THE EFFECT OF CO-ADMINISTERED DRUGS ON OXAPROZIN BINDING TO HUMAN SERUM-ALBUMIN

The binding of the non-steroidal anti-inflammatory drug oxaprozin to h uman serum albumin was studied by bioaffinity high-performance liquid chromatography using a column based on immobilized human serum albumin . Displacement studies using marker compounds for the major drug bindi ng sites showed that oxaprozin has a high affinity for the benzodiazep ine/indole site and binds to the warfarin site but with a significantl y lower affinity. Biochromatography and ultrafiltration techniques wer e used to screen for possible competition and allosteric interactions between oxaprozin and potential co-administered drugs including non-st eroidal anti-inflammatory drugs, antipyretics, hypoglycaemics, inhibit ors of angiotensin-converting enzyme, anaesthetics, metal ions and ant icancer agents. Competition occurred mainly with drugs bound at the be nzodiazepine site (benzodiazepines, various non-steroidal anti-inflamm atories).