Elevation of gastric pH with ranitidine does not affect the release characteristics of sustained release ibuprofen...

The effect of elevating gastric pH on the release characteristics of a single unit sustained release (SR) ibuprofen tablet (MOTRIN-SR, Upjohn) was evaluated in 12 young, healthy men. Using a randomized crossover-type design, each subject received three treatments--ibuprofen SR 800 mg, ranitidine 300 mg followed by ibuprofen SR 800 mg, and conventional ibuprofen tablets (2 x 400 mg). Gastric pH, which was monitored radiotelemetrically, was maintained above pH 6 for at least 4 h after pretreatment with ranitidine. In absence of ranitidine, the pH remained mostly below pH 3. Serum levels of ibuprofen were measured for 24 h and urine was collected for 48 h after each treatment. Similarity of the serum levels after the two treatments with ibuprofen SR 800 mg indicated that the release of ibuprofen was unaffected by elevation in gastric pH. Comparison of profiles with the immediate release dosage form indicated that dose dumping did not occur in any subject.