title: Modulation of drug release kinetics of shellac-based matrix tablets by in-situ polymerization through annealing process.
abstract: A new oral-controlled release matrix tablet based on shellac polymer was designed and developed, using metronidazole (MZ) as a model drug. The shellac-based matrix tablets were prepared by wet granulation using different amounts of shellac and lactose. The effect of annealing temperature and pH of medium on drug release from matrix tablets was investigated. The increased amount of shellac and increased annealing temperature significantly affected the physical properties (i.e., tablet hardness and tablet disintegration) and MZ release from the matrix tablets. The in-situ polymerization played a major role on the changes in shellac properties during annealing process. Though the shellac did not dissolve in acid medium, the MZ release in 0.1N HCl was faster than in pH 7.3 buffer, resulting from a higher solubility of MZ in acid medium. The modulation of MZ release kinetics from shellac-based matrix tablets could be accomplished by varying the amount of shellac or annealing temperature. The release kinetics was shifted from relaxation-controlled release to diffusion-controlled release when the amount of shellac or the annealing temperature was increased.
authors: Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand.
authors: Sontaya
authors: S
authors: Limmatvapirat
authors: Chutima
authors: C
authors: Limmatvapirat
authors: Satit
authors: S
authors: Puttipipatkhachorn
authors: Jurairat
authors: J
authors: Nunthanid
authors: Manee
authors: M
authors: Luangtana-anan
authors: Pornsak
authors: P
authors: Sriamornsak
mesh_terms: D000465:Algorithms; D002152:Calorimetry, Differential Scanning; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods*; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D008795:Metronidazole / Q000008:administration & dosage / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis; D012116:Resins, Plant / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013607:Tablets; D013696:Temperature
chemical_list: D003692:Delayed-Action Preparations; D011108:Polymers; D012116:Resins, Plant; D013607:Tablets; D008795:Metronidazole; C003934:shellac