In-vitro and In-vivo Assessment of Novel Sustained-release Local Drug Delivery Systems for Periodontal Therapy

Background: Local drug delivery (LDD) systems have gained prominence in periodontal therapy due to their ability to achieve high drug concentrations at diseased sites while minimizing systemic adverse effects. Sustained-release formulations may further enhance therapeutic efficacy by prolonging drug bioavailability within periodontal pockets. Methods: This combined in-vitro–in-vivo experimental study evaluated a novel biodegradable sustained-release LDD system containing doxycycline hyclate. In-vitro analysis assessed drug release kinetics, antibacterial efficacy, and biocompatibility. In-vivo evaluation involved 60 patients with chronic periodontitis randomly allocated to three groups: Group I (scaling and root planing [SRP] + sustained-release doxycycline gel), Group II (SRP + conventional doxycycline gel), and Group III (SRP alone). Clinical parameters, including probing pocket depth (PPD), clinical attachment level (CAL), and gingival index (GI), were recorded at baseline, 1 month, and 3 months. Results: In-vitro testing demonstrated sustained drug release up to 14 days with a cumulative release of 92.6 ± 3.1%. Group I showed significantly greater reductions in PPD (3.1 ± 0.6 mm) and CAL gain (2.8 ± 0.5 mm) at 3 months compared with Group II and Group III (P < 0.001). Microbial reduction was highest in Group I (78.4%). Conclusion: The novel sustained-release LDD system demonstrated superior in-vitro release characteristics and enhanced clinical outcomes when used as an adjunct to SRP, supporting its potential role in advanced periodontal therapy.