title: Performance of a modified starch hydrophilic matrix for the sustained release of theophylline in healthy volunteers.
abstract: Two experimental formulations of theophylline with a hydrophilic starch matrix were evaluated for their sustained-release characteristics after single administration in healthy human volunteers. Theo-dur was chosen as a reference sustained-release formulation. In a first study, the extent of absorption was similar for a syrup, for Theo-dur, and for the experimental formulation of theophylline with 70% drum-dried corn starch as the sustained-release agent (DDCS-70). The maximal plasma concentration (Cmax) was significantly lower, and the time to reach Cmax as well as the time span during which the plasma concentration was at least 75% of the Cmax were significantly higher for Theo-dur than for the DDCS-70 formulation. A sustained-release profile, as for Theo-dur, was not reached for DDCS-70. In a second study the influence of the starch:drug ratio on the bioavailability was investigated. The decrease in starch content from 70 to 50% of the formulation did not improve the plasma concentration-time profile towards a sustained-release profile.
authors.affiliation: Laboratory of Pharmaceutical Technology, State University of Ghent, Belgium.
authors.forename: G M
authors.initials: GM
authors.lastname: Vandenbossche
authors.forename: R A
authors.initials: RA
authors.lastname: Lefebvre
authors.forename: G A
authors.initials: GA
authors.lastname: De Wilde
authors.forename: J P
authors.initials: JP
authors.lastname: Remon
mesh_terms: D000328:Adult; D001682:Biological Availability; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D002627:Chemistry, Physical; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005260:Female; D006801:Humans; D008297:Male; D013213:Starch / Q000493:pharmacokinetics*; D013806:Theophylline / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D013213:Starch; D013806:Theophylline