All4Nutra
The objective of the present study was to investigate the effect of the pellet core materials isomalt, sugar, and microcrystalline cellulose on the in vitro drug release kinetics of coated sustained-release pellets as well as to evaluate the influence of different ratios of polymethacrylate copolymers exhibiting different permeability characteristics on the drug release rate. For characterization of the drug release process of pellets, the effect of osmolality was studied using glucose as an osmotically active agent in the dissolution medium. The pellet cores were layered with diclofenac sodium as model drug and coated with different ratios of Eudragit® RS30D and Eudragit® RL30D (ERS and ERL; 0:1 and 0.5:0.5 and 1:0 ratio) in a fluid bed apparatus. Physical characteristics such as mechanical strength, shape, and size proved that the inert cores were adequate for further processing. The in vitro dissolution tests were performed using a USP Apparatus I (basket method). The results demonstrated that, besides the ratio of the coating polymers (ERS/ERL), the release mechanism was also influenced by the type of starter core used. Sugar- and isomalt-type pellet cores demonstrated similar drug release profiles. Continue reading on Evaluation of Drug Release From Coated Pellets Based on Isomalt, Sugar,and Microcrystalline Cellulose Inert Cores
Received 9 October 2009; accepted 16 February 2010; published online 17 March 2010
Hydroxypropyl methylcellulose (HPMC; Pharmacoat 606, Shin-Etsu Chemical Ltd., Japan) was used as binder for the drug- layering process. Polymethacrylate copolymers (Eudragit® RL30D and Eudragit® RS30D, Degussa, Germany)—ERL and ERS—were used as film-forming polymers. Triethyl citrate (TEC; Fluka Chemie AG, Switzerland) served as plasticizer and micronized talc (Sigma-Aldrich Chemie GmbH, Germany) was used as an antiadhesion agent. Glucose anhydrate (MOLAR, Hungary) served as an osmotically active ingredient.
