Preclinical drug or pharmaceutical research in mouse and rat species is inevitable in the scientific investigations of a chemical substance or lead entity. The administration routes are the experimental study design, and regulatory requirements may influence the study of humans' intended therapeutic/clinical route. Specific route selection in the investigation of test substances must be profoundly well-versed to the research scientists and approved by local ethics committee members. Every route has advantages and disadvantages in absorption, bioavailability, metabolism, and distribution of substances, which should be carefully considered while selecting a route. Routes of administration can be performed painlessly if proper heed is given to the restraint and holding of animals and using adequate technical skills by technical persons and research scientists. This review describes the principal and common routes used in early drug discovery programs and preclinical research, including guidelines for safe injection volumes, sites of administration, preparation of sites, advantages & disadvantages, limitations, handling and restraint techniques, vehicle selection, and formulation strategies. Conclusion: This can be concluded knowledge of available methods for administration and handling techniques and the disposition pattern as well as formulation strategies will aid the scientist in choosing the most suitable route for the compound to be investigated.
INTRODUCTION:Scientific investigation of the test substance or lead molecule in rodents, particularly mouse and rat species, is indispensable in preclinical pharmaceutical research or biomedical research 1 . Test substance administration in rodents is one of the major methods for evaluating biological activity.