Toxicology

'Toxicology' traditionally known as the 'science of poisons' began with early cave dwellers who recognized poisonous plants and animals and used their extracts for hunting or warfare. Simultaneously, with time, to determine the effectiveness of a particular compound the concept of toxicology was developed.

Toxicology basically is defined as the study of the effects of chemical agents on biological material with special emphasis on the harmful effects. After gaining relevant information on the harmful effects of a compound the levels for its safe usage or the degree of its safeness is established, which is also known as its (compound) Biosafety level.

Toxicology division of MODI LABORATORY, an autonomous body, was established nearly 25 years ago. Since then it has catered to various industries with a professional outlook and time bound results. It has been involved in generating unbiased preclinical, toxicological and biosafety data. A very large list of satisfied customers over the past 25 years bears eloquent testimony to the scientific culture of the institute.

A wide range of toxicological studies are being undertaken as per national and International guidelines. Our Institute has been recommended by US FDA for 510 K registration for testing of medical devices. The safety levels of various chemicals are established through experimentation on animals as models of human biochemical, physiological and pathological responses

Major thrust areas for toxicological studies are :-

Various studies undertaken by MODI LABORATORY, as per National and International guidelines are:

1) Acute Toxicity Study :-

This study provides information regarding the possible health hazards which are likely to occur, if human are exposed to a single dose of a substance. This way, can help determine the level of usage of that substance. This study also serves as a basis for classification and labelling & also initial information on the mode of toxic actions of a substance.

The various routes of exposure for acute toxicity can be :-

2) Sub Acute Toxicity Study :-

This study provides a detailed information on the toxic effects caused by repeated exposure and also the delayed effect which may result due to the cummulative effect of the chemicals on the tissues or other biochemical mechanisms. This study also helps in establishing the level of the safe usage of a compound.

The likely routes are :-

The period of exposure may vary from 14 days to 90 days.

3) Chronic Toxicity Studies :-

Chronic toxicity is done to characterize the profile of a substance in a mammalian species following prolonged and repeated exposure. The routes of exposure are most likely the ones to which the human are exposed to that particular compound.

4) Irritation Study :-

The surface effects of a chemical on the skin and the mucous membrane is important because accidental contamination is always a possibility, hence to check any such effects the following studies are performed

↠ Irritation to mucous membrane

↠ Primary skin Irritation

5) Allergic Sensitization :-

Repeated exposure of a test substance can activate the immunological system that can be activated by prior exposure and the response may be characterized by various external factors like erythema & edema.

This study gives information regarding the sensitization of the immune system towards a particular compound.

6) Reproductive Toxicity :-

Many chemicals can effect the fertility and reproduction, often in an insidous manner without any overt signs of toxicity. Fertility of males & females can be affected or adverse effects on the developing embryo or fetus may result due to the exposure of chemicals. Keeping in view the health of mankind as well as its progeny the following studies are conducted :-

A. Segmental Studies:-

↠ Segment I : Deals with the general reproductive performance of males & females.

↠ Segment II : Teratogenicity

↠ Segment III : Effect on lactating dams and pups

B. Two/Three Generation Studies:-

7) Carcinogenicity :-

Main objective of this study is to check any neoplastic lesions caused by any compound when exposed for a prolonged period.

8) Mutagenicity :-

Adverse effects caused by any chemical / compound on the genetic material of the cells i.e. DNA, or by altering its structure or function can be checked out by :-

» In- Vitro method : Ame's test

» In-Vivo method : Rodent Dominant lethal study Micronucleus study

9) Biocompatibility Study :-

To determine the toxic effects of the medical devices (if any) as well the effects by leachables, the following studies are performed :

↠ In-Vivo method : Systemic / Intracutaneous toxicity/ Implantation

↠ In- Vitro method : Cytotoxicity

10) Ecotoxicology Studies :-

Effects caused by various chemicals on the beneficial organisms in the environment can be checked by :-

↠ Bee toxicity

↠ Fish toxicity

↠ Toxicity to birds

↠ Toxicity to Daphnia

11) Supplementary toxicity Studies :-

↠ Neurotoxicity studies on Egg laying hens

↠ Synergism & Potentiation Studies ( Combined effects of various chemicals)

ANIMAL HOUSE :-

To cater to the needs of industries for regulatory toxicology an animal house facility has been maintained which houses :-

↠ Mice - Rats

↠ Rabbits - Guinea Pigs

↠ Chicken - Pigeon - Quails

INSTRUMENTS :-

For various Biochemical, Histopathological and Haematological parameters the toxicology division houses a variety of instruments like :-

↠ Haematology Analyzer - Biochemistry Analyzer

↠ Various microscopes including inverted microscope

↠ Urine Analyzer

↠ Inhalation instrument (nose only)

↠ CO2 Incubator

↠ Automatic tissue processor

↠ Deep freezer

↠ Microtome