In situ mucoadhesive hydrogel based on methylcellulose/xyloglucan for periodontitis

Novel hydrogels of 5, 6, and 7% w/v of methylcellulose (5MC, 6MC, and 7MC) with 1.5% w/v of tamarind seed xyloglucan (TSX) were developed via an in situ gel forming process. The MC and MC/TSX solutions formed two gel types: a soft gel and a turbid hard gel respectively upon heating. These samples were characterized using a test-tube-tilting method (TTM), rheological, and turbidity measurements. The interactions and the mechanism of gelation were studied using ATR-FTIR. The release of metronidazole (MTZ) from the hydrogels was also investigated. Based on the TTM results, 6MC/TSX, 7MC, and 7MC/TSX were solution at room temperature but could form gel at body temperature. ATR-FTIR demonstrated stronger hydrophobic associations of MC in the turbid gel than in the soft gel which corresponded to the higher intensity of the C-O band of MC. The peak intensity was greater in the presence of TSX, reflecting the role of TSX to increase hydrophobicity and decrease gelation temperature of MC. SEM revealed a microporous morphology of 6MC/TSX, 7MC, and 7MC/TSX and the pore size of the soft gel was greater than that of the turbid gel. The high relative rheological synergism at 37 degrees C indicated a high mucoadhesive property of the MC/TSX hydrogels. MC and MC/TSX exhibited a suitable syringeability to ease of administration at 25 degrees C. MTZ exhibited a more sustained release from 7MC/TSX than from a commercial formulation. Therefore, 7MC/TSX hydrogel could be potentially used for the in situ delivery of MTZ for the treatment of periodontitis.