Carbamic acid, (2-hydroxypropyl)-, compd. with 1-amino-2-propanol (1:1)

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Remarks:

based on generations indicated in Effect levels (migrated information)

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study; Read-across

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: US EPA OPPTS 870.3650

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-aminopropan-2-ol hydrochloride

EC Number:

231-948-5

EC Name:

1-aminopropan-2-ol hydrochloride

Cas Number:

7780-04-3

IUPAC Name:

1-aminopropan-2-ol hydrochloride

Constituent 2

Reference substance name:

2-propanol, 1-amino-, hydrochloride (1:1)

IUPAC Name:

2-propanol, 1-amino-, hydrochloride (1:1)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany
- Age at study initiation: 11-13 wks
- Weight at study initiation: Males: 267-309 g; Females: 187-218 g
- Housing: individual
- Diet and water: ad libitum (except during the fasting period and measurement of motor activity)
- Acclimation period: at least 6 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
For preparation of the administration solutions, the test substance was weighed in a graduated measuring flask, toped with tap water and dissolved by shaking. The test substance solutions were prepared at the beginning of the administration period and thereafter at intervals that took into account the stability of the test substance preparation.

VEHICLE
- vehicle: tap water
- Concentration in vehicle: test group 1 - 0; test group 2 - 1.53 g/100 ml; test group 3 - 4.59 g/100 ml; test group 4 - 15.29 g/100 ml
- Amount of vehicle including test substance solution (if gavage): 10 ml
- Purity: calculated value taking into accout the nominal active ingredient content of 65.4g/100ml

Details on mating procedure:

Each of the male and female animals was mated overnight in a 1 : 1 ratio for a maximum of 2 weeks. Throughout the mating period, each female animal was paired with a predetermined male animal from the same dose group.
The animals were paired by placing the female in the cage of the male mating partner from about 4.00 p.m. until 7.00 - 9.00 a.m. of the following morning. Deviations from the specified times were possible on weekends and public holidays and were reported in the raw data. A vaginal smear was prepared after each mating and examined for sperm. If sperm was detected, pairing of the animals was discontinued. The day on which sperm was detected was denoted "day 0" and the following day "day 1" post coitum.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentration control analyses were conducted with samples drawn from all doses at the start and at the end of the administration period. Analyses of the test substance dosing solutions in tap water confirmed the targeted concentrations. Generally, the analytical values of the samples corresponded to the expected values within the limits of the analytical method, i.e. were above 90% and below 110% of the nominal concentrations

Duration of treatment / exposure:

Total exposure period: males: 38 days; females: 46 days
Premating exposure period (males and females): 13 days

Duration of test: 54 days

Frequency of treatment:

once daily

Details on study schedule:

At least 13 days after the beginning of treatment, males and females from the same dose group were mated overnight in a ratio of 1:1 (details of pairing see 3.7.2.). On study day 36, a functional observational battery and motor activity measurement were carried out in the first five male animals per group. Blood from 5 F0 males per group was sampled under Isoflurane anesthesia on study day 38 followed by necropsy of all male animals under CO2 anesthesia. The females were allowed to litter and rear their pups until day 4 after parturition. On study day 43 a functional observational battery and motor activity measurement were carried out in the first five female animals per group. Blood from 5 F0 females per group was sampled under Isoflurane anesthesia on study day 45 followed by necropsy of all female animals and their pups under CO2 anesthesia.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300, 1000 mg/kg bw per day
Basis:
actual ingested
as the hydrochloride salt of isopropanolamine

No. of animals per sex per dose:

12

Control animals:

yes, concurrent vehicle

Positive control:

none

Examinations

Statistics:

Means and standard deviations were calculated. Weight of the anesthetized animals and absolute and relative organ weights were analysed by Kruskal-Wallis and Wilcoxon test.
Further statistical methods used for clinical examination and/or clinical pathology:
DUNNETT, C.W. (1955): A multiple comparison procedure for comparing several treatments with a control. JASA, Vol. 50, 1096 – 1121
DUNNETT, C.W. (1964). New ables for multiple comparisons with a control. Biometrics, Vol. 20, 482 - 491
Siegel S. (1956): Non-parametric statistics for behavioural sciences. McGraw-Hill New York
Nijenhuis, A.; Wilf, H.S. (1978): Combinatorial Algorithms. Academic Press New York, 32-33
Hettmansperger, T.P. (1984); Statistical Inference based on Ranks. John Wiley & Sons New York, 132-142

Results and discussion

Results: P0 (first parental generation)

Details on results (P0)

There were no indications from clinical, gross and histopathological examinations, that the Hydrochloride salt of Isopropanolamine adversely affected fertility or reproductive performance of the F0 parental animals at dose levels as high as 1000 mg/kg body weight/day. Most of the 0, 100, 300 and 1000 mg/kg F0 parental animals proved to be fertile. The scattered occurrence of individual infertile rats in test groups 0, 1 and 2 (0, 100
and 300 mg/kg) did not suggest any relation to treatment. Gross and histopathological examinations of the respective animals of both genders did not reveal test substance-induced findings, which may have accounted for the observed infertility. Mating behavior, conception, gestation, parturition, lactation and weaning; sexual organ weights as well as gross and histopathological findings of these organs were comparable between the rats of the test substance-treated test groups and the corresponding controls and ranged within the historical control data of the test facility.
Clinical observations for signs of general toxicity revealed post-dose salivation in all high dose males and most high dose females. Moreover, urine discoloration was observed for all mid and high dose rats. Both findings are considered to be without toxicological relevance and are, if seen in isolation, not assessed as being adverse. The test compound did not affect food consumption and body weight gain at dose levels as high as 1000 mg/kg body weight/day. Detailed clinical examinations in an open field, detailed observations in a functional observational battery (FOB) and measurements of motor activity did not reveal any indications of test substance-induced effects in low, mid and high dose rats.
Clinical pathology examinations revealed slightly, but statistically significantly reduced hemoglobin and hematocrit values, which are indicative of a mild anemic process, in high dose males. This is considered as an adverse substance-induced effect. No treatmentrelated effects were noted in hematology investigations of females and serum enzyme examinations of both sexes. Furthermore, reduced urine volumes with subsequently increased specific gravity were excreted by treated animals of either sex. It is likely, that this was caused by a decreased water intake. A reduction in water intake could also well account for the slightly increased urea and albumin levels of the high dose males and/or females. It is concluded that the changes in urinalysis and in blood chemistry examination are not caused by a direct toxic effect of the test compound and are not adverse in nature. This assessment is supported by the fact, that kidney weights as well as gross and histopathological evaluations of this organ did not give any indications for substance-induced alterations.
The test substance did not cause adverse effects regarding terminal body and organ weights, macroscopic evaluation or histopathologic evaluation. The statistically significantly increased liver weights in top dose males and females of the top dose group, which correlated with a minimal to mild diffuse hypertrophy of hepatocytes in several high dose males, mirror adaptive responses to the test substance administration. They are not
assessed as adverse particularly, because liver enzymes in these rats remained unaffected.

Effect levels (P0)

1

Dose descriptor:

NOAEL

Remarks:

parental general, systemic toxicity

Effect level:

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

Based on:

other: hydrochloride salt of isopropanolamine

Sex:

female

2

Dose descriptor:

NOAEL

Remarks:

parental general, systemic toxicity

Effect level:

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

Based on:

other: hydrochloride salt of isopropanolamine

Sex:

male

Basis for effect level:

other: some indications for a mild anemic process

3

Dose descriptor:

NOAEL

Remarks:

reproductive performance and fertility

Effect level:

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

Based on:

other: hydrochloride salt of isopropanolamine

Sex:

male/female

Results: F1 generation

Details on results (F1)

No test substance-induced signs of developmental toxicity were noted in the progeny of the F0 parents up to and including 1000 mg/kg body weight/day. The number of delivered F1 pups/litter, their postnatal survival and their body weights remained unaffected by the test substance. Clinical and/or gross necropsy examinations of the F1 pups revealed only findings, which were considered to be spontaneous in nature.

Effect levels (F1)

Dose descriptor:

NOAEL

Remarks:

developmental toxicity

Generation:

F1

Effect level:

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

Based on:

other: hydrochloride salt of isopropanolamine

Sex:

male/female

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Executive summary:

In a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test (OECD TG 422) 1-amino-2-propanol was tested as hydrochloride salt to avoid damage to the gastrointestinal tract following gavage administration due to the caustic mode of action. Testing the salt also provides the ability to distinguish between symptoms caused by local effects such as irritation or corrosion and symptoms that are due to systemic toxicity.

1 -Amino-2 -propanol hydrochloride was administered orally via gavage to groups of 12 male and 12 female Wistar rats at doses

of 100, 300, and 1000 mg/kg body weight/day (Schneider, 2005). The study was intended to detect possible effects of the test substance on the integrity and performance of the reproductive system of both sexes and to obtain information about the general toxicological profile after repeated oral administration. The duration of treatment covered a 2 week premating period and a mating period in both sexes, approximately 2 weeks post-mating in males (in total 38 days exposure), and the entire gestation period and 4 days of lactation in females (in total 46 days of exposure).

There were no indications from clinical, gross and histopathological examinations, that the test substance adversely affected fertility or reproductive performance of the F0 parental animals at dose levels as high as 1000 mg/kg body weight/day. Detailed clinical examinations in an open field, detailed observations in a functional observational battery (FOB) and measurements of motor activity did not reveal any indications of test substance-induced effects. Clinical pathology examinations revealed slightly, but statistically significantly reduced hemoglobin and hematocrit values, which are indicative of a mild anemic process, in high dose males only. The test substance did not cause adverse effects regarding terminal body and organ weights, macroscopic evaluation or histopathologic evaluation. The statistically significantly increased liver weights in top dose males and females, which correlated with a minimal to mild diffuse hypertrophy of hepatocytes in several high dose males, mirror adaptive responses to the test substance administration. They are not assessed as adverse particularly, because liver enzymes in these rats remained unaffected.

Under the conditions of this reproduction/developmental toxicity screening test the NOAEL for reproductive performance and fertility is 1000 mg/kg body weight/day for the parental rats. The NOAEL for general, systemic toxicity of the test substance is 300 mg/kg body weight/day for the parental males based on some indications for a mild anemic process. The NOAEL for parental females was found to be 1000 mg/kg body weight/day. The NOAEL for developmental toxicity was 1000 mg/kg body weight/day.