For mild to moderate pain, an initial dose of 1000 mg followed by 500 mg every 12 hours is recommended for most patients. Following the initial dose, some patients may require 500 mg every 8 hours. A lower dosage may be appropriate depending on such factors as pain severity, patient response, weight, or advanced age; for example, 500 mg initially, followed by 250 mg every 8-12 hours. For osteoarthritis and rheumatoid arthritis, the suggested dosage range is 500 mg to 1000 mg daily in two divided doses. The dosage of DOLOBID may be increased or decreased according to patient response. Maintenance doses higher than 1500 mg a day are not recommended.

To a solution of human serum albumin (Sigma, 40 mg/mL in 50 mM phosphate buffered saline, pH 7.4), Diflunisal were added to a final concentration of 20 mkg/mL in 1 mL total volume. The mixtures were allowed to equilibrate for 1 h at room temperature and were then centrifuged at 86 000 x g for 18 h. The resulting gradient was fractionated into 5 x 200 mkL samples and extracted with acetonitrile in preparation for analysis by reverse-phase high-performance liquid chromatography. A mobile phase of 55:45 CH3CN/0.1% trifluoroacetic acid at a flow rate of 1 mL/min with a Luna C18 (100 x 4.6 mm) column and ultraviolet detection at 210 nm were used for compound detection. To calculate the fraction of free Diflunisal , the area of the chromatographic compound peak for the upper protein-free fraction was divided by the total peak area for the entire gradient.