Microparticles containing propolis and metronidazole: in vitro characterization, release study and antimicrobial activity against periodontal pathogens.

Ethylcellulose microparticles containing metronidazole and propolis extractive solution were prepared and evaluated in vitro against periodontal pathogens. Scanning electron microscopy, particle size analysis, drug entrapment efficiency and drug release of microparticles were determined. The antimicrobial activity of microparticles was evaluated against microorganisms of periodontal importance (Enterococcus faecalis, Streptococcus pyogenes, Streptococcus mutans, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli). It was obtained particles with regular morphology, mean diameter of 1.23 µm, and entrapment efficiency for propolis and metronidazole were 91.41% and 22.23%, respectively. In vitro release studies of propolis and metronidazole from microparticles showed prolonged drug release and controlled by Fickian diffusion. Both propolis and metronidazole displayed activity against the tested strains. Moreover, the results showed that the strains of E. faecalis, S. pyogenes and S. mutans were more susceptible to the propolis and E. faecalis to the metronidazole. It was also observed that the amount of metronidazole to inhibit the microorganism strains in the physical mixture with propolis was smaller than in the metronidazole alone, suggesting potentiation effect between propolis and metronidazole. These microparticles would be useful for developing intermediary or eventual dosage form to be administered into the periodontal pocket more easily and safely.

Preparation and characterization of mucoadhesive thermoresponsive systems containing propolis for the treatment of vulvovaginal candidiasis.

This work describes the preparation and characterization of mucoadhesive thermoresponsive systems consisted of poloxamer 407 (P407), Carbopol® 934P (C934P), and propolis to treat vulvovaginal candidiasis (VVC). Systems were obtained with different percentages of P407 and C934P to deliver propolis, a potent drug against VVC. Temperature of gelation, hardness, compressibility, adhesiveness, elasticity, cohesiveness, mucoadhesion, rheology (continuous flow and oscillatory), in vitro drug release, and antimicrobial activity were evaluated. Increasing the polymer content or temperature and the drug presence significantly increased mechanical properties of formulations. These exhibited pseudoplastic flow and low degrees of thixotropy. In most samples, increasing the C934P content significantly changed the oscillatory rheological properties. Formulations showed thermoresponsive behavior, existing as a liquid at room temperature and gel at 34°C-37°C. Propolis release from formulations was controlled by phenomenon of relaxation of polymer chains or displayed anomalous behavior, dependent of concentration of each polymer. The in vitro antimicrobial activity of preparations was evaluated against microorganisms of vaginal importance (Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, and Saccharomyces cerevisiae), displaying activity against all yeast tested. The data obtained for these systems indicate a potentially useful role in the treatment of VVC and suggest they are worthy of clinical evaluation.