title: The influence of Surelease and sodium alginate on the in-vitro release of tamsulosin hydrochloride in pellet dosage form.
abstract: The objective of this study was to prepare controlled-release pellets containing 0.2 mg tamsulosin hydrochloride using a pelletizer-equipped piston extruder and double-arm counter-rotating rollers with Surelease and sodium alginate. The release of tamsulosin HCl from pellets coated with the commercial aqueous ethylcellulose dispersion (Surelease) was investigated at different coating loads. In addition, the effect of sodium alginate on drug release was investigated by varying the ratio of sodium alginate to microcrystalline cellulose (MCC). Dissolution studies were first performed in 500 mL simulated gastric fluid (pH 1.2) containing 0.003% (w/w) polysorbate 80 and then in simulated intestinal fluids (pH 7.2). The morphology of pellet surfaces and cross sections were examined by scanning electron microscopy (SEM). Apparently, the spherical pellets were prepared using a pelletizer-equipped piston extruder and double-arm counter-rotating rollers. The release profiles of tamsulosin HCl from Surelease-coated pellets were significantly affected by changing the content of Surelease, the pH of the dissolution medium and the ratio of sodium alginate to MCC. The drug release rates not only decreased with increase in the coating load, but also increased when the pH of the dissolution medium was increased from 1.2 to 7.2 regardless of the sodium alginate-to-MCC ratio. Moreover, the drug release rate at pH 7.2 was gradually increased by increasing the ratio of sodium alginate to MCC. SEM showed smooth surfaces of Surelease-coated pellets. These results suggest that Surelease and sodium alginate would be useful excipients in the preparation of controlled-release pellets with the desired release profiles.
authors.affiliation: National Research Lab. of Pharmaceutical Technology, College of Pharmacy, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejeon 305-764, Korea.
authors.forename: Min-Soo
authors.initials: MS
authors.lastname: Kim
authors.forename: Seoung Wook
authors.initials: SW
authors.lastname: Jun
authors.forename: Sibeum
authors.initials: S
authors.lastname: Lee
authors.forename: Tae Wan
authors.initials: TW
authors.lastname: Lee
authors.forename: Jeong-Sook
authors.initials: JS
authors.lastname: Park
authors.forename: Sung-Joo
authors.initials: SJ
authors.lastname: Hwang
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D003692:Delayed-Action Preparations; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012995:Solubility; D013449:Sulfonamides / Q000737:chemistry*; D013499:Surface Properties; D000077409:Tamsulosin
chemical_list: D000464:Alginates; D003692:Delayed-Action Preparations; D006603:Hexuronic Acids; D013449:Sulfonamides; C013517:ethyl cellulose; D020723:Glucuronic Acid; D002482:Cellulose; D000077409:Tamsulosin; C109691:microcrystalline cellulose