Subchronic Toxicity Studies
The 90 day studies provide information on the possible health hazards likely to arise from repeated exposure over a period of 'rapid growth' of the animals into young adulthood. These studies give insights into the major toxic effects, they indicate the target organs of toxicity, and the possibility of drug accumulation, and can provide an estimate of a no-observed-adverse-effect level (NOAEL) of exposure, which can be used in selecting dose levels for chronic studies and for establishing safety criteria for human exposure.
Three Month Toxicity Studies precede the 6-12 chronic toxicity studies and can range from:
- 3 - 4 Months in mice or rats by most routes.
Chronic Toxicity Studies
The objective of 6-12 month chronic toxicity tests is to characterise the profile of a pharmaceutical or chemical substance in a mammalian species following a prolonged and repeated exposure period. These studies should generate data to correlate the majority of chronic effects with the test article, and to determine dose-response relationships with those toxicities observed. Ideally, the design and conduct of these tests should allow for the detection of general toxicity including neurological, physiological, biochemical, and hematological effects, and exposure-related morphological (pathology) effects.
The duration of these chronic toxicity studies are usually:
- 6, 9 or 12 Months duration in mice or rats by most routes.
Clinical Pathology
Both clinical biochemistry and haematology investigations are available.
Necropsy
Performed under the direct supervision of a US Board Certified veterinary pathologist to GLP standards.
Histology
Trimming and organ sampling is performed according to RITA guidelines followed up with necessary slide staining procedures.
Histopathology
A US Board Certified veterinary pathologist also undertakes histopathological assessment of the prepared slides.