A review on green nanoemulsions for cosmetic applications with special emphasis on microbial surfactants as impending emulsifying agents

Nanoemulsions are being increasingly utilized in the pharmaceutical, cosmetics, and food industries. They have gained special attention in the cosmetic sector owing to their smaller size and higher kinetic stability and their ability to improve the cutaneous penetration of active ingredients. In addition, they reduce transepidermal water loss, which augments the skin's barrier function. In recent years, the increased awareness among consumers about the health-linked benefits of natural ingredients in cosmetics has urged finding green cosmetic ingredients that are benign to the skin. One of the natural motivations for this quest is finding suitable emulsifier candidates with negligible side effects that are sourced from plants or microbes, which can serve as viable replacements to the erstwhile used synthetic surfactants. Formulating a stable nanoemulsion system for cosmetic application entails a systematic understanding of important attributes of the surfactant candidate such as critical micelle concentration, hydrophilic lipophilic balance, critical packing parameter, and Winsor ratio that are pivotal to the overall performance of the emulsion system. The current review attempts to portray the salient features of nanoemulsion systems in cosmetic formulations, by essentially capturing the important characteristics of the emulsifier that dictate the overall stability of a nanoemulsion system. The recent transition toward the use of green ingredients such as emulsifiers and oils that are dermatologically safe has been delineated, by highlighting their important properties. Furthermore, the progress made so far in the application of microbial biosurfactants in nanoemulsion formulations is presented. Finally, the factors that dictate the overall stability of the nanoemulsion are briefly reviewed.     

Chitosan nanoencapsulation of Pogostemon cablin (Blanco) Benth. essential oil and its novel preservative effect for enhanced shelf life of stored Maize kernels during storage: Evaluation of its enhanced antifungal,antimycotoxin, antioxidant activities and possible mode of action

The present evaluation aimed to synthesis and characterise the Pogostemon cablin essential oil encapsulated chitosan nanoemulsion (PCEO-CN) and evaluated its antifungal antimycotoxin and antioxidant activities. A total of twenty-six different chemical compounds were identified from P. cablin essential oil (PCEO), among which patchoulol (34.93%), α-bulnesene (17.76%) and α-guaiene (15.44%) were recorded as major components. The average size of PCEO-CN was 18.20 nm. The PCEO-CN showed concentration-dependent broad-spectrum antifungal and antimycotoxin activities. The in vivo evaluation showed that PCEO-CN significantly protected maize seeds from mould-induced biodeterioration and aflatoxin B₁ biosynthesis for up to 30 days. The PCEO-CN significantly inhibits ergosterol biosynthesis and cellular integrities of A. flavus. Based on the present study, PCEO-CN could be used as a food preservative to control mould and mycotoxin contamination in stored maize.     

Physical,antimicrobial and antibiofilm properties of Zataria multiflora Boiss essential oil nanoemulsion

It was evaluated physical, antibacterial and antibiofilm properties of Zataria multiflora Boiss essential oil (ZEO) and its nanoemulsion. Long‐term stability of nanoemulsion prepared by emulsion phase inversion was satisfying based on low narrow size distribution (polydispersity index ?0.2) and low droplet size (200 nm) over 21 days of storage. Nanoemulsion showed lower minimum inhibitory concentration (MIC) on Listeria monocytogenes (2500 µg mL^?1) than Salmonella Typhimurium (5000 µg mL^?1). Killing kinetics study revealed that nanoemulsion was more effective in inhibiting the growth of bacteria in milk than culture media. Both bacteriostatic and bactericidal effects were observed depending on the type of bacteria, nanoemulsion concentration and the time of exposure. Nanoemulsion at 4×MIC concentration reduced 64% and 75% of one‐day‐old biofilm of L. monocytogenes and S. Typhimurium, respectively. In conclusion, nanoemulsion revealed antimicrobial activity, but converting the ZEO to nanoemulsion did not improve its antibacterial activity; however, antibiofilm properties were enhanced.     

Technological Aspects of Nanoemulsion Formation of Low‐Fat Foods Enriched with Vitamin E by High‐Pressure Homogenization

Formation of a low‐fat oil‐in‐water (O/W) nanoemulsion enriched with vitamin E using the nonionic surfactant Tween 40 is studied by means of a high‐pressure homogenizer. The effect of different process variables of the emulsification process, including pressure, temperature, and concentration of the emulsifying agent, is evaluated. The relation between pressure and the obtained mean droplet diameter is derived and described by an equation which can be taken as a basis of any process design. The droplet size can be decreased by increasing the vitamin E concentration. A higher fat content slightly affects the droplet size distribution and the mean droplet diameter of the nanoemulsion, so it is recommended to use preparations of nanoemulsions with low fat contents enriched with vitamin E for dietary supplement.     

复方地克珠利纳米乳的制备

通过绘制伪三元相图优选处方,制备了复方地克珠利纳米乳;用透射电子显微镜(TEM)、Nicom p388/ZetaPALS激光粒度测定仪分别考察了其形态和粒径;通过恒温加速实验检验了其稳定性。复方地克珠利纳米乳的最佳配方为:w(地克珠利)=5%,w(维生素K3)=10%,w(吐温-80)=30%,w(无水乙醇)=5%,w(乙酸乙酯)=3.9%,w(二甲基甲酰胺)=2.5%,w(蒸馏水)=43.6%;纳米乳在透射电镜下呈圆球形,分布均匀;平均粒径(Z-Average)为14.0 nm,多分散系数(Pdl)为0.064;恒温加速实验结果显示其仍澄明均一,未出现分层。复方地克珠利纳米乳稳定性好,制备工艺简单,有望应用于兽医临床。     

Enhanced transdermal delivery of carvedilol using nanoemulsion as a vehicle

The aim of the present study was to develop nanoemulsion as a possible vehicle for enhanced transdermal penetration of carvedilol (CVD). For screening of nanoemulsion components, solubility of CVD in oils, surfactants and co-surfactants was determined. Various surfactants and co-surfactants were screened for their ability to nanoemulsify the selected oily phases. The obtained results indicated that Acconon CC6® had shown good nanoemulsification efficiency (minimum surfactant required S _min?=?46.52%?w/w) among the selected surfactants and further improved in presence of CO-20® (S _min?=?37.11%?w/w). The ranges of nanoemulsion existence were delineated through the construction of the pseudo-ternary phase diagram at different ratio of surfactant mixture (S/CoS), and various nanoemulsions were selected from phase diagram of S/CoS ratio 1?:?1. The effect of content of oil and S/CoS (1?:?1) on the skin permeation of CVD was evaluated through an excised wistar rat skin using Franz diffusion cell. All the nanoemulsions showed a high skin permeation rate (92.251–161.53?µg/cm²/h), good enhancement ratio (3.5–6.2) and high permeability coefficient in comparison to control groups. The optimised nanoemulsion formulation with the highest skin permeation rate (161.53?µg/cm²/h) consisted of 0.25%?w/w CVD, 12.5%?w/w Miglyol 810®, 50%?w/w Acconon CC6®/CO-20® (1?:?1) and water. The above formulation had the smallest mean globules size (9.28?nm). The superior transdermal flux of CVD may be due to nanorange size of oil globules that lead to intimate contact with the skin layer. These studies suggest that the nanoemulsion system is a promising vehicle for the transdermal delivery of CVD.     

葡萄柚籽提取物及其纳米乳对大肠杆菌和金黄色葡萄球菌生物菌膜的抑制作用

目的：研究葡萄柚籽提取物(grapefruitseedextract,GSE)及其纳米乳(grapefruitseedextract nanoemulsion,GNE)对大肠杆菌和金黄色葡萄球菌生物菌膜的抑制作用。方法：分析菌膜黏附菌数变化、胞外聚合物(extracellular polymeric substances,EPS)含量并进行微观结构观察,比较GSE和GNE对两菌菌膜(单种菌膜和混合菌膜)形成的抑制作用和已形成菌膜的清除效果。结果：与对照组相比,1/2最小抑菌浓度(minimum inhibitory concentration,MIC)GSE和GNE可以抑制两菌单种菌膜形成时黏附菌和EPS产生,且对金黄色葡萄球菌的抑制作用更强。扫描电子显微镜(scanning electron microcopy,SEM)和共聚焦激光扫描显微镜(confocal laser scanning microscope,CLSM)所观察到的微观结构变化也显示出GSE和GNE对两菌菌膜形成具有抑制作用。GSE和GNE对已形成菌膜也有良好清除效果,且对金黄色葡萄球菌菌膜的清除作用更强,但混合菌膜...     

水/FC-72纳米乳液振荡热管传热特性研究

通过超声方法将水和FC-72乳化制备得到了不同体积浓度的水/FC-72纳米乳液,对以水/FC-72纳米乳液为工质的振荡热管开展了传热特性的实验研究。结果表明,使用纳米乳液后振荡热管冷热段温差明显下降,传热性能得到增强,且存在与充液率有关的最佳水相体积浓度,30%、50%和70%充液率下的浓度最佳值分别为11%、9%和9%。与使用纯FC-72时相比,充注最佳水相体积浓度纳米乳液的振荡热管在充液率为30%、50%和70%时冷热段温差最大可分别下降约3.3℃(或18.7%)、3.1℃(或13.7%)和4.3℃(或23.5%)。分析发现,纳米乳液的有效热导率和比热容均随着纳米水滴体积浓度的增加而明显增大,这可能是引起振荡热管传热能力增强的主要原因。     

Nanocarrier-based topical drug delivery for an antifungal drug

Objective: The conventional liposomal amphotericin B causes many unwanted side effects like blood disorder, nephrotoxicity, dose-dependent side effects, highly variable oral absorption and formulation-related instability. The objective of the present investigation was to develop cost-effective nanoemulsion as nanocarreir for enhanced and sustained delivery of amphotericin B into the skin.

Methods and characterizations: Different oil-in-water nanoemulsions were developed by varying the composition of hydrophilic (Tween® 80) surfactants and co-surfactant by the spontaneous titration method. The developed formulation were characterized, optimized, evaluated and compared for the skin permeation with commercial formulation (fungisome 0.01% w/w). Optimized formulations loaded with amphotericin B were screened using varied concentrations of surfactants and co-surfactants as decided by the ternary phase diagram.

Results and discussion: The maximum % transmittance obtained were 96.9?±?1.0%, 95.9?±?3.0% and 93.7?±?1.2% for the optimized formulations F-I, F-III and F-VI, respectively. These optimized nanoemulsions were subjected to thermodynamic stability study to get the most stable nanoemulsions (F-I). The results of the particle size and zeta potential value were found to be 67.32?±?0.8 nm and –3.7?±?1.2?mV for the final optimized nanoemulsion F-I supporting transparency and stable nanoemulsion for better skin permeation. The steady state transdermal flux for the formulations was observed between 5.89?±?2.06 and 18.02?±?4.3?µg/cm²/h whereas the maximum enhancement ratio were found 1.85- and 3.0-fold higher than fungisome and drug solution, respectively, for F-I. The results of the skin deposition study suggests that 231.37?±?3.6?µg/cm² drug deposited from optimized nanoemulsion F-I and 2.11-fold higher enhancement ratio as compared to fungisome. Optimized surfactants and co-surfactant combination-mediated transport of the drug through the skin was also tried and the results were shown to have facilitated drug permeation and skin perturbation (SEM).

Conclusion: The combined results suggested that amphotericin B nanoemulsion could be a better option for localized topical drug delivery and have greater potential as an effective, efficient and safe approach.