Modification of Biodegradable Drug-loaded Guar Gum Microcapsules by Poly(ethylene glycol)

By adding tripolyphosphate solution dropwise into the mixed solutions of a cationic guar gum and poly(ethylene glycol) (PEG), the PEG_modified guar gum microcapsules with good biodegradability were prepared, resulting from the ionotropic gelation of the polyelectrolytes. The morphology and particle size of the resulting guar gum microcapsules were investigated by electron transmission microphotography. By investigating the encapsulation and loading percentages of the unmodified and PEG_modified guar gum microcapsules for two model drugs with various concentrations, bovine serum albumin and aspirin, an enhanced encapsulation and loading capacity was found for the PEG_modified guar gum microcapsules in comparison with the unmodified guar gum microcapsule.