The bioavailability of glyburide (glibenclamide) under fasting and feeding conditions: a comparative study

Abstract

This investigation was conducted to study the effect of food on the oral absorption and disposition of glyburide (glibenclamide). The study was carried out under US Food and Drug Administration guidelines on 18 healthy male volunteers, under fasting and feeding conditions using a single oral dose (5 mg tablet) of glyburide. Following drug administration, blood samples were collected over 24 h, and serum harvested from the blood was analysed using a sensitive and specific high-performance liquid chromatographic assay. The results of this investigation indicated that there was a statistically significant difference in the concentration—time profiles of the drug and the obtained pharmacokinetic parameters under fasting and feeding conditions. In fasting conditions, area under the serum concentration—time curve for 24 h and peak serum concentration were significantly higher than feeding conditions. Lag time between administration and appearance of the drug in serum was significantly reduced in fasting conditions compared with feeding situations. There was no significant difference in the time needed to reach peak concentration. These findings clearly indicate that the extent and rate of glyburide absorption is delayed when administered under feeding conditions. The study demonstrates the importance of administration of the drug on empty stomach to achieve a better pharmacokinetic profile.