title: Optimization and development of a core-in-cup tablet for modulated release of theophylline in simulated gastrointestinal fluids.
abstract: A triple-layer core-in-cup tablet that can release theophylline in simulated gastrointestinal (GI) fluids at three distinct rates has been developed. The first layer is an immediate-release layer; the second layer is a sustained-release layer; and the last layer is a boost layer, which was designed to coincide with a higher nocturnal dose of theophylline. The study consisted of two stages. The first stage optimized the sustained-release layer of the tablet to release theophylline over a period of 12 hr. Results from this stage indicated that 30% w/w acacia gum was the best polymer and concentration to use when compressed to a hardness of 50 N/m2. The second stage of the study involved the investigation of the final triple-layer core-in-cup tablet to release theophylline at three different rates in simulated GI fluids. The triple-layer modulated core-in-cup tablet successfully released drug in simulated fluids at an initial rate of 40 mg/min, followed by a rate of 0.4085 mg/min, in simulated gastric fluid TS, 0.1860 mg/min in simulated intestinal fluid TS, and finally by a boosted rate of 0.6952 mg/min.
authors.affiliation: Department of Pharmacy, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Gauteng, South Africa.
authors.forename: M P
authors.initials: MP
authors.lastname: Danckwerts
mesh_terms: D000704:Analysis of Variance; D001249:Asthma / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003692:Delayed-Action Preparations; D005750:Gastric Juice / Q000187:drug effects*; D006170:Gum Arabic / Q000494:pharmacology; D013607:Tablets; D013806:Theophylline / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D001993:Bronchodilator Agents; D003692:Delayed-Action Preparations; D013607:Tablets; D006170:Gum Arabic; D013806:Theophylline