👉 The referring fluid, also known as the base fluid or carrier fluid, is a substance in which the drug of interest is dissolved or dispersed to achieve therapeutic concentrations. It serves as the medium through which the active pharmaceutical ingredient (API) is transported within the body, ensuring its bioavailability and efficacy. Common referring fluids include water, saline solutions, and various organic solvents, depending on the drug's properties and the desired route of administration. The choice of referring fluid is crucial as it can significantly affect the drug's absorption, distribution, metabolism, and excretion (ADME) profile.
