The document summarizes various toxicity studies including male fertility studies, female reproduction and developmental toxicity studies, and carcinogenicity studies. It discusses the key aspects of each study such as the species and number of animals used, dosing duration and levels, and parameters assessed. For example, it notes that female reproduction and developmental toxicity studies (segments I-III) are carried out in two species, usually rats and rabbits, to study effects on fertility, embryo-fetal development, and perinatal/postnatal development. It also describes carcinogenicity studies using two rodent species dosed for most of their lifespan to evaluate cancer potential.

1. Reproduction &
Developmental Toxicity
and
Carcinogenicity Studies
BY PRASHANT SHIVGUNDE

2. Content
• Male Fertility Study
• Female Reproduction and DevelopmentalToxicity Studies
• Carcinogenicity Studies
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3. One rodent
species
• RAT Pref.
Three groups
+ Control
(n=6 males)
• Dose selection from 14-28 DaysTox.
study
Dosing
• Minimum 28 days and maximum 70 days before
mating (1:2)
•Continued during pairing-Till the detection of
vaginal plug or 10 days
Assessment
• Pregnant females examined for their fertility
index after day 13 of gestation
• Weights and histology of each testis and
epididymis for male animals
• Sperms examined for their motility and
morphology
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4. Female Reproduction and Developmental
Toxicity Studies
• These studies need to be carried out for all drugs proposed to be
studied or used in women of child bearing age.
• Segment I, II and III studies - Performed in albino mice or rats, and
• Segment II study should include albino rabbits also as a second test species.
• When the test article is not compatible with the Rabbit
• Segment II data in the mouse may be substituted
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5. Female Fertility Study (Segment I)
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6. One rodent
and one non-
rodent
• Preferably rat
and rabbit
Drug Administration
• Three dose levels + Control
• Highest dose should cause
minimum maternal toxicity
• Throughout the period of
organogenesis, as described
for segment I
• N= 20 pregnant rats/rabbits at
each dose level
Observations
• Foetuses-All for the total number,
gender, body length, weight, gross
examination, one for skeletal
abnormalities and the other half for
visceral abnormalities
• Dams- signs of intoxication, BW,
food intake, uterus, ovaries and
uterine contents, number of corpora
lutea, implantation sites, resorptions
(if any
Teratogenicity Study (Segment II)
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7. Perinatal Study (Segment III)
•Recommended if the drug is to be
given to pregnant or nursing
mothers for long periods or where
there are indications of possible
adverse effects on foetal
development
Significance
•One rodent species
•Three dose levels + Control (n=15)
•Administered throughout the last
trimester of pregnancy (from day 15
of gestation) and then the dose that
causes low foetal loss should be
continued throughout lactation and
weaning
Dosing •Litters should be selected at weaning
and treated with vehicle or test
substance (n= 15 M and 15 F in each
group)
•Dosing throughout their periods of
growth to sexual maturity, pairing,
gestation, parturition and lactation.
F1 generation
•Growth parameters should be
monitored till weaning
F2 generation
Observations
1) Dams- BW, food intake, general signs of intoxication, progress of gestation/ parturition periods and gross pathology (if any);
2) Pups- the clinical signs, sex-wise distribution in dose groups, body weight, growth parameters, gross examination, survival and autopsy (if
needed) and where necessary, histopathology.
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8. Carcinogenicity Testing
For all drugs when
Expected to be clinically used for more than 6 months
Used frequently in an intermittent manner in the treatment of chronic or recurrent conditions
Emanating carcinogenic potential from previous demonstration
Structure-activity relationship suggests carcinogenic risk
Evidence of preneoplastic lesions in repeated dose toxicity studies
Long-term tissue retention of parent compound or metabolite(s) results in local tissue reactions or
other pathophysiological responses.
Completed rodent carcinogenicity studies are not needed in advance of the
conduct of large scale clinical trials,
• Unless there is special concern for the patient population
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9. Carcinogenicity Studies
Rodent
species
• Pref. Rat (justify for mice)
• Should not have a very high or very low incidence
of spontaneous tumors.
Dosing
• three dose levels + Control
• highest dose should be sub-lethal, and it should not reduce the life
span of animals by more than 10% of expected normal
• 24 months for rats and 18 months for mice
Observations
• Macroscopic changes
• Histopathology
• Additional on a case to case basis.
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