Niridazole biodegradable inserts for local long-term treatment of periodontitis: possible new life for an orphan drug

Periodontal pocket inserts of niridazole (NZ) made with Resomer(R) (grades RG 503H and RG858, designated as RH and RG, respectively) were studied. Various formulation variables were evaluated to obtain a biodegradable delivery systems showing device degradation and drug depletion parallel to each other in vitro. Drug release from the prepared inserts was evaluated using a static dissolution setup (for 1 month). Incorporation of 3 parts of RG in 1 part of RH inserts caused a 50% decrease in the initial release rate. The RH-NZ inserts showed a spurt in release around the 10th day of the study, which coincided with the decrease in device weight, suggesting onset of device degradation. Pilot-scale clinical trials in 12 patients indicated improvements in clinical indices from the baseline values. The average pocket depth was reduced significantly (alpha = 0.05) from 6.34 +/- 1.86 mm at baseline to 5.94 +/- 0.28 mm after 28 days of treatment.