Reaction Mass of 6-(1-bromoethyl)-4-chloro-5-fluoropyrimidine and Toluene

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 2001

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

6-(1-bromoethyl)-4-chloro-5-fluoropyrimidine

Cas Number:

188416-28-6

Molecular formula:

C6H5BrClFN2

IUPAC Name:

6-(1-bromoethyl)-4-chloro-5-fluoropyrimidine

Test material form:

liquid

Details on test material:

Amber Oil

Specific details on test material used for the study:

Amber to yellow liquid (batch number 5494/96/I)

Test animals

Species:

rat

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals in the main study were in the weight range of 82 to 118 g and approximately five to seven weeks of age prior to dosing (Day I), All the rats were acclimatised to the experimental environment for a minimum period of at ifive days prior to the start of the study. The rats were allocated without conscious bias to cages within the treatment groups. They were housed in groups of up to five rats of the same sex in metal cages (RS Biotech Sub-Dividable Rodent Cages - polished stainless steel (20cm high x 39cm wide x 39cm long)), The cages were fitted with grid floors to ensure rapid removal of waste material to undertrays. The cages were suspended in mobile stainless steel racks. A standard laboratory rodent diet (Special Diet Services RM1(E) SQC expanded pellet) and drinking water were provided ad libitum. Access to food only was prevented overnight prior to and kw approximately 4 hours after dosing. The batch of diet used for the study was analysed for certain nutrients, possible contaminants and nncro-organisms. Results of routine physical and chemical examination of drinking water, as conducted by the supplier, are made available to Huntingdon Life Sciences Ltd, as quailed)! summaries.
Thermostatic controls were set to maintain a temperature of 22 ±. 3*C, Relative humidity vi,'as not fully controlled but was anticipated to be in the range 30 70%. Temperature and humidity were recorded continuously using a seven day recorder. Actual measurement of these parameters revealed that animal room temperature was in the range 21 to 25°C and relative humidity was in the range 40 - 62%,
Permanent daily recordings of these parameters were made and these are archived with other Departmental raw data. Air exchange was maintained at approximately 18 air changes per hour and lighting was controlled by means of a time switch to provide 12 hours of artificial light (0700 - 1900 hours) in each 24-hour

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Details on oral exposure:

UK-134,821 was administered initially as supplied at a variable dose volume to achieve the desired dosage and during the latter stage of the study to enhance accuracy at the lower dose concentrations was administered formulated at various w/v concentrations in 1% ‘v/v aqueous methylcellulose and administered at a fixed dose volume of 10 mi/kg boclyweight.

Doses:

Initial Study: 500, 2000mg/kg
Main Study: 50, 200 and 500 mg/kg

No. of animals per sex per dose:

5 males/5 females

Control animals:

yes

Details on study design:

A group of 5 males and 5 females received a single oral gavage dose of the test substance at a dose level of 500 mg/kg bodyweight. This dose level was chosen after review of findings in the first phase of preliminary investigations, However, as a result of mortalities at 500 mg/kg a further group of ten rats was dosed at 50 mg/kg bodyweight. This latter dosage was selected after consideration of preliminary study results and in compliance with the test guidelines.

Results and discussion

Preliminary study:

In the absence of precise toxicological information a preliminary study was conducted to help define the toxic potential of the test substance and aid in selection oía suitable dosage for the main study, Initially, one female rat was treated at 500 mg/kg and for further clarification one fixt/her female rat was dosed at 2000 mg/kg bodyweight.
The animal treated at 500 mg/kg survived treatment and this dose level was a considered suitable for commencement of the main study. However, as a result of mortalities in the main study at 500 mg/kg further preliminary investigations were undertaken to further define the toxic potential of the test substance. In these further investigations, one female was treated at 50 mg/kg and a further female treated at 200 mg/kg.

Effect levels

Sex:

male/female

Dose descriptor:

discriminating dose

Effect level:

50 mg/kg bw

Based on:

test mat.

Mortality:

Cages of rats were checked at least twice daily for mortalities

Clinical signs:

other: Animals were observed, soon after dosing and at frequent intervals for the remainder of Day L On subsequent days, surviving animals were observed once in the morning and again at the end of the experimental day (with the exception of the last day of obser

Gross pathology:

Macroscopic examination of decedent animals revealed congestive changes (characterised by dark tissue/pr(minent blood vessels) in the subcutaneous tissue, brain, heart, lungs. liver, spleen, kidneys, stomach and along the alimentary tract accompanied by enlargediswollen tissues in the brain, liver and stomach. Gaseousdistension and fluid contents (-yellow/red), food and pallor were noted in the stomach and along the alimentary tract. Pallor was also noted in the urinary bladder. In animals surviving treatment and killed at study termination (Day 15) enlarged, swollen or thickened tissues were noted in the stomach of two females dosed at 50 ml/kg

Applicant's summary and conclusion

Conclusions:

The discriminating oral dose to rats of UK-134,821 was indicated to be 50 mg/kg bodyweight

Executive summary:

This study was performed to assess the acute oral toxicity of UK-134,821 to the rat. The method followed to be compliant with that described in: EEC Methods for the determination of toxicity, Annex. to Directive 92/69/EEC (Official Journal No, 1,383A, 29.12,92), Part B, Methiml B.1 bis, Acute toxicity (oral) fixed dose method. OECD Guideline for Testing of Chemicals No.420 'Acute Oral Toxicity - Fixed Dose Method' Adopted 17 July 1992, A group of ten fasted rats (five males and five females) received a single oral gavage dose of the test substance, administered as supplied at a dose level of 500 mg/kg bodyweight. This dose level was chosen after review of findings in the preliminary study. As a result of mortalities at 500 mg/kg a further group of rats was dosed at 50mg/kg: bodyweight Three males and four females dosed at 500 m g/kg died during the study, All remaining animals treated at 500 mg/kg and animals subsequently dosed at 50 mg/kg were killed as scheduled at study termination (Day 15) and subjected to a macroscopic examination. Clinical signs of reaction to treatment characterised by piloerection (first evident in all rats within nine minutes of dosing) seen in all rats, and accompanied at later intervals on Day 1 or thereafter by hunched posture, waddlinglunstea4 gait, lethargy, pallid extremities, walking on toes, increased salivation, unp,roomed appearance and dark colouring to eyes (notable in all rats at 500 mg/kg). Also observed in one or more animals were, partially closed eyelids, abnormal respiration, abnormal faeces, abnormal urine, increased lacrimation, increased sensitivity to touch, thin appearance, body tremors, clonic convulsion, prostation, blue/cold extremities and swollen abdomen. Recovery in all surviving rats was complete on Day 2 at 50 mg/kg and Day 14 at 500 mg/kg. All surviving rats in the main study were considered to have achieved satisfactory bodyweight gains during the study. Macroscopic examination of the decedents at 500 mg/kg in the main study revealed congestive changes to the majority of tissues and organs with gaseous distension and fluid contents in the stomach and along the alimentary tact. In animals surviving treatment and killed at study termination (Day 15) enlarged, swollen or thickened tissues were noted in the stomach of two females dosed at 50 mg/kg. The discriminating oral dose to 'rats of UK-134,821 was indicated to be 50 mg/kg bodyweight On the basis of findings in this study and in accord with EU hazard classification UK-134,821 will require labelling with the risk phrase .R22 "Harmful if swallowed", in accordance with Commission Directive 93/21,,EEC,