ABSTRACT
AIM:To study the effects of pH and ionic strength of release media on in vitro berberine hydrochloride(BH)released from carboxymethyl konjac glucomannan(CMKGM)pellets and to evaluate its characteristics.METHODS:The CMKGM pellets were prepared by ionotropic gelation with BH as the model drug.In vitro drug release,dynamic swelling and erosion percent of the pellets were studied respectively in release media with different pH(pH 1.0、pH 5.0、pH 6.8、 pH 7.4)or different ionic strength(pH 6.8 PBS with 2、4、6、8 g/L NaCl).The amount of BH released were confirmed in different equation to evaluate BH release mechanism of the pellets.RESULTS:With the increased of pH value or the decreased of ionic strength of the release media,the swelling ratio and erosion percent of the pellets increased,the BH release rate increased.The release of BH in HCl solution was film-controlled and exhibited zero order kinetic equation;the release of BH in PBS was non-Fickian release that coupled diffusion and erosion of the pellets matrix,exhibited Peppas equation.CONCLUSION:The swelling ratio and erosion percent of CMKGM pellets is related to pH and ionic strength of the release media,which influence BH released and release mechanism of the pellets.