The Application Of Starch Microspheres In Medicament

Starch were prepared starch microspheres as medicament carrier because of theirnon-toxic, non-immunogenic, good biocompatibility and biodegradability, low price and goodstorage stability. Starch microspheres with certain medicament targeting tropism can reduce avariety of adverse medicament reactions and improve medicament selectivity, therebyimproving the therapeutic index.Starch microspheres were prepared from soluble starch by inverse microemulsion withepichlorohydrin as the cross-linking agent, Span-60as the emulsifying agent and the bean oilas the organic phase.The products were characterized by microscope. The morphologiescharacteristics, the influences of factors on adsorption ratio of starch microspheres, theoptimal conditions for preparation were studied. Then aspirin, gentamycin sulfate anddoxorubicin were adsorbed in the microspheres, and medicament loading rate, embedding rateand dissolution in-vitro were observed separately.The adsorption ratios of methylene blue were presented their rules by changing dosage ofsurfactants、starch solution, volume ratio between cyclohexane and bean oil, dosage ofcross-linking agent and stirring speed respectively. The results showed:(1) The adsorptionratio curve of starch microspheres was presented single-peak, and the peak value was98.24%with dosage of surfactants was0.1g.(2) The adsorption ratio curve of starch microsphereswas presented single-peak too. When starch solution was8%, the adsorption ratio was top.(3)The adsorption ratio curve of starch microspheres was presented two-peak. When the volumeratio between cyclohexane and bean oil was1∶4, the adsorption ratio came to a head.(4)The adsorption ratio curve of starch microspheres was also presented two-peak. When thedosage of cross-linking agent was4.0mL, the adsorption ratio was higher.(5) The adsorptionratio curve of starch microspheres changed quiet smoothly with the increased of stirringspeed.When stirring speed was920r/min, the adsorption ratio was maximum.Then the preparation conditions were optimized on the basis of the results above. Theresults showed that the optimal conditions for preparing starch microspheres V(cyclohexane)∶ V(bean oil), starch solution, dosage of Span-60, dosage of epichlorohydrin,and stirring speed were1∶4,9.2%,0.09g,4.2mL, and920r/min respectively. Themicrospheres were white, round, no adhesion, with uniform size and fine-mesh. The averagesize of microspheres was38.75μm, which was up to the mustard of oral, nasal and arterialembolization administration.Medicament-carring starch microspheres were prepared by the adsorption betweenmicrospheres and aspirin, gentamycin sulfate and doxorubicin. The average loading rate ofaspirin, gentamycin sulfate and doxorubicin were6.27%,298.32U/mg and2.74%,simultaneously the average embedding rate of aspirin, gentamycin sulfate and doxorubicinwere82.66%,49%and66%. It was obvious that these medicament-carring microsphereswere released from the microspheres in their sustained manners and the release profiles couldbe described with the first-order kinetics equation or the higuchi equation.The research showed that the starch microspheres had strong adsorption of medicament,and sustained release in-vitro to become a good medicament carrier.