| With the progress of nanotechnology and understanding of the various barriers inhuman body, advantages of nano-drug delivery system, such as reduce the toxic ofdrugs themselves, achieve the effect of targeted drug delivery and sustained release,attracted more and more attention from people. Developing new nano drug deliverysystem will contribute to prevention and treatment of various diseases and reduce thetoxicity of certain drugs in the human metabolic process.In this paper, with the polysaccharide konjac glucomannan (KGM) degradedspecifically by colon enzyme β-glucomannan as the drug carrier, diclofenac sodium asthe model drug, the techniques of high-voltage electrostatic spray to prepare KGM anddrug loaded KGM miccrospheres were studied. Drug loaded quasi-nanoscale KGMparticles were successfully produced, and effects of cross-linkers and particle size ofmicrocapsule on the in vitro drug release characteristics were studied subsequently. Theobtained results were listed as below：(1) High-voltage electrostatic spray technology is an excellent technique forpreparing microcapsules under mild conditions, the diameter of microcapsule iscontrollable, and the diameter distribution is uniform. At the optimized preparationconditions, the distance between the positive and negative electrodes was1cm, thesolvent was ethanol and distilled water with the volume ratio of1:1(V/V), theconcentration of diclofenac sodium and KGM were1mg/mL and5mg/mL respectively,the voltage was-6.5kV, the drug loaded capsules with the particle size of1.474μm wasprepared.(2) There was no degradation and drug release in artifical gastric acid from drugloaded KGM capsules though the cosslinked KGM can still be degraded by β-mannanase.(3) Drug loaded KGM nanoscale capsules overcame the burst release effect, and ithad a better controlled release effect for drugs.(4) It is easy to adjust the drug release patterns of drug loaded KGM nanoscalecapsules only by applying various cross-linking agents.In summary, high-voltage electrostatic spray technology can be applied in thepreparation of quasi-nanometer drug loaded KGM capsules. An expected drug releasepatterns can be obtained with the application of corresponding crosslinking agent. Therefore, KGM is expected to become an excellent carrier material in preparation ofcolon targeted drug delivery with effect of controlled release. |
