Development and validation of an HPLC method for the simultaneous monitoring of bromazepam and omeprazole

Bromazepam and omeprazole are frequently administered to hospitalized patients to decrease anxiety and prevent stress ulcers, respectively. In patients under enteral nutrition, these drugs are administered via a nasogastric feeding tube. However, this mode of administration renders their bioavailability highly variable, and calls for their therapeutic monitoring. Given the absence of published data on the compared bioavailability of the two drugs given orally or via a nasogastric feeding tube, we have developed a high performance liquid chromatography method with UV detection (HPLC-UV) suitable for their simultaneous monitoring in human plasma. The method involves solid phase extraction of 2 mL plasma samples. Linearity was demonstrated in a concentration range of 5-100 ng/mL and 20-2000 ng/mL for bromazepam and omeprazole, respectively. The lower limit of quantification was 5 ng/mL and 20 mg/mL for bromazepam and omeprazole, respectively. The method proved its worth in the simultaneous monitoring of bromazepam and omeprazole administered to healthy volunteers.