Preparation And Evaluation Of Metronidazole-loaded Colon Specific Drug Delivery Systems

[Objective] To establish a preparation technique of Metronidazole- loaded colon specific drug delivery systems by centrifuge coating granulation method. [Method] First, Acetaminophen was preliminary selected as a model drug. Cornstarch, 50% sucrose syrup and aqueous polymethacrylate dispersion were used as core pellet excipient, adhesion reagent and coating solution, respectively. The coating pellets were characterized by size distribution, angle of repose, resistance to abrasion, moisture content and dissolution test in different pH solution. The preparation method of metronidazole-loaded colon specific drug delivery systems (CSDDS) were studied based on the previous work. The effect of low submitted hydroxypropylcellulose (L-HPC), Eudragit S 100 and ethyl cellulose on the dissolution of metronidazole -loaded CSDDS were evaluated in the simulated gastric fluid and simulated intestinal fluid. [Results] More than 88% of Acetaminophen pellets are in the range of 210-1660?m and the angle of repose is 20.06 o. Result of resistance to abrasion test of pellets is 1.11±0.79%, moisture content is 9.05%. The drug release of acetaminophen pellets were have a tendency of decrease while the coating weight, rotary speed of coating pan and coating air pressure increase, but coating speed reduced. The dissolution data of indicated that a higher amount of coating weight and EC in reduced metronidazole release.The metronidazole-loaded pellets showed a kind of dissolution phenomenon similar to pulsed and CSDDS, while formulated with 3% L-HPC as disintegrant and coated by 25% Eudragit S 100 and 15% DEP as Plasticizer. [Conclusion] Metronidazole-loaded CSDDS was successively established by centrifuge coating granulation method with low batch variation and reproducible.