Background: Periodontitis is a localized inflammatory disorder. If not treated timely, the
disease can result in loosening and subsequent loss of teeth. In situ hydrogel prepared with phase separation
technique has emerged as an attractive alternative for periodontal pocket injection.
Objective: Minocycline (MCL)-loaded in situ hydrogel was prepared composed of poly(lactide-coglycolide)
(PLGA) and N-methylpyrrolidone (NMP) to improve the topical treatment effect of periodontitis.
Method: A series of reasonable and applicable formulations were optimized by investigating their syringeability,
viscosity and in vitro drug release. The rheological profiles, antimicrobial activities and
pharmacodynamics were further studied to evaluate its effect on periodontitis treatment.
Results: The prepared MCL/PLGA hydrogel exhibited the characteristic of Newton fluid with acceptable
syringeability. Drug release could last for more than 48 hours with an acceptable “burst release”. It
also had obvious antimicrobial activities and pharmacodynamics efficiency similar to the commercial
Conclusion: MCL/PLGA in situ hydrogel may be a promising clinical formulation for periodontitis