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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 July 2003 to 27 August 2003
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report date:
2004

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)
Deviations:
no
GLP compliance:
yes
Test type:
fixed dose procedure
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
452-330-3
EC Name:
-
Cas Number:
314020-40-1
Molecular formula:
C14H20N2O2
IUPAC Name:
2-(2,6-diethyl-4-methyl-phenyl)propanediamide
Test material form:
solid: particulate/powder
Details on test material:
- Physical state: Powder, yellowish
- Storage condition of test material: In the dark at ambient temperature

Test animals

Species:
rat
Strain:
other: Alpk:APfSD (Wistar-derived)
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: 186-245 g
- Fasting period before study: Rats were fasted overnight prior to dosing
- Housing: 5 per cage
- Diet: ad libitum
- Water: Mains water ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 30-70 %
- Air changes (per hr): 15 per hour minimum
- Photoperiod (hrs dark / hrs light): 12 hours light (artificial), 12 hours dark

IN-LIFE DATES: From: 30 July 2003 To: 27 August 2003

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
CMC (carboxymethyl cellulose)
Remarks:
0.5 % w/v (aqueous)
Details on oral exposure:
VEHICLE
- Concentration in vehicle: Doses were prepared by adjusting the concentration of the test material in the dosing preparations
- Amount of vehicle (if gavage): Each dose volume was calculated for animals individually based on its weight at the time of dosing.

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bodyweight was administered as a standard dose volume
Doses:
Sighting study: 300 or 2000 mg/kg bodyweight
Main test: 300 or 2000 mg/kg bodyweight
No. of animals per sex per dose:
Sighting study: one initially
Main test: A further four animals were tested from both dosing groups
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: All rats were examined for physical and behavioural abnormalities prior to dosing. Post dosing, animals were examined for systemic toxicity twice on day 1 and daily up to day 15 thereafter. All animals were weighed prior to fasting, immediately before dosing and on days 8 and 15.
- Necropsy of survivors performed: Animals were sacrificed by halothane vapour overdose followed by exsanguination. All animals were subject to a macroscopic examination of the thoracic and abdominal viscera. All abnormalities were recorded but tissues were not submitted for histopathological examination.

Results and discussion

Effect levels
Sex:
female
Dose descriptor:
discriminating dose
Effect level:
300 mg/kg bw
Based on:
test mat.
Mortality:
Following a single oral dose of 300 mg/kg, none of the animals died. Signs of slight systemic toxicity were seen in all animals, with complete recovery by day 2. Following a single oral dose of 2000 mg/kg four of the animals showed signs of toxicity including (in two animals) convulsions and were killed in extremis on day 1.
Clinical signs:
In the 300 mg/kg dose group, signs of slight systemic toxicity were seen in all animals, with complete recovery by day 2. Following a single oral dose of 2000 mg/kg four of the animals showed signs of toxicity including (in two animals) convulsions and were killed in extremis. The surviving animal in this group was fully recovered by day 2.
Body weight:
All animals initially lost weight due to the pre-dose fast but all surviving animals showed an overall bodyweight gain during the study.
Gross pathology:
One animal dosed with 300 mg/kg was found to have a speckled thymus at post mortem. This was a spontaneous finding and was not considered to be related to treatment. One of the animals killed in extremis after dosing with 2000 mg/kg had red staining around the nose and mouth. This was a non-specifiec finding related to treatment.

Any other information on results incl. tables

Table 1: Bodyweights of female rats dosed with 300 or 2000 mg/kg of test material

Dose

Animal no.

Day

Pre-dosing

(day -1)

Dosing

(day 1)

day 2

day 8

Terminal

(day 15)

300 mg/kg

49

206

184

Not performed

231

246

4

190

168

Not performed

243

264

5

192

168

Not performed

230

242

6

192

173

Not performed

225

233

7

186

170

Not performed

234

239

2000 mg/kg

63

245

218

227

282

311

72

199

181

-

-

-

73

209

191

-

-

-

74

243

194

-

-

-

75

202

188

-

-

-

Applicant's summary and conclusion

Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information Classification derived using the criteria reported in Annex II of the OECD Guideline 420. Criteria used for interpretation of results: EU
Conclusions:
Under the conditions of the test, the highest fixed dose of the test material administered in this study without causing any lethality (i.e. the discriminating dose-level) was 300 mg/kg to female rats. The study is considered to be reliable, relevant and adequate for risk assessment and classification and labelling purposes.
Executive summary:

The acute oral toxicity of the test material was determined in accordance with the standardised guideline OECD 420 using the fixed dose procedure. Single female rats initially received one oral dose of 300 or 2000 mg/kg of the test material and were assessed daily for the following 14 days for any signs of systemic toxicity. From the results of the initial phase, fixed dose levels of 300 and 2000 mg/kg were selected for the main phase study. In the main phase, groups of four female rats were dosed and assessed for signs of toxicity for 14 days following dosing. Bodyweights were recorded at intervals during the study. Animals in extremis and those surviving to the end of the study were killed and, together with those found dead, were examined post mortem. The initial females were included in the main phase of the study, to give a total of five animals per group.

None of the animals in the 300 mg/kg group died. Signs of slight systemic toxicity were seen in all animals, all of which had fully recovered by day 2. All animals showed an overall bodyweight gain during the study. There were no treatment related abnormalities post mortem. Following a single oral dose of 2000 mg/kg, four of the animals showed signs of severe toxicity including (in two animals) convulsions and were killed in extremis on day 1. The surviving animal showed signs of toxicity following dosing but had recovered by day 2 and showed an overall body weight gain during the study. At examination post mortem one of the animals killed in extremis had red staining around the nose and mouth.

The highest fixed dose of the test material administered in the study without causing any lethality (i.e. the discriminating dose-level) was 300 mg/kg to female rats.