The pharmacodynamics of lansoprazole administered via gastrostomy as intact, non-encapsulated granules.

Abstract

Because of its acid-labile nature, lansoprazole is usually administered as encapsulated enteric-coated granules. The gelatin capsule and acid-resistant coating of the granules have been considered essential for effective drug absorption and optimal bioavailability. Lansoprazole may attain effective plasma levels when given as non-encapsulated intact granules, but effects on intragastric acidity are unknown. To test the effectiveness of non-encapsulated. intact lansoprazole granules in suppressing intragastric acidity when administered through a gastrostomy. Eight men, each with an established gastrostomy, underwent baseline 24 h intragastric pH monitoring while off any acid-suppressing medication. Via the gastrostomy, they then received 7 days of once-daily dosing with 30 mg lansoprazole as intact granules in 3 fl. oz. of orange juice. Intragastric pH monitoring was repeated on day 7. Mean intragastric pH pre-dosing was 1.96+/-0.5 (s.d.). This increased to 4.7+/-0.6 on day 7 (P < 0.0001). Median intragastric pH rose from 1.5 to 5.2 (P < 0.0001). Before lansoprazole, the proportions of time when intragastric pH was above 3, 4 and 5 were 23.2, 13.5 and 7.5%, respectively. Corresponding values after 7 days of lansoprazole were 81.1, 70.2 and 52.3% (P < 0.0001 for each comparison). Lansoprazole can effectively suppress intragastric acidity when given through a gastrostomy as intact, non-encapsulated granules in orange juice.