Different Types of Gel Carriers as Metronidazole Delivery Systems to the Oral Mucosa

Abstract

Periodontal diseases are some of the most widespread oral afflictions, and they are labeled as chronic infections caused by the accumulation of bacteria in dental plaque that produces localized inflammation of the periodontium. The use of local drug delivery systems to treat periodontal diseases has received greater attention, because the active substance is targeted directly to the affected area, which minimizes its systemic side effects. Therefore, the purpose of the investigation was to develop and characterize different types of gel formulations-bigel, hydrogel and oleogel-as local delivery systems containing metronidazole (MET), which can be applied to the oral mucosa. The influence of the formulation type on the mechanical, rheological and mucoadhesive properties were examined. Moreover, in vitro release of metronidazole, its ex vivo permeation through buccal porcine mucosa and antimicrobial activity measured by the plate diffusion method were estimated. It was found that the gel formulations obtained were non-Newtonian systems, showing a shear-thinning behavior and thixotropic properties with good textural features such as firmness, compressibility and adhesiveness. Moreover, the preparations designed possessed beneficial mucoadhesive properties. The formulated hydrogels and bigels containing micronized MET were considered as better formulations in terms of drug release and antimicrobial activity compared to commercially available metronidazole ointment. An ex vivo permeation study with the use of porcine buccal mucosa demonstrated that the bigel formulation was characterized by higher initial permeability rate providing a fast therapeutic effect with simultaneous moderate retention in mucosal tissue to decrease the risk of local cytotoxicity.

Thermosensitive Bioadhesive Hydrogels Based on Poly(N-isopropylacrilamide) and Poly(methyl vinyl ether-alt-maleic anhydride) for the Controlled Release of Metronidazole in the Vaginal Environment

“…This feature was associated with the hydroxyl group contribution of the MTZ that increased the probability of H-bonding interactions between the skin tissue surface and the MTZ-containing hydrogels. Wróblewska et al [ 42 ] found that MTZ-containing gel formulations (bigels, hydrogels, oleogels) exhibit higher adhesive forces on porcine buccal mucosa than the formulations without MTZ.…”

Oleogel-Based Systems for the Delivery of Bioactive Compounds in Foods

“…Bigels display the merits of both the aqueous and oil phase, including the ability to deliver simultaneously hydrophilic and lipophilic active agents, and improved viscoelasticity [ 26 ]. Bigels have been mainly applied in cosmetic/pharmaceutical formulations, since their hybrid characteristics are proven to maximize moisturizing benefits for the skin and simplify the penetration of active agents to deeper layers of the skin tissue [ 27 , 28 , 29 , 30 ]. These benefits may also be very valuable for food applications in the delivery of bioactive compounds [ 31 ].…”

Multilayer Films Based on Chitosan/Pectin Polyelectrolyte Complexes as Novel Platforms for Buccal Administration of Clotrimazole

“…The plates were subsequently incubated at 37.0 ± 0.1 • C either for 24 h (C. albicans, C. krusei) or 48 h (C. parapsilosis). After that time, the inhibition zones were measured [48]. For pure DMSO, no effect on the fungi proliferation was observed.…”

“…Considering the potential effect of the freezing process on the buccal mucosa integrity, we tried to minimize the effect of storage conditions on the measurement's variations according to the previous attempts performed by our research group [46,48]. For that purpose, the buccal mucosa was carefully selected in order to eliminate potential differentiations arising from inhomogeneity of the mucosal surface.…”