title: Psyllium: a promising polymer for sustained release formulations in combination with HPMC polymers.
abstract: Psyllium has a mucilaginous property that makes it a good candidate to be utilized as an excipient in the preparation of controlled release systems. Various formulations were prepared using theophylline as a model drug and investigated with a view to achieve an ideal slow drug release profile. The addition of hydroxypropyl methylcellulose (HPMC) to psyllium significantly reduced the burst release; however, the percentage of drug release within a 12 h period was too slow and thereby inadequate. This was overcome by the addition of lactose as a hydrophilic filler that enabled a slow release with roughly 80% drug release in 12 h. The inclusion of HPMC within psyllium formulations changed the drug release kinetics from Fickian diffusion to anomalous transport. Granulated formulations demonstrated slower drug release than ungranulated or physical mixture and caused a change in the dissolution kinetics from Fickian diffusion to anomalous transport. Milled granules showed more efficient controlled drug release with no burst release. Milling of the granules also changed the drug release kinetics to anomalous transport. Although psyllium was proved to be a promising polymer to control the drug release, a combination of psyllium-HPMC and formulation processes should be considered in an attempt to achieve a zero-order release.
authors.affiliation: Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent , Kent , UK .
authors.forename: Waseem
authors.initials: W
authors.lastname: Kaialy
authors.forename: Parastou
authors.initials: P
authors.lastname: Emami
authors.forename: Kofi
authors.initials: K
authors.lastname: Asare-Addo
authors.forename: Saeed
authors.initials: S
authors.lastname: Shojaee
authors.forename: Ali
authors.initials: A
authors.lastname: Nokhodchi
mesh_terms: D001993:Bronchodilator Agents / Q000008:administration & dosage*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D011620:Psyllium / Q000737:chemistry*; D012995:Solubility; D013806:Theophylline / Q000008:administration & dosage*
chemical_list: D001993:Bronchodilator Agents; D003692:Delayed-Action Preparations; D065347:Hypromellose Derivatives; D011620:Psyllium; D008747:Methylcellulose; D013806:Theophylline