PEGylated chitosan xerogels for localized periodontal therapy: design, characterization, and drug release.

It is essential to adopt effective therapy strategies for periodontal diseases to achieve optimal results while avoiding adverse effects on the system. This study has developed various PEGylated chitosan-based biodegradable xerogels for localized release of doxycycline hyclate (DH) to treat periodontal infectious diseases. The xerogels were formulated using the solvent casting method, and the solvent (0.25 M HCl) was slowly evaporated at ambient conditions. Two different molecular weights were employed for chitosan and polyethylene glycol, and twelve combinations, including the placebos and controls, were prepared for the formulation of xerogels. Different physical and chemical characteristics of the prepared DH xerogels were studied, such as drying time and rate, thickness, moisture content, swelling index, organoleptic characteristics, scanning electron microscopy, FTIR spectrometry, differential scanning calorimetry, drug release and kinetics, and antibacterial activity. The results revealed that the drug transforms from a crystalline to an amorphous state, thus rapidly releasing the drug (> 60% in 30 min. in all xerogels), followed by a sustained release up to 10 h. The release kinetics results revealed that the drug followed the Korsmeyer-Peppas model. It is concluded that the formulated DH-loaded xerogels showed promising results for use in the periodontal pockets to treat various infectious diseases.