Types of toxicological studies

 There are two types i.e.

      1-      Short term/acute toxicological studies

      2-      Long term toxicological studies

We also study sub-acute/ sub chronic studies, chronic studies.

      1-      Short term/acute toxicological studies:

Administer drug for short period of time, for one day or multiple dose

Observation:

Observe given animal for 30 days and not any toxicological effects of drug on animal. Two type of observation are carried out

      A-    Behavioural changes:

It include sleeping pattern, eating habits, dinking, head tail and other movements.

      B-    Biochemical changes:

Collect urine, blood, feces, or any other body secretion and note any change in its characteristics. If there is any color change in body secretion it means drug shows short term/acute toxicity.

      2-      Sub-acute/Sub chronic studies:

Sometime acute toxicity is note observe with drugs so we perform sub-acute/sub chronic studies. In this case administer the drug for two week OD or at suitable intervals and then observe the effects after 2 weeks. Side effects are observed during this period and after this period.

Estimation of drug dose:

After observation of

·         P.k and P.D of drug

·         Side effects of drug

Example:

If drug shows side effect at 10 mg then clinical trials studies are started with 1/10 mg of initial dose.

Chronic studies:

These studies are performed with those drugs which are administered of prolong period of time. I.e. for every drug molecule duration of use is different e.g.

·         Analgesics are taken for 1-2 days.

·         Antibiotics are prescribed for longer period of time e.g. 5, 7 or 10 days.

·         Chronic studies are performed for these types of drug. Administer dose regularly for 90-180 days then observe the effects.

      3-      Long term studies:

These types of toxicological studies are performed for those type of drug which are used for chronic ailments e.g. blood pressure, diabetes, arthritis.

Administer the drug for the period of 1 year after this observe the side effect and toxic effect produce in long term studies further following studies are performed e.g. carcinogenic studies, reproductive studies, genotoxic studies.

Carcinogenic studies:

These are long term studies in which drugs areadministered for 18-24 months and then after this time animal is killed and observe various organ for the tumor/malignancy.

Reproductive studies:

These are also type of long term studies. In this after the administration of drug, overall behavior of parents is observed.

Observe mating effects of parents and observe, what is effect of new drug molecule on the offspring embryo and fetus?

Genotoxic studies:

Salmonella typhaemurium specie of bacteria is used to study genotoxicity. A new drug molecule is administered to bacteria and then genetic changes are observed in bacteria.

We see,

·         New drug molecule to cure mutation or not?

·         Drug molecule cause any change in genetic sequence/genetic make-up or not?

Note:

         Short term studies are done before INDA submission.

         Long term studies are carried out along with clinical trials.