Colon drug delivery systems are widely used to deliver active substances and provide better therapeutic effects to the site of disease in the colon, i.e., treatment for intestinal fibrosis. In this study, we aimed to formulate tetrandrine into calcium-alginate beads coated by Hydroxypropylmethyl Cellulose Phthalate (HPMCP), Cellulose Acetate Phthalate (CAP), Eudragit L100-55 or Eudragit L100 as colon targeted dosage. Tetrandrine, a compound which exhibits antifibrosis effect, was used as a drug model. Calcium alginate-tetrandrine beads were prepared in three formulae with various concentrations of calcium chloride as a crosslinking agent (2%, 3%, and 4%). All formulae were characterized for its morphology, particle size, moisture content, process efficiency, entrapment efficiency, thermal character, crystallinity, and swelling. The obtained beads possessed almost spherical and particle size distribution of 742.753 780.683μm. Formula 2, with a ratio of sodium alginate and CaCl2 2:3, showed the best entrapment efficiency of 82.46 ± 2.73%. Formula 2 was then coated with HPMCP HP-55, CAP, Eudragit L100-55 or Eudragit L100 and measured for its drug release profile in-vitro. The results showed that tetrandrine was better released in colon condition from the beads which were coated with 10% CAP (67.68%). This result also confirmed with the in-vivo test. Beads which were coated by CAP 10% could be found in the rat intestine.
Key words: Beads, tetrandrine, calcium alginate, ionic gelation, colon-targeted
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