Methyl N-[4-[(2-bromo-6-chloro-4-nitrophenyl)azo]phenyl]-N-(3-methoxy-3-oxopropyl)-β-alaninate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

December 1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

Hazleton Manual of Standard Operating Procedures as applied to ICI Ltd., Central Toxicology Lahoratory procedure number CT20-90, Rat acute oral toxicity test; (HLE protocol no. 548/1).

GLP compliance:

no

Remarks:

Pre-dates GLP

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl N-[4-[(2-bromo-6-chloro-4-nitrophenyl)azo]phenyl]-N-(3-methoxy-3-oxopropyl)-β-alaninate

EC Number:

261-874-9

EC Name:

Methyl N-[4-[(2-bromo-6-chloro-4-nitrophenyl)azo]phenyl]-N-(3-methoxy-3-oxopropyl)-β-alaninate

Cas Number:

59709-38-5

Molecular formula:

C20H20BrClN4O6

IUPAC Name:

methyl N-[4-[(2-bromo-6-chloro-4-nitrophenyl)azo]phenyl]-N-(3-methoxy-3-oxopropyl)-β-alaninate

Test material form:

solid: granular

Details on test material:

Disperse Brown 19

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals
Thirteen male and 13 female rats of the Wistar strain, obtained from Bantin and Kingman Ltd., Grimston, Aldbrough, Nr. Hull, were used for this study. They were conditioned to the laboratory environment for not less than 6 days. On the day before dosing individual body weights were as follows: males 140 - 200 g, females 111 - 160 g. Two female animals (No. 1 - 114 g, No. 5 - 111 g) were martinally outside the body weight range stated in the protocol (115 - 160 g), but were dosed as it was thought such marginal changes would not affect the study.

Diet
With the exception of the overnight fast (for 18-20 hours before treatment) the animals were allowed free access to mains water and food (Rat and Mouse No. 1 Expanded Diet, BP Nutrition (U.K.) Ltd., Witham, Essex). The food was reintroduced immediately after dosing.

Environment
All animals were housed in a single air-conditioned room maintained at a temperature of 22 + 3°C, relative humidity 50 + 10% and exposed to natural lighting conditions. They were caged in groups of five, by sex or two by sex as appropriate in grid floor polypropylene boxes.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

A single oral dose of test article, based on the fasted body weight of the animals at the time of treatment, was administered by gavage using a metal stomach tube (14g x 8cm).
The animals were then returned to their cages for observation.

Doses:

250, 500, 1000, 2000, 5000 mg/kg bw (preliminary test)
5000 mg/kg bw (main test)

No. of animals per sex per dose:

Four groups each of 4 fasted rats (2 males, 2 females) and one group of 10 fasted rats (5 males, 5 females) were dosed according to the schedule.

Control animals:

no

Details on study design:

Dose range, finding study - phase 1
Four groups each of 4 fasted rats (2 males, 2 females) and one group of 10 fasted rats (5 males, 5 females) were dosed according to the schedule. Animals were observed for mortality over the following 48 hours.

Dose range finding study -phase 2
Mortality at a level of 50% or greater in any group did not occur during phase 1 and the surviving animals in groups 1-4 were killed. The group 5 animals were retained for observation for a further 12 days.

Observations on the group 5 animals (main test)
Animals were observed for overt toxicity and mortality at ¼, 1, 2 and 4 hours after treatment and subsequently once daily for 14 days and the observations were recorded. Body weights of survivors were recorded 2, 3, 8 and 14 days after treatment. Animals dying during the working day, animals killed in extremis and animals showing signs of toxicity at the end of the observation period were subjected to necropsy to determine any macroscopic signs of abnormalities.
At the end of the observation period all surviving animals were killed.

Results and discussion

Preliminary study:

Mortality at a level of 50% or greater in any group did not occur during dose range finding phase 1.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: main test (single dose 5000 mg/kg bw)

Mortality:

Two female animals died within 48 hours of treatment, and 1 male died within 72 hours of treatment.

Clinical signs:

other: Group 5 animals All male animals showed signs of lethargy within 48 hours of treatment. One male died; the remaining 4 animals appeared normal within 72 hours of treatment and throughout the remaining observation period. All female survivors appeared norm

Gross pathology:

Necropsy was not performed on any of the animals on test.

Other findings:

No further findings specified in the study report.

Any other information on results incl. tables

Mortality in the dose range finding study up to 48 hours

Dose (mg/kg)	Mortality			Cumulative mortality (%)
	Male	Female	Total
250	0/2	0/2	0/4	0
500	0/2	0/2	0/4	0
1000	0/2	0/2	0/4	0
2000	0/2	0/2	0/4	0
5000	0/5	2/5	2/10	20

 

Mortality and signs of reaction in group 5 rats given a single-oral dose

Dosage (mg/kg)	Observation	Animal number and sex										Number showing effect during
		Male					Female					Hour		Day
		1	2	3	4	5	1	2	3	4	5	1	4	1	2	3	4	5	6	7	8-14
5000	Body weights (g) Day 1 (Pre-fast) Day 1 (post-fast) Day 2 Day 3 Day 8 Day 14 Increment	155 150 149 174 195 220 65	157 141 118 155 197 238 81	167 149 142 176 208 253 88	154 135 104 - - - -	164 144 138 173 205 239 75	114 101 - - - - -	123 107 120 126 137 157 34	125 112 118 129 143 170 45	122 111 126 131 148 168 46	111 102 - - - - -
	Mortality				*		*				*	0/10	0/10	1/10	2/10	3/10	3/10	3/10	3/10	3/10	3/10
	Time when deaths noted (hr)				72		48				24
	Signs of reaction Lethargy	+	+	+	+	+						0/10	0/10	1/9	5/8	0/7	0/7	0/7	0/7	0/7	0/7
	Necropsy NP

NP = Not performed

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 (rats, gavage) was greater than 5000 mg/kg bw in a limit test. The substance is not classifiable according to CLP criteria.

Executive summary:

This study was undertaken to determine the oral median lethal dose (LD50) of Disperse Brown 19 in rats. It was performed in accordance with Standard Operating Procedures.

 

Four groups each of 4 fasted rats (2 males, 2 females) and one group of 10 fasted rats (5 males, 5 females; main study) were dosed according to the schedule. Animals were observed for mortality over the following 48 hours.

Treatment schedule

Study	Dose group	Dose level (mg/kg)	Solution concentrations (mg/ml)	Treatment volume (ml/kg)
Dose range finding	1 2 3 4 5	250 500 1000 2000 5000	500 500 500 500 500	0.5 1.0 2.0 4.0 10.0

Mortality at a level of 50% or greater in any group did not occur during phase 1 and the surviving animals in groups 1-4 were killed. The group 5 animals were retained for observation for a further 12 days.

 

Results

Two female animals died within 48 hours of treatment, and 1 male died within 72 hours of treatment.

Mortality

Dose (mg/kg)	Mortality			Cumulative mortality (%)
	Male	Female	Total
250	0/2	0/2	0/4	0
500	0/2	0/2	0/4	0
1000	0/2	0/2	0/4	0
2000	0/2	0/2	0/4	0
5000	1/5	2/5	3/10	30

 

Group 5 Animals-All male animals showed signs of lethargy within 48 hours of treatment. One male died; the remaining 4 animals appeared normal within 72 hours of treatment and throughout the remaining observation period. All female survivors appeared normal throughout the observation period.

All surviving male animals showed decreases in body weight at day 3 of observation but these animals and all female survivors showed normal body weight gains at the end of the observation period.

Necropsy was not performed on any of the animals on test.

 

Conclusion

Following a dose range finding study in rats of the Wistar strain it was concluded that test article was relatively non-toxic and the oral LD50 was greater than 5000 mg/kg. This results was confirmed by the main study (5000 mg/kg bw).