EDTA-mediated crosslinking of guar gum: a sustainable platform for transdermal curcumin delivery

Abstract

The crosslinking of carbohydrate polymers is advantageous for specific applications in food, textiles, biomedical fields, pharmaceuticals, etc. In the present study, guar galactomannan is crosslinked with ethylenediaminetetraacetic acid (EDTA), which is a green, competent, economic, and efficient crosslinker, under aqueous conditions at ambient temperature to incorporate all carbons of the reactants into the crosslinked product. Intriguingly, EDTA acted as an autocatalyst under mild acidic conditions, resulting in water as the side product. The reaction parameters were optimized by varying the concentration of EDTA (0.25, 0.5, 0.75, and 1 g), temperature (55 ± 1 °C, 120 ± 1 °C, 130 ± 1 °C, and 140 ± 1 °C) and time (3, 2, and 1 min) to synthesize porous and flexible EDTA-crosslinked guar films. The mechanism of crosslinking with EDTA is proposed for the first time. A detailed analysis of the films is achieved by NMR spectroscopy, SEM-EDX analysis, FTIR spectroscopy, XRD and TGA. Furthermore, transdermal delivery of the loaded curcumin within the best optimized crosslinked film is studied. Mechanistic study of the curcumin release profile via the Korsmeyer–Peppas model demonstrated a non-Fickian diffusion-controlled release mechanism (DCR) with a CPDR of 49.8% ± 0.01% in 720 min. The antibacterial, antifungal and antioxidant results indicate that the synthesized bio-compatible, crosslinked biomaterial has potential utility in controlled and sustained drug delivery apart from other biomedical applications such as TDDS and wound healing.