The magic of nano cosmetics?

As a representative of high technology, nanotechnology has become a research and development hotspot in the cosmetics industry after it has emerged in the fields of electronics and materials. Nano skin care products including shower gel, cleansing oil, facial mask, essence, sunscreen, etc. appear on the market. So, does nanotechnology represent high technology and safety? Are nano cosmetics so amazing? Today we will find out.

1. What is the principle of nano cosmetics

First, we first understand the concept of nano. Nano, like centimeters and micrometers, is a unit of length measurement: a nanometer is equal to one billionth of a meter, and one thousandth of a micrometer, which is about the width of three or four atoms. Nanotechnology refers to the study of the composition of matter within the nanometer size range, by directly manipulating and arranging atoms and molecules to rearrange and combine them to form new materials or structures with nanometer scales, further studying their characteristics, and manufacturing Devices with new functions, materials and scientific methods that can be applied to various other aspects.

The European Union Cosmetics Regulations (EC1223/2009) clarified the definition of nanomaterials in cosmetics, that is, raw materials that cannot be dissolved or biodegraded and are processed by humans with an external size or internal structure of 1-100 nanometers. The EU cosmetics regulations do not specify the size distribution of nanomaterials in the definition of nanomaterials. The European Commission (2011) recommends that raw materials containing 50% or more of 1-100 nanometers should be defined as nanomaterials.

On November 5, 2020, the official website of the National Medical Products Administration released the "Regulations for the Registration and Filing of New Cosmetic Ingredients" (draft for comments). With reference to EU regulations, the definition of nanomaterials is given, which means in the three-dimensional structure Insoluble and non-biodegradable artificial materials with at least one dimension in the size of 1-100 nanometers or composed of them as basic units. Nano cosmetics are cosmetics produced using nano-level raw materials or applying nanotechnology.

So, what is the technical principle of nano cosmetics? When the substance is broken down into nanoparticles (one nanometer is equivalent to one eighty-thousandth of the diameter of a hair), these nanoparticles usually exhibit new and active properties.

For example, studies have confirmed that certain minerals, such as zinc oxide, which is widely used in sunscreens, are white oily when they are in their natural state; but when they are decomposed into nanoparticles, these minerals The minerals will be transformed into a state that is more transparent and easier to be absorbed by the skin. Similarly, when the emulsifiers often used in hair conditioners and makeup removers are broken down into nanoparticles, their oiliness is also reduced, and their effects on hair and skin are more pronounced.

The technical principle of nano cosmetics can be vividly described as: the gap of human epidermal cells is one-tenth the thickness of hair, while nano-particles are one-tenth of the thickness of hair, which is a thousand times smaller than skin gap. Grade substances can penetrate into skin cells more freely, and its effective ingredients are more easily absorbed by the skin.

2. How to apply nanotechnology to cosmetics

The application of nanotechnology in nanocosmetics is mainly embodied in two aspects: active ingredients and carriers. Take nano sunscreen cosmetics as an example below.

Nano sunscreen cosmetics are sunscreen cosmetics developed by using nanotechnology. It specially processes the active ingredients in sunscreen cosmetics into extremely tiny nanoscale structures, and combines various new nano-carrier systems to greatly enhance the sunscreen effect and has some novelties. Characteristics.

The choice of sunscreen is the core of sunscreen cosmetic formulations. Traditional sunscreen cosmetics often use organic compounds as ultraviolet absorbers. In order to protect the skin from ultraviolet rays as much as possible, it is necessary to increase the amount of their addition, which will increase product costs and reduce product safety. Compared with traditional sunscreen cosmetics, nano sunscreen cosmetics have significant advantages, which are reflected in the following four aspects.

First, stronger sun protection performance.

Titanium dioxide and zinc oxide are nanosized and ultrafine, and the surface of the powder is coated with groups with hydrophilic and lipophilic functions, which can improve the suitability of the powder, and significantly improve the performance of the two without reducing the transparency. UVA shielding effect.

The second is weaker irritation.

Traditional organic sunscreens are highly active and irritating, and may have toxic and side effects on the skin. Nano-inorganic materials overcome the shortcomings of traditional formulations and are very safe to use.

Third, good light stability and heat resistance.

Some organic UV absorbers will volatilize or decompose when used at high temperature, but nano-zinc oxide has very stable heat resistance.

Fourth, stable nano-encapsulation technology.

Currently, composite sunscreens are mostly used in sunscreen cosmetics, and nanotechnology is used to wrap various sunscreens in nano-microspheres, which can optimize the performance of multiple sunscreens, make their formulations stable, and the effective active ingredients can be stored for a long time and the effect is doubled. In addition, it can release effective active ingredients in a controlled manner, significantly increasing the SPF value of the product.

The key to the application of nanotechnology in sunscreen cosmetics is as follows: ① Active ingredients: zinc oxide and titanium dioxide are currently commonly used ingredients in physical sunscreens, and nano-grade zinc oxide and titanium dioxide are more effective. ②Carrier: The new carrier is the key to the active transmission technology of sunscreen cosmetics, and the difference of the carrier directly affects the performance of the sunscreen. The development of nanotechnology has brought a variety of new carrier systems such as nanoparticle suspensions, liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, polymer nanoparticles, magnetic nanocarriers and inorganic material nanocarriers Wait.

Compared with traditional carriers, new nano-carrier systems, such as solid lipid nanoparticles, have many advantages: ①protect unstable compounds (such as vitamin A and vitamin E) to reduce their chemical degradation; ②control the release of active substances, such as The ingredients attached to the outer shell of the carrier have the characteristics of immediate release, while the active ingredients can be placed in the core of the liposome to control their sustained release; ③As an encapsulant, it can be used to increase the hydration of the skin; ④It can block ultraviolet rays The potential of it can play a physical sunscreen effect by itself, and it can also be used in combination with other sunscreens to obtain better light protection.

3. Are nano cosmetics safe?

At present, there is no data showing that cosmetics using nanotechnology will harm human health, but the impact of nanomaterials on health, safety and the environment is still scientifically uncertain in many respects.

Because nanoparticles are extremely small and have strong permeability, it is easy to cause people to worry about the safety of nano-cosmetics. Some scientists worry that the highly permeable nanoparticles may pass through the skin, enter the human blood circulatory system, and be transmitted to the brain, lungs and other human organs, posing safety risks to human health. Early research on carbon nanoparticles in other fields also showed that nanoparticles have a tendency to accumulate in cell tissues.

Because nanomaterials are emerging materials and their safety assessment experience is limited, EU cosmetics regulations have some special requirements for the use of nanomaterials. For example, cosmetics containing nanomaterials must be marked with [NANO] in the product full-component label. When using new nanomaterials, cosmetics companies need to inform the European Commission six months before the product goes on the market, which instructs the European Scientific Committee on Consumer Safety (SCCS) to conduct safety evaluations.

SCCS issued guidelines for the evaluation of nanomaterials in cosmetics in 2012. Generally speaking, the safety evaluation of nanomaterials is not significantly different from traditional ingredient safety evaluation. At the same time, SCCS has made corresponding safety evaluations on commonly used nanomaterials in cosmetics such as titanium dioxide, zinc oxide and carbon black (CI77266), and believes that they are safe in non-inhalation products within specific material specifications and limited concentrations.

SCCS also provided further explanations for sprayable products that cannot contain nanomaterials. In the newly released "Registration and Filing Data Specifications for New Cosmetic Raw Materials" (draft for comments), China has also put forward specific data requirements for the preparation process, quality control standards, and safety evaluation data of nano-raw materials.

Nanomaterials have gradually become another driving force to promote cosmetic innovation due to their unique physical properties. At the same time, the safety evaluation of their applications has also attracted the attention of research institutions and related regulatory agencies in various countries. Only by taking the positive and negative aspects of nanotechnology seriously can we make good use of this "double-edged sword" and truly promote the effective application of nanotechnology in the cosmetics industry.

Today, nanotechnology is widely used in cosmetic products such as skin care, sunscreen, perfume, make-up, etc., and its application trend in the cosmetics field has been unstoppable. As a new and fast-developing technology, there is still a lack of relevant data and methods for the environmental and human risk assessment of nanomaterials.

From an international perspective, regulatory measures and laws and regulations lag behind the development of nanotechnology. The vast majority of countries have not carried out effective supervision of nanomaterials in cosmetics, and the EU and other legislation also emphasized that the development of nanotechnology requires timely adjustment of regulatory policies and regulations. The development of my country's nano-cosmetics industry is also very rapid, and it is also facing the same regulatory difficulties. For this reason, the development trend of international regulatory measures is worthy of our government and enterprises' attention and reference.

With the unification of international nano-cosmetics standards and the establishment of national regulatory systems, the potential risks of nano-cosmetics will be controlled, the quality and safety of cosmetics will be further regulated, and people can rest assured to enjoy the convenience it brings, and nano-cosmetics will also usher in new Development Opportunities.