title: The preparation and drug-release behaviour of CTA/EC and PMS/EC composite microcapsules.
abstract: A cellulose triacetate (CTA) and three different molecular weights of poly(alpha-methyl styrene) (PMS) were used as co-wall materials to prepare composite microcapsules with ethylcellulose (EC). A non-solvent-addition phase-separation method was used. The core material was theophylline (TH) and the solvent-non-solvent pair was dichloromethane-n-hexane, and the drug-release rates of the microcapsules prepared from these two types of co-wall materials were compared. The effects of their phase-separation range on the properties of the microcapsules, such as particle size, release rate and the morphology of the microcapsules are also discussed. The release rate of microcapsules was also affected by the compatibility of the co-wall materials and the EC. The dissolution studies indicated that the drug-release time of CTA/EC and PMS/EC composite microcapsules was sustained to 10 and 3.5 times, respectively, in comparison with that for pure EC microcapsules.
authors.affiliation: Department of Chemical Engineering, National Central University, Chung-Li, Taiwan, Republic of China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Tsai
authors.forename: H T
authors.initials: HT
authors.lastname: Tien
authors.forename: H
authors.initials: H
authors.lastname: Chen
mesh_terms: D002214:Capsules / Q000737:chemistry / Q000302:isolation & purification; D002482:Cellulose / Q000031:analogs & derivatives; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D006801:Humans; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011137:Polystyrenes; D013806:Theophylline / Q000008:administration & dosage
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D011137:Polystyrenes; C013517:ethyl cellulose; D002482:Cellulose; C024671:cellulose triacetate; D013806:Theophylline