Synthesis of hydrocortisone containing dietary fiber almond gum-based hydrogels as sustained drug delivery carriers for use in colon inflammation

Keeping in view the advantages of the dietary fiber almond gum in food and health care, herein this work, modification of the gum has been carried out to prepare the hydrogels for use as drug delivery systems (DDS). The almond gum-polyacrylic acid hydrogels containing hydrocortisone drug were synthesized to improve the therapeutic potential of the drug to treat colon inflammation. The polyacrylic acid was grafted onto almond gum in the presence of a crosslinker to form the hydrogels. These co-polymers were characterized by FTIR, XRD, ¹³C NMR, and microscopic analysis. The in vitro drug release and various properties such as thrombogenecity, haemolytic potential, mucoadhesion test, antioxidant activity, and gel strength of hydrogels and bigels were measured. The incorporation of the polyacrylic acid into the hydrogel network was observed due to the presence of an intense peak at 1705.00 cm⁻¹ in FTIR spectra and a peak at 178.44 (C=O) of poly(AAc) in 13C NMR along with the broad XRD due to amorphous nature of hydrogels. Further, during microscopic analysis, it has been found that as the content of the organogel was increased in the biphasic bigel matrix, the dimensions of the droplets (number and size) were enlarged. The results of properties indicated that bigel formation has enhanced the thrombogenecity, mucoadhesion and antioxidant activity of the hydrogel formulations. However, the addition of organogel in the hydrogels has reduced the gel strength. The gel strength of hydrogel was found higher (5.46 ± 0.09N) than bigel (2.32 ± 0.28 N). The values of haemolytic index of the hydrogel and bigel matrix were less than 2% indicating the biocompatible nature of the material. The release of hydrocortisone from DDS occurred in a slow and sustained manner with non-Fickian diffusion in colonic pH 7.4.