title: Variability in absorption lag time of pyridoxal phosphate under fasting and pre- and post-meal conditions.
abstract: Inter-individual variations in the absorption lag time of pyridoxal phosphate were determined after administration of an enteric-coated tablet (EC) or a plain capsule (PC) to 113 healthy volunteers under fasting, pre-meal, and post-meal conditions. The absorption lag time of pyridoxal phosphate was assessed from the urinary excretion of 4-pyridoxic acid after administration of EC and PC. Significantly larger lag times after administration of both formulations were observed under post-meal conditions than under pre-meal conditions (0.477 +/- 0.315 h versus 0.081 +/- 0.086 h for PC and 1.995 +/- 1.345 h versus 1.064 +/- 1.327 h for EC), indicating that the mean gastric emptying rates of both a solution and a tablet were delayed after food intake. The lag time for PC showed little inter-individual variation with (0-1.2 h) or without food (0-0.25 h), whereas that for EC showed markedly large inter-individual variation, from 0.25 to 2.63 h (median, 1.5 h) in the fasting condition, from 0.25 to > 5.5 h (median 0.25 h) under pre-meal conditions, and from 0.25 to > 5.5 h (median 1.25 h) under post-meal conditions. The effect of food on the gastric emptying rate of a solution appears to be almost uniform, whereas that for a tablet is so unpredictable that a reliable absorption rate for an enteric-coated tablet cannot be expected, particularly under pre- and post-meal conditions.
authors.affiliation: Department of Biopharmaceutics, Meiji College of Pharmacy, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Ogata
authors.forename: N
authors.initials: N
authors.lastname: Nagai
authors.forename: K
authors.initials: K
authors.lastname: Sugito
authors.forename: H
authors.initials: H
authors.lastname: Shimamura
mesh_terms: D000042:Absorption; D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D016503:Drug Delivery Systems; D004435:Eating / Q000502:physiology*; D005215:Fasting / Q000378:metabolism*; D005260:Female; D005746:Gastric Emptying / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011732:Pyridoxal Phosphate / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011735:Pyridoxic Acid / Q000652:urine*; D013608:Tablets, Enteric-Coated
chemical_list: D002214:Capsules; D013608:Tablets, Enteric-Coated; D011735:Pyridoxic Acid; D011732:Pyridoxal Phosphate