Registration Dossier

Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian germ cell study: cytogenicity / chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study was conducted according a protocol that is similar to the appropriate EU test method. It was not compliant with GLP. Some information required by the current guideline was not included in the study report. Read across to the registered substance is considered scientifically justified.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1975
Report Date:
1975

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.22 (Rodent Dominant Lethal Test)
Deviations:
yes
Remarks:
no information given on determination that mating has occurred
GLP compliance:
no
Type of assay:
dominant lethal assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Compound FDA 71-54, citric acid, granular
- Substance type: monoconstituent substance
- Physical state: solid

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Flow Laboratories random-bred, closed colony
- Age at study initiation: 10-12 weeks
- Weight at study initiation: 325-375 g
- Assigned to test groups randomly: yes
- Fasting period before study:
- Housing: 1-5 per cage
- Diet:.ad libitum
- Water: ad libitum
- Acclimation period: 4-11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no information
- Humidity (%): no information
- Air changes (per hr): no information
- Photoperiod (hrs dark / hrs light): no information

IN-LIFE DATES: no information

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: physiol. saline
- Justification for choice of solvent/vehicle: none given
- Concentration of test material in vehicle: no information
- Amount of vehicle (if gavage or dermal): no information
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: no information
Duration of treatment / exposure:
Test 1 and test 2: 1 and 5 days
Frequency of treatment:
Test 1 and test 2: single dose and daily for 5 days
Post exposure period:
Treated male rats were mated with two virgin female rats each week for 7 (test 1) or 8 (test 2) weeks. Two weeks after mating, female rats were sacrificed and the fertility index, preimplantation loss and lethal effects were determined and compared with those same parameters from negative and positive control animals
Doses / concentrations
Remarks:
Doses / Concentrations:
test 1: 1.2, 12.0, 120 mg/kg bw; test 2; 300, 500, 3500 mg/kg bw
Basis:

No. of animals per sex per dose:
10 male rats per dose
Control animals:
yes, concurrent vehicle
Positive control(s):
- triethylenemelamine
- Justification for choice of positive control(s): none given in report
- Route of administration: ip injection
- Doses / concentrations: 0.3 mg/kg bw

Examinations

Tissues and cell types examined:
The uterus was examined for corpora lutea, deciduomata (early deaths) late foetal deaths and total implantations.
Statistics:
Fertility index: pregnant females/mated females: treatments compared with controls using chi square, Armitage's trend for linearity;
Total number of implants: t-test, regression;
Total number of corpora lutea: t-test;
Preimplantation losses and dead implants: Freeman-Tukey transformation followed by t-test and regression;
One or more dead implants: chi-square and Armitage's trend, and probit regression analysis;
Two or more dead implants: chi-square and Armitage's trend, and probit regression analysis;
Dead implants per total implants: Freeman-Tukey arc-sine transformation.

Treatments were compared with historical controls. a nested model was used to take variations between males into account, and an analysis of weeks was provided.

Results and discussion

Test results
Sex:
not specified
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls valid:
yes
Negative controls valid:
not applicable
Positive controls valid:
yes

Any other information on results incl. tables

In both the acute and sub-acute studies in test 1, statistically significant effects were seen in week 4.

Test 1, acute study: significant, dose related increase in average resorptions in high level dose group. Low and intermediate groups showed a less significant increase.

Test 1, subacute: significant increase in average preimplantation losses was noted at week 4 for the high level dose group.

Test 2 (carried out subsequent to test 1).

The apparent effects shown in week four in test 1 were not reproduced.

The positive control gave expected results.

Table 2 Representative results Test 1 Subacute study

Endpoint

time from dosing of mating (week number)

Historical control

Negative control

1.2 mg/kg bw

12.0 mg/kg bw

120 mg/kg bw

Fertility index

1

0.67

0.60

0.74

0.55

0.45

4

0.78

0.80

0.80

0.80

0.64

7

0.87

0.90

0.95

0.80

0.70

Preimplantation losses per female (average)

1

1.5

1.7

0.9

0.9

1.6

4

0.6

1.3

1.8’

3.9*

0.7

7

1.0

1.3

1.6

0.4

2.1

Proportions with one or more dead implants

1

0.31

0.25

0

0.19

0.23

4

0.37

0.25

0.38

0.38

0.50

7

0.30

0.45

0.37

0.44

0.29

*significantly different from control, p < 0.01

‘significantly different from control, p < 0.05

Table 3 Representative results Test 2 Acute study

Endpoint

time from dosing of mating (week number)

Historical control

Negative control

500 mg/kg bw

3500 mg/kg bw

Positive control

Fertility index

1

0.67

0.80

0.60

0.50

0.55

4

0.84

0.80

0.80

0.80

0.55*

8

0.83

0.70

0.80

0.75

0.70

Preimplantation losses per female (average)

1

2.0

2.0

1.4

2.9

3.3’

4

1.6

1.4

1.8

1.8

6.8*

8

2.0

3.1

1.2

1.8

1.9

Proportions with one or more dead implants

1

0.28

0.31

0.333

0.40

1*

4

0.40

0.31

0.50

0.56

1*

8

0.39

0.29

0.44

0.27

0.57

*significantly different from control, p < 0.01

*significantly different from control, p < 0.01

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
CItric acid has been tested in a valid study according to a protocol that is similar to EU method B 22 (rodent dominant lethal assay). A statistically significant increase in resorptions was noted in a single week of the 7 (single dose) or 8 (repeated doses) studies in the first test. a repeat test showed no evidence of any effects. It is concluded that citric acid is negative for the induction of dominant lethals under the conditions of the study.