Research Of Pectin-chitosan-lecithin Composite For Drug Delivery To The Colon

In this paper, pectin, chitosan and lecithin were combined to prepare oral colon-specific drug delivery system. The effects of chitosan and lecithin on pectin gel were studied. The properties of chitosan-lecithin-pectin gel spheres were compared with those of different cross-linking agents Ca2+and Zn2+, and the performance of two drug models, KTP and IDM. The effects of various parameters such as chitosan concentration, lecithin concentration, drug-gel ratio, crosslinker concentration, pH value of cross-linking agent and molecular weight of pectin were investigated. The effects of various parameters on gel diameter (L), encapsulation efficiency (EE) and drug release rate. At last, the best formula of the formula was determined by orthogonal experiment. The release rate of ketoprofen gel in chitosan - lecithin - pectin - zinc system in different colonic fluid was also discussed.The results showed that the average particle size of chitosan-lecithin-pectin gel spheres was 1.10-1.75mm, the average weight was 1.16-2.18mg, the drug loading range was 6.87-19.09%, the encapsulation efficiency was 57.59-94.99%. The results of drug release were as follows:(1) By comparing the drug release rate of KTP in calcium and zinc system, calcium system can not meet the effect of colonic drug delivery, zinc system has a certain effect of colonic drug delivery system .we found that the release rate of calcium system gel in the simulated small intestinal fluid (SIF) was over 90%, and the effect of zinc The drug release rate was 10% in SIF stage, 83.21% in SCF (simulated colon fluid)93.21% in total drug release.(2) Different drugs model contrast: the drug release rate load KTP has a better effect of colonic drug delivery than load IDM, load KTP drug release rate was 83.21% in SCF phase,load IDM in SCF phase drug release rate was 54.57%.(3) The release rate of pectin gel spheres modified by chitosan and lecithin was decreased from 18.31% to. 10% compared with chitosan modified pectin gel spheres(loaded ketoprofen) ; The release rate of pectin gel spheres (loaded ketoprofen) increased from 75.63% to 83.21% in the SCF stage compared with the lecithin alone. Therefore,chitosan, lecithin modified pectin gel beads can better achieve the effect of colon administration.(4) The release rate of Chitosan-lecithin-pectin-zinc system loading ketoprofen gel beads in different simulated colon fluid was different. The release rate of the gel from the small intestine after 6 hours to the pH 5.0 (plus pectinase) phosphate buffer was the fastest;to the pH 6.8 (plus pectinase) phosphate buffer; to pH7.4 (plus pectinase) in the phosphate buffer of the release The drug rate was the lowest.