title: A squeeze-type osmotic tablet for controlled delivery of nifedipine.
abstract: Osmotic delivery systems are based on osmotic driving force. Nifedipine tablets, available under the trade names Procardia XL (Pfizer) and Adalat (Bayer), are commercialized drug-delivery systems of an elemental osmotic pump that the push-pull osmotic tablet operates successfully in delivering water-insoluble drugs. For the improvement of the release pattern and the solubility of the drug, we developed a squeeze-type osmotic tablet (SQT) for nifedipine as a model drug. The SQT was composed of one or more ring type of squeeze-push layer (squeeze-disc) and a centered drug core. Squeeze-discs were stacked up with different physicochemical properties with gradient such as viscosity, swelling ratio and water absorption ratio using the osmotic agents from a disc of bottom to top. The present work investigated the effect of different preparation factors, such as hydrophilic polymers, the molecular weight of polymers, coating process, orifice size and types of excipient on release performance of nifedipine. With the purpose of delivering water-insoluble nifedipine at an approximate zero-order rate and step-function rate for 24 h, SQT has been successfully prepared, and significantly improved in the release rate and patterns in comparison with the Adalat push-pull system in vitro release features.
authors.affiliation: BK-21 Polymer BIN Fusion Research Team, Chonbuk National University, 664-14 Dukjin, Jeonju 561-756, South Korea.
authors.forename: Jung Soo
authors.initials: JS
authors.lastname: Park
authors.forename: Jun Hyun
authors.initials: JH
authors.lastname: Shin
authors.forename: Dong Hun
authors.initials: DH
authors.lastname: Lee
authors.forename: Moon Suk
authors.initials: MS
authors.lastname: Kim
authors.forename: John M
authors.initials: JM
authors.lastname: Rhee
authors.forename: Hai Bang
authors.initials: HB
authors.lastname: Lee
authors.forename: Gilson
authors.initials: G
authors.lastname: Khang
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000493:pharmacokinetics*; D065347:Hypromellose Derivatives; D008567:Membranes, Artificial; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D008970:Molecular Weight; D009543:Nifedipine / Q000737:chemistry / Q000493:pharmacokinetics*; D009995:Osmosis; D009997:Osmotic Pressure; D011092:Polyethylene Glycols / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry; D011189:Potassium Chloride / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D013607:Tablets; D014215:Triacetin / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D008567:Membranes, Artificial; D013607:Tablets; C005062:acetylcellulose; D065347:Hypromellose Derivatives; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D011189:Potassium Chloride; D011142:Polyvinyl Alcohol; D002482:Cellulose; D008747:Methylcellulose; D009543:Nifedipine; C109691:microcrystalline cellulose; D014215:Triacetin