Pharmacokinetics of ibuprofen: comparison of the fixed combination of ibuprofen plus caffeine with ibuprofen lysinate or ibuprofen acid

Abstract

Analgesics containing readily soluble ibuprofen (e.g. as the lysinate) were developed with the aim of ensuring a more rapid relief of pain than ibuprofen acid through faster absorption in the gastrointestinal tract. Since the degree of gastric filling can have a significant influence on absorption, two studies investigated the pharmacokinetics of ibuprofen lysinate and ibuprofen acid (combined with caffeine) on an empty (fasted) stomach and after a standard breakfast. The absorption of ibuprofen as the lysinate was only faster when taken on an empty stomach; after a standard breakfast, the time to peak plasma levels with ibuprofen acid (with caffeine) was actually shorter than for ibuprofen lysinate. Since analgesics are usually not taken on an empty stomach, this reduces the alleged advantages of ibuprofen lysinate.