title: Oral bioavailability of slow-release theophylline from unencapsulated beads in preschool children with chronic asthma.
abstract: The relative bioavailability of two slow-release theophylline formulations using bead-filled capsules. Slo-bid and Theo-Dur Sprinkle, was examined in randomized crossover multiple-dose trials using collected saliva. Two groups of seven preschool-age asthmatic children received one of these and Slo-Phyllin Gyrocaps as a reference. Dose-normalized areas under the saliva concentration-time curves were significantly less than the reference for Theo-Dur Sprinkle (p = .02) but not for Slo-bid with the relative bioavailability determinations of 66 +/- 8% (mean +/- SEM) and 109 +/- 5% for Theo-Dur Sprinkle and Slo-bid, respectively. The less complete absorption of Theo-Dur Sprinkle during clinical use in preschool-age children is consistent with the malabsorptive effects of food previously reported for the former but not the latter formulation.
authors.affiliation: Pediatric Allergy and Pulmonary Division, College of Medicine, University of Iowa, Iowa City 52242.
authors.forename: L M
authors.initials: LM
authors.lastname: Vaughan
authors.forename: G
authors.initials: G
authors.lastname: Milavetz
authors.forename: M M
authors.initials: MM
authors.lastname: Weinberger
authors.forename: G D
authors.initials: GD
authors.lastname: Smith
authors.forename: J B
authors.initials: JB
authors.lastname: Harris
mesh_terms: D000284:Administration, Oral; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism; D001682:Biological Availability; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D002986:Clinical Trials as Topic; D003692:Delayed-Action Preparations; D006801:Humans; D007223:Infant; D011897:Random Allocation; D013806:Theophylline / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D003692:Delayed-Action Preparations; D013806:Theophylline