Acute toxicity: single or multiple doses in 24 hours.
Subacute: continuous or multiple doses from 24 hours and 28 days.
Subchronic: continuous or multiple doses usually 90 days, not more than 10% of lifespan. Intravenous studies defined as 14 to 28 days.
Chronic: A major part of the lifespan. Usually have a duration of 6 to 12 months.
Selection of Species:
The rat or mouse are the preferred animal. With Rabbits being an option for dermal or implantation studies.
The weights of study animals should be within 20% of the mean weight for the gender. Females should be nulliparous and non-pregnant.
Animal numbers of 5, 10 (5 per sex), 20 (10 per sex) and 40 (20 per sex) when using rodents for acute, subacute, subchronic and chronic time points, respectively. Animal numbers of 3, 6 (3 per sex), 8 (4 per sex) when using non rodents for acute, subacute and subchronic timepoints, respectively. Suggested animal number for non rodent chronic toxicity is not given.
Negative or sham treated controls should be incorporated into every systemic toxicity study.
Body weight change is a required evaluation of acute, subacute, subchronic and chronic studies.
Clinical Observations are a required evaluation of acute, subacute, subchronic and chronic studies.
Clinical pathology is a required evaluation of subchronic and chronic studies and should be considered or subacute studies.
Gross pathology is a required evaluation of subacute, subchronic and chronic studies.
Organ weights is a required evaluation of subacute, subchronic and chronic studies.
Histopathology is a required evaluation of subchronic and chronic studies and should be considered or subacute studies.
Acute systemic toxicity:
A rat or mouse will be used. Other species require justifications. Body weights are measured daily for the first three days after dosing and weekly after the first dose if the duration of the study encompasses this.
Clinical observations for 3 days on an acute systemic toxicity.
Hematology and clinical chemistry performed when clinically indicated. Urinalysis not necessary unless toxicity is expected.
Gross pathology is considered when indicated clinically.
Histopathology is not typically carried out on animals in an acute systemic toxicity study.
For pharmacopoeial type tests the test animals cannot exhibit signs significantly greater than that of the control animals. If two or more animals die or exhibit convulsions or prostration or if a weight loss of 10% or more occurs in 3 or more animals the sample does not meet the requirements of the test. If one animal dies and the rest have minor symptoms the test is repeated in 10 animals. On the retest no animals may demonstrate a meaningful observation in order to pass the requirements of the retest.
Subacute, subchronic and chronic systemic toxicity:
A 5 day acclimation period prior to testing is specified.
A rat or mouse will be used. Other species require justifications.
Animal numbers of 10 (5 per sex), 20 (10 per sex) and 40 (20 per sex) when using rodents for subacute, subchronic and chronic time points, respectively. Animal numbers of, 6 (3 per sex), and 8 (4 per sex) when using non rodents for subacute and subchronic timepoints, respectively. Suggested animal number for non rodent chronic toxicity is not given.
The dosing is to be 7 days a week.
Ophthalmic exams should be prior to administration and at the completion of the study.
Clinical chemistry and hematology should be conducted at the end of the study.
Urinalysis is not typically necessary.
A full necropsy with organ weights on the adrenals, brain,epididymides, heart, liver, kidney, testes, thymus, spleen, ovaries and uterus.
Evaluation of results is on a summary of all findings in all groups.
Routes of administration include, Dermal, Implantation, Inhalation, Intradermal, Intramuscular, Intraperitoneal, Intravenous, Oral, and Subcutaneous.
A table of Maximum dosages volumes per route of administration for each species is presented.
A table of clinical observations and the system involved is presented but it does not delineate what is a significant clinical observations and what is a minor clinical observation. The categories include respiratory, motor activities, reflexes, salivation, and gastrointestinal amongst others.
The parameters for hematology, clinical chemistry and urinalysis are listed out. It is important to note that clotting potential is listed amongst the hematology tests. The hematology is a simple complete blood count with a white blood cell differential. The chemistry profile is electrolytes and liver and kidney panels. The urinalysis evaluations (when performed) are standard parameters.
A suggested list of organs for preservation, weight and processing is provided and it is a very thorough list. There are 43 tissues listed on the list.
There is an an annex for pyrogenicity. There is an informative discussion and then it states to follow USP, EP or JP methods for conducting the test in rabbits.