Gastroscopic and pharmacokinetic evaluation of a new pivmecillinam tablet

Three different pivmecillinam preparations, a conventional 200 mg tablet (P tablet) and two new formulations containing respectively pivmecillinam 200 mg and 400 mg plus Avicel (microcrystalline cellulose) as a disintegrator (PA tablet), were compared in vitro and in a gastroscopic study in 8 healthy volunteers. Disintegration of the PA tablet was significantly more rapid both in vitro and in the stomach. Following disintegration, the content of the PA tablet was spread over a larger area of the gastric mucosa (1088 mm2) than was observed with the P tablets (408 mm2). Three of the 8 volunteers taking the P tablet developed hyperaemia, interstitial bleeding or erosions of the mucosa of the stomach. No such reactions were seen with the PA tablets. Serum concentrations of mecillinam following ingestion of pivmecillinam tablets were determined in three groups of subjects; fasting volunteers, both supine and ambulant, and in ambulant subjects who took the preparation with a light meal. There was a tendency for the new PA tablets to produce a higher peak serum level as well as greater bioavailability of mecillinam. Administration of the PA tablets with a meal significantly increased the peak serum level and total bioavailability of the drug. On the basis of our observations we recommend adoption of the new PA tablet, because of its quick passage through the oesophagus and its more rapid and complete disintegration in the stomach.