Physiological Disposition of Fenoprofen in Man I: Pharmacokinetic Comparison of Calcium and Sodium Salts Administered Orally

Because orally administered dl-2-(3-phenoxyphenyl)-propionic acid, fenoprofen, may be useful for maintenance anti-inflammatory/analgesic therapy in man, evaluations were begun of certain pharmacokinetic parameters related to the absorption and disposition of this compound. This study compares these parameters for two salts of fenoprofen. A two-compartment open model was used to analyze plasma concentration data; the model accurately described the plasma levels following oral administration of sodium and calcium fenoprofen. A one-compartment model also provided reasonably accurate descriptions and was used to simulate plasma concentrations in multiple-dose situations from single-dose data. Under the conditions of the study, fenoprofen, administered orally as the sodium or calcium salt, was readily absorbed from the GI tract; however, absorption after the calcium salt was delayed slightly compared to the sodium salt. The bioavailability, distribution, and elimination of fenoprofen appeared to be independent of the salt form of the drug.