The purposes of this investigation were to determine and to compare the oral absorption characteristics of micronized griseofulvin (500 mg) after its administration to humans in the form of a corn oil-in-water emulsion containing dispersed drug, an aqueous suspension, and two different commercial tablets (A and B). The four dosage forms were administered in a random crossover fashion to five fasting subjects, and drug absorption was assessed from urinary excretion data for the major metabolite of the antibiotic (6-desmethylgriseofulvin). The drug was most rapidly, uniformly, and completely absorbed from the corn oil-in-water emulsion. As compared to either the aqueous suspension, Tablet A, or Tablet B, three- to fourfold increases in the maximum body levels and a twofold enhancement in the bioavailability of the antibiotic were observed after administration of the emulsion dosage form. A mechanism based on the ability of the linoleic and oleic acids liberated during the digestion of corn oil to inhibit GI motility and stimulate gallbladder evacuation may explain the marked enhancing effect of emulsified corn oil on griseofulvin absorption in humans. This new lipid-in-water emulsion dosage form of micronized griseofulvin appears to offer several clinical advantages in the treatment of fungal infections.