Excipients are medically inactive or inert substances without nutritive value added to pharmaceutical formulations to dilute, give form or consistency and provide stability so that the active substance can easily be produced in a dosage form such as in a pill and administered and absorbed by the body. The active substance is typically dissolved in or mixed with the excipient. Monoglyceride is an excipient used to coat vitamin tablets to prevent deterioration, while magnesium stearate is a lubricant used to facilitate removal of compressed tablets from a die punch. Modified food starch is used as a thickening agent in some drug formulations.