UNSUCCESSFUL DELIVERY OF TETRANDRINE FROM COLON-TARGETED DOSAGE FORMS COMPRISING ALGINATE/HYDROXYPROPYL METHYLCELLULOSE AND ALGINATE–CHITOSAN BEADS

Objective: The objective of this study was to optimize the formulations of antifibrotic tetrandrine beads using alginate and various concentrations ofhydroxypropyl methylcellulose (HPMC) and chitosan.Methods: Beads were formulated with six (F1–F6) concentrations of polymer and were then characterized using scanning electron microscopy,differential scanning calorimetry, and X-ray diffraction; these beads were used for measurements of moisture contents, swelling, and in vitro drugrelease.Results: Beads with the highest concentrations of HPMC and chitosan produced the highest entrapment efficiencies of 49.83% and 50.71%,respectively. Moreover, drug release under stomach conditions (HCl pH 1.2 medium) was restricted to 75.01%, 61.01%, 51.86%, 74.84%, 66.00%,and 41.63% with increasing HPMC and chitosan concentrations (F1–F6, respectively).Conclusion: Beads of all formulations showed inadequate retention of tetrandrine under pH conditions of the upper gastrointestinal tract and wouldlikely be unsuccessful as colon-targeted dosage forms