ethyl N2-dodecanoyl-.sc.l.sc.-argininate hydrochloride

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From March 23, 1998 to August 6, 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Cross-reference

Reason / purpose for cross-reference:

other: Preliminary study

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From March 23, 1998 to August 6, 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

other: Tolerance study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Crl:CD BR

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Limited, Margate, Kent, England
- Age at study initiation: approximately 10 to 11 weeks of age
- Weight at study initiation: 196 to 269 g
- Housing: Rats were housed in TR18 cages from Arrowmight Biosciences, Hereford, England and RB3 modified cages from North Kent Plastic Cages Limited, Erith, Kent, England. The cages consisted of stainless steel (TR18) or high density polypropylene (RB3) bodies with lids and floors of stainless steel grid and were suspended in batteries over trays covered with absorbent paper which was replaced twice weekly or daily during pairing.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: minimum of 10 days acclimatisation

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-25°C
- Humidity (%): 40-70%
- Air changes (per hr): 15 room air changes per hour
- Photoperiod (hrs dark / hrs light): 12-hour light: 12-hour dark cycle

IN-LIFE DATES: From: February 18, 1998 To: March 26, 1998

Route of administration:

oral: gavage

Vehicle:

other: Methylcellulose

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): freshly each day

VEHICLE
- Justification for use and choice of vehicle (if other than water): Methylcellulose
- Concentration in vehicle: suspension in 1% Methylcellulose

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Information on the homogeneity of mixing, stability and concentration of the test material in the vehicle was determined. Specimen formulations of 600 ml were prepared at each of the highest and lowest concentrations. These were then separated into 3 x 200ml aliquots for each concentration. Aliquot 1 was stored at 21°C and analysed at one, two, four and 48 hours; aliquots 2 and 3 were stored at 4°C and analysed at 48 hours and 8 days respectively.

Details on mating procedure:

Females were paired on a one-to-one basis with stock males of the same strain. Each morning following pairing, the trays beneath the cages were checked for ejected copulation plugs and a vaginal smear was prepared from each female and examined for the presence of spermatozoa.
The day on which a sperm positive vaginal smear or at least three copulation plugs were found was designated Day 0 of gestation.

Duration of treatment / exposure:

From Day 6 to 19 of gestation.

Frequency of treatment:

Daily to each animal based upon the animal's bodyweight on that day

Duration of test:

From April 17, 1998 to May 3, 1998

Dose / conc.:

0 mg/kg bw/day

Dose / conc.:

200 mg/kg bw/day

Dose / conc.:

600 mg/kg bw/day

Dose / conc.:

2 000 mg/kg bw/day

No. of animals per sex per dose:

6 females per dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dosages of 200, 600 and 2000 mg/kg bw/day were based on results from a tolerance study performed at these laboratories. In that study 2000 mg/kg bw/day was considered to the highest dosage that could be administered to the rat on a daily basis without exceeding guideline figures for volume dosage.
- Rationale for animal assignment (if not random): Rat was chosen because it satisfies the requirement for a rodent species by regulatory agencies. The Charles River Crl: CD® BR rat strain was used because of the historical control data available in this laboratory.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were observed at least twice daily throughout the study and any visible signs of reaction to treatment were recorded, with details of type, severity, time of onset and duration.

BODY WEIGHT: Yes
- Time schedule for examinations: Females were weighed on Days 0, 3 and 6 to 20 inclusive after mating.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes. Food consumption was recorded for the periods Days 0-2, 3-5, 6-8, 9-11, 12-15, 16-17 and 18-19 after mating.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes. For each animal, mean daily intakes were calculated for periods of Days 0-2, 3-5, 6-8, 9-11, 12-15, 16¬17 and 18-19 of gestation. Group mean daily intakes and SD were calculated for these periods.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: Each animal was first examined macroscopically for evidence of disease or adverse reaction to treatment and specimens of abnormal tissues were retained.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes
- Skeletal examinations: No data
- Head examinations: No data

Statistics:

The small sample size in this study precluded meaningful statistical evaluation. Inter-group differences were assessed by reference to control data previously recorded in these laboratories.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

The general condition of the animals was satisfactory and 21 of the 23 females surviving to the end of the study were pregnant. For simplicity, one female in the Control group has been termed “not pregnant” and excluded from group mean values although staining the uterus revealed a single implantation site. One female (F7) receiving 200 mg/kg/day was killed in extremis on Day 19 of gestation after showing reduced food intake on Days 18-19 of gestation, (only 2g/day) and bodyweight loss from Day 18 to 19 o f 40g. This female had signs of pallor, piloerection, brown staining around left orbital, red urine and a perigenital discharge at despatch. Necropsy revealed a large amount of dark red fluid within the vagina and both uterine horns. The uterus contained 15 late resorptions. Salivation after dosing was occasionally seen in 3 of the 6 animals receiving 600 mg/kg/day and on about 50% of occasions in all animals receiving 2000 mg/kg/day. One female in each of the treated groups had periods when respiration sounded noisy. There were no other significant clinical signs recorded in either the control group or any of the treatment groups,

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One femalle (F7) was killed in extremis.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

There were no intergroup differences in bodyweight or bodyweight gain which were considered to be treatment-related. Occasional animals in all groups showed slight bodyweight loss during the first two days of treatment but this was considered to be related to animals adapting to the dosing process rather than to the test material itself.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Food consumption was similar for all groups of animals throughout the treatment period, apart from the one female (F7) at 200 mg/kg/day which showed slightly reduced food intake during days 16-17 and then virtually stopped eating.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no necropsy findings which were considered to be related to treatment.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Number of abortions:

not examined

Pre- and post-implantation loss:

effects observed, non-treatment-related

Description (incidence and severity):

One control female (F1) had only one single implantation site, revealed by staining the uterus, and has been excluded from group mean values. Rats with very low implantation rates frequently show spontaneous resorption at an early stage of pregnancy. Another two animals, one in each of the groups receiving 200 mg/kg/day and 2000 mg/kg/day showed high pre-implantation losses, but because these losses almost certainly occurred before the start of treatment these individual incidences arc considered not to be treatment related. The group mean value for post-implantation loss was slightly higher in animals receiving 600 mg/kg/day than other groups, but in the absence of similar effect in the highest dosage group this was considered to be unrelated to treatment.

Total litter losses by resorption:

not examined

Early or late resorptions:

not examined

Dead fetuses:

not examined

Changes in pregnancy duration:

not examined

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined

Changes in number of pregnant:

not specified

Other effects:

no effects observed

Key result

Dose descriptor:

dose level: Highest dosage for the teratology study.

Effect level:

2 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

There were no obvious treatment related effects upon fetal development as assessed by fetal weight and macroscopic examination at necropsy.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

There were no obvious treatment related effects upon fetal development as assessed by fetal weight and macroscopic examination at necropsy.

Skeletal malformations:

not examined

Visceral malformations:

not examined

Other effects:

no effects observed

Key result

Dose descriptor:

dose level: Highest dosage for the teratology study.

Effect level:

2 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Fetal weight and macroscopic examination at necropsy.

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

The results of the analyses of the concentration of test material in formulations confirm acceptable homogeneity and stability and that concentrations of analysed preparations from the first and last weeks of treatment were satisfactory.

Conclusions:

Assessment of influence on progress and outcome of pregnancy in CD rats in order to establish suitable dosages for a main embryo-fetal toxicity study of Nα-Lauroyl-L-arginine ethyl ester monohydrochloride (LAE) by oral gavage administration. 2000 mg/kg bw/day of LAE would be suitable as the highest dose level for a main embryo-fetal study in the rat.

Executive summary:

In this preliminary study, the influence of N^α-Lauroyl-L-arginine ethyl ester monohydrochloride (LAE) study,was assessed in sexually mature rats of the CD strain, to establish suitable dosages for a main embryo-fetal toxicity study.

 

The oral route was selected to simulate the conditions of possible human exposure. Dosages of 200, 600 and 2000 mg/kg bw/day were based on results from a tolerance study. In that study 2000 mg/kg bw/day was considered to the highest dosage that could be administered to the rat on a daily basis without exceeding guideline figures for volume dosage.

 

For this purpose, LAE was administered by gavage at dosages of 200, 600 or 2000 mg/kg bw/day to groups of 6 presumed pregnant rats from Day 6 to 19 after mating, inclusive. Control animals received the vehicle, 1% w/v Methylcellulose, throughout the same period.

 

Surviving females were killed on Day 20 after mating for examination of their uterine contents. Results

 

There were no significant treatment related effects on females receiving LAE at 200, 600 or 2000 mg/kg bw/day from Day 6 of gestation until just before the expected time of parturition, or upon the survival or development of their fetuses. Salivation, seen after dosing particularly in the highest dosage group, is a common non-specific response to gavage treatment which may relate to the taste or pH of the test material. It usually has no toxicological significance.

There were no obvious treatment related effects upon fetal survival or fetal development as assessed numbers of live fetuses, fetal weight and macroscopic examination of the fetuses at necropsy.

 

It was, therefore, concluded that 2000 mg/kg bw/day of LAE would be suitable as the highest dose level for a main embryo-fetal study in the rat. This dosage is considered to be the maximum achievable dosage in relation to formulation and volume dosage under the condition of use.

 

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

434-630-6

EC Name:

-

Cas Number:

60372-77-2

Molecular formula:

Hill formula: C20H41N4O3Cl

IUPAC Name:

ethyl N2-dodecanoyl-l-argininate hydrochloride

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material: Nα-Lauroyl-L-arginine ethyl ester monohydrochloride
- Physical state: White powder
- Lot/batch No.: IN 16.2.98/1
- Analytical purity: 69.1%
- Storage condition of test material: In a refrigerator at approximately 4 ° C

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Limited, Margate, Kent, England
- Age at study initiation: approximately 10 to 11 weeks of age
- Weight at study initiation: 217 to 267 g
- Housing: Rats were housed in TR18 cages from Arrowmight Biosciences, Hereford, England and RB3 modified cages from North Kent Plastic Cages Ltd, Erith, Kent, England. The cages consisted of stainless steel (TR18) or high density polypropylene (RB3) bodies with lids and floors of stainless steel grid and were suspended in batteries over trays covered with absorbent paper which was replaced twice weekly or daily during pairing.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: minimum of 5 days acclimatisation

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23°C
- Humidity (%): 40-70%
- Air changes (per hr): 15 room air changes per hour
- Photoperiod (hrs dark / hrs light): 12-hour light: 12-hour dark cycle

IN-LIFE DATES: From: May 26, 1998 To: June 20, 1998

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: Methylcellulose

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): freshly each day

VEHICLE
- Justification for use and choice of vehicle (if other than water): Methylcellulose
- Concentration in vehicle: suspension in 1% Methylcellulose

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Information on the homogeneity of mixing, stability and concentration of the test material in vehicle was determined. Specimen formulations of 600 ml were prepared at each of the highest and lowest concentrations. These were then separated into 3 x 200 ml aliquots for each concentration. Aliquot 1 was stored at 21 ºC and analysed at one, four and 48 hours; aliquots 2 and 3 were stored at 4 ºC and analysed at 48 hours and eight days respectively. Concentration of test material in formulations was analysed. On one day for each of the first and last weeks of dosing, 4 x 2ml samples were taken from each group. Two samples for each group were analysed for test material content.

Details on mating procedure:

Females were paired on a one-to-one basis with stock males of the same strain. Each morning following pairing, the trays beneath the cages were checked for ejected copulation plugs and a vaginal smear was prepared from each female and examined for the presence of spermatozoa. The day on which a sperm positive vaginal smear or at least three copulation plugs were found was designated Day 0 of gestation.

Duration of treatment / exposure:

From Day 6 to 19 of gestation.

Frequency of treatment:

Daily to each animal based upon the animal's bodyweight on that day

Duration of test:

From May 26, 1998 to June 20, 1998

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

200 mg/kg bw/day

Doses / concentrations 3

Dose / conc.:

600 mg/kg bw/day

Doses / concentrations 4

Dose / conc.:

2 000 mg/kg bw/day

No. of animals per sex per dose:

22 females per dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dosages of 200, 600 and 2000 mg/kg bw/day were based on results from a preliminary study where it was concluded that dosages of up to 2000 mg/kg bw/day had no significant effect upon maternal food consumption, bodyweight gain, embryo-fetal survival or development. The 14 day dosing period was chosen to encompass the period of organogenesis and fetal development.
- Rationale for animal assignment (if not random): Rat was chosen because it satisfies the requirement for a rodent species by regulatory agencies. The Charles River Crl: CD® BR rat strain was used because of the historical control data available in this laboratory.

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were observed at least twice daily throughout the study and any visible signs of reaction to treatment were recorded, with details of type, severity, time of onset and duration.

BODY WEIGHT: Yes
- Time schedule for examinations: Females were weighed on Days 0, 3 and 6 to 20 inclusive after mating. Group mean values and SD were calculated on Days 0, 3 and 6 to 20 inclusive of gestation. Weight changes were plotted graphically with respect to Day 6 of gestation. In the absence of any effects upon maternal weight or fetal weight no adjustments were made to allow for the weight of the gravid uterus.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes. Food consumption was recorded for the periods Days 0-2, 3-5, 6-8, 9-11, 12-15, 16-17 and 18-19 after mating.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes. For each animal, mean daily intakes were calculated for periods of Days 0-2, 3-5, 6-8, 9-11, 12-15, 16-17 and 18-19 of gestation. Group mean daily intakes and SD were calculated for these periods.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: Each animal was first examined macroscopically for evidence of disease or adverse reaction to treatment and specimens of abnormal tissues were retained.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes. Each fetus was weighed, sexed and examined for any external abnormalities. Individual placental weights and placental abnormalities were recorded.
- Soft tissue examinations: Yes
- Skeletal examinations: Yes
- Head examinations: Yes
- Other: The neck and the thoracic and abdominal cavities of approximately half of each litter were dissected and examined. All fetal abnormalities were recorded and the offspring eviscerated prior to fixation in industrial methylated spirit.

Statistics:

Formal statistical analysis was not performed as there were no intergroup differences suggestive of treatment related effect.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

The general condition of the surviving animals was satisfactory and all the females were pregnant.
Noisy respiration was seen during the treatment period in three animals receiving 200 mg/kg/day, and in a total of 7 animals at 600 and 9 animals at 2000mg/kg/day (including animals which were killed prematurely).
Salivation at the time of dosing was seen in all animals receiving 2000mg/kg/day on approximately 50% of dosing occasions reaching peak daily incidence at about Day 14 of gestation. Fourteen animals receiving 600mg/kg/day showed occasional incidences of salivation during the dosing period, and at 200mg/kg/day salivation was seen in only one animal on one occasion.
Neither noisy respiration nor salivation were seen in the Control group.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Three females receiving 2000mg/kg/day (F68, F77 and F87) were killed in extremis on Days 7 or 8 of gestation (the second or third day of treatment). All three animals showed signs of noisy and gasping respiration, and salivation after dosing. Two females (F77 and 87) showed bodyweight loss before termination and F87 showed signs of underactive behaviour and piloerection. Necropsy revealed large amounts of gaseous material in the stomach in F68 and F77 and in F87 the entire gastro-intestinal tract was distended with gas. In addition F68 had enlarged and prominent lymph nodes, and F77 had haemorrhagic lungs, large amounts of pale yellow viscous material in the ileum, reduced and dehydrated caecal contents, dark and enlarged adrenals and a pronounced internal structure of the kidneys. All animals were pregnant.
Two females at 600mg/kg/day (F54 and F59) were similarly affected towards the end of gestation, both showing signs of noisy respiration, salivation at the time of dosing and bodyweight losses. F54 was killed for humane reasons and F59 was killed in extremis, both had reached Day 17 of gestation. Necropsy of these animals revealed that gastro-intestinal tract was distended with gaseous material. Both animals had grossly normal implantations.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There were no overall treatment related effects upon bodyweight. Occasional animals in all groups receiving LAE showed transient bodyweight losses for periods following commencement of treatment at Day 6 and some animals receiving 600 mg/kg/day also showed weight losses towards the end of treatment. Many of the cases of weight loss coincided with episodes of respiratory distress. There were no similar bodyweight losses in the Control group

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There were no overall treatment related effects upon food consumption, group mean values were similar for all groups. However there were occasional animals in the treatment groups which showed periods of reduced food intake, which appealed to be associated with episodes of respiratory distress.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no maternal necropsy findings which were considered to be related to treatment.

Neuropathological findings:

no effects observed

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Maternal developmental toxicity

Number of abortions:

not specified

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

There were no effects on fetal survival as indicated by the extent of pre- and post-implantation loss and the numbers of lives fetuses.

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

no effects observed

Description (incidence and severity):

There were no effects on fetal survival as indicated by the extent of pre- and post-implantation loss and the numbers of lives fetuses.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified

Changes in number of pregnant:

not specified

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Severe respiratory distress was recorded at a low frequency among animals receiving 600 or 2000 mg/kg bw/day. Three females had to be killed after 2 or 3 days of dosing at 2000 mg/kg bw/day and two females had to be killed after 11 or 12 doses at 600 mg/kg/day. Necropsy of these animals did not detect damage to the lungs and gross changes were limited to accumulation of gas within the gastro-intestinal tract. This may relate to gasping respiration following possible aspiration of increased secretions and/or traces of the dosing material following treatment with the more concentrated/viscous suspensions at the higher doses.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

clinical signs

mortality

Maternal abnormalities

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

other: Clinical signs, mortality

Results (fetuses)

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Fetal and placental weights, and the incidences of fetal abnormalities and variants were unaffected by treatment.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

Fetal and placental weights, and the incidences of fetal abnormalities and variants were unaffected by treatment.

Skeletal malformations:

no effects observed

Description (incidence and severity):

Fetal and placental weights, and the incidences of fetal abnormalities and variants were unaffected by treatment.

Visceral malformations:

no effects observed

Description (incidence and severity):

Fetal and placental weights, and the incidences of fetal abnormalities and variants were unaffected by treatment.

Other effects:

no effects observed

Details on embryotoxic / teratogenic effects:

There were no obvious treatment related effects upon fetal development as assessed by fetal weight and macroscopic examination at necropsy.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

2 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: fetotoxicity

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Any other information on results incl. tables

The results of the analyses of the concentration of test material in formulations confirm acceptable homogeneity and stability and that concentrations of analysed preparations from the first and last weeks of treatment were satisfactory.

Applicant's summary and conclusion

Conclusions:

Assessment of influence on progress and outcome of pregnancy in CD rats in order to establish suitable dosages for a main embryo-fetal toxicity study of Nα-Lauroyl-L-arginine ethyl ester monohydrochloride (LAE) by oral gavage administration. It was concluded that 200 mg/kg bw/day was the no-adverse-effect-level (NOAEL) for the dam and 2000 mg/kg bw/day was the NOAEL for the fetus.

Executive summary:

The influence of N^α-Lauroyl-L-arginine ethyl ester monohydrochloride (LAE) upon the progress and outcome of pregnancy was assessed in sexually mature rats of the CD strain. For this purpose, LAE was administered by gavage at dosages of 200, 600 or 2000 mg/kg bw/day to groups of 22 presumed pregnant rats from Day 6 to 19 after mating, inclusive. Control animals received the vehicle, 1% w/v Methylcellulose, throughout the same period.

All surviving females were killed on Day 20 after mating for examination of their uterine contents followed by detailed fetal examination.

Severe respiratory distress was recorded at a low frequency among animals receiving 600 or 2000 mg/kg bw/day: three females had to be killed after 2 or 3 days of dosing at 2000 mg/kg/day and two females had to be killed after 11 or 12 doses at 600 mg/kg bw/day. Necropsy of theseanimals did not detect damage to the lungs and gross changes were limited to accumulation of gas within the gastro­intestinal tract. This may relate to gasping respiration following possible aspiration of increased secretions and/or traces of the dosing material following treatment with the more concentrated/viscous suspensions at the higher doses. Under the circumstances the respiratory distress seen in animals receiving 600 or 2000 mg/kg/day is considered not to be a systemic toxic response to oral ingestion of LAE. It is thought to be unlikely to extrapolate to man but may suggest possible bronchial irritation if the test material is inhaled.

 

With the exception of transient effects on bodyweight and food consumption associated with individual animals showing respiratory distress, at 600 and 2000 mg/kg bw/day, there were no adverse effects of treatment on the mother and there were no adverse effects on fetal survival and development at dosages of up to 2000 mg/kg bw/day.

There were no overall treatment related effects on bodyweight or food consumption, although occasional animals in treatment groups showed periods of bodyweight loss and reduced food intake which were related to-respiratory distress.

There were no apparent treatment related effects upon fetal survival, growth or development.

It was concluded, because of the maternal deaths at 600 and 2000 mg/kg bw/day, that 200 mg/kg bw/day was the no-adverse-effect-level (NOAEL) for the dam but 2000 mg/kg bw/day was the NOAEL for the fetuses of dams that survived to the end of pregnancy.