The pharmacokinetic properties of two new HB 420 glibenclamide preparations, Semi-Euglucon N 1.75 mg and Daonil N 1.75 mg, and of two older HB 419 glibenclamide preparations, Semi-Euglucon 2.5 mg and Daonil 2.5 mg, were compared in a randomized cross-over study in eight healthy volunteers. The HB 420 glibenclamide preparations induced peak plasma glibenclamide concentrations up to about 90 ng/ml at 1.3 to 1.4 hours after ingestion. Administration of the HB 419 preparations induced significantly lower peak plasma glibenclamide concentrations at 1.8 to 2.3 hours after ingestion. Glibenclamide was absorbed and eliminated more rapidly after administration of both HB 420 preparations than after administration of the HB 419 preparations. The mean elimination half-life of glibenclamide was 1.3 +/- 0.1 hours in the case of both HB 420 preparations and 2.0 to 2.5 +/- 0.2 hours in the case of HB 419 preparations. Although the HB 420 preparations contained lower doses of glibenclamide than the HB 419 preparations, the AUC values after administration of the former were similar to the AUC value obtained after administration of one of the HB 419 preparations, indicating improved absorption of glibenclamide from the newly developed preparations. However, the other HB 419 preparation was associated with the greatest AUC value of all, suggesting that glibenclamide was absorbed from this preparation almost as completely as from the HB 420 preparations.