Inulin Surfactants for Drug Delivery

In this work the preparation of inulin surfactant capsules and their behavior as a release system for vitamin E are shown. Inulin is a storage polysaccharide found in plants such as onion, garlic, artichoke, chicory, and agave. Inulin is interesting for biomedical applications because humans metabolize it only in the colon by enzymatic means. Synthesis of chicory inulin surfactants was optimized in order to match the HLB value required for vitamin E emulsification. This was carried out by adjusting the molar relationship between inulin (hydrophile) and stearyl chloride (lipophile) during the synthesis. Emulsions were prepared from inulin surfactants and the microcapsules formed were cross-linked with glutaraldehyde to improve their stability. The release of vitamin E was determined by means of UV absorbance at 290 nm in tests using fructozyme at pH 6.8. The results showed that a relationship 0.86 mol of stearyl chloride per fructose unit yielded a surfactant with HLB of 8.6, close enough to the required HLB of 8 for vitamin E. The molecular weight of the inulin-derived surfactant was 2,609 Da with a polydispersity of 2.1. Under emulsification as much as 78% of the added vitamin E was encapsulated within the micelles. Size of the micro spheres before cross-linking varied between 2 and 32 ìm. Release tests using fructozyme showed that approximately 11% of the total vitamin E encapsulated was released within a period of 5 h when the capsules were cross-linked with glutaraldehyde compared to 37% without cross-linking.