Registration Dossier

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
June 19, 1990 through July 12, 1990 (in life)/ July 9, 1990 through July 12, 1990 (Cesarean Section)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OPP 83-3 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: 50% solution
Details on test material:
Suttocide A (50% solution) - clear, colorless liquid Lot: PLI-4D Stability samples of the test article were submitted on June 25 and July 12, 1990. Results: 57% measured on July 2 and 53.8% measured on August 8, 1990.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS- Source: Charles River Laboratories, Inc., Wilmington, Massachusetts - Age at study initiation: 101 days- Weight at study initiation: 238-296 grams- Fasting period before study: Not applicable- Housing: Rats were housed individually in stainless steel!" wire mesh cages sized in accordance with the "Guide for the Care and Use of Laboratory Animals" of the Institute of Laboratory Animal Resources, National Research Council. Nesting materials were not provided as sacrifice was scheduled prior to anticipated parturition. - Diet: Purina Certified Rodent Chow, Lot #0222901A, ad libitum. Feeders were designed to reduce soiling, bridging, and scattering. - Water: fresh tap water, ad libitum- Sanitization: Waste material was removed twice weekly. Cages and feeders were sanitized every two weeks. - Acclimation period: The rats were acclimated for eleven days. During this conditioning period the rats were weighed and observed for any clinical signs of disease or inadequate weight gain. All rats with any evidence of disease or physical abnormalities were discarded.ENVIRONMENTAL CONDITIONSLight cycle - 12 hours light, 12 hours dark. Temperature/Humidity - Every attempt was made to maintain a temperature of 22° C ± 3°C (66 °F to 77° F), and a hmnidity of 30 to 70%. :

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
Deionized
Details on exposure:
The test article was prepared daily in the vehicle to obtain 5% w/v active aqueous solution. Human exposure is unlikely by the oral route. However, the oral route was chosen to maximize systemic exposure to the test article.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples of the test article vehicle mixtures and vehicle control were submitted to sponsor on June 25, 1990 (Day 6) and July 5, 1990 (Day 15).
Details on mating procedure:
Animals from respective groups were mated by placing one male and one or two females, selected at random in a breeding cage until females exhibited evidence of copulation. These females were then assigned to respective groups consecutively. Vaginal examinations and slides were made daily to determine if sperm were present. The day of observation of a vaginal plug and sperm or only sperm was designated as Day O of gestation.
Duration of treatment / exposure:
Once daily beginning after implantation (Day 6 of gestation) and continuing through gestation to Day 15 of pregnancy with Day 0 defined as the day a vaginal plug and/or sperm were found. Concurrently, another group of mated females received deionized water at a dose volume of 9 ml/kg/day and served as the vehicle control.
Frequency of treatment:
once daily
Duration of test:
20 days
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
150 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
450 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
27 mated female Sprague Dawley rats to produce at least 20 litters per dose group.
Control animals:
yes, concurrent vehicle

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes - Time schedule: Throughout the test period, each animal was observed at least once daily- Cage side observations were included. Pertinent changes and signs of toxicity including mortality were recorded. BODY WEIGHT: Yes- Time schedule for examinations: The females were weighed the day copulation was confirmed (Day 0) and on Days 6, 9, 12, 15 and 20 of presumed gestation. The amount of test material administered to the individual females during the dosing period was based on the most recent body weights.FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes Food consumption was recorded for gestation Days 0-6, 6-9, 9-12, 12-15 and 15-20.WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): NoPOST-MORTEM EXAMINATIONS: Yes - Sacrifice on day 20- both actual and corrected body weights (subtract weight of gravid uterus) were recorded.- Necropsy was performed and the carcass discarded. All fetuses were individually weighed, sexed, numbered, tagged and examined for external malformations and variations.
Ovaries and uterine content:
The number and location of viable and non-viable fetuses, early and late resorptions, total implantations and corpora lutea were recorded on the log form for the individual dam.
Fetal examinations:
Approximately one-half of the fetuses were placed in Bouin's fluid for subsequent soft tissue examination by free-hand sectioning. The remaining fetuses were placed in ethyl alcohol (95%), later macerated with potassium hydroxide and stained with Alizarin Red S (Lot #126F-0315) for subsequent skeletal examination. Fetal alterations were classified as malformations or developmental variations.
Statistics:
Statistical analyses compared the treatment groups to the control group with the level of significance at p< 0.05 . Only gravid females were used in statistical analyses. Maternal body weight, body weight gain, food consmnption and the mean number of viable fetuses, non-viable fetuses, total implantations and corpora lutea were compared by analysis of variance (one-way classification), to judge significance of differences from the respective control mean. Non-parametric statistics were used where variances were significantly different between groups as per Bartlett's Test. The number of early resorptions, late resorptions, pre- and post-implantational losses and percentages of these resorptions and losses were compared by the Mann-Whitney U-Test to judge significance of differences. The male and female fetal sex distribution and the number of litters with malformations were compared using Chi-Square test. Statistics were calculated using Systat by Systat Inc., Evanston, IL (Pharmakon S.O.P. PH-083).

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Six dams in the 150 mg/kg/day dose group exhibited post-dose salivation. The majority of the dams in the 300 and 450 mg/kg/day dose groups exhibited post-dose salivation. Additional signs noted in these dose groups included chromodacryorrhea, decreased activity, poor grooming, abnormal stance, abnormal gait and decreased body tone. These deaths were attributed to technical error (pulmonary intubation) and not the result of test article toxicity.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Two dams from the 150 mg/kg/day dose group died during the study. Necropsy revealed hydrothorax, dark red lungs, ascities and air filled red discolored intestines.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
450 mg/kg/day dose group: suppressed body weight gain but not statistically significant.
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
450 mg/kg/day dose group: statistically significant reduced food consumption
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed

Maternal developmental toxicity

Number of abortions:
no effects observed
Description (incidence and severity):
No statistically significant differences were observed in the mean number of corpora lutea, implantations, viable fetuses, non-viable fetuses, late resorptions, early resorptions, fetal body weight, fetal sex distribution, or the number and percentage of pre- or post-implantation losses.
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
not examined
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Changes in number of pregnant:
not specified
Other effects:
not specified
Details on maternal toxic effects:
Maternal toxic effects:yesDetails on maternal toxic effects:Maternal toxicity was observed in the 450 mg/kg/day dose group as evidence by suppressed body weight gain and reduced food consumption. All dams in the high dose group exhibited either decreased activity, post dose salivation or both.

Effect levels (maternal animals)

Dose descriptor:
NOEL
Effect level:
300 mg/kg bw/day (actual dose received)
Based on:
test mat.
Basis for effect level:
other: maternal toxicity

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not specified
Reduction in number of live offspring:
no effects observed
Description (incidence and severity):
There was one fetal death observed at cesarean section from the 300 mg/kg/day (mid dose) dose group. Necropsy revealed pale placenta, maceration, edema and lack of bone ossification. This death was judged coincidental and not related to treatment with the test article.
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
not specified
Changes in postnatal survival:
no effects observed
External malformations:
no effects observed
Skeletal malformations:
effects observed, non-treatment-related
Description (incidence and severity):
Eight fetuses with skeletal malformations were detected during the study: seven low dose fetuses (2.1%) from one litter (4.2%) and one high dose fetus (0.3%) from one litter (3.8%). The first seven exhibited abnormally shaped scapula (broad and flat) and short appendicular bones (humerus, radius, ulna, femur, tibia and fibula). While this produced statistical significance in the total number of skeletal malformations in this low dose group compared to controls, litter incidence was not statistically significant. The one fetus from the high dose group exhibited unaligned vertebrae. All eight skeletal malformations were not observed dose dependent, were inconsistant in type and incidence and are considered spontaneous and not related to treatment with Suttocide A.
Visceral malformations:
no effects observed
Other effects:
no effects observed

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
450 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
reduction in number of live offspring
changes in sex ratio
changes in litter size and weights
changes in postnatal survival
external malformations
skeletal malformations
visceral malformations

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Based upon this study, the no-observed effect level for maternal toxicity is 300 mg/kg/day and the no-observed effect level for developmental toxicity is 450 mg/kg/day. Suttocide A, Lot #PLI-40 did not exhibit selective toxicity toward the developing conceptus.
Executive summary:

One hundred and eight female Sprague Dawley rats were mated for use in a study to determine the potential of Suttocide A, Lot #PLI-4D, to produce or alter the incidence of congenital malformations in offspring of pregnant female rats pretreated with the test article. The test article was administered orally by gavage, at doses of 150, 300 and 450 mg/kg/day from Day 6 through Day 15 of gestation. Two dams from the 150 mg/kg/day dose group died during the study. Each death was attributed to technical error and not the result of test article toxicity. All other dams survived the duration of the study. All dams in the high dose group exhibited either decreased activity, post-dose salivation or both. Post-dose salivation was also observed in females exposed to the mid-dose group. Although not statistically significant, the females in the 450 mg/kg/day dose group gained only 69% of control body weight (i.e. 31% reduction) during the Days 6 through 15 dosing interval. A significant decrease was also observed in the amount of feed consumed for the 450 mg/kg/day dose group during Days 6 through 9 and 9 through 12 of gestation. Therefore, maternal toxicity was observed in the 450 mg/kg/day dose group as evidence by suppressed body weight gain and reduced food consumption.

Based upon the number of gravid animals per group, there were no statistically significant differences in the total number of implantation sites, viable fetuses, non-viable fetuses, early resorptions, late resorptions, fetal sex distribution, fetal body weights, corpora lutea, the number and percentage of pre-implantation or post-implantation losses. There were no soft tissue malformations detected in the study but eight fetal skeletal malformations were present. Seven occured in one litter of the low dose and one occurred in one litter of the high dose group. However, each malformation was considered spontaneous. A variety of spontaneous developmental variations were also observed in the control and Suttocide A treated groups. There were no significant differences observed in the number of fetuses exhibiting these variations.

Based upon these findings the no-observed effect level for maternal toxicity is 300 mg/kg/day and the no-observed effect level for developmental toxicity is 450 mg/kg/day. Suttocide A, Lot #PLI-40 did not exhibit selective toxicity toward the developing conceptus.