Multi-Antibiotic Porous Systems for Tailored Drug Delivery in Dentistry: Formulation Strategy, Physicochemical...

Background/Objectives: Although triple antibiotic paste is effective in managing infected primary teeth, its incomplete removability from tooth structure remains a major limitation, prompting the search for alternative drug-delivery systems. The aim of this study was to obtain a multi-antibiotic porous composite system for tailored drug delivery, to develop a formulation strategy, and to characterize the physicochemical properties and drug release. Methods: The developed composites consisted of a porous composite matrix (PCM; chitosan/bioactive filler) and two or three antibiotics (ciprofloxacin [CIP], metronidazole [MET], clindamycin [CLI]). Three methods of incorporating antibiotics were used: applying an antibiotic solution to the stabilized PCM; introducing an antibiotic solution into the polymer matrix; and introducing an antibiotic into the polymer matrix as nanoparticles. The physicochemical properties of the composites, including microstructure, compressive strength, and swelling, were assessed. The antibiotic release profile was assessed for up to 168 h. Results: The most advantageous method for introducing MET and CLI, in terms of release profile, was applying them to the PCM surface, whereas ciprofloxacin exhibited stable release when incorporated directly into the polymer matrix and entrapped during the stabilization process. The composites with nanoparticles, including MET or CIP, did not release any active substances during the experimental period. Conclusions: The results demonstrate that the developed formulation strategy enables the production of composites that rapidly release substantial amounts of the active substances within a short time frame and maintain their concentration for an extended period, which may be beneficial for the treatment of bacterial infections.