title: Development and characterization of extended release Kollidon SR mini-matrices prepared by hot-melt extrusion.
abstract: Kollidon SR as a drug carrier and two model drugs with two different melting points, ibuprofen and theophylline, were studied by hot-melt extrusion. Powder mixtures containing Kollidon SR were extruded using a twin-screw extruder at temperatures 70 and 80 degrees C for ibuprofen and 80 and 90 degrees C for theophylline. The glass transition temperature (T(g)) and maximum torque were inversely related to ibuprofen concentrations, indicating its plasticizing effect. The results of differential scanning calorimetry (DSC) and X-ray diffraction analysis showed that ibuprofen remained in an amorphous or dissolved state in the extrudates containing drug up to 35%, whereas theophylline was dispersed in the polymer matrix. The increase in amounts of ibuprofen or theophylline in the hot-melt extrudates resulted in the increase in the drug release rates. Theophylline release rate in hot-melt extruded matrices decreased as the extrusion temperature increased. In contrast, a higher processing temperature caused the higher ibuprofen release. This was a clear indication of the plasticizing effect of ibuprofen on Kollidon SR and a result from water uptake. Theophylline release rate from hot-melt extrudates decreased with increasing triethyl citrate (TEC) level because of the formation of a denser matrix. By adding of Klucel LF as a water-soluble additive to the hot-melt extruded matrices, an increase in ibuprofen and theophylline release rates was obtained.
authors.affiliation: College of Pharmacy, Freie Universität Berlin, Berlin, Germany. isik.ozguney@ege.edu.tr
authors.forename: Işik
authors.initials: I
authors.lastname: Ozgüney
authors.forename: Duangratana
authors.initials: D
authors.lastname: Shuwisitkul
authors.forename: Roland
authors.initials: R
authors.lastname: Bodmeier
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000737:chemistry; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods*; D006358:Hot Temperature; D011205:Povidone / Q000008:administration & dosage / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011205:Povidone