Scientists throughout the world are in search of novel modified biopolymer to fabricate smart drug delivery systems based on hydrogel formulations using several cross-linkers like glutaraldehyde, glyoxal, epichlorhydrin, adipic acid dihydrazide, carbodiimide, genipin, etc. Agents that are fused into the polymeric structure like isocyanates, glutaraldehyde, polyepoxides, etc., and are extremely toxic in nature. In addition, these are susceptible to percolate out into the body on biodegradation of polymeric structure. As an alternative to these toxic cross-linking agents, the periodate-Schiff base staining technique is widely being used for cross-linking in biology and biochemistry. The mechanism of this cross-linking technique is based on the reaction in-between the Schiff reagent and the aldehydes produced via the periodate oxidation. During the past few decades, several researchers have already been studied on the natural gums and also, developed their dialdehyde derivatives via the periodate oxidation technique. These periodate oxidized gums are being used to cross-link gelatin, other proteins and chitosan to develop various smart systems for drug delivery, tissue engineering, wound dressing, edible films, etc. The current review presents a comprehensive discussion of the available reported literature on the periodate oxidation of various gums and their use as natural cross-linker.

Objective: In this study, xanthan gum was oxidized by sodium periodate to form xanthan dialdehyde. This oxidized gum was used as crosslinking agent as an alternative to somewhat toxic glutaraldehyde, the basis of which is the reaction between the Schiff reagent and the aldehydes formed by periodate oxidation. Methods: Formation of aldehyde groups were confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Microparticles of metoprolol succinate were fabricated using crosslinking of a chitosan/gelatin mix system by dialdehyde Xanthan gum. The properties of the developed microparticles were investigated with swelling equilibrium studies, differential scanning calorimeter (DSC), in vitro drug release studies and scanning electron microscopy (SEM). Results: The in vitro drug release from these microparticles was affected by total polymer amount, oxidation reaction time and chitosan to gelatin ratio. The cumulative percent release of metoprolol succinate was observed within the range of 46 to 95% at 8 h from different formulations studied. The factors identified as significant to produce any impact on drug loading as well as drug release were both the polymer and inter actions of polymer and Xanthan gum dialdehyde. Conclusion: The release mechanism followed the super case II model kinetics.