| This subject studied on the performance of loading and sustained release of oral colon targeted drug delivery system based on pectin modified by lecithin as the carrier carrying curcumin. Curcumin/lecithin/pectin composite microspheres were prepared by using curcumin(Cur) as the model drug, Cacl2 and ZnCl2 as cross-linkings agent, lecithin(PC) as the modifier to improve the hydrophobic performance of pectin. Then its performance of drug loading and drug release and the modification effect of lecithin on pectin system were investigated, and the performance of composite microspheres carrying curcumin was studied.The beads were prepared by dripping method. According to the single factor experiment, the prescription was optimized, regarding the mass ratio of curcumin to pectin, the mass ratio of lecithin to pectin, NaOH concentration, crosslinking agent concentration and pectin concentration as the process parameters. The morphology of the beads was studied by SEM and the curcumin content was determined by UV756pc Spectrophotometer.This subject investigated the modified pectin calcium system and pectin zinc system carrying curcumin, and studied their performance. Results are follows:In the pectin calcium system, the microspheres were homogeneous spherical with diameter of 1.30～1.67 mm, mass of 1.28～2.98 mg, drug loading of 12.07%～36.47%, encapsulation efficiency of 36.95%～77.76%. With the mass ratio of Cur:Pectin 16:20, the mass ratio of PC:Pectin 3:4, NaOH concentration 30 g/L, Cacl2 concentration 60 g/L and the pectin concentration 40 g/L, the slow release effect of pectin calcium was good, which the cumulative drug release rate in 8 h was 0.43%, and the cumulative drug release rate in simulated colon environment in 36 h was 19.64%.In the pectin zinc system, the microspheres were homogeneous spherical with diameter of 1.34～1.64 mm, mass of 1.74～3.45 mg, drug loading of 6.94%～30.13%, encapsulation efficiency of 34.69%～85.81%. With the mass ratio of Cur:Pectin 16:20, the mass ratio of PC:Pectin 5:4, NaOH concentration 30 g/L, Zncl2 concentration 70 g/L and pectin concentration 40 g/L, the slow release effect of pectin zinc was good, which the cumulative drug release rate in 8 h was 0.95%, and the cumulative drug release rate in simulated colon environment in 36 h was 68.72%.The stability experiment showed that the stability of curcumin in pectin/lecithin composite microsphere was better than curcumin and that in pectin microspheres in the condition of high temperature and light.By studying the performance of pectin gel system modified by lecithin carrying curcumin, it was discovered that the addition of lecithin had less effect on pectin calcium system carrying curcumin and had bigger improvement on pectin zinc system. After adding lecithin, in pectin zinc system, the drug loading was 18.03%, and the encapsulation efficiency was 85.81%, and the cumulative drug release rate in simulated small intestinal environment in 8 h was 0.95%, and the cumulative drug release rate in simulated colon environment in 36 h was 68.72%. |
