housing: 2 per cage,
- Cages: TECHNIPLAST filter top cages type 2145 F with an G-Temp (PSU) durable filter cover, 480x265x210 mm³, floor area 940 cm²,
- Source: Techniplast Company, Italy
- Diet: ad libitum, M3, BONAGRO Ltd., reg. CZ 10174, Czech Republic
- Water: ad libitum, tap water
- Acclimation period: 9 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 40 - 70
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE: Suspension in water

- Amount of vehicle: 10 ml/kg
- single daily adminisration at similar times each day

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

54 administrations, (2 weeks before mating, 2 weeks during mating and 26 days after mating)
dissection ca. 24 hours after the last administration

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 400, 1600 mg/kg body weight (mg/kg bw)
Basis:
actual ingested

No. of animals per sex per dose:

12 males, satelite groups (control and highest dosage): 5 males each

Control animals:

yes

Details on study design:

- Control groups: drinking water
- Dose selection rationale: Results of an acute toxicity study with oral administration to male and female rats
- Result: no effects up to and including 2000 mg/kg bw.
- Rationale for animal assignment: randomly grouped
- Section schedule rationale: all animals were sacrificed

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: on administration days 1, 8, 15, 22, 29, 36, 42, 50 and on day of autopsy

FOOD CONSUMPTION : 2 weeks before mating, after 2 week mating period and weekly until the end of the study

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day 14 (before mating) and prior to autopsy from the satelite groups and from the control and highest dose group.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:day 14 (before mating) and prior to autopsy from the satelite groups and from the control and high dose group.

URINALYSIS: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
- Organ weights: brain, heart, thymus, spleen, liver, testis, epididymis, kidney, adrenal gland

HISTOPATHOLOGY: Yes: high dose and control animals
- Organ: medulla oblongata, brain, heart, pancreas + lymphnode, spleen, liver, lung, small intestine, stomach, kidneys, adrenal gland, testes, prostrate, urinary bladder, bone + bone marrow, thymus, trachea, white + brown fat, muscle, pituitary gland

Statistics:

Statistical evaluation was operated using the software SPPS version 16.0. Group data were represented by mean, standard deviation and median. Statistical analysis in case of data measured once during the study (organ weight, haematology, clinical chemistry) : Mann-Whitney U test for pairwise comparison between control and individual experimental groups on significance level alpha = 0.05.
Statistical analysis in case of repeated data measurement (body weight, food intake): Repeated measures ANOVA (procedure General Linear Model (GLM) for Repeated Measures in SPSS statistical software).

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

statistically significant decrease after dosages of 1600 mg/kg bw./day

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS:
- 100, 400 and 1600 mg/kg bw/day:
no differences to the control animals observable

MORTALITY: no

BODY WEIGHT GAIN: 1600 mg/kg bw: reduced

FOOD CONSUMPTION: no statistical differences

HAEMATOLOGY/ CLINICAL CHEMISTRY:
Haematology and clinical chemistry reveales some statistically significant differences, but these were neither related to dosage not confirmed by the findings in other groups, for example by the results of the satelite groups, or the effects are of biological low relevance i.e..

URINALYSIS: not examined

NEUROBEHAVIOUR: not examined

ORGAN WEIGHTS: no statistical differences

GROSS PATHOLOGY: no dosage related effects

HISTOPATHOLOGY: NON-NEOPLASTIC: no statistical differences

HISTOPATHOLOGY: NEOPLASTIC: no statistical differences

HISTORICAL CONTROL DATA: not given

Effect levels

1

Key result

Dose descriptor:

NOEL

Effect level:

400 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

2

Dose descriptor:

LOEL

Effect level:

1 600 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: decrease in body weight (not exeeding 10%)

Target system / organ toxicity

Critical effects observed:

no

Applicant's summary and conclusion

Conclusions:

Daily dosages of 0, 100, 400, and 1600 mg/kg bw of the test substance were administered by stomach tube to groups of 12 male rats for 54 days. Satellite animals in a control and the highest dose group (1600mg/kg bw) with 5 individual each were also included.The test-article was formulated in drinking water and administered in 10 ml/kg bw..
At dosages of 100 and 400 mg/kg bw. the animals showed no differences to the control animals (NOAEL).
1600 mg ASC plus/kg bw. , considered as the LOEC, may have induced an influence on the body weight gain of the males (and the survival of pups until day 4 after birth).
NOAEL: 400 mg/kg bw.

Executive summary:

The repeated dose toxicity of the test substance to rats was determined in accordance with the OECD Guideline for Testing of Chemicals 422. Doses of 0, 100, 400, and 1600 mg/kg bw/day of the test substance were administered by stomach tube to groups of 12 male rats for 54 days. The test-article was formulated in drinking water and administered in 10 ml/kg bw. At dosages of 100 and 400 mg/kg bw/day the animals showed no differences to the control animals (NOEL). All examined organs and tissues showed a normal histological structure. 1600 mg/kg bw/day may have induced an influence on the body weight gain of the males (and the survival of pups until day 4 after birth). The NOEL and NOAEL for the test substance is defined as 400 mg/kg bw/day. The LOEL for the test substance is defined as 1600 mg/kg bw/day. The test substance was the carboxylic acid component of the tosyl salt. Read-across between the tosyl salt carboxylic acid (6-[(p-Tosyl)amino]hexanoic acid) and the registered substance is considered justified as the registered substance is manufactured directly from 6-[(p-Tosyl)amino]hexanoic acid by simple neutralisation with triethanolamine (TEA). Other than ionization of the carboxylic acid group, the 6-[(p-Tosyl)amino]hexanoic acid remains chemically unchanged upon salt formation. In water, the acid and amine components of 6-[(p-Tosyl)amino]hexanoic acid, compound with 2,2’,2’’-nitrilotriethanol (1:1) dissociate completely and behave essentially as independent substances. Since TEA can be considered non-hazardous, it is the acid component of the salt that will have a more significant impact on the outcome of any (eco)toxicological or environmental tests. The pKa of the carboxylic acid group in 6-[(p-Tosyl)amino]hexanoic acid (pKa = 4.90) is the same in the free acid as it is in the TEA salt. As a result, 6-[(p-Tosyl)amino]hexanoic acid will respond to changes of pH in the same way whether it is in the salt form or as the parent carboxylic acid and hence it’s bioavailability will be the same.