Effects of pH regulators used as additives on the bioavailability of ibuprofen from hard gelatin capsules.

In our previous study the reasons for fast absorption of ibuprofen from sodium bicarbonate based hard gelatin capsules stayed unclear. These were not investigated using pH regulators (aluminium hydroxide, calcium carbonate, tartaric acid) with different chemical and physical properties. Ibuprofen absorption was much slower with aluminium hydroxide capsules (MRT 5.