Chitosan (degree of deacetylation ≥ 75%, viscosity 20–300 cps), anhydrous calcium chloride granules (7.0 mm, 93.0%), ferric chloride hexahydrate (ACS reagent, 97%), montmorillonite, cupric chloride dihydrate (ACS reagent, ≥ 99.0%) were purchased from Sigma-Aldrich, Mumbai, India. Sodium alginate (pure) from Sisco laboratories, Chennai and carboxymethyl cellulose from Molychem, Mumbai, were obtained. Norfloxacin (C16H18FN3O3, Analytical standard, ≥98%) purchased from Merck, Mumbai. Distilled deionized water (Millipore system) was used in all experiments, and all other chemicals were directly utilized with no additional purification.