Investigation of Factors Influencing Formation of Nanoemulsion by Spontaneous Emulsification: Impact on Droplet Size, Polydispersity Index, and Stability

Extrusion-based 3D printing for development of complex capsular systems for advanced drug delivery

This review explores the feasibility of extrusion-based 3D printing techniques for producing complex dosage forms (such as capsular shells/devices) that provide controlled drug release and targeted delivery. The current discussion explores how extrusion-based 3D printing techniques, particularly Fused Deposition Modelling (FDM) and Pressure-Assisted Modelling (PAM), offer significant advantages in fabricating such complex dosage forms. This technology enables the fabrication of single-, dual-, or multi-compartment capsular systems with customized designs/geometry of the capsular shell to achieve delayed, sustained, or pulsatile drug release. The impact of customized design/geometry on the biopharmaceutical performances of loaded therapeutics is comprehensively discussed. The potential of 3D printing techniques for different specialized drug delivery purposes like gastric floating, implants, suppositories, and printfills are also addressed. This technique has the potential to significantly improve the therapeutic outcomes, and patient adherence to medication regimens, and pave the way for personalized medicine.

Antifungal Activity of Piperine-based Nanoemulsion Against Candida spp. via In Vitro Broth Microdilution Assay

Candidemia leaves a trail of approximately 750,000 cases yearly, with a morbidity rate of up to 30%. While Candida albicans still ranks as the most predominantly isolated Candida species, C. glabrata comes in second, with a death rate of 40-50%. Although infections by Candida spp are commonly treated with azoles, the side effects and rise in resistance against it has significantly limited its clinical usage. The current study aims to address the insolubility of piperine and provide an alternative treatment to Candida infection by formulating a stable piperine-loaded O/W nanoemulsion, comprised of Cremophor RH40, Transcutol HP and Capryol 90 as surfactant, co-surfactant, and oil, respectively. Characterization with zetasizer showed the droplet size, polydispersity (PDI) and zetapotential value of the nanoemulsion to be 24.37 nm, 0.453 and -21.10 mV, respectively, with no observable physical changes such as phase separation from thermostability tests. FTIR peaks confirms presence of piperine within the nanoemulsion and TEM imaging visualized the droplet shape and further confirms the droplet size range of 20-24 nm. The MIC90 value of the piperine-loaded nanoemulsion determined with in vitro broth microdilution assay was approximately 20-50% lower than that of the pure piperine in DMSO, at a range of 0.8-2.0 mg/mL across all Candida spp. tested. Overall, the study showed that piperine can be formulated into a stable nanoemulsion, which significantly enhances its antifungal activity compared to piperine in DMSO.

Formulation of a Novel Hesperetin-Loaded Nanoemulsion and Its Promising Effect on Osteogenesis

Alternative therapies associating natural products and nanobiotechnology show new perspectives on controlled drug release. In this context, nanoemulsions (NEs) present promising results for their structural design and properties. Hesperetin (HT), a flavonoid mainly found in citrus fruits, presents highlighted bone benefits. In this context, we developed a hesperetin-loaded nanoemulsion (HT-NE) by sonication method and characterized it by dynamic light scattering, analyzing its encapsulation efficiency, and cumulative release. The biocompatibility in human osteoblasts Saos-2-like was evaluated by the cytotoxicity assay and IC50. Then, the effects of the HT-NE on osteogenesis were evaluated by the cellular proliferation, calcium nodule formation, bone regulators gene expression, collagen quantification, and alkaline phosphatase activity. The results showed that the formulation presented ideal values of droplet size, polydispersity index, and zeta potential, and the encapsulation efficiency was 74.07 ± 5.33%, showing a gradual and controlled release. Finally, HT-NE was shown to be biocompatible and increased cellular proliferation, and calcium nodule formation, regulated the expression of Runx2, ALPL, and TGF-β genes, and increased the collagen formation and alkaline phosphatase activity. Therefore, the formulation of this NE encapsulated the HT appropriately, allowing the increasing of its effects on mechanisms to improve or accelerate the osteogenesis process.

Fabrication of Eco-Friendly Hydrolyzed Ethylene-Maleic Anhydride Copolymer-Avermectin Nanoemulsion with High Stability, Adhesion Property, pH, and Temperature-Responsive Releasing Behaviors

In this study, novel amphiphilic polymer emulsifiers for avermectin (Avm) were synthesized facilely via the hydrolysis of ethylene-maleic anhydride copolymer (EMA) with different agents, and their structures were confirmed by various techniques. Then, water-based Avm-nanoemulsions were fabricated with the emulsifiers via phase inversion emulsification process, and superior emulsifier was selected via the emulsification effects. Using the superior emulsifier, an optimal Avm-nanoemulsion (defined as Avm@HEMA) with satisfying particle size of 156.8 ± 4.9 nm, encapsulation efficiency (EE) of 69.72 ± 4.01% and drug loading capacity (DLC) of 54.93 ± 1.12% was constructed based on response surface methodology (RSM). Owing to the emulsifier, the Avm@HEMA showed a series of advantages, including high stability, ultraviolet resistance, low surface tension, good spreading and high affinity to different leaves. Additionally, compared to pure Avm and Avm-emulsifiable concentrate (Avm-EC), Avm@HEMA displayed a controlled releasing feature. The encapsulated Avm was released quite slowly at normal conditions (pH 7.0, 25 °C or 15 °C) but could be released at an accelerated rate in weak acid (pH 5.5) or weak alkali (pH 8.5) media or at high temperature (40 °C). The drug releasing profiles of Avm@HEMA fit the Korsmeyer-Peppas model quite well at pH 7.0 and 25 °C (controlled by Fickian diffusion) and at pH 7.0 and 10 °C (controlled by non-Fickian diffusion), while it fits the logistic model under other conditions (pH 5.5 and 25 °C, pH 8.5 and 25 °C, pH 7.0 and 40 °C).

Self-Assembled Acid-Responsive Nanosystem for Synergistic Anti-Angiogenic/Photothermal/Ferroptosis Therapy against Esophageal Cancer

Esophageal cancer (EC) treatment via anti-angiogenic therapy faces challenges due to non-cytotoxicity and non-specific biodistribution of the anti-angiogenic agents. Hence, the quest for a synergistic treatment modality and a targeted delivery approach to effectively address EC has become imperative. In this study, an acid-responsive release nanosystem (Bev-IR820@FeIII TA) that involves the conjugation of bevacizumab, an anti-angiogenic monoclonal antibody, with TA and Fe3+ to form a metal-phenolic network, followed by loading with the near-infrared photothermal agent (IR820) to achieve combinational therapy, is designed. The construction of Bev-IR820@FeIII TA can be realized through a facile self-assembly process. The Bev-IR820@FeIII TA exhibits tumor-targeting capabilities and synergistic therapeutic effects, encompassing anti-angiogenic therapy, photothermal therapy (PTT), and ferroptosis therapy (FT). Bev-IR820@FeIII TA exhibits remarkable proficiency in delivering drugs to EC tissue through its pH-responsive release properties. Consequently, bevacizumab exerts its therapeutic effects by obstructing tumor angiogenesis, thereby impeding tumor growth. Meanwhile, PTT facilitates localized thermal ablation at the tumor site, directly eradicating EC cells. FT synergistically collaborates with PTT, giving rise to the formation of a reactive oxygen species (ROS) storm, subsequently culminating in the demise of EC cells. In summary, this amalgamated treatment modality carries substantial promise for synergistically impeding EC progression and showcases auspicious prospects for future EC treatment.

Evaluating the effects of surfactant types on the properties and stability of oil-in-water Rhodiola rosea nanoemulsion

Different types and ratios of surfactant, co-surfactant, and oil phase, have a greater impact on nanoemulsion preparation. The presence of surfactants in the nanoemulsion can reduce surface tension and characteristic stability. In this study, four groups of oil-in-water (O/W) nanoemulsions (NEs) with different ratios of surfactant and co-surfactant, and two oils were formulated as carriers of Rhodiola rosea. The variable optimization was investigated and then indicated as optimization group A (Opt A) with the formula of 10% of transcutol, 16.63% of tween 80, Opt B with 10% of tween 80, 29.87% of span 80, Opt C with 28.42% of transcutol, 30% of labrasol, and Opt D with 30% of transcutol, 30% of tween 80. Labrafac and soybean oil were used as the oil phase. The optimized formula using the response surface method (RSM) by design expert software showed the ideal conditions with a higher desirability score. Desirability score are 0.72% (Opt A), 0.81% (Opt B), 0.76% (Opt C) and 0.98% (Opt D), the desirability rating close to 1 indicates a high possibility that the projected values would closely match the experimental results for the optimum formula. All of the optimized formulation were also checked for the characteristics of nanoemulsion including particle size, polydispersity index (PDI), zeta potential, viscosity, encapsulation efficiency, transmission electron microscope (TEM), antioxidant activity, skin irritation test and stability studies. Our study provides a promising combination of surfactant-co-surfactant and oil phases to produce a stable nanoemulsion that can be used in pharmaceuticals and cosmetics in the future.

A Comprehensive Study on Peppermint Oil and Cinnamon Oil as Nanoemulsion: Preparation, Stability, Cytotoxicity, Antimicrobial, Antifungal, and Antioxidant Activity

BACKGROUND

Recent studies have shown that nanoemulsions prepared with essential oils have significant antimicrobial potential against multidrug-resistant pathogens due to increased chemical stability. Nanoemulsion also promotes controlled and sustained release, which increases their bioavailability and efficacy against multidrug-resistant bacteria.

OBJECTIVE

This study aimed to investigate the antimicrobial, antifungal, antioxidant, and cytotoxicity properties of cinnamon essential oil and peppermint essential oil as nanoemulsions compared to pure forms. For this purpose, analyses of the selected stable nanoemulsions were carried out.

METHOD

The droplet sizes and zeta potentials of peppermint essential oil nanoemulsions and cinnamon essential oil nanoemulsions were found to be 154.6±1.42 nm and -17.1±0.68 mV and 200.3±4.71 nm and -20.0±0.81 mV, respectively. Although the amount of essential oil used in nanoemulsions was 25% w/w, antioxidant and antimicrobial activities were found to be more effective compared to pure essential oils.

RESULTS

In cytotoxicity studies on the 3T3 cell line, both essential oil nanoemulsions showed higher cell viability than pure essential oils. At the same time, cinnamon essential oil nanoemulsions exhibited a higher antioxidant property than peppermint essential oil nanoemulsions and showed superiority in the antimicrobial susceptibility test conducted against four bacteria and two fungi. Cell viability tests determined that cinnamon essential oil nanoemulsions showed considerably higher cell viability compared to pure cinnamon essential oil.

CONCLUSION

These findings indicated that the prepared nanoemulsions in the current study might positively influence the dosing regimen and clinical outcomes of antibiotic therapy.

Development, stabilization, and characterization of nanoemulsion of vitamin D3-enriched canola oil

In this study, the oil-in-water nanoemulsion (NE) was prepared and loaded with vitamin D3 in food-grade (edible) canola oil and stabilized by Tween 80 and Span 80 by using a water titration technique with droplet sizes of 20 to 200 nm. A phase diagram was established for the influence of water, oil, and S-Mix concentration. The outcomes revealed that the particle size of blank canola oil nanoemulsion (NE) ranged from 60.12 to 62.27 (d.nm) and vitamin D3 NE ranged from 93.92 to 185.5 (d.nm). Droplet size and polydispersity index (PDI) of both blank and vitamin D3-loaded NE results were less than 1, and zeta potential results for blank and vitamin D3 loaded NE ranged from -9.71 to -15.32 mV and -7.29 to -13.56 mV, respectively. Furthermore, the pH and electrical conductivity of blank NE were 6.0 to 6.2 and 20 to 100 (μs/cm), respectively, whereas vitamin D3-loaded NE results were 6.0 to 6.2 and 30 to 100 (μs/cm), respectively. The viscosity results of blank NE ranged from 0.544 to 0.789 (mPa.s), while that of vitamin D3-loaded NE ranged from 0.613 to 0.793 (mPa.s). In this study, the long-term stability (3 months) of canola oil NE containing vitamin D3 at room temperature (25 C) and high temperature (40 C) was observed.

Lomustine's nanoemulsion as nose-to-brain drug delivery system for CNS tumor treatment

Nose-to-brain delivery allows the direct targeting of drug molecules bypassing the Blood Brain Barrier and systemic effect. Nanoemulsion is one of the novel strategies to deliver drug in this route due to its simplicity in manufacturing, long-term stability, and strong solubilization property for drug. The anticancer drug lomustine had poor oral bioavailability in addition to its serious side effect, therefore, developing more effective drug delivery with direct targeting towards the brain through intra-nasal administration applying nanoemulsion technology is a promising alternative. The work involved lomustine solubility screening in oils, surfactants and cosurfactants as well as emulsifier ratio (Smix) nanoemulsion area was identified using pseudo-ternary phase diagrams. Eighteen nanoemulsion formulas were produced for optimization, then characterized for droplet size, polydispersity index, zeta potential, entrapment efficiency, conductivity, transmittance, dilution, visual transparency, physical stability and in vitro release. The optimum NE formula showed droplet size, zeta potential, polydispersity index, entrapment efficiency, %transmittance, conductivity of 31.31 nm, -30.65 mV, 0.159, 98.12%, 99.08%, and 951 us/cm, respectively. The best formula released 100% lomustine within 15 min which is a promising potential drug delivery system that may deliver the drug quickly and directly to the brain as a safe and effective alternative to oral delivery.

Formulation and Characterization of a Novel Palm-Oil-Based α-Mangostin Nano-Emulsion (PO-AMNE) as an Antimicrobial Endodontic Irrigant: An In Vitro Study

Aim: To formulate and characterize a palm-oil-in-water-based α-Mangostin nano-emulsion (PO-AMNE) endodontic irrigant, in order to evaluate its antibacterial efficacy against Enterococcus faecalis, Staphylococcus epidermidis, and Candida albicans biofilms, as well as its capacity to remove smear layer. Methods: The solubility of α-Mangostin in various oils was determined and selected, surfactants and co-surfactants were used for the nano-emulsion trial. PO-AMNE was prepared and optimized. The MIC was performed, and the antimicrobial efficacy was estimated against biofilms. The optimized 0.2% PO-AMNE irrigant antimicrobial efficacy in a tooth model was done using colony-forming units. The treated teeth were processed by scanning electron microscopic examination for debris and smear layer removal. An Alamar Blue assay was used to evaluate cell viability. The optimization of the PO-AMNE irrigant was performed using Box–Behnken statistical design. Results: The optimized 0.2% PO-AMNE irrigant was found to have a particle size of 340.9 nm with 0.246 PDI of the dispersed droplets, and a zeta potential (mV) of −27.2 ± 0.7 mV. The MIC values showed that 0.2% PO-AMNE (1.22 ± 0.02) were comparable to 2% CHX (1.33 ± 0.01), and 3.25% NaOCl (2.2 ± 0.09) had the least inhibition for E. faecalis. NaOCl (3.25%) showed the maximum inhibition of S. epidermidis (0.26 ± 0.05), whereas 0.2% PO-AMNE (1.25 ± 0.0) was comparable to 2% CHX (1.86 ± 0.07). For C. albicans, 2% CHX (8.12 ± 0.12) showed the least inhibition as compared to 0.2% PO-AMNE (1.23 ± 0.02) and 3.25% NaOCl (0.59 ± 0.02). The 0.2% PO-AMNE irrigant was then evaluated for its antimicrobial efficacy against the three biofilms, using colony-forming units. The 0.2% PO-AMNE was comparable to both 3.25% NaOCl and 2% CHX in inhibiting the growth of biofilms. The 0.2% PO-AMNE and 17% EDTA eliminated the smear layer with the lowest mean scores (p < 0.001). Finally, 0.2% PO-AMNE was shown to be biocompatible when compared to 17% EDTA, 3.25% NaOCl, and 2% CHX in immortalized oral keratinocyte cells. Conclusion: Overall, the formulated 0.2% PO-AMNE irrigant was an effective antimicrobial and biocompatible which could combat endodontic-infection-related polymicrobial biofilms.

Green Synthesis of Titanium Dioxide Nanoparticles Using Ocimum sanctum Leaf Extract: In Vitro Characterization and Its Healing Efficacy in Diabetic Wounds

Diabetes mellitus is one of the most prevalent metabolic disorders characterized by hyperglycemia due to impaired glucose metabolism. Overproduction of free radicals due to chronic hyperglycemia may cause oxidative stress, which delays wound healing in diabetic conditions. For people with diabetes, this impeded wound healing is one of the predominant reasons for mortality and morbidity. The study aimed to develop an Ocimum sanctum leaf extract-mediated green synthesis of titanium dioxide (TiO₂) nanoparticles (NPs) and further incorporate them into 2% chitosan (CS) gel for diabetic wound healing. UV-visible spectrum analysis recorded the sharp peak at 235 and 320 nm, and this was the preliminary sign for the biosynthesis of TiO₂ NPs. The FTIR analysis was used to perform a qualitative validation of the biosynthesized TiO₂ nanoparticles. XRD analysis indicated the crystallinity of TiO₂ NPs in anatase form. Microscopic investigation revealed that TiO₂ NPs were spherical and polygonal in shape, with sizes ranging from 75 to 123 nm. The EDX analysis of green synthesized NPs showed the presence of TiO₂ NPs, demonstrating the peak of titanium ion and oxygen. The hydrodynamic diameter and polydispersity index (PDI) of the TiO₂ NPs were found to be 130.3 nm and 0.237, respectively. The developed TiO₂ NPs containing CS gel exhibited the desired thixotropic properties with pseudoplastic behavior. In vivo wound healing studies and histopathological investigations of healed wounds demonstrated the excellent wound-healing efficacy of TiO₂ NPs containing CS gel in diabetic rats.