title: Design of a 24-hour controlled porosity osmotic pump system containing PVP: formulation variables.
abstract: OBJECTIVE
  The purpose of this study was to design a 24-hour controlled porosity osmotic pump system that utilizes polyvinyl pyrrolidone (PVP) as an osmotic-suspending/release retarding agent of drugs.
  
  
  METHODS
  Osmotic tablet cores containing various ratios of ketoprofen and PVP were prepared by wet granulation and initially spray coated with similar solution of cellulose acetate. A formulation containing ketoprofen and PVP at a ratio of 1:7 was selected for further studies.
  
  
  RESULTS
  The final formulation containing PVP K-30 in the tablet core augmented the release of ketoprofen (poorly water-soluble) up to 90 % over 24 hours much higher than either PVP K-25 or PVP K-90 and retarded the release of pseudoephedrine HCl (highly water-soluble) up to 18 hours.
  
  
  CONCLUSIONS
  This study proposed the dual use of PVP in osmotic pump systems containing solids to modulate the release of either poorly or highly water-soluble drug.
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, Malaysia. rabsyakubu@yahoo.com
authors.forename: Rabiu
authors.initials: R
authors.lastname: Yakubu
authors.forename: Kok K
authors.initials: KK
authors.lastname: Peh
authors.forename: Yvonne T F
authors.initials: YT
authors.lastname: Tan
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003692:Delayed-Action Preparations; D005079:Excipients / Q000737:chemistry*; D007660:Ketoprofen / Q000737:chemistry; D008970:Molecular Weight; D009994:Osmolar Concentration; D009995:Osmosis; D010592:Pharmaceutic Aids / Q000737:chemistry*; D016062:Porosity; D011205:Povidone / Q000737:chemistry*; D054199:Pseudoephedrine / Q000737:chemistry; D012995:Solubility; D013607:Tablets; D013678:Technology, Pharmaceutical; D014783:Viscosity
chemical_list: D003692:Delayed-Action Preparations; D005079:Excipients; D010592:Pharmaceutic Aids; D013607:Tablets; D054199:Pseudoephedrine; D007660:Ketoprofen; D011205:Povidone