Objective: Periodontitis is an oral disease categorized by disturbance of periodontal tissue and creation of periodontal pockets. Thymol (TH) loaded microsponge in situ gelling system was formulated for local action in the periodontal
cavity for the management of periodontitis.
Method: Solvent evaporation technique was utilized for preparation of microsponges. A Fractional factorial design (FFD)
was used to screen the high risk variables impacting the characteristics of the (TH) microsponges and further optimized using Box-Behnken design. The optimized microsponges were then characterized by DSC, SEM, antimicrobial activity, in–
vitro release and then incorporated in the in situ gelling system. Ligature model was used to induce periodontitis in Sprague
Results: The microsponges showed good characteristics such as particle size, entrapment efficiency and mucoadhesiveness
45 µm, 92.99±0.2%, 96±0.26% respectively. SEM revealed the spherical morphology of the microsponges with sustained
release of TH for 10h and antimicrobial activity against S.mutans and C.albicans. Treatment with thymol loaded in situ gel
(THLMG) showed decrease in gingival inflammation and tooth mobility as well as in serum biochemical parameters like serum C-reactive proteins, leucocyte count, alkaline phosphatase and tartrate-resistant acid phosphatase when compared to
disease group. The histopathological study of the periodontium confirmed significant reduction of inflammation and alveolar bone destruction (p < 0.05) in rats.
Conclusion: Thus THLMG decreased infiltration of inflammatory cells and prevented osteoclatogenesis and osteoblast
apoptosis which further favored decrease in inflammation and alveolar bone loss in periodontitis. Thus THLMG could be a
better alternative to synthetic antimicrobials and antibiotics to treat periodontitis.