Study On Release Behavior Of Lecithin/Pectin Beads And Rheological Properties Of Gel

Pectin gel formation ability,good stability,safety and non-toxic,good biocompatibility,rich in origin and easy to colon colon bacteria produce enzymatic degradation,is a good application prospect of colon positioning drug delivery materials.In addition,the simulated release behavior in vitro is an important method and means to study the drug delivery to the colon,and predicts the drug release in vivo.In this paper,different kinds of lecithin-containing pectin gel beads were prepared and their swelling and drug release behavior and release of zinc ions were studied in Me Ilvaine(M),Sorensen(S)and Tris(T)Gel system for rheological studies,in order to supplement and improve the in vitro simulated release method.First of all,the swelling and release behavior of zinc gel balls in three kinds of buffer solution shows that the swelling tendency is the same in the three kinds of buffer solution,but the shapes of zinc gel balls are completely different.The cumulative release rate of 6h is M>S>T,Zn gel balls only interact with M and S to form ZnHPO4 and Zn3(PO4)2 ·242O,and have different effects on the release behavior of zinc gel balls.The former promotes the drug release,and the latter on the contrary.The release behavior of zinc ions in buffer solution was studied.It was found that zinc gel contains a large amount of free zinc ions,and the zinc ion content in zinc gel ball affects the stability of gel balls.The zinc gel balls in M are unstable,While S is the opposite.Add lecithin,reducing the swelling of the gel ball,slowing drug release.Secondly,the swelling and release behavior of calcium gel balls in three buffer solutions shows that the swelling degree of three calcium buffers is completely different from that of zinc gel.However,the interaction with S forms the same substance,CaHPO4 ·242O,which promotes drug release.After the addition of lecithin,gel swelling of the ball increases,the release of the drug basically no effect.Finally,the rheological properties of Ca-Zn pectin gel system were studied respectively.The steady-state rheological properties of the Ca-Zn pectin gel system showed that the two systems both had pseudoplastic fluid properties and had shear thinning effect.Under the corresponding conditions,the shear stress apparent viscosity is greater than the zinc system,may be due to both the ionic radius and hydration.Oscillatory rheological properties show that the zinc gel is significantly affected by the zinc ion content,only when the zinc chloride concentration is 2 mol/L,the gel exhibits elastic solid properties.The calcium gel system has significant dependence on the frequency,the low-frequency system shows solid elastic properties,while the high-frequency area is the fluid properties.The gel properties of calcium gel are superior to those of zinc gel.On the contrary,the effect of lecithin on the elastic properties of the two systems increases the elastic modulus of the zinc system and decreases the calcium system.