Polyelectrolyte complexes based on the electrostatic interactions between the polymers mixed are of increasing importance, therefore, the aim of this study was to develop hydrogels composed of anionic tragacanth gum and cationic chitosan with or without the addition of anionic xanthan gum as carriers for buccal drug delivery. Besides the routine quality tests evaluating the hydrogel's applicability on the buccal mucosa, different methods directed toward the assessment of the interpolymer complexation process (e.g., turbidity or zeta potential analysis, scanning electron microscopy and Fourier-transform infrared spectroscopy) were employed. The addition of xanthan gum resulted in stronger complexation of chitosan that affected the hydrogel's characteristics. The formation of a more viscous PEC hydrogel with improved mucoadhesiveness and mechanical strength points out the potential of such polymer combination in the development of buccal drug dosage forms.
Keywords: buccal delivery; chitosan; hydrogel; polyelectrolyte complex; tragacanth gum; xanthan gum.