Formulation and evaluation of periodontal in situ gel

Background: The present study was aimed to develop and optimize in situ gel for the treatment of periodontal disease. Materials and Methods: Temperature‑sensitive in situ gel containing 0.1% w/v Chlorhexidine hydrochloride was formulated by cold method using different polymers. Preliminary study was carried out to optimize different types and concentration of polymers such as Poloxamer 188, Poloxamer 407, Gellan gum, and Carbopol 934P. Central composite design was employed for optimization of the effect of independent variables such as Poloxamer 407 and Carbopol 934P on responses such as gelation temperature, spreadability, cumulative percentage release at 2 h, and time for 50% drug release (t50 %). Each formulations were evaluated for clarity, pH, gelation temperature, spreadability, drug content, in vitro drug release, t50 %, and cumulative percentage drug release at 2 h. Results: Results of evaluation parameters revealed that the drug release, gelation temperature was considerably decreased with increasing t50 % as the concentration of each polymer was increased. The desirability function was utilized to find out optimized formulation of the factorial design. Formulation F6 showed the highest overall desirability of 0.6283 and, therefore, this formulation was considered to be the optimized formulation. The % relative error was calculated, which showed that observed responses were in close agreement with the predicted values calculated from the generated regression equations. Conclusion: The clarity, pH, drug content of all formulations was found to be satisfactory. Further, all the formulations showed sustained drug release for a period of 6 h, which satisfied to treat periodontal disease.