Route-of-administration selection in mammals is a pharmacokinetic, pharmacodynamic, formulation, animal-welfare, and translational decision, not a default technical choice. The selected route should match the study goal: intravenous dosing is most useful when complete systemic exposure and rapid onset are required, oral dosing is most translational for orally intended medicines but is affected by absorption and first-pass metabolism, subcutaneous or intramuscular dosing can provide slower systemic exposure, and intraperitoneal dosing can be useful in rodent proof-of-concept studies but may have limited clinical translation. Published route-comparison studies show that the same compound can produce different exposure, onset, bioavailability, tissue distribution, and tolerability depending on route; therefore, route choice should be supported by pilot pharmacokinetic or pharmacodynamic evidence when the literature is insufficient. Unresolved questions include how to standardize route sel
Selection of Administration Routes
Routes of administration in animal experiments primarily include the gastrointestinal tract (e.g., gavage, dietary admixture), injection (e.g., intravenous, intraperitoneal, subcutaneous, and intramuscular), and administration via the respiratory tract or skin and mucous membranes. Since different routes directly influence drug absorption rates, bioavailability, and the first-pass effect, the choice of route must be scientifically determined based on the experimental objectives, the physicochemical properties of the drug, and the animal species. During the experiment, the single-dose volume and dosage must be strictly controlled to prevent unnecessary harm to the animals caused by excessive volume or local irritation.
Related Experimental Schemes
