Merck Manuals states that the properties of the pill's additives as well as the overall size of the drug's particles determine how long it takes for the pill to be absorbed. Pill capsules filled with liquid are usually absorbed faster than pills filled with particles.
In addition to the composition of the pill, the contents of one's stomach and any digestive problems the person has can also impact how long it takes for a pill to be absorbed, according to Merck Manuals. For instance, calcium supplements and foods high in fiber can actually keep a pill from being absorbed by binding to it. If part of the digestive tract has been removed, or if a person has taken laxatives or has diarrhea, then the rate of absorption can also be affected, notes Merck Manuals.