Polysaccharide-silicate composite hydrogels: Review on synthesis and drug delivery credentials

In recent years, silicate-polysaccharide composite systems have emerged as an appealing performing material for use as drug delivery carriers, owing to the fact that they exhibit a unique combination of advantageous chemical and physical characteristics that cannot be achieved by either phase alone. The composite materials improve material properties including mechanical, rheological, drug permeation, and controlled release characteristics compared to the biopolymers alone. It is expected that the coupling of a flexible, non-toxic, biodegradable polysaccharide with a hard inorganic porous material will allow for greater control of the drug loading capacity and drug release profiles, which will be advantageous in the preparation of enhanced drug delivery systems. Adding silicates to composite polysaccharide matrices can alter the swelling, erosion, and dissolving behavior of the polysaccharide matrices, and as a result, can be used to control drug release kinetics. Further, the type, quantity of silicates, and the manufacturing techniques can be adjusted to incorporate bioactives into the composite carriers and subsequently monitor release mechanism of the active ingredient. A clear understanding of silicate-polysaccharide is of utmost importance in designing new drug release carriers. In this paper, the hybrid material properties, silicate-polysaccharide interaction, green synthesis of polysaccharide composites using magnesium aluminium silicate, montmorillonite, and calcium silicate, as well as drug release mechanisms have been critically reviewed.