title: An Investigation on the Effect of Polyethylene Oxide Concentration and Particle Size in Modulating Theophylline Release from Tablet Matrices.
abstract: Polyethylene oxide has been researched extensively as an alternative polymer to hydroxypropyl methylcellulose (HPMC) in controlled drug delivery due to its desirable swelling properties and its availability in a number of different viscosity grades. Previous studies on HPMC have pointed out the importance of particle size on drug release, but as of yet, no studies have investigated the effect of particle size of polyethylene oxide (polyox) on drug release. The present study explored the relationship between polymer level and particle size to sustain the drug release. Tablets produced contained theophylline as their active ingredient and consisted of different polyethylene oxide particle size fractions (20-45, 45-90, 90-180 and 180-425 μm). It was shown that matrices containing smaller particle sizes of polyox produced harder tablets than when larger polyox particles were used. The release studies showed that matrices consisting of large polyox particles showed a faster release rate than matrices made from smaller particles. Molecular weight (MW) of the polymer was a key determining step in attaining sustained release, with the high MW of polyox resulting in a delayed release profile. The results showed that the effect of particle size on drug release was more detrimental when a low concentration of polyox was used. This indicates that care must be taken when low levels of polyox with different particle size fractions are used. More robust formulations could be obtained when the concentration of polyox is high. Differential scanning calorimetry (DSC) traces showed that particle size had no major effect on the thermal behaviour of polyox particles.
authors.affiliation: Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, ME4 4 TB, UK.
authors.forename: Saeed
authors.initials: S
authors.lastname: Shojaee
authors.affiliation: Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, ME4 4 TB, UK.
authors.forename: Parastou
authors.initials: P
authors.lastname: Emami
authors.affiliation: Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, ME4 4 TB, UK.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mahmood
authors.affiliation: Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, ME4 4 TB, UK.
authors.forename: Yemisi
authors.initials: Y
authors.lastname: Rowaiye
authors.affiliation: Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, ME4 4 TB, UK.
authors.forename: Alusine
authors.initials: A
authors.lastname: Dukulay
authors.affiliation: School of Pharmacy, Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, WV1 1LY, UK.
authors.forename: Waseem
authors.initials: W
authors.lastname: Kaialy
authors.affiliation: Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, ME4 4 TB, UK.
authors.forename: Iain
authors.initials: I
authors.lastname: Cumming
authors.affiliation: School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK. a.nokhodchi@sussex.ac.uk.|Drug Applied Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran. a.nokhodchi@sussex.ac.uk.
authors.forename: Ali
authors.initials: A
authors.lastname: Nokhodchi
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations / Q000737:chemistry*; D065546:Drug Liberation; D065347:Hypromellose Derivatives / Q000737:chemistry; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012995:Solubility; D013607:Tablets / Q000737:chemistry*; D013806:Theophylline / Q000737:chemistry*; D014783:Viscosity
chemical_list: D003692:Delayed-Action Preparations; D011108:Polymers; D013607:Tablets; D065347:Hypromellose Derivatives; D011092:Polyethylene Glycols; D013806:Theophylline
keywords: DSC traces; particle size; polyox; sustained release; theophylline