Tea Tree Oil Nanoemulsion-Based Hydrogel Vehicle for Enhancing Topical Delivery of Neomycin

The essential oil of Melaleuca alternifolia incorporated into hydrogel induces antimicrobial and anti-inflammatory effects on infected wounds by Staphylococcus aureus

Staphylococcus aureus is one of the most common bacterial isolates found in wounds. Thus, innovative dressings, such as hydrogels, are interesting vehicles for incorporating bioactive compounds like those from Melaleuca alternifolia essential oil (MaEO). In this study, we evaluated the antimicrobial and anti-inflammatory potential of MaEO incorporated into an alginate and chitosan hydrogel for treating wounds infected by S. aureus. The hydrogel incorporated with MaEO 1% (HMa 1%) was homogeneous with a bright pale-yellow color and the characteristic smell of Melaleuca. The incorporation of MaEO 1% does not affect the stability of the hydrogel, which was stable up to 90 days of storage. The Scanning electron microscopy analysis revealed that hydrogels showed irregular surfaces and interconnected porous structures with accumulations of oil crystals distributed throughout the formulation. HMa 1% has a high moisture content (95.1%) and can absorb simulated wound fluid. Regarding the antimicrobial effects, HMa 1% reduced the growth of S. aureus ATCC 6538 in both in vitro conditions and in an ex vivo model of wounds using porcine skin. In addition, the dairy topical treatment of murine skin lesions with HMa 1% induced a significant reduction of the wound area, inflammation score, and bacterial load, as well as tissue re-epithelialization and modulation of inflammatory mediators. Therefore, hydrogel incorporated with MaEO 1% has excellent potential to be used in the pharmacotherapy of infected wounds.

Application of the Quality by Design Concept (QbD) in the Development of Hydrogel-Based Drug Delivery Systems

Hydrogel-based drug delivery systems are of interest to researchers for many reasons, such as biocompatibility, high diversity, and the possibility of administration from different routes. Despite these advantages, there are challenges, such as controlling the drug release rate and their mechanical properties during the manufacturing of these systems. For this reason, there is a need for the production and development of such drug delivery systems with a scientific strategy. For this reason, the quality by design (QbD) approach is used for the development of drug delivery systems. This approach, by identifying the most effective factors in the manufacturing of pharmaceutical products and controlling them, results in a product with the desired quality with the least number of errors. In this review article, an attempt is made to discuss the application and method of applying this approach in the development of hydrogel-based drug delivery systems. So that for the development and production of these systems, according to the type of drug delivery system, what target characteristics should be considered (QTPP) and what factors, such as material properties (CMA) or process parameters (CPP), should be taken into account to reach the critical quality attributes of the product (CQA).

Date Palm Extract (Phoenix dactylifera) Encapsulated into Palm Oil Nanolipid Carrier for Prospective Antibacterial Influence

It is worthwhile to note that using natural products today has shown to be an effective strategy for attaining the therapeutic goal with the highest impact and the fewest drawbacks. In Saudi Arabia, date palm (Phoenix dactylifera) is considered the principal fruit owing to its abundance and incredible nutritional benefits in fighting various diseases. The main objective of the study is to exploit the natural products as well as the nanotechnology approach to obtain great benefits in managing disorders. The present investigation focused on using the powder form of date palm extract (DPE) of Khalas cultivar and incorporates it into a nanolipid formulation such as a nanostructured lipid carrier (NLC) prepared with palm oil. Using the quality by design (QbD) methodology, the most optimized formula was chosen based on the number of assigned parameters. For more appropriate topical application, the optimized DP-NLC was combined with a pre-formulated hydrogel base forming the DP-NLC-hydrogel. The developed DP-NLC-hydrogel was evaluated for various physical properties including pH, viscosity, spreadability, and extrudability. Additionally, the in vitro release of the formulation as well as its stability upon storage under two different conditions of room temperature and refrigerator were investigated. Eventually, different bacterial strains were utilized to test the antibacterial efficacy of the developed formulation. The optimized DP-NLC showed proper particle size (266.9 nm) and in vitro release 77.9%. The prepared DP-NLC-hydrogel showed acceptable physical properties for topical formulation, mainly, pH 6.05, viscosity 9410 cP, spreadability 57.6 mm, extrudability 84.5 (g/cm2), and in vitro release 42.4%. Following three months storage under two distinct conditions, the formula exhibited good stability. Finally, the antibacterial activity of the developed DP-NLC-hydrogel was evaluated and proved to be efficient against various bacterial strains.

Gum arabic/guar gum stabilized Hydnocarpus wightiana oil nanohydrogel: Characterization, antimicrobial, anti-inflammatory, and anti-biofilm activities

Hydnocarpus wightiana oil has proven to inhibit the growth of pathogenic microorganisms; however, the raw form is highly susceptible to oxidation, and thus it becomes toxic when uptake is in high amounts. Therefore, to minimize the deterioration, we formulated Hydnocarpus wightiana oil-based nanohydrogel and studied its characteristics as well biological activity. The low energy-assisted hydrogel was formulated by including gelling agent, connective linker, and cross-linker and it resulted in internal micellar polymerization of the milky white emulsion. The oil showed the presence of octanoic acid, n-tetradecane, methyl 11-(2-cyclopenten-1-yl) undecanoate (methyl hydnocarpate), 13-(2-cyclopenten-1-yl) tridecanoic acid (methyl chaulmoograte), and 10,13-eicosadienoic acid. The amount of caffeic acid was 0.0636 mg/g, which was higher than the amount of gallic acid (0.0076 mg/g) in the samples. The formulated nanohydrogel showed an average droplet size of 103.6 nm with a surface charge of -17.6 mV. The minimal inhibitory bactericidal, and fungicidal concentrations of nanohydrogel against pathogenic bacteria and fungi were ranging from 0.78 to 1.56 μl/mL with 70.29-83.62 % antibiofilm activity. Also, nanohydrogel showed a significantly (p < 0.05) higher killing rate for Escherichia coli (7.89 log CFU/mL) than Staphylococcus aureus (7.81 log CFU/mL) with comparable anti-inflammatory activity than commercial standard (49.28-84.56 %). Therefore, it can be concluded that being hydrophobic, and having the capability of target-specific drug absorption as well as biocompatibility nanohydrogels can be utilized to cure various pathogenic microbial infections.