An excipient is a substance formulated alongside the active ingredient of a medication. They enhance the active ingredient's therapeutic properties; to facilitate drug absorption, to modify viscosity, to enhance solubility, to improve long-term stabilization. During the manufacturing process, excipients can improve the handling of active substances and facilitate powder flow. The choice of excipients depends on factors such as the intended route of administration, the dosage form, and compatibility with the active ingredient.