Utilization of pH-driven methods to fortify nanoemulsions with multiple polyphenols

Simple but effective methods are required to incorporate multiple bioactive polyphenols into delivery systems to increase their dispersibility,stability and bioavailability.We developed and tested three p Hdriven protocols for creating nanoemulsions loaded with multiple lipophilic polyphenols.These protocols differed in how the different polyphenols were incorporated into the nanoemulsions.The impact of these three methods on the formation,properties,and gastrointestinal fate of nanoemulsions loaded with curcumin,resveratrol,and quercetin was investigated.The three methods produced nanoemulsions with similar initial particle properties:droplet diameters(0.15,0.16,and 0.15μm)and zeta-potentials(–59,–58,and–58 m V),respectively.However,the average encapsulation efficiencies(82%,88%,and 61%),gastrointestinal stabilities(83%,97%,and 29%)and bioaccessibilities(77%,90%,and 73%)for curcumin,resveratrol,and quercetin were somewhat different.In particular,more quercetin degradation occurred using the approach that held it under alkaline conditions for extended periods.In general,the p H-driven method provides researchers with a versatile approach of incorporating multiple polyphenols with different characteristics into functional food and beverages using a simple and inexpensive method.

Evaluation of the Antibacterial and Antifungal Capacity of Nanoemulsions Loaded with Synthetic Chalcone Derivatives Di-Benzyl Cinnamaldehyde and Benzyl 4-Aminochalcone

With the increase in antimicrobial resistance,it has become necessary to explore alternative approaches for combating and preventing diseases.DB-cinnamaldehyde(CNM)and Benzyl4-amino(B4AM)are bioactive compounds derived from chalcones but with restricted solubility in aqueous media.Nanoemulsions can enhance the solubility of compounds and can be a promising alternative in the development of novel antimicrobials,with reduced side effects and prolonged release.The objective of this study was to evaluate the stability of oil-in-water nanoemulsions loaded with two distinct types of chalcones at two different dosages,to propose a stable formulation with antimicrobial properties.Results showed that nanoemulsions presented high encapsulation efficiency,low polydispersity index(PDI)and particle size below 200 nm,indicating that emulsification was a suitable method for nanoemulsion preparation.Nanoemulsions with higher dosages exhibited significant antimicrobial effects when compared to free chalcones and positive controls.Notably,B4AM nanoemulsions at higher dosages showed expressive activity against Salmonella minnesota,with a 420%greater inhibitory response compared to the free form and showing equivalence to the positive control.CNM nanoemulsions showed excellent inhibitory activity at the highest dosage,equivalent to the positive control against S.minnesota and Staphylococcus aureus.The greater number of conjugated bonds in CNM increased the antimicrobial activity in comparison with B4AM,and the formation of nanometric domains enhanced the bioavailability,being a promising alternative for antimicrobial applications.

Preparation and Characterization of Bifenthrin Nanoemulsions

[ Objective] The paper was to prepare bifenthrin nanoemulsions, and to characterize its property. [ Method ] Oil in water type of bifenthrin nanoemul- sions was prepared using emulsion phase transition method at constant temperature of 25℃. The formation mechanism of nanoemulsions was investigated, and the property of bffenthrin nanoemulsions was characterized by dynamic light scattering（DIS）, transmission electron microscopy （TEM）, contact angle meter, interfa- cial tension meter and high performance liquid chromatogTaphy （HPLC）. [ Result ] Phase transition occurred during the formation progress of bifenthrin nanoemul- sions ; the particles of nancomulsions system was spherical, and the particle size was mainly distributed in the range of 25 -30 ran; the contact angle on paraffin was less than 90° with good wetting effect; the surface tension was less than 40 mN/m, and the emulsification effect was also good, so the utilization rate of bifenthrin nancomulsions was improved. HPLC results showed that bffenthrin was not easy to decompose or precipitate with good stability. [ Conclusion] The result provided basis for the preparation of new types of insecticides.

The effect of surfactant on the physical properties of coconut oil nanoemulsions

The aim of this study was to develop the water compatible form of coconut oil through nanoemulsification. The effect of different types and amounts of surfactants on the physical characteristics of nanoemulsions containing coconut oil was investigated. Coconut oil nanoemulsions containing varied amounts of surfactants including polyethylene glycol octyl phenyl ether(PGO), polyoxyethylene sorbitan monostearate(POS), polyethylene glycol hydrogenated castor oil(PHC), sodium lauryl sulfate(SLS) and poloxamer 407(PLX) were formulated and comparatively evaluated for their physical properties. The results showed that the coconut oil nanoemulsions using PGO, POS and PHC as surfactants exhibited low percent creaming index indicating excellent stability, while those containing SLS and PLX demonstrated the higher percent creaming index suggesting lesser physical stability. The droplet sizes of nanoemulsions consisting of 5%(w/w) PGO, POS and PHC were 22.843, 4.458 and 0.162 μm, respectively. Thus, coconut oil nanoemulsions with the smallest size could be obtained when PHC was applied. Furthermore, the droplet size of nanoemulsions decreased from 33 μm to less than 200 nm with an increase in the amount of PHC from 1% to 10%(w/w). Additionally, the properties of coconut oil based nanoemulsions containing PHC were not changed through temperature cycling test. From these results, it was suggested that the fabrication of stable coconut oil nanoemulsions with small particle size could be easily achieved by using 5%(w/w) PHC as a surfactant. The knowledge gained from the study might provide the basic guideline for the fabrication of stable nanoemulsions for food, cosmetic and pharmaceutical fields in the future.

Fabrication and characterization of spearmint oil loaded nanoemulsions as cytotoxic agents against oral cancer cell

Spearmint oil(SMO), a commonly used essential oil for oral care products, possesses various interesting functions, especially for anticancer property. However, the application of SMO for cancer treatment is limited due to water insoluble. In the present study, nanoemulsions, which have been widely accepted as dosage forms for poorly water-soluble drugs, were selected as candidate carriers for SMO to inhibit oral cancer cell. The nanoemulsions were fabricated using phase inversion temperature method. The factors affecting formation and properties of nanoemulsions including type and amount of surfactants, oil loading and ratio of SMO to virgin coconut oil(VCO) were investigated. Among the surfactants used, the nanoemulsions containing polyoxyethylene castor oil derivatives(Kolliphor ?EL; PCO35, Cremophor ?RH40; PCO40, Eumulgin ?CO60; PCO60) and polyoxyethylene sorbitan fatty acid esters(PSF80) showed 100% creaming after temperature cycling test indicating excellent physical stability while those containing PCO40 demonstrated more transparency and better physical stability. With an increasing amount of PCO40, the droplet size tended to decrease and was in the nano-size range( < 1000 nm) after increasing to more than 5%(w/w). SMOVCO loading also influenced on the droplet size. At 5%(w/w) PCO40, the maximum SMO-VCO loading of 25%(w/w) to attain nanoemulsions was observed. Moreover, the composition of oils had an impact on size of emulsions. The transparent nanoemulsions were only prepared in the range of SMO-VCO from 40:60 to 80:20, suggesting the optimum ratio of SMO tosurfactant and the composition of oils were the critical factors for formation of nanoemulsions. NMR study disclosed that the interaction between PCO40 with both VCO and SMO should be a possible stabilization mechanism. Furthermore, the SMO-VCO nanoemulsions exhibited significant cytotoxic effect against oral carcinoma(KON) cell line using MTT assay. The finding, therefore, revealed the good feasibility of SMO-VCO nanoemulsions as novel carriers for treating of oral cancer.

Factors affecting formation of nanoemulsions containing modified coconut oil and spearmint oil

Dental caries is one of the major oral health problems in most countries,affecting more than 50%of school children and majority of adults.Normally,we can prevent the disease by utilization of suitable antiseptics,e.g.alcohols and chlorhexidine[1].However,most antiseptics cause irritation or straining of the mucous membrane and teeth.Therefore,finding a more safe and efficient antiseptics is still a matter of interest to eradicate the causative pathogen.Volatile oils from plants including spearmint oil(SMO)could reduce the number of Streptococcus mutans counts in plaques and saliva.

Preparation and physical properties of itraconazole-loaded nanoemulsions using pineapple starch as co-emulsifier

Pineapple plant(Ananascomosus L.Merr.)is a leading edible member of the Bromeliaceae family[1].Nanoemulsions containing itraconazole,a poorly water-soluble drug using pectin as a polymeric emulsifier,are currently under investigation[2].The physicochemical and rheological properties as well as structural characterizations of cassava and mungbean starches have been reported[3].However,the application of pineapple starch as co-emulsifier of pharmaceutical excipients for pharmaceutical industry has not been investigated.

Current State of Nanoemulsions in Drug Delivery

Nanoemulsions have attracted great attention in research, dosage form design and pharmacotherapy. This is as a result of a number of attributes peculiar to nanoemulsions such as optical clarity, ease of preparation, thermodynamic stability and increased surface area. Nanoemulsions also known as submicron emulsions serve as vehicles for the delivery of active pharmaceutical ingredients as well as other bioactives. They are designed to address some of the problems associated with conventional drug delivery systems such as low bioavailability and noncompliance. The importance of design and development of emulsion nanocarrier systems aimed at controlling and/or improving required bioavailability levels of therapeutic agents cannot be overemphasized. Reducing droplet sizes to the nanoscale leads to some very interesting physical properties, such as optical transparency and unusual elastic behaviour. This review sheds light on the current state of nanoemulsions in the delivery of drugs and other bioactives. The morphology, formulation, characteristics and characterization of nanoemulsions were also addressed.

Impact of formulation parameters on physical characteristics of spray dried nanoemulsions and their reconstitutions

Nanoemulsion as small droplet dispersion allows them to uniformly deposit on substrates,increases the rate of bioavailability,absorption and has a better uptake.Although it is generally accepted that nanoemulsions are stable for years,Oswald ripening which can damage nanoemulsion has been reported[1].In this study,converting nanoemulsion as liquid formulation into solid powders was attempted by using spray drying method.The obtained powders were then characterized,reconstituted and compared to the initial nanoemulsion.

The accelerated blood clearance phenomenon of PEGylated nanoemulsion upon cross administration with nanoemulsions modified with polyglycerin

For investigating the accelerated blood clearance(ABC) phenomenon of polyglycerin modified nanoemulsions upon cross administration with polyethylene glycol(PEG) covered nanoemulsion, we used the 1,2-distea-royl-sn-glycero-3-phosphoethanolamine-npolyglycerine-610 and the 1,2-distearoyl-n-glycero-3-phosphoethanolamine-n-[methoxy(polyethylene glycol)-2000] as modify materials, the dialkylcarbocyanines as fluorescence indicator. Exhausted macrophages rat model was established and new material containing polycarboxyl structure was synthesized. The microplate reader and the in vivo optical imaging system were applied to measure the concentration of nanoemulsions in tissues.The results show that the first dose of polyglycerin modified nanoemulsion can induce the ABC phenomenon of the second dose of PEGylated nanoemulsion. With the increase in the amount of the surface polyglycerin, the extent of the ABC phenomenon decreases. Liver accumulation has positive relationship with the ABC phenomenon. Furthermore, kupffer cells in liver can get more immune information from polyhydroxy structure than polycarboxyl group in the modify compound. The results of our work imply that the polycarboxyl structure has advantages to eliminate the ABC phenomenon.

Antimicrobial Oil-in-Water Nanoemulsions： Synergistic Effect of Nisin and Carvacrol against Bacillus subtilis

The aim of this study was to elucidate the mode of action of two antimicrobial compounds, nisin, which is hydrophilic, and the lipophilic compound carvacrol. For that purpose, both antimicrobials were loaded into Oil-in-/Water nanoemulsions, and their antimicrobial activity against Bacillus subtilis was investigated. The experimental results indicated that the O/W nanoemulsions loaded with both, nisin and carvacrol, having Sauter mean diameter （d3,2） of around 120 nm, were considerably stable under the conditions investigated （up to 1 week storage at room temperature）. The interfacial tension between nisin aqueous solutions and soybean oil could be reduced up to 12 mN/m, as compared to that of pure water and soybean oil （21 mN/m）, so that demonstrating the potential of nisin to be used as emulsifier. The results obtained for O/W nanoemulsions loaded with both antimicrobial compounds indicated a reduction of nearly two log cycles （around 100 times） on B. subtilis population upon incubation for 24 h, compared to the blank （10 mM phosphate buffer）.

Therapeutic Effects of Curcumin Nanoemulsions on Prostate Cancer

The therapeutic potential of curcumin(Cur) is hampered by its poor aqueous solubility and low bioavailability. The aim of this study was to determine whether Cur nanoemulsions enhance the efficacy of Cur against prostate cancer cells and increase the oral absorption of Cur. Cur nanoemulsions were developed using the self-microemulsifying method and characterized by their morphology, droplet size and zeta potential. The results showed that the cytotoxicity and cell uptake were considerably increased with Cur nanoemulsions compared to free Cur. Cur nanoemulsions exhibited a significantly prolonged biological activity and demonstrated better therapeutic efficacy than free Cur, as assessed by apoptosis and cell cycle studies. In situ single-pass perfusion studies demonstrated higher effective permeability coefficient and absorption rate constant for Cur nanoemulsions than for free Cur. Our study suggested that Cur nanoemulsions can be used as an effective drug delivery system to enhance the anticancer effect and oral bioavailability of Cur.

Influence of Ozonized Oil Nanoemulsions on B-16 Melanoma Cells: An <i>in Vitro Study</i>

In this study, we aimed to use a novel approach to overcome the current limitations of ozone therapy in medicine through ozonized oil nanoemulsions (OZNEs). We evaluated dose-dependency on the cellular activities of B-16 melanoma cell line which were incubated with various OZNE doses (v/v). Antitumor effects of OZNE against cancer cell lines were evaluated by cellular morphology, apoptosis and cell cycle analysis. Flow cytometry results showed that OZNE induced DNA damage, apoptosis, and arrested cell cycle in G0-1 phase in B-16 melanoma cells. Thus, OZNE treatment could pose an effective way to act as a potential therapeutic for patients with tumors in the future.

Functional nanoemulsions: Controllable low-energy nanoemulsification and advanced biomedical application

Nanoemulsions are widely used as advanced pharmaceutical delivery systems in biomedical field, due to their high encapsulation efficiency and good therapy efficacy.Nanoemulsification techniques that produce nanoemulsions with controllable sizes and compositions are promising for creating advanced nanoemulsion systems for pharmaceutical delivery.This review summarizes recent advances on low-energy emulsification techniques for producing nanoemulsions, and the use of these nanoemulsions as advanced pharmaceutical delivery systems and as templates to create drug-loaded functional particles for biomedical application.First, nanoemulsification techniques that utilize elaborate interfacial physics/chemistry and micro-/nano-fluidics, featured with relatively-low energy input, to produce nanoemulsions with controllable sizes and compositions, are introduced.Uses of these nanoemulsions to create nanoemulsionincorporated milli-particles, drug-loaded nanoparticles and nanoparticle-incorporated microparticles with sizes ranging from several millimeters to sub-10 nm are emphasized.Flexible and efficient use of the nanoemulsions, functional nanoparticles and milli-/micro-particles integrated with nanoemulsions or nanoparticles for advanced pharmaceutical delivery in biomedical field are highlighted, with focus on how the interplay between their sizes and compositions achieve desired pharmaceutical-delivery performances.Finally, perspectives on further advances on the controllable production of nanoemulsions are provided.

Intranasal delivery of nanostructured lipid carriers,solid lipid nanoparticles and nanoemulsions:A current overview of in vivo studies

The management of the central nervous system(CNS)disorders is challenging,due to the need of drugs to cross the blood-brain barrier(BBB)and reach the brain.Among the various strategies that have been studied to circumvent this challenge,the use of the intranasal route to transport drugs from the nose directly to the brain has been showing promising results.In addition,the encapsulation of the drugs in lipid-based nanocarriers,such as solid lipid nanoparticles(SLNs),nanostructured lipid carriers(NLCs)or nanoemulsions(NEs),can improve nose-to-brain transport by increasing the bioavailability and site-specifc delivery.This review provides the state-of-the-art of in vivo studies with lipid-based nanocarriers(SLNs,NLCs and NEs)for nose-to-brain delivery.Based on the literature available from the past two years,we present an insight into the different mechanisms that drugs can follow to reach the brain after intranasal administration.The results of pharmacokinetic and pharmacodynamics studies are reported and a critical analysis of the differences between the anatomy of the nasal cavity of the different animal species used in in vivo studies is carried out.Although the exact mechanism of drug transport from the nose to the brain is not fully understood and its effectiveness in humans is unclear,it appears that the intranasal route together with the use of NLCs,SLNs or NEs is advantageous for targeting drugs to the brain.These systems have been shown to be more effective for nose-to-brain delivery than other routes or formulations with non-encapsulated drugs,so they are expected to be approved by regulatory authorities in the coming years.

Nanoemulsions for drug delivery

Emulsions are liquid-liquid dispersions with one liquid phase dispersed in the other liquid phase as small droplets.Nanoemulsions are nano-sized emulsions with sizes ranging from tens to hundreds of nanometers,and have great potential applications in pharmaceutics,foods and cosmetics due to their attractive properties,such as small sizes,high surface area per unit volume,improved dispersion of active hydrophobic components and enhanced absorption.The article provides an overview of nanoemulsions for drug delivery,starting with an introduction of emulsion types,nanoemulsion preparation and nanoemulsion stability.Surfactants play critical roles in producing and stabilizing nanoemulsions.Different types of surfactants are summarized including small molecule surfactants,particle surfactants,phospholipids,peptide and protein surfactants.Then the applications of nanoemulsions as nanomedicine in drug delivery are presented.Finally,clinical applications of nanoemulsions are discussed.

Permeation into but not across the cornea:Bioimaging of intact nanoemulsions and nanosuspensions using aggregation-caused quenching probes

Nanoemulsions(NEs) and nanosuspensions(NSs) show great potential in enhancing the ocular bioavailability of therapeutics through topical delivery. However, transocular fate of intact NEs and NSs is still inconclusive. In this study, an aggregation-caused quenching fluorescent probe is used to track precorneal retention and transocular transportation of intact NEs and NSs, while coumarin 6 is used to mimick the cargo. NEs show superior precorneal retention to NSs. Both the two types of nanocarriers can permeate into but not across the cornea. The smaller NEs(100 nm) permeate better into the cornea than the bigger ones(210 nm). Nanocarriers in the cornea serves as depots. The released cargo molecules can penetrate across the cornea and diffuse into the lens. Moreover, the conjunctiva-scleral route may be potential to deliver drugs to the back of the eye, In conclusion, the study provides useful tools and information in the field of transocular transportation of nanoparticles.

Tween 80 containing lipid nanoemulsions for delivery of indinavir to brain

Indinavir is a protease inhibitor used in the treatment of HIV infection.However,it has limited efficacy in eradicating the virus in the brain due to efflux by P-glycoprotein(P-gp)expressed at the blood–brain barrier(BBB).The objective of this work was to develop an o/w lipid nanoemulsion(LNE)of indinavir using Tween 80 as co-emulsifier to improve its brain specific delivery.LNEs were prepared with different compositions and were characterized for globule size,polydispersity index,zeta potential and in vitro drug release.Five formulations were then evaluated for drug content,entrapment efficiency and stability after which brain uptake studies were carried out using fluorescent labeled LNEs and pharmacokinetic(PK)and tissue distribution studies were conducted after intravenous administration in mice.Brain uptake of indinavir was shown to be improved for a 1%Tween 80 containing formulation(F5)compared to a formulation containing 0.3%cholesterol(F2).In PK studies,the brain level of indinavir subsequent to administration of F5 was significantly(Po0.05)higher than produced by administration of a drug solution(2.44-fold)or a control nanoemulsion(F1)(1.48-fold)or formulation F2(1.6-fold).The increased brain specific accumulation of indinavir from F5 is probably due to enhanced low density lipoprotein-mediated endocytosis and P-gp inhibition by Tween 80 at the BBB.These results suggest Tween 80 containing LNEs could provide a simple but effective means of delivering indinavir to brain.

Perfluorooctyl bromide nanoemulsions holding MnO_(2) nanoparticles with dual-modality imaging and glutathione depletion enhanced HIFU-eliciting tumor immunogenic cell death

Tumor-targeted immunotherapy is a remarkable breakthrough,offering the inimitable advantage of specific tumoricidal effects with reduced immune-associated cytotoxicity.However,existing platforms suffer from low efficacy,inability to induce strong immunogenic cell death(ICD),and restrained capacity of transforming immune-deserted tumors into immune-cultivated ones.Here,an innovative platform,perfluorooctyl bromide(PFOB)nanoemulsions holding MnO_(2) nanoparticles(MBP),was developed to orchestrate cancer immunotherapy,serving as a theranostic nanoagent for MRI/CT dual-modality imaging and advanced ICD.By simultaneously depleting the GSH and eliciting the ICD effect via highintensity focused ultrasound(HIFU)therapy,the MBP nanomedicine can regulate the tumor immune microenvironment by inducing maturation of dendritic cells(DCs)and facilitating the activation of CD8^(+)and CD4^(+)T cells.The synergistic GSH depletion and HIFU ablation also amplify the inhibition of tumor growth and lung metastasis.Together,these findings inaugurate a new strategy of tumor-targeted immunotherapy,realizing a novel therapeutics paradigm with great clinical significance.

Destructing surfactant network in nanoemulsions by positively charged magnetic nanorods to enhance oil-water separation

The separation of ultrafine oil droplets from wasted nanoemulsions stabilized with high concentration of surfactants is precondition for oil reuse and the safe discharge of effluent.However, the double barriers of the interfacial film and network structures formed by surfactants in nanoemulsions significantly impede the oil-water separation. To destroy these surfactant protective layers, we proposed a newly-developed polyethyleneimine micelle template approach to achieve simultaneous surface charge manipulation and morphology transformation of magnetic nanospheres to magnetic nanorods. The results revealed that positively charged magnetic nanospheres exhibited limited separation performance of nanoemulsions, with a maximum chemical oxygen demand(COD) removal of 50%, whereas magnetic nanorods achieved more than 95% COD removal in less than 30 s. The magnetic nanorods were also applicable to wasted nanoemulsions from different sources and exhibited excellent resistance to wide pH changes. Owing to their unique one-dimensional structure, the interfacial dispersion of magnetic nanorods was significantly promoted, leading to the efficient capture of surfactants and widespread destruction of both the interfacial film and network structure, which facilitated droplet merging into the oil phase. The easy-toprepare and easy-to-tune strategy in this study paves a feasible avenue to simultaneously tailor surface charge and morphology of magnetic nanoparticles, and reveals the huge potential of morphology manipulation for producing high-performance nanomaterials to be applied in complex interfacial interaction process. We believe that the newly-developed magnetic-nanorods significantly contribute to hazardous oily waste remediation and advances technology evolution toward problematic oil-pollution control.