Cellulose Acetate Butyrate-Based In Situ Gel Comprising Doxycycline Hyclate and Metronidazole

Area of Science:

• Biomaterials Science
• Pharmaceutics
• Periodontology

Background:

• Periodontitis requires localized drug delivery for effective treatment.
• Biodegradable cellulose esters offer promising matrices for drug delivery systems.
• In situ gels enable high drug concentrations at the target site.

Purpose of the Study:

• To develop and characterize a novel cellulose acetate butyrate (CAB)-based in situ gel for periodontitis therapy.
• To incorporate and evaluate the release kinetics of metronidazole and doxycycline hyclate.
• To assess the antimicrobial efficacy and suitability of the developed formulation for periodontitis treatment.

Main Methods:

• Formulation of CAB-based in situ gels with varying polymer concentrations.
• Physicochemical characterization including gelation, mechanical properties, and morphology.
• In vitro drug release and permeation studies using porcine buccal membranes.
• Antimicrobial activity assessment against *S. aureus* and *P. gingivalis*.

Main Results:

• CAB concentration influenced gel properties, mechanical strength, and phase inversion rate.
• Sustained release of metronidazole and doxycycline hyclate over 7 days was achieved, with diffusion-controlled kinetics.
• Higher CAB concentrations resulted in porous structures and enhanced synergistic antibacterial activity.
• The formulation demonstrated superior antibacterial efficacy retention against *P. gingivalis*.

Conclusions:

• Cellulose acetate butyrate in situ gels provide a promising platform for sustained delivery of antibiotics for periodontitis.
• The developed formulation exhibits synergistic antibacterial effects and improved drug retention.
• This injectable system holds potential for advanced periodontitis therapy, particularly against *P. gingivalis*.