Research On Non-Injectable Delivery Systems For Insulin Loaded In Mesoporous Materials

This paper studied non-injection drug delivery systems of insulin which used mesoporous materials as drug-carriers. First, the influence of types, pore sizes and surface charges of mesoporous materials and the pH values of release mediums on the release profile of insulin was studied. MCM-41(2.9nm), SBA-15(7.7nm) were refluxed in anhydrous toluene with 3-aminopropyltrimethoxysilane to yield 3-aminopropyl-functionalized MCM-41 (AP-MCM-41) and 3-aminopropyl-functionalized SBA-15 (AP-SBA-15), respectively. By using mesoporous materials with different surface functional groups or different pore sizes to load insulin, we investigated the release behaviors of insulin in different release mediums. After modifying mesoporous materials with 3-aminopropyltrimethoxysilane, the loading amount of insulin increased to three folds. The release rate of insulin from SBA-15(7.7nm) was lowest at different mesoporous materials. The release rate of insulin at pH5.0 was lower than at pH2.5 and pH7.5. Therefore, the desired sustained or delayed release of insulin could be achieved by selecting the appropriate mesoporous material.In this paper diabetic rats were used as animal models to study the effect of mesoporous materials supporting insulin transdermal and oral drug delivery. First, male SD rats were injected intraperitoneally with a dose of streptozotocin for establishing diabetic rat model. Each drug system was studied by three groups which were the blank control group, the insulin treatment group and the insulin loaded in mesoporous materials group. Blood glucose was measured at certain period of time. Mesoporous material and insulin were labeled with rhodamine B and fluorescein isothiocyanate, respectively. The distribution of FITC-insulin in skin was investigated by confocal microscopy through focusing. Experimental results showed that insulin-loaded in mesoporous materials had no hyperglycemic effect. FITC-insulin was gathered in hair follicles of the skin. Mesoporous materials which may assist insulin in passing through the skin needed further studies. Compare to non-loading insulin, insulin-loaded in mesoporous materials SBA-15(7.7 nm) had remarkable hypoglycemic effect.