ABSTRACT
The aim of this study was to evaluate a semi-solid system containing metronidazole (MDZ) in presence of challenging conditions for drug release, as well its antimicrobial effect against Porphyromonas gingivalis biofilm. Biofilms grown in culture medium were exposed to a formulation containing MDZ or its vehicle. After 24, 48, and 72 h, biofilm viability were analyzed while MDZ was quantified in culture medium and buffer solution (control). MDZ formulation reduced bacterial viability when compared to control groups. The vehicle formulation also affected bacterial viability in relation to control at all periods. Culture medium impaired MDZ release compared to buffer solution at 24 h. The semi-solid system reported herein is able to release MDZ and maintain its levels at concentrations that control viability of P. gingivalis in 1- to 3-day-old biofilms.
Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Metronidazole/pharmacology , Porphyromonas gingivalis/drug effects , Anti-Bacterial Agents/administration & dosage , Drug Liberation , Metronidazole/administration & dosage , Time FactorsABSTRACT
The effect of a drug-delivery system containing antibacterial metronidazole (MDZ) prescribed for periodontitis on supragingival biofilm was evaluated, and possible interference by this biofilm in the drug release profile was investigated. Streptococcus mutans biofilms were grown and exposed to a controlled-release formulation of MDZ or the same formulation without MDZ (vehicle control). Untreated biofilms were used as a negative control (NC). Biofilms and culture medium (containing detached cells) were collected 24, 48, 72, and 96 h after first exposure to treatments. The biomass of the MDZ group was lower than that of the NC group at all times. Although MDZ yielded low drug-release rates in the presence of the biofilm, it was sufficient for reducing viability for 24 h and affecting bacterial metabolism for 48 h. These results suggest that MDZ appears to destabilize supragingival biofilm. This biofilm may interfere with MDZ release from the formulation.
