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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
fertility, other
Remarks:
based on test type
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13/2/86 to 28/07/86
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Conducted per protocol and in accordance with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
EPA OPP 83-4 (Reproduction and Fertility Effects)
Principles of method if other than guideline:
The purpose of this study was to evaluate the possible effects of this candidate drug on the reprod uctive processes of female rats and the development of their offspring.
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Erythromycin
EC Number:
204-040-1
EC Name:
Erythromycin
Cas Number:
114-07-8
Molecular formula:
C37H67NO13
IUPAC Name:
6-{[4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl]oxy}-14-ethyl-7,12,13-trihydroxy-4-[(5-hydroxy-4-methoxy-4,6-dimethyltetrahydro-2H-pyran-2-yl)oxy]-3,5,7,9,11,13-hexamethyloxacyclotetradecane-2,10-dione (non-preferred name)

Test animals

Species:
rat
Strain:
other: Crl:Co(SD)BR
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: charles River Breeding Labs., Portage, MI
- Age and weight at study initiation: The females were sexually mature (at least 220 g) at the times of their initial treatments. Males were not treated but were at least 80 days old when used for breeding.
- Housing:Except during the periods of mating and lactation rats were individually housed.
- Diet (e.g. ad libitum): Certified Rodent Chow® #50023 ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period:All animals were allowed to acclimate to their new environment for at least S
days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):(72 ± 5°F).
- Humidity (%):Temperature and humidity were monitored daily.


IN-LIFE DATES: February 13, 1986 through April 27, 1986

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: saline with 0.2 % hydroxypropylmethylcellulose
Details on exposure:
Test doses were identical to those employed in a rat teratology study performed at Abbott



PREPARATION OF DOSING SOLUTIONS: All suspensions were freshly prepared at least once
each week. Stability data are available in support of this formulation schedule. During the course of th e study a sample of each formulation was analyzed as to concentration A
VEHICLE
- Amount of vehicle (if gavage): Treatment volumes were 1.0 ml/100 g body weight in all cases.
- Lot/batch no. (if required):lot #113-02
Details on mating procedure:
- M/F ratio per cage: 1/2
- Length of cohabitation: aximum of 10 days
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as day 0 of pregnancy:The pr esence of a mating sign (spermatozoa in vaginal lavage or a copulatory plug) was recorded.
- After 10 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged (how):After a mating sign was observed in a female, that animal was returned to its individual cage and was not again placed with a male .

At least 5 days prior to breeding, all males were placed in breeding cages. In all matings, the females were transferred to the male' s cage.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Assay results for the submitted test formulations ranged from 100.6% to 101.8% of target concentrati ons. During the course of the study a sample of each formulation was analyzed as to concentration by D-417 (Analytic Research) personnel.
Duration of treatment / exposure:
Daily for two weeks prior to mating then daily during mating period, gestation period and 3-week lac tation period
Frequency of treatment:
Daily for two weeks prior to mating then daily during mating period, gestation period and 3-week lac tation period
Details on study schedule:
Age at mating of the mated animals in the study: males 80 days . females when sexually mature .

Doses / concentrationsopen allclose all
Dose / conc.:
150 mg/kg bw/day (actual dose received)
Remarks:
Analytical concentration
Dose / conc.:
50 mg/kg bw/day (actual dose received)
Remarks:
Analytical concentration
Dose / conc.:
15 mg/kg bw/day (actual dose received)
Remarks:
Analytical conc.
No. of animals per sex per dose:
For each dose and vehicle control 12 males and 24 females
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The purpose of this study was to evaluate the possible effects of this c andidate drug on the reproductive processes of female rats and the development of their offspring.T est doses were identical to those employed in a rat teratology study performed at Abbott. Dosages t ested in that study were 15, 50 and 150 mg/kg/day.The high dose was maternally toxic (diminished weight gain and food consumption) as well as fetotoxic, while the low-dose approximated the anticipated clinical dose. The rat is an acceptable model for reproduction studies.Historical data on fertility, litter size and pup survival indices are available.

T0 - Vehicle control
T1 - 15 mg/kg/day, ABBOTT-56268
T2 - 50 mg/kg/day, ABBOTT-56268
T3 - 150 mg/kg/day, ABBOTT-56268

- Rationale for animal assignment (if not random):
- Other:
Positive control:
No

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: 1-2 hours after treatment as well as prior to treatment.
- Cage side observations checked where recroded in the report.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: 1-2 hours after treatment as well as prior to treatment.

BODY WEIGHT: Yes
- Time schedule for examinations: once each week; Individual dosage volumes were readjusted b ased on the most recent weekly body weight determination. In addition, sperm positive females were also weighed on gestational days 0, 6, 9, 12, 15 and 20.

OTHER: Observations of Female Rats
1.Body weight (gm) on Treatment Days 0, 7, and 14.
2.The estrous cycle (=1, 2, 3, or 4; 5 days a cycle) during which a mating sign was observed.
3. The status of pregnancy in mated females
Oestrous cyclicity (parental animals):
Beginning approximately 7 days prior to treatment initiation, daily vaginal smears were initiated on all females as a check on the estrous cycle. The cell types observed in the smear were recorded.
Sperm parameters (parental animals):
Observations of Dams
1. Body weight (gm) on Gestation Days O, 6, 9, and 12 for interim kill dams; weight gain (gm) from
Gestation Days O to 12.
2. Body weight (gm) on Gestation Days O, 6, 9, 12, 15, and 20, and on Postpartum Days O, 4, 12, an d 21 for dams permitted to deliver; weight gain (gm) between Gestation Days O and 20.
3. Length of gestation = Parturition date - sperm positive date
4. Uterine Contents at Interim Kill



The number of viable fetuses, implantations, and corpora lutea.
The percent of viable fetuses, of early or late resorptions or both, relative to the number of implantations.
Litter observations:
Observations of Fl Pups
1. The percent of livebirths and stillbirths (pups dead at first observation), relative to the number of pups delivered.
2. The male/female sex ratio of pups.
3. Body weight (gm) of all pups on Postnatal Days O, 4, 12, and 21; body weight (gm) of male and female pups on Postnatal Day 21.
4.The percent of pups surviving on Postnatal Days 1, 4, 12, and 21, relative to the number born alive.

PARAMETERS EXAMINED
The following parameters were examined in [F1 / F2 / F3] offspring:
[number and sex of pups, stillbirths, live births, presence of gross anomalies, weight gain, physical or behavioural abnormalities, other: Pups were recounted on postpartum day 1, then weighed and counted on days 4, 12 and 21.
Each dam and pup was observed daily for survival.The quality of maternal care was noted

GROSS EXAMINATION OF DEAD PUPS:
[yes, .All pups dying during the lactation period (found intact) were examined for skeletal defects. Possible cause of death was not determined for pups born or found dead.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals [describe when, e.g. as soon as possible after the last litters in each generation were produced.]
- Maternal animals: All surviving animals [describe when, e.g. after the last litter of each generation wa s weaned.]

GROSS NECROPSY
- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.]

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated in Table [#] were prepared for microscopic examination and weighed, respec tively.

All females failing to deliver offspring by approximately 24 days after their mating date or last contact with a male were necropsied for evidence of pregnancy or conditions which might have interfered with pregnancy.
Postmortem examinations (offspring):
GROSS NECROPSY
- Gross necropsy consisted of [external examinations ).
Statistics:
Possible areas of drug action include effects on female weight gain, the estrous cycle, female libido and fertility, embryo survival and development, the parturition process, lactation and pup growth and survival. Appropriate statistical evaluation was performed on variables selected by the Study Director. Results of these statistical analyses, as well as a description of the statistical methods employed, and recorded in the report.
Reproductive indices:
Female fertility was unaffected by the test agent. The slightly lower



mating indices seen in the r2 and T3 groups resulted from failure of one female in each of these group s to mate until its fourth estrous cycle in
the presence of a male. No biological significance is attributed to this since 18 of 24 T2 females and
19 of 24 T3 females mated during their first estrous cycle in the presence of a male .
Offspring viability indices:
Population Data at Parturition: pups delivered mean of 12.9 control and then 13.6- 12.9 for treatment groups.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
- Drug- and dose-related occurrences of salivation at time of treatment. A few treated rats had loca lized hair loss.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
No statistically significant adverse effects were noted. Transitory weight loss noted during first few treatment days at high (150 mg/kg) dose.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No statistically significant adverse effects were noted. Transitory weight loss noted during first few treatment days at high (150 mg/kg) dose.
Organ weight findings including organ / body weight ratios:
not examined
Histopathological findings: non-neoplastic:
not examined
Other effects:
not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
no effects observed
Reproductive performance:
no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS): None of the test animals dosed with
ABBOTT-56268 or vehicle died.

Effect levels (P0)

Key result
Dose descriptor:
NOAEL
Effect level:
150 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
clinical signs

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
no mortality observed
Description (incidence and severity):
Postnatal survival was quite good in all groups and no detrimental effects of ABBOTT-56268 on this p arameter were discerned.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
No significant differences in male/female sex ratios or in mean body weights at selected days during the nursing period were evident. Pups born to T3 dams tended to weigh slightly less than their control counterparts
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
no effects observed
Description (incidence and severity):
With the exception of one r 2 pup with a hematoma on its head and a second T2 pup with a pr otruding tongue all pups appeared grossly normal.
Histopathological findings:
not examined

Details on results (F1)

GROSS PATHOLOGY (OFFSPRING); Skeletal evaluation of pups dying during the 3-week nursing period revealed only minor skeletal variations. Major drug-associated abnormalities were not found.

OTHER FINDINGS (OFFSPRING): Observations at laparotomy on gestational day 13; Mean numbers of implants, viable fetuses or corpora lutea, as well as the percentage of postimplantation loss (early and late resorptions) were not adversely affected by maternal administration of ABBOTT-56268. A
few of the 13-day-old embryos were developmentally retarded and an occasional embryo appeared
to lack an umbilical vessel.Such findings were as common among control as among ABBOTT-56268- exposed embryos.All T3 (150 mg/kg) embryos examined were found to be normal

Effect levels (F1)

Remarks on result:
not determinable due to absence of adverse toxic effects

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Aside from slight, transitory effects on maternal weight gain and perinatal pup weights at the 150 mg/ kg/day dosage, ABBOTT-56268 was free of adverse effects on the parameters evaluated in this ferti lity and general reproductive performance study. The "no-significant-effect" level is judged to be 150 mg/kg.