Fabrication and Optimization of Essential-Oil-Loaded Nanoemulsion Using Box–Behnken Design against Staphylococos aureus and Staphylococos epidermidis Isolated from Oral Cavity

Abstract

Oral bacterial infections are fairly common in patients with diabetes mellitus; however, due to limited treatment options, herbal medicines are considered an alternate solution. This study aimed to formulate a stable essential-oil-loaded nanoemulsion for the treatment of oral bacterial infections. Essential oils from edible sources including coriander, clove, cinnamon and cardamom were extracted by hydrodistillation. The response surface methodology was used to optimize the nanoemulsion formulation by applying the Box–Behnken design. The oil concentration, surfactant concentration and stirring speed were three independent factors, and particle size and polydispersity index were two responses. The particle size, polydispersity index and zeta potential of the optimized formulation were 130 mm, 0.222 and −22.9, respectively. The ATR-FTIR analysis revealed that there was no incompatibility between the active ingredients and the excipients. A significant release profile in active ingredients of nanoemulsion, i.e., 88.75% of the cinnamaldehyde and 89.33% of eugenol, was recorded after 24 h. In the ex vivo goat mucosal permeation study, 71.67% of the cinnamaldehyde permeated and that of the eugenol 70.75% from the nanoemulsion. The optimized formulation of the essential-oil-loaded nanoemulsion showed a 9 mm zone of inhibition against Staphylococcus aureus and Staphylococcus epidermidis, whereas in anti-quorum sensing analysis, the optimized nanoemulsion formulation showed an 18 mm zone of inhibition. It was concluded that formulated essential-oil-loaded nanoemulsion can be used against S. epidermidis and S. aureus infections in oral cavity.

Development and Evaluation of Essential Oil-Based Nanoemulgel Formulation for the Treatment of Oral Bacterial Infections

“…Furthermore, the higher HLB values are helpful for producing a uniform and fine nanoparticle [ 24 ]. As the oil concentration rises, the nanoemulsion particle size expands, and the concentration of the surfactants is forced to keep up with the oil droplets’ rising concentration [ 30 ]. (The GC-MS Profile of clove essential oil as shown in Figure S1 .)…”

“…FTIR analysis was performed with aim to see any incompatibility between the excipients and active components of the formulation as described earlier [ 30 ]. The FTIR analysis of olive oil, cinnamon essential oil and Carbopol 940 performed in both loaded and unloaded formulations of nanoemulgel.…”

“…The non-irritant and non-toxic nature of carbapols make them widely acceptable for topical applications [ 29 ]. A high molecular weight limits their penetration into the skin, and they thus are considered as good substitutes for oil-based vehicles [ 30 ]. Based on the widespread prevalence of oral microbial infections and importance of NEGs, this project was designed to develop a muco-adhesive nanoemulgel for the treatment of oral bacterial infections.…”

Revisiting the Therapeutic Effects of Essential Oils on the Oral Microbiome

“…Another study by Marinkovic et al used a product containing C. martinii and T. zygis , which showed antimicrobial activity in the root canals of extracted teeth [ 115 ]. Regarding the permanent filling of the root canals, new resin sealers containing natural oils show potential in endodontics due to their favorable physical and chemical properties, antimicrobial effects, and compatibility with cells compared to a commonly used commercial sealer [ 116 , 117 ]. New studies are showing that nano-emulsions EOs-based are showing promising activity against microorganisms for root canal and periodontal treatments.…”

Nanoemulsions of some edible oils and their antimicrobial, antioxidant, and anti-hemolytic activities

“…Nano-emulsions (NEs) of olive oils planned for the intravenous drug delivery was established (Karami et al 2019) and NEs displayed low hemolysis (4.6%); therefore, it was considered safe for intravenous administration. Recently, a successful trial for oral S. aureus, S. epidermidis, Chromobacterium voilaceum treatment was documented using oils NEs (Ullah et al 2022). Also, NEs were prepared and experimented against phytopathogenic bacteria by means of in vitro and in vivo investigations.…”