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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
21 July- 17 October 1977
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Principles of method if other than guideline:
Diallylphthalate was administered by gavage to groups of rats for 13 weeks to evaluate the cumulative toxicity of diallylphthalate, characterize lesions and to determine the doses to be used in a 2-year study.
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): diallylphthalate
- Physical state: pale yellow liquid
- Analytical purity: 99% (thin-layer and gas chromatographic analysis)
- Lot/batch No.: 25-121
- Storage condition of test material: 4°C
- Storage of reference samples at -20°C
- Diallylphthalate was found to be stable for 2 weeks at temperatures up to 60°C in the presence of light.
- No change in the purity of the bulk chemical supply was observed throughout the studies, which was checked by periodical analyses using gas chromatography and infrared spectroscopy.

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Frederick Cancer Research Center
- Age at study initiation: 8 wk old
- Housing: 5 animals per cage; cages Polycarbonate (Lab Products. Garfield, NJ. and Hazleton Systems, Aberdeen, MD)
- Diet:Purina Lab Chow@ (ground); provided ad libitum except for night before dosing when feed was removed from cages (Ralston Purina Co., St. Louis, MO)
- Water (e.g. ad libitum):Tap water in bottles, acidified to pH 2.5 with HCl; provided ad libitum
- Acclimation period: 4 wk

ANIMAL DISTRIBUTION
Randomized so that the average cage weights for each sex and species were approximately equal

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23
- Humidity (%): 30-70
- Air changes (per hr): 12-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: necropsy date: 18 October 1977

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analyses for diallylphthalate in the dosing solutions were performed periodically to confirm that the correct doses were administered. The analyses involved extraction of the test chemical from corn oil using carbon disulfide followed by gas chromatography. One set of dose mixtures prepared for the 13-week studies was analyzed and found to be within 10% of their target concentrations.
Duration of treatment / exposure:
13 wk
Frequency of treatment:
5 times/wk
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 25, 50, 100, 200 & 400 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
10
Control animals:
yes, concurrent vehicle
Details on study design:
Dose volume: 3.33 ml/kg
Positive control:
Not applicable

Examinations

Observations and examinations performed and frequency:
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day on working days and once a day on weekends

BODY WEIGHT: Yes
- Time schedule for examinations: weekly
Sacrifice and pathology:
SACRIFICE:
Moribund animals and survivors (fasted overnight) at the end of the 13-week studies were killed by carbon dioxide asphyxiation.

GROSS PATHOLOGY: Yes, necropsies on all animals

HISTOPATHOLOGY:

all groups except 25 mg/kg bw:
kidneys, liver and colon

vehicle control group + 400 mg/kg bw group:
mandibular lymph node, salivary gland, sternebrae (including marrow), thyroid gland, parathyroids, colon, small intestine, prostate/testes or ovarieduterus, lungs and bronchi, heart, esophagus, stomach, brain, thymus, trachea, pancreas, spleen, pituitary gland, eyes (if grossly abnormal), mammary gland, gross lesions, urinary bladder, and adrenal glands

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
no effects observed
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
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not specified
Details on results:
CLINICAL SIGNS AND MORTALITY
400 mg/kg and less frequently at 200 mg/kg.: diarrhea, rough hair coat or alopecia around the head, hunched posture, general emaciation
No clinical signs were observed in lower dose groups.
400 mg/kg male: 6/10 dead + 2 in a moribund condition

BODY WEIGHT AND WEIGHT GAIN
400 mg/kg male: mean body weight gain depressed

FEED CONSUMPTION
Feed consumption was lower in the 400 mg/kg groups of both sexes than in other groups for weeks 1-3 of study but matched or exceeded the feed consumption for vehicle control groups thereafter.

GROSS PATHOLOGY
400 mg/kg for all males: gross abnormalities of the liver in the 8 dead male rats: enlarged, mottled and pale livers, with rough, granular or pitted surface texture; darkened or bright red lungs.
200 mg/kg for 5/10 males:similar liver lesions as at 400 mg/kg with dose related severity
400 mg/kg for most but not all females: similar liver lesions as for males + abnormal coloration of the kidneys

HISTOPATHOLOGY:
400 mg/kg for males that died during the study: acute, necrotizing colitis characterized by the loss of surface and glandular epithelium, mucosal and submucosal edema, acute inflammatory cell infiltration, three males exhibited multifocal renal cortical tubular necrosis ;
200 & 400 mg/kg for both sexes: periportal hepatocellular necrosis and fibrosis, bile duct hyperplasia, hepatocellular nodular hyperplasia;
Hepatocellular alterations in the periportal region were observed with decreasing frequency and severity at doses as low as 50 mg/kg (males) or 100 mg/kg (females): hepatocellular basophilia, cellular and nuclear hypertrophy, nuclear hyperchromatism.

Effect levels

open allclose all
Dose descriptor:
LOEL
Effect level:
200 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: clinical signs; gross pathology; histopathology: periportal hepatocellular necrosis and fibrosis, bile duct hyperplasia, hepatocellular nodular hyperplasia
Dose descriptor:
LOEL
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
female
Basis for effect level:
other: histopathology: hepatocellular basophilia, cellular and nuclear hypertrophy, nuclear hyperchromatism
Dose descriptor:
LOAEL
Effect level:
50 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: histopathology: hepatocellular basophilia, cellular and nuclear hypertrophy, nuclear hyperchromatism
Dose descriptor:
NOAEL
Effect level:
25 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: histopathology: hepatocellular basophilia, cellular and nuclear hypertrophy, nuclear hyperchromatism

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

TABLE: Survival and mean body weights of rats in the thirteen-week repeated-administration gavage studies of diallylphthalate

Dose

Survival

Mean body weights (grams)

Initial

Final

Change

MALE

 

 

 

 

0

10/10

186

311

125

25

10/10

185

321

136

50

10/10

189

322

133

100

10/10

188

312

124

200

10/10

186

303

117

400

2/10

184

273

89

FEMALE

 

 

 

 

0

10/10

134

192

58

25

10/10

133

202

69

50

10/10

134

197

63

100

10/10

135

199

64

200

10/10

133

197

64

400

10/10

134

191

57

 

 

Applicant's summary and conclusion

Conclusions:
More than 50% mortality was observed at 400 mg/kg bw in males (LD50 between 200 and 400 mg/kg bw), whereas no mortality occurred among females (LD50 > 400 mg/kg bw). Comparing these results with the acute (LD50=656-891 mg/kg bw) and 14-day study (LD50=350 mg/kg bw), sub-chronic exposure did not decrease the LD50 significantly.
The liver was the primary target organ in this study with dose related histopathological effects at and above 50 mg/kg bw for males and 100 mg/kg bw for females.