Functionalized pristine barley grain (Hordeum vulgare L.)-based superabsorbent as methylene blue loading and delivery device for the potential treatment of methemoglobinemia

The design and development of a novel approach for the administration of a drug to the targeted area within the therapeutic dosage have been an ongoing progression for the last few decades. Developing biopolymer-based hydrogels as site-specific drug delivery devices is one such strategy gaining lots of attention. Herein, the present study reports the synthesis of novel, pH-responsive hydrogel using whole barley grain ( Hordeum vulgare L. ) and a biocompatible monomer, 2-acrylamido-2-methylpropanesulfonic acid through copolymerization method. The synthesized polymeric material has been characterized using various characterization methods and detailed swelling studies. After exploring the pH-responsive behavior and appreciable swelling at pH 7.4 (3925%) and pH 4.0 (3033%), suitable for blood-related ailments and anticancer studies, respectively. The synthesized superabsorbent has been explored as a drug delivery device using methylene blue (MB) as a drug against methemoglobinemia. MB dosage has been regulated within the therapeutic dosage (1–2 mg/kg) using synthesized material loaded at varied initial MB concentrations (50–500 ppm). The release mechanism has been determined using various kinetic models: zero-order, first-order, Higuchi, Korsmeyer–Peppas, and Hixson–Crowell. It was found that the release mechanism followed the Korsmeyer–Peppas model with ‘ n ’ values of 0.78 (500 ppm), 0.84 (300 ppm), 0.77 (100 ppm), 0.34 (50 ppm) at pH 7.4 and 0.69 (500 ppm), 0.86 (300 ppm), 0.73 (100 ppm) and 0.31 (50 ppm) at pH 4.0, respectively, at 37 °C in 7 h, which significantly depicted non-Fickian diffusion with controlled release of MB. Graphical abstract