This document outlines the principles and types of non-clinical toxicity studies conducted in animals prior to testing pharmaceuticals in humans. It discusses general principles like complying with Good Laboratory Practice, using standardized equipment and protocols. It also describes the different types of toxicology studies including toxicokinetic, reproductive toxicity, teratogenicity and perinatal studies. The goal is to assess safety and predict potential adverse effects in humans by administering test substances to animals and observing toxicity.
toxicology study according to OECD guidelines, organisation for economic co-orporation and developement, jasdeep singh , maharaja ranjit singh punjab technical university bathinda
OECD Test Guideline 420: Acute Oral Toxicity - Fixed Dosepp_shivgunde
OECD Test Guideline 420: Acute Oral Toxicity - Fixed Dose
Guideline 420 was adopted in July 1992 as the first alternative to the conventional acute toxicity test.
toxicology study according to OECD guidelines, organisation for economic co-orporation and developement, jasdeep singh , maharaja ranjit singh punjab technical university bathinda
OECD Test Guideline 420: Acute Oral Toxicity - Fixed Dosepp_shivgunde
OECD Test Guideline 420: Acute Oral Toxicity - Fixed Dose
Guideline 420 was adopted in July 1992 as the first alternative to the conventional acute toxicity test.
Dermal Irritation and Dermal Toxicity Studies Dinesh Gangoda
Dermal irritation and Corrosion test guidelines 204.
Dermal irritation is the production of reversible damage of the skin following the application of a test chemical for up to 4 hours.
Corrosive reactions are typified by ulcers, bleeding, bloody scabs, and, by the end of observation at 14 days, by discolouration due to blanching of the skin, complete areas of alopecia, and scars. Histopathology should be considered to evaluate questionable lesions. [1]
Dermal corrosion is the production of irreversible damage of the skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test chemical for up to four hours.[2]
REFERENCES
OECD/OCDE, Test No. 404: ‘‘Acute Dermal Irritation/Corrosion’’, 28 July 2015 OECD Publishing, peris, Page no, 1- 8.
Robert A., Turner., Screening Methods in Pharmacology; 1st edition; Academic press an imprint of Elsevier, pp, 279- 281.
OECD Guideline for testing of chemicals (1981). ‘‘Repeated Dose Dermal Toxicity’’, 21/28- day Study.
This presentation enlists all the studies which are required before submission of IND. It include IND introduction , time period of study ,flowchart showing preclinical studies...
Historically, drugs were discovered by identifying the active ingredient from traditional remedies or by serendipitous discovery, as with penicillin. More recently, chemical libraries of synthetic small molecules, natural products or extracts were screened in intact cells or whole organisms to identify substances that had a desirable therapeutic effect in a process known as classical pharmacology. After sequencing of the human genome allowed rapid cloning and synthesis of large quantities of purified proteins, it has become common practice to use high throughput screening of large compounds libraries against isolated biological targets which are hypothesized to be disease-modifying in a process known as reverse pharmacology. Hits from these screens are then tested in cells and then in animals for efficacy
Dermal Irritation and Dermal Toxicity Studies Dinesh Gangoda
Dermal irritation and Corrosion test guidelines 204.
Dermal irritation is the production of reversible damage of the skin following the application of a test chemical for up to 4 hours.
Corrosive reactions are typified by ulcers, bleeding, bloody scabs, and, by the end of observation at 14 days, by discolouration due to blanching of the skin, complete areas of alopecia, and scars. Histopathology should be considered to evaluate questionable lesions. [1]
Dermal corrosion is the production of irreversible damage of the skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test chemical for up to four hours.[2]
REFERENCES
OECD/OCDE, Test No. 404: ‘‘Acute Dermal Irritation/Corrosion’’, 28 July 2015 OECD Publishing, peris, Page no, 1- 8.
Robert A., Turner., Screening Methods in Pharmacology; 1st edition; Academic press an imprint of Elsevier, pp, 279- 281.
OECD Guideline for testing of chemicals (1981). ‘‘Repeated Dose Dermal Toxicity’’, 21/28- day Study.
This presentation enlists all the studies which are required before submission of IND. It include IND introduction , time period of study ,flowchart showing preclinical studies...
Historically, drugs were discovered by identifying the active ingredient from traditional remedies or by serendipitous discovery, as with penicillin. More recently, chemical libraries of synthetic small molecules, natural products or extracts were screened in intact cells or whole organisms to identify substances that had a desirable therapeutic effect in a process known as classical pharmacology. After sequencing of the human genome allowed rapid cloning and synthesis of large quantities of purified proteins, it has become common practice to use high throughput screening of large compounds libraries against isolated biological targets which are hypothesized to be disease-modifying in a process known as reverse pharmacology. Hits from these screens are then tested in cells and then in animals for efficacy
GENERAL GUIDELINES FOR TOXICOPATHOLOGY STUDYRahul Kadam
The nonclinical safety study recommendations for the marketing approval
of a pharmaceutical usually include single and repeated dose toxicity
studies, reproduction toxicity studies, genotoxicity studies, local tolerance
studies, and for drugs that have special cause for concern or are intended
for a long duration of use, an assessment of carcinogenic potential. Other
nonclinical studies include pharmacology studies for safety assessment
(safety pharmacology) and pharmacokinetic (absorption, distribution,
metabolism, and excretion (ADME)) studies. These types of studies and
their relation to the conduct of human clinical trials are presented in this
guidance.
clinical and preclinical approaches to drug discovery.Here we mainly deals with preclinical approaches, ie. Pharmacological approach and toxicological approach
Pre-discovery
Understand the disease
Target Identification
Choose a molecule to target with a drug
Target Validation
Test the target and confirm its role in the disease
Drug Discovery
Find a promising molecule (a “lead compound”)
that could become a drug
To accomplish a desired systemic effect, drug molecules must reach the systemic circulation after extravascular administration. The percent of the taken dose that reaches intact to the systemic circulation is called “bioavailability, BA”. Absolute Bioavailability compares the BA of the active drug in systemic circulation following non-intravenous administration
Preclinical Toxicity Studies-Tool of Drug Discoverydynajolly
As per WHO “Drug is any substance or product that is used or is intended to be used to modify or explore physiological systems or pathological states for the benefit of the recipient”. Hence the prime objective of using any substance as a drug is that it must be beneficial for the humans. A large number of compounds are synthesized every year but they cannot be directly used in humans as drugs because no one knows or can predict the possible harmful effects of these compounds in humans. That is why to explore the complete pharmacological profile of these compounds and to ensure complete human safety they are first tested on animals before clinical use. Preclinical Studies thus can be defined as “Testing the newly discovered compound in animals with the objective of gaining information regarding the various aspects of the compound with respect to the biological systems so that the same can be extrapolated for the use of that compound in humans”. As the evaluation progresses undesirable compounds gets rejected at each step, so that only a few out of thousands reach the stage when administration to the humans is considered.
Pharmacovigilance and Pharmacoepidemiology journal accepts articles from different disciplines as below but not constrained to only these Pharmacovigilance signal, Pharmacovigilance data management, Design and development of drug, Principles of pharmacology, Quality system and pharmacovigilance, Pharmacovigilance softwares, Drug regulatory activities, Drug reactions and diagnosis, Reporting systems, Clinical trials and pharmacovigilance, Marketing surveillance, Pharmacovigilance ethics and regulations, Biomarkers and pharmacology , Concepts and trends in pharmacovigilance, Pharmaceutical medicines, Drug delivery systems, Statistics and data management.
The guidelines describe about the subacute toxicity studies in rodents with a comparison with the previous guideline.it also includes the comparison of all three subacute toxicity studies OECD 407, OECD 410, and OECD 412
This screening Test Guideline describes the effects of a test chemical on male and female reproductive performance. It has been updated with endocrine disruptor endpoints, in particular measure of anogenital distance and male nipple retention in pups and thyroid examination.
The test substance is administered in graduated doses to several groups of males and females. Males should be dosed for a minimum of four weeks. Females should be dosed throughout the study, so approximately 63 days. Matings "one male to one female" should normally be used in this study. This Test Guideline is designed for use with the rat. It is recommended that each group be started with at least 10 animals of each sex. Generally, at least three test groups and a control group should be used. Dose levels may be based on information from acute toxicity tests or on results from repeated dose studies. The test substance is administered orally and daily. The results of this study include clinical observations, body weight and food/water consumption, oestrous cycle monitoring, offspring parameters observation/measurement, thyroid hormone measurement, as well as gross necropsy and histopathology. The findings of this toxicity study should be evaluated in terms of the observed effects, necropsy and microscopic findings. Because of the short period of treatment of the male, the histopathology of the testis and epididymus should be considered along with the fertility data, when assessing male reproductive effects.
Toxicological Approach to Drug DiscoverySuhas Reddy C
For better understanding of students. This will give you a detailed explanation of Toxicological approach. Contact me through comment section if you need any assistance in understating
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
2. CONTENT:
NON CLINICAL TOXICITY STUDIES
GENERAL PRINCIPLES
TOXICOKINETIC STUDIES
RELEVANT TEST MODELS
TOXICOLOGY
TYPES OF TOXICOLOGY
REPRODUCTIVE TOXICOLGY STUDIES
1.MALE FERTILITY
2.FEMALE REPRODUCTION AND
DEVELOPMENTAL STUDIES.
3. ANIMAL TOXICOLOGY
NON – CLINICAL TOXICITY
STUDIES
GENERAL PRINCIPLES:
Toxicity studies should comply with the norms of
Good Laboratory Practice (GLP).
Briefly , these studies should be performed by
suitably trained and qualified staff employing
properly calibrated and standardized equipment
of adequate size and capacity.
Studies should be done as per written protocols
with the modifications.
Standard operating procedures (SOPs) should be
followed for all laboratory tasks related to these
studies.
4. Test substances and test systems (in-vitro or in-
vivo) should be properly characterized and
standardized.
All documents belonging to each study , including
its approved protocol , raw data , draft report ,
final report , and histological slides and paraffin
tissue blocks should be preserved for a minimum
of 5years marketing of the drug.
5. TOXICOKINETIC STUDIES
Generation of pharmacokinetic data to access
systemic exposure achieved in animals.
Relation to dose level and the time course of
toxicity study.
To support choice of species and treatment
regimen.
Design on clinical studies accordingly.
6. RELEVANT TEST MODELS
Pharmacodynamic responses.
Pharmacokinetic profile.
Species, sex , age of experimental animals.
Susceptibility , sensitivity and reproducibility of
test system.
In vitro: isolated organs , tissues cell – cultures.
Mechanism of effect in vivo.
7. WHY DO WE REQUIRE NON CLINICAL STUDIES IN
ANIMAL BEFORE ADMINISTERED TO MAN??
Pharmacological effects are same in man as in
animals.
Toxic effect in species will predict adverse effects
in man.
Giving high doses in animals improve
predictability to man.
Risk assessment can be made by comparison of
toxic doses in test species can be made by
comparison of toxic doses in test species with
predicted therapeutic dose in man.
8. TOXICOLOGY
One of the main concerns of the regulatory
agencies around the world is the safety of the
compound to be administered in the human body.
To data , one of the most reliable ways to asses
the safety of a foreign substance is to administer
it in a living system and monitor the toxicity of the
substance.
The first non clinical toxicology guidance was
published in 1949. since then, the toxicity studies
have undergone rigorous scrutinization regarding
the toxicity of the pharmaceuticals in humans and
animals.
It is generally accepted that a new molecular
identity has to be tested for toxicity in two species
9. The dosage of the compound to be tested in the
animal should ensure adequate safety margin ,
and the toxic potential of the compound should
be fully delineated.
Generally , in toxicity studies data are
incorporated from physical examination, clinical
signs (preliminary behavioral change , respiratory
distress etc.)
Serum chemistry , hematology , urinalysis , gross
pathology , organ weight changes and
histopathology.
10. TYPES OF TOXICOLOGICAL STUDIES
1. systemic toxicology studies.
a) single dose studies
b) repeated dose studies
2. Reproductive toxicology studies.
a) male fertility
b) female reproduction and developmental
studies.
3. local toxicity studies.
4. hypersensitivity studies.
5. genotoxicity studies.
6. carcinogenicity studies.
11. REPRODUCTIVE TOXICOLOGY
The section of the package insert label regarding
pregnancy is one of the most important uses of non
clinical data.
The effects of a compound on the developing
concepts as well as the possible effects on fertility
concern almost every user of prescription drugs and
this effects both the possibilities , whether a drug
should be used to all e.g. retinoid in women who
might be pregnant.
In attempting to make the information in the label
more useful , not only the teratogenic changes are
delineated , but comparison of animal dose where the
finding are observed to the expected clinical dose is
also provided. The patient or doctor can then make
their own informed decision on drug use.
12. Reproductive changes are reported in early
clinical studies , due to largely exclusion of
women of childbearing potential from these
experiments.
Conventional toxicology studies carried out prior
to the first human studies include histo
pathological examination of both the female and
male reproductive tracts , incorporating
examination of testes and ovaries.
Additional reproductive toxicity studies , which
include structural and functional alterations in the
first generations.
The three classes of reproductive toxicity include
affects on fertility , parturition , lactation.
13. The duration of these studies dosing has been a
source of much discussion at the ICH. Initially males
dosed for 10 weeks prior to mating to affect several
cycles of sperm production.
ICH recommends the treatment for 2weeks.
The major change in the recommendation is the
histopathological observations are the most sensitive
and informative parameter to examine.
Guideline for industry is detection of toxicity to
reproduction for medical products. Similarly between
pharmacologic and reproductive development
toxicological mechanisms.
14. Types of reproductive toxicology studies are
1. male fertility
2. female reproduction and developmental
studies.
15. 1. MALE FERTILITY STUDY :
one rodent species preferably rat should be used.
Dose selection should be done from the results of the
previous 14 or 28 day toxicity study in rat.
Three dose groups , the highest one showing minimal
toxicity in systemic studies , and a control group
should be taken.
Each group should consist of 6 adult male animals.
16. Animals should be treated with the test substance
by the intended route of clinical use for minimum
28 days and maximum 70 days before they are
paired with female animals of proven fertility in a
ratio of 1:2 for mating.
Drug treatment of the male animals should
continue during pairing.
Pairing should be continued till the detection of
vaginal plug or 10 days , whichever is earlier.
Females getting thus pregnant should be
examined for their fertility index after day 13 of
gestation.
17. Weights of each testis and epididymis should be
separately recorded.
Sperms from one epididymis should be examined
for their motility and morphology.
The other epididymis and both testes should be
examined for their histology.
18. 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 1 , 2 , and 3studies are to be performed
in albino rats or mice.
Segment 3 study should include albino rabbits
also as a second test species.
19. On the occasion , when the test article is not
compatible with the rabbit (e.g. antibiotics which
are effective against gram positive , anaerobic
organisms and protozoa's) the segment 2 data in
the mouse may be substituted.
SEGMENT 1 fertility and general
reproductive
performance study.
SEGMENT 2 Teratogenicity
implantation
embryogenesis.
20. At least 15 males and 15 females should be used per
dose group.
Control and the treated groups should be of similar
size.
The route of administration should be the same as
intended for therapeutic use.
Dams should be allowed to litter and their medication
should be continued till the wearing of pups.
Observations on body weight , food intake , clinical
signs of intoxication , mating behavior , progress of
gestation/ parturition periods , length of gestation ,
parturition , post – partum health and gross pathology
(and histopathology of affected organs) of dams
should be recorded.
21. The pups from both treated and control groups
should be observed for general signs of
intoxication , sex-wise distribution in different
treatment groups , body weight , growth
parameters , survival , gross examination, and
autopsy.
Histopathological of affected organs should be
done.
22. TERATOGENICITY STUDY (SEGMENT 2):
One rodent (preferably rat) and one non – rodent
(rabbit) species to be used.
The drug should be administered throughout the
period of organogenesis , using three dose levels
as described for segment 1.
The highest dose should cause minimum
maternal toxicity and the lowest one should be
proportional to be the proposed dose for clinical
use in humans or a multiple of it.
23. The route of administration should be the same
as intended for humans therapeutic use.
The control and the treated groups should consist
of at least 20 pregnant rats (or mice) and 12
rabbits , on each dose level.
All fetuses should be subjected to gross
examination , one of the fetuses should be
examined for skeletal abnormalities and the other
half for visceral abnormalities.
24. Observation parameters should include : (dams)
signs of intoxication , effect on body weight ,
effect on food intake , examination of uterus ,
ovaries and uterine contents , number of corpora
lutea , implantation sites , resorptions (if any); and
for the fetuses , the total number , gender , body
weight , weight and gross/visceral/skeletal
abnormalities , if any.
25. PERINATAL STUDY (SEGMENT 3):
This study is specially 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 fetal development.
One rodent species (preferably rat) is needed.
Dosing at levels comparable to multiples of
human dose should be done by the intended
clinical route.
26. At least 4 groups (including control) , each
consisting of 15 dams should be used.
The drug should be administered throughout the
last trimester of pregnancy (from day 15 of
gestation) and then the dose that causes low fetal
loss should be continues throughout lactation and
wearing .
Dams should then be sacrificed and examined as
descibed below.
27. One male and one female from each litter of F1
generation (total 15 males and 15 females in
each group) should be selected at weaning and
treated with vehicle or test substance (at the dose
levels described above) throughout their periods
of growth to sexual maturity , pairing , gestation ,
parturition and lactation.
Mating performance and fertility of F1 generation
should thus be evaluated to obtain the F2
generation whose growth parameters should be
monitored till weaning.
28. Animals should be sacrificed at the end of the
study and the observation parameters should
include (dams) bodyweight , food intake , general
signs of intoxication , progress of
gestation/parturition periods and gross pathology
(if any); and for 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.