Oecd 541 guidelines

The Organization for Economical and Co-operation Development was used for testing of chemicals.
The original OECD guideline 451 for carcinogenecity study was adopted in 1981.
A Major carcinogenicity study is done on rodents
Mainly there routes of administration: oral, dermal, and inhalation.

1. Organization For Economic Co-operation And Development Guidelines – 451. By- Ms. Prajakta Hingole Ms. Debrupa Dutta Mr. Gopal Khodve Mr. Devesh Rana OECD carcinogenicity testing 1

2. CONTENTS 2

3. INTRODUCTION The objectives of carcinogenicity studies covered by this test guideline include: To identification of the carcinogenic properties of a chemical, To identification of target organ(s) of carcinogenicity To identification of the time to appearance of neoplasms Characterization of the tumor dose-response relationship To Identification of a no-observed-adverse-effect level (NOAEL) or point of departure for establishment of a Benchmark Dose (BMD) To Extrapolation of carcinogenic effects to low dose human exposure levels The Organization for Economical and Co-operation Development (OECD) was used for testing of chemicals. The original OECD guideline 451 for carcinogenicity study was adopted in 1981. Major carcinogenicity study is done on rodents Mainly there route of administration : oral , dermal and inhalation. 3

4. PRINCIPLE The test substance is administered daily in graduated doses. Observed closely for the signs of toxicity and for the development of neoplastic lesions. Died or killed animals are necropsied and at the conclusion of surviving animals are also killed and necropsied. Route of administration Oral Intradermal Inhalation 4

5. DESCRIPTION OF METHOD Rats and mice have been preferred experimental models because of their relatively short life span, their widespread use in pharmacological - and toxicological studies, their susceptibility to tumor induction, and the availability of sufficiently characterised strains. Young healthy adult animals of commonly used laboratory strains should be employed. Selection of Animal Species Animals may be housed individua lly , or may be caged in small groups of same sex. Individual sometime. Temperature in room 22  C(± 3  C). H umidity at least 30% not < 70%. Lighting 12hr dark & 12hr light. Feeding diet, unlimited supply of drinking water . D iet should meet all the nutritional requirements of species tested meet the nutritional requirements of the animals. Housing and feeding Healthy animals, not been subjected to previous experimental procedures. Test animals should be characterised as to species, strain, source , sex, weight and age. Animals randomly assigned to the control and treatment groups. Each animal assigned a unique identification number, and permanently marked with this number by tattooing, microchip implant, or other suitable method. Preparation of animals 5

6. PROCEDURE Duration of study The duration of the study will normally be 24 months for rodents, representing the majority of the normal life span of the animals to be used. Shorter or longer study durations may be used, dependent on the lifespan of the strain of the animal species in the study Dose groups and dosage Guidance on all aspects of dose selection and dose level spacing is provided in Guidance Document No. 116 (7). At least three dose levels and a concurrent control should be used. Number and sex of animals Both sexes should be used. A sufficient number of animals should be used so that a thorough biological and statistical evaluation is possible. The study may make provision for interim kills, e.g., at 12 months, to provide information on progression of neoplastic changes and mechanistic information, if scientifically justified. Provision for interim kills and satellite (sentinel) groups The route and method of administration is dependent on the purpose of the study, the physical/chemical properties of the test chemical, its bioavailability and the predominant route and method of exposure of humans. Preparation of doses and administration of test chemical 6

7. OBSERVATIONS All animals should be checked for morbidity or mortality, usually at the beginning and the end of each day, including at weekends and holidays. Animals should additionally be checked once a day for specific signs of toxicological relevance. Particular attention should be paid to tumor development; and the time of tumor onset, location, dimensions, appearance, and progression of each grossly visible or palpable tumor should be recorded . 7

8. 8 Observation study

9. PATHOLOGY GROSS NECROPSY- Done in all animals except sentinel and other satellite animals. Careful examination of external body surface, all cavities, orifices and their contents are done. Organ weights are not part of carcinogenetic study as to geriatric changes and tumor causes variation. In satellite study, organs should be collected within 1year after initiation of study. Both paired organs needs to be preserved. Target organs based on known properties of test compound should be preserved. In dermal route of administration, oral organs and skin is preserved. In inhalation study, TG412 and TG413 recommendations are followed to preserve respiratory tissues. Histopathology- All tissues from high dose and control group. All tissues of died/killed animals. All tissues showing macroscopic abnormalities, tumors. Both organs of paired organs. 9

10. DATA & REPORTING DATA- Individual experimental animals data of all evaluated parameters are presented. Summarised data in tabular form are presented for each test group including no. of animals used, no. of animals died, signs of toxicity, onset, duration and severity of toxicity, lesions etc. Mean and SD are evaluated. Historical control data should be from same laboratory and same age and strain of animal generated during 5years preceding the studying. Proper statistical method and data should be selected during design of study. TEST REPORTS- TEST CHEMICAL VEHICLE TEST ANIMAL Rationale for route of administration and dose selection . Statistical methods. Test chemical formulation details. Analytical data on concentration, homogeneity and stability of preparations. route for inhalation studies. Actual doses and conversion factors. Food and water quality details TEST CONDITIONS 10

11. 1 2 3 4 General Clinical findings Necropsy data Histopathology Survival data; Body weight changes; F ood consumption, calculations of food efficiency, if made, and water consumption; T oxicokinetic data if available; O phthalmoscopy; Hematology ; C linical chemistry (if available); Signs of toxicity; Incidence (and, if scored, severity) of any abnormality; Nature, severity, and duration of clinical observations (whether transitory or permanent); Terminal body weight; Organ weights and their ratios, if applicable; Necropsy findings; Incidence and severity of abnormalities Non neoplastic histopathological findings; Neoplastic histopathological findings; Correlation between gross and microscopic findings RESULTS 11

12. 12 REFERENCE OECD/OCDE 451, OECD GUIDELINE FOR THE TESTING OF CHEMICALS, 25 JUNE 2018.

13. Thank you Thank you 13