Desmedipham

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990 -11-08 to 1991-03-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Desmedipham

EC Number:

237-198-5

EC Name:

Desmedipham

Cas Number:

13684-56-5

Molecular formula:

C16 H16 N2 O4

IUPAC Name:

ethyl 3´-phenylcarbamoyloxycarbanilate

Test material form:

solid: particulate/powder

Details on test material:

The test material is Desmedipham but the purity has not been specified.

Specific details on test material used for the study:

The test material, a white powder, was stored in the dark under ambient conditions.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Females nulliparous and non-pregnant: yes
- Age at study initiation: Young adults, 6-8 weeks.
- Weight at study initiation: 149-171 g.
- Fasting period before study: 18 h before dosing
- Housing: The rats were housed by sex in polypropylene cages with mesh floors suspended over absorbent paper lined trays with a maximum of 5 animals per cage.
- Diet: Rat and Mouse No. 1 Diet.
- Water: ad libitum.
- Acclimation period: 7 days.
The diet and water are analysed on a regular basis.

ENVIRONMENTAL CONDITIONS
- Temperature: 19 - 21°C
- Humidity: 50%
- Photoperiod: 12 h light/dark (light hours 0700-1900 h)

The rats were uniquely identified within the study using an ear punch system.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% aqueous CMC

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg bw

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

DOSAGE PREPARATION:
On the day of dosing, Desmedipham was freshly prepared in 0.5% CMC at a concentration of 200 mg/mL

Doses:

Single dose of 2000 mg/kg bw

No. of animals per sex per dose:

5/sex

Control animals:

no

Remarks:

Not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The rats were observed frequently on the day of dosing and once daily for 14 days following dosing. They were weighed immediately prior to dosing, 7 days after dosing and at sacrifice at the end of the 14 day observation period.
- Necropsy of survivors performed: yes, at the end of the observation period and sacrifice by carbon dioxide asphyxiation, each animal was subjected to necropsy.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No deaths at the limit dose

Mortality:

No mortality was observed

Clinical signs:

other: other:

Body weight:

other body weight observations

Gross pathology:

No abnormalities detected

Any other information on results incl. tables

Table 1: Desmedipham: Acute Oral Toxicity (Limit) Test in Rats Test Results 2000 mg/kg bw

Sex	Animal	Mortality	Clinical signs	Necropsy Findings
Males	1 2 3 4 5	0/5	NAD NAD NAD NAD NAD	NAD NAD NAD NAD NAD
Females	6 7 8 9 10	0/5	NAD NAD NAD NAD NAD	NAD NAD NAD NAD NAD

NAD = No abnormalities detected

 

Table 2: Desmedipham: Acute Oral Toxicity (Limit) Test in Rats Body Weights 2000 mg/kg bw

Sex	Animal	Body weight (g)
		At Dosing	After 7 days	After 14 days	Gain (Loss)
Males	1 2 3 4 5	159 171 163 163 156	220 239 231 240 213	265 275 280 270 245	106 104 117 107 89
	Mean ± S.D.	162 6	229 12	267 14	105 10
Females	6 7 8 9 10	151 149 158 152 156	195 194 205 190 199	209 211 215 201 217	58 62 57 49 61
	Mean ± S.D.	153 4	197 6	211 6	57 5

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral LD50 of desmedipham was >2000 mg/kg/bw in male and female rats under the conditions of this study. Desmedipham does not require classification for oral acute toxicity in any category according to the CLP criteria.

Executive summary:

The acute oral toxicity potential of Desmedipham, was investigated in rats. The vehicle for the dosing solution was 0.5% carboxymethylcellulose (CMC).  There were no deaths following a single orally administered dose of Desmedipham at the limit dose level of 2000 mg/kg bw to a group of 5 male and 5 female rats. No clinical signs or necropsy findings were noted.  The Median Oral Lethal Dose (LD₅₀) of Desmedipham in male and female rats is greater than 2000 mg/kg bw.  Desmedipham does not require classification for oral acute toxicity in any category according to the CLP criteria.