The pharmacokinetics of glipizide were studied in 6 type 2 diabetics following single dose intravenous administration of Img, and oral administration of 2.5 mg as a solution, a 2.5 mg tablet and a 5 mg tablet. The serum concentrations of the drug were measured by high pressure liquid chromatography. Glipizide showed a rapid distribution fitting a 2-compartment model. The distribution volume at assumed distribution equilibrium was small (10L), and the elimination half-life was short (2 to 4 hours). Gastrointestinal bioavailability was 100%. In one patient, glipizide absorption from tablets was retarded due to delayed tablet disintegration and drug dissolution. Each dose of glipizide reduced blood glucose levels rapidly in all patients.