Study On Straw Cellulose Sustained-release Material

Straw is a kind of natural resource existing in nature and often be burned aswaste, which not only wastes resource but also causes environmental pollution. Itwill have high research value by modifying it and preparing biomass productswith excellent property and could be used in chemical, medical, pesticides fieldand etc. Drug sustained-release means the drug is released steadily in particularlocation, with improving the efficacy of pharmaceutical within specific period oftime. There are several sustained-release formulations, such as homogeneoussystem, the combination of drug and polymer, polymerization of drug itself andother types. However these sustained-release materials have some disadvantages,for example uneven dispersion and bigger amount of release. Sustained-releasemicrospheres and fibers have solved the above problems. But the raw materialsare expensive and drug embedding rates are low, which caused difficult to beapplied in industry. While biomass straw cellulose is a kind of cheap resources,distributing widely, it could be used to prepare sustained-release materials withhigh embedding efficience, well-distribution and stable release rate.In this paper, two sustained-release materials were prepared, sustained-release fiber and sustained-release microspheres, when glucose was choosed asan analog-release drug. Straw was used to prepared acetate cellulose, which isthe carrier of sustained-release fibers. Glucose/sustained-release fiber wasprepared by electrospinning technique. Using ethyl cellulose as raw material,glucose/ethyl cellulose sustained-release microspheres was prepared by W/O/Wdouble emulsion. The article compared the drug release behaviors of twosustained-release materials with that of sustained-release membrane.Using straw, acetic anhydride as the materials, sulfuric acid as the catalyst,we prepared acetate cellulose with different substitution degree. When thesubstitution degree was2.4, the drugs embedding rate of sustained-release fiber was the highest. We prepared sustained-release fiber by electrospinningtechnique, and observed fiber morphology. When the mass fraction of celluloseacetate was15%, glucose embedding was5%, the drug embedding rate was thehighest,56.78%. According to the results of TG and XRD tests, we confirmedthat the sustained-release fiber was physical embedding. We researched theinfluence of temperature and pH on the drug release behavior of sustained-release fiber. Temperature had little impact on sustained-release fiber, thecumulative release increased with the increasing temperature. In the condition ofalkaline environment, burst release was the main release behavior. The resultsindicated that sustained-release fiber is suitable for the neutral and acidicenvironment.As a coating material, ethyl cellulose was used to prepare sustained-releasemicrospheres by W/O/W double emulsion. We researched the influence ofmethod and time on colostrum stability in colostrum preparation process.Colostrum could reach the maximum stability by5min’s ultrasoundemulsification. With the embedding rate as the evaluation index, according to L9(34) orthogonal experiments, the impacts of different factor on the drugembedding rate of the microspheres were investigated. The optimum conditionwas: the volume ratio of colostrum and external phase1:20,1500r/min stirringspeed,50℃. The highest drug-embedded rate of microspheres was62.86%.When the content of PVA was2%, the microspheres had smooth surface anddispersed evenly. We researched the impact of different glucose embedding onrelease behavior of microsphere. The results showed that using distilled water asa buffered medium of the drug release, when the drug embedding was5%, therelease behavior of microspheres was steady.Compare the performance of two sustained-release materials and sustained-release membrane, in drug embedding rate, both of the two sustained-releasematerials were higher than sustained-release membrane. In drug release behavior,sustained-release membrane had the burst release behavior, two sustained-releasematerials’ release rate was constantly and smoothly with a low burst release.Calculating similarity factor, sustained-release microsphere and fiber had theclose drug release behavior.