title: In vitro evaluation of micronized low-substituted hydroxypropylcellulose as an insoluble swellable matrix for sustained-release tablets.
abstract: Micronized low-substituted hydroxypropylcellulose (L-HPC) was evaluated in vitro as an insoluble swellable matrix carrier for sustained-release tablets, using procainamide hydrochloride, theophylline and indomethacin. The amount of water-soluble fraction and the degree of aggregation of L-HPC particles in water increased with decreases in the particle size. The mechanisms of formation of non-disintegrating matrix tablets by micronized L-HPC are discussed on the basis of fast hydration and gel formation due to loss of the fibrous structural integrity of the cellulose polymer. Simple power law analysis suggests that the drug release from directly compressed L-HPC matrices is affected not only by polymer swelling but also by the drug solubility and the amount of soluble fraction in the matrices.
authors.affiliation: Pharmaceutical Formulation Research Center, Daiichi Pharmaceutical Co., Ltd, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakagami
authors.forename: M
authors.initials: M
authors.lastname: Nada
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations / Q000737:chemistry*; D005069:Evaluation Studies as Topic; D007213:Indomethacin / Q000008:administration & dosage / Q000493:pharmacokinetics; D010316:Particle Size; D011208:Powders; D011342:Procainamide / Q000008:administration & dosage / Q000493:pharmacokinetics; D013806:Theophylline / Q000008:administration & dosage / Q000493:pharmacokinetics; D014961:X-Ray Diffraction
chemical_list: D003692:Delayed-Action Preparations; D011208:Powders; D002482:Cellulose; C008079:hydroxypropylcellulose; D013806:Theophylline; D011342:Procainamide; D007213:Indomethacin