*3.4.1 Encapsulation of lipophilic components using nano-emulsions*

Encapsulation is a useful technique to deliver bioactive molecules within living cells. Here, the bioactive ingredient is entrapped in a core or filled within a carrier (coating, matrix, membrane, capsule, or shell) [38].

This technology is used in food industry to:


Another important application of this technique that is worth mentioning is in probiotics [38]. (Probiotics are the microorganisms that provide health benefits when consumed in adequate amounts) (**Figure 7**).

Biologically active lipids such as omega-3 fatty acids can be encapsulated by nano-emulsions from food grade ingredients. Omega-3 fatty acid supplementation has a protective effect against cancer, cardiac death, sudden death, cognitive aging, asthma, inflammation and myocardial infarction [38]. *α*-Linolenic acid (ALA), an Omega-3 fatty acid, is one of two essential fatty acids together with linoleic acid. ALA is necessary for health and cannot be synthesized within the human body [38].

**Figure 7.** *Applications of nano-emulsion based delivery systems in food industry [38].*

### **3.5 Nanoemulsions in cosmetics**

**What are cosmetics?** *'Personal Care Products' or 'Beauty Products' such as skin creams, lotions, perfumes, lipsticks, fingernail polishes, eye and face make-up products, hair dyes and deodorants which are used by people to cleanse or change the look of the face or body are cosmetics. They do not alter the body's structure and function. Cosmetics are superficial and can also be therapeutic.*

Nanoemulsions are potential vehicles for optimum dispersion of active ingredients and their controlled delivery in particular skin layers. Their lipophilic interior makes them more suitable for the transport of lipophilic substances when

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wet wipes [11].

for lotions and sprays [41, 42].

*An Update on Nanoemulsions Using Nanosized Liquid in Liquid Colloidal Systems*

compared to liposomes. Small sized droplets and high surface area of nano-emulsions contribute greatly in inhibiting inherent creaming, flocculation, sedimentation and coalescence which are frequently observed in macroemulsions [33]. They have gained popularity in cosmetics due to ease of permeability and penetration into the skin owing to their small size and high surface area, solubility, transpar-

• As mentioned earlier, nano-emulsions help to overcome problems such as inherent creaming, flocculation, coalescence, and sedimentation.

• Relatively less surfactants (5–10%) [39] are used for nano-emulsion formulation (approved for human use) making them non-toxic and non-irritant. Hence, they can be easily applied onto the skin and mucous membranes [40].

• Healthy human and animal cells are not damaged by nano-emulsions. As a result, they are best suited for human and veterinary therapeutic purposes [40].

• Nano-emulsions can also be easily formulated in the form of foams, cream,

• Significant improvement in dry hair aspect (after several shampoos) is obtained with a prolonged effect after a cationic nanoemulsion use [39].

Oil in water nanoemulsions, due to their lipophilic interior have numerous applications in cosmetics such as formulation of lotions, sunscreens and skin creams, hair care products and make up removal substances. Other extremely important and fast growing applications include Emulsion based wet wipes and

The recent trends are shifting towards highly effective safer and natural cosmetic products. Cosmetic manufacturers are developing new methods to prepare nano versions of formulations for better permeability, effectiveness and increased customer satisfaction. This new technology is based on manufacturing low viscosity oil in water nanoemulsions which are free of synthetic chemicals like PEG. The phase inversion method of fabricating nanoemulsions leads to an important application in the cosmetic industry -formulating lotions to be impregnated in wet wipes. These are primarily used for make-up removal and

Industries are working on developing low energy methods coupled with low input homogenizers and absence of PEG, energy input for heating/cooling steps to formulate natural products [11]. The main constituents of this formulation are PEG free emulsifiers, cosmetic oils in high amounts and co-surfactants. When water is added to such a liquid and clear oil phase, a temporary micro-emulsion is formed which is then converted to stable, low-viscosity nanoemulsion. This low viscous phase is beneficial as it helps in converting the emulsion from water in oil to oil in water nanoemulsion. This step being dependent on water concentration is termed as phase inversion concentration which occurs by elimination of the co-surfactant into water. Some of these products developed are TEGO Wipe DE and TEGO Wipe DE PF which are based on nanoemulsions impregnated in wet-wipes and also used

*DOI: http://dx.doi.org/10.5772/intechopen.84442*

Advantages of using Nanoemulsions in cosmetics

PEG (Polyethylene glycol) free nanoemulsions [40].

*3.5.1 PEG free nanoemulsions and emulsion based wet wipes*

ency and color.

liquids, sprays.
