Preparation Of Chitosan-palygorskite-polyvinyl Alcohol Ternary Complex Film And Its Sustained Release Behaviors To Ivermectin

Based on the review of the drug-sustained releasing mechanism, the classification ofcommon carrier-materials and the composite drug-carrier materials, the dissertation includedfollowing contents.1.Palygorskite was treated with acid and heat. A new ternary complex film was preparedwith chitosan, polyvinyl alcohol and modified palygorskite as raw material, andglutaraldehyde as cross-linking agent. The structure of the composite membranes werecharacterized by the methods of FT-IR, SEM and XRD. The results show that the rawmaterials formed a stable complex by interaction. Compared with the chitosan-polyvinylalcohol film, the crystallinity of chitosan-palygorskite-polyvinyl alcohol film is declined, andthe surface area is significantly increased. We also discuss how the amount of palygorskite,the concentration of crosslinking agent and the film thickness affect on composite membranes.The experimental results show that the transparency declined with the increase of the amountof palygorskite and film thickness, the degree of swelling of the film is declined with theincrease of the concentration of crosslinking agent.2.Drug-containing ternary composite film was prepared with ivermectin as drug,chitosan-palygorskite-polyvinyl alcohol composite membrane as drug carrier. The researchemphasized on how the concentration of crosslinking agent, modified palygorskite, contentof the alcohol solution, the membrane thickness and stirring speed influenced the cumulativerelease rate. Studies show that the mass ratio of chitosan, polyvinyl alcohol and palygorskiteis1:1:0.5, the concentration of glutaraldehyde solution is1%,20mL casting solution isneeded, stirring speed is100r/min and the release medium contained20%alcohol. In thiscondition, the sustained-release time up to7h and the cumulative release rate up to98%. Therelease curve was fitted with the zero-order kinetics equation, first-order kineticsequation,Higuchi equation and Ritger-Peppas equation. As a result, under acidic conditions,sustained release behavior was more in line with first-order kinetics equation and it wascontrolled by diffusion, while in the neutral condition, sustained release behavior was more inline with Higuchi equation and it was controlled by diffusion and dissolution, mainlycontrolled by diffusion. It shows that ivermectin could be well slowly released from the film.