Fabrication of a superabsorbent and pH-responsive, glucomannan-based hydrogel: crosslinking, characterization, toxicological evaluation, and sustained release of itopride

Abstract

Herein, we described the esterification of a hydrogelable polysaccharide extracted from the seeds of sweet basil using citric acid (CA). The formation of citric acid crosslinked sweet basil seeds hydrogel, i.e., crosslinked sweet basil hydrogel (CL-SBH), was ascertained through FTIR and solid-state CP/MAS 13 C NMR. SEM pictures revealed the existence of microscopic channels in CL-SBH. The CL-SBH was evaluated for its pH-and saline-dependent swelling properties. During swelling-deswelling studies, the CL-SBH displayed high swelling ability in DW and at pH 7.4, whereas negligible ability in ethanol, normal saline, and at pH 1.2 repetitively. Tablets based on CL-SBH and the drug (Itopride) were prepared and results revealed that the Itopride release was prolonged for 4 h at pH 6.8 and 7.4, whereas approximately 30% drug was released at pH 1.2. The drug release followed the first-order kinetics and Fickian diffusion. The acute oral and dermal toxicity studies of CL-SBH were conducted on Swiss albino rats and albino rabbits. The CL-SBH appeared non-toxic and non-irritating, as no change in hematological, biochemical, or histopathological parameters was observed in animal models. Hence, the CL-SBH could be a potential non-toxic material synthesized through a green cross-linking agent for prolonged, pHdependent, and site-specific drug delivery applications.