Preparation, Physicochemical, and Antibacterial Characterization of Nanostructured Lipid Carrier System Containing Tinidazole for Buccal Mucosa Delivery

Tinidazole (TNZ) is one of the first-hand selections for periodontitis—a chronic inflammatory condition caused by an imbalance in anaerobic Gram-negative bacteria and the protective mechanism in periodontal tissue. A carrier system to reduce particle size and increase drug encapsulation efficiency is a need to increase bioavailability and reduce drug side effects of TNZ. The aim of the study was to formulate nanostructured lipid carriers (NLCs) containing TNZ (TNZ-NLCs) and to evaluate the physicochemical and antibacterial properties of the prepared NLCs. TNZ and lipids such as Gelot 64 and Capryol 90 were used in the study. TNZ-NLCs were prepared by the hot homogenization method. Formula factors, including types and proportions of solid and liquid lipids and surfactants, were investigated. The physicochemical and antibacterial properties of NLCs were evaluated by dynamic light scattering, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, different scanning calorimetry, in vitro drug release, and antibacterial activity. The prepared NLCs, which composed of TNZ, Gelot 64, Capryol 90, and Tween 80, had an average size of 91.77 ± 1.55 nm, a polydispersity index of 0.210 ± 0.020, and an encapsulation efficiency of 57.99 ± 1.04%. TNZ NLCs were spherical in shape and the drug was mostly in amorphous form. TNZ-NLCs could prolong the drug release at pH 6.8 medium for up to 24 h. Higuchi equation best described the release kinetics of TNZ from NLCs. TNZ NLCs exhibited enhanced antibacterial activity against Porphyromonas gingivalis in a time- and concentration-dependent manner. TNZ NLCs were promising for further investigation on buccal mucosa delivery to treat periodontitis.