“Despite enormous potential of nanocosmetics, toxicity risks raise health concerns,” flag researchers

21 Sep 2022 --- A promising prospect for nanocosmetics has heightened concerns over health issues due to toxicity risks for researchers based in Pakistan, Mexico and Poland. They conduct a review over ten valuable nanoparticles and nanoliposomes (UV filters and delivery vehicles), followed by EU, US, Chinese and Australian regulatory opinions on the use of nanocosmetics.

Other concerns outline “large-scale production and conversion of nanocarriers dosage to final cosmetic form (cream/gel) which sometimes lead to drug leakage or change in particle size, thus affecting its skincare efficiency.”

The two highlighted uses of nanomaterials in cosmetics are UV filters and the release of active components in the deeper layer of skin to enhance the bioavailability of the substance, say the researchers.They also provide an overview on nanoparticles like cubosomes, liposomes, dendrimer, nanoemulsion, solid lipid nanoparticles, nanocrystals, nanocapsule, nanogold, nanosilver and niosomes.

No compromise on safety
As the researchers stress that safety considerations “cannot be neglected,” they suggest that manufactures should design and sell nanocosmetics per country regulation. 

Additionally, further studies should be conducted to provide customers with accurate and scientific information on the benefits, safety, toxicity and regulatory aspects of nano-technology based cosmetics. To do this, specialized preparation equipment and formulation optimizations are essential. 

“Nanotechnology has been effectively utilized in the cosmetic industry; therefore, the new term known as nanocosmetics has emerged,” they explain. “Generally, any cosmetic formulation having active nanosized ingredients with superior properties compared to its bulk counterpart is termed as nanocosmetics.” 

The definition and recognition of nanomaterial aligns between the aforementioned regulatory bodies – ranging from at least one dimension nanoscale to 100 nm, and the US extends this to 1000 nm.

Cross global regulations
The researchers compare the regulations between the EU Commission (EC), US Food and Drug Administration (USFDA), Chinese Food and Drug Administration (CFDA) and Australian National Industrial Chemicals Notification and Assessment Scheme (NICNAS).Nanomaterials range from at least one dimension nanoscale to 100 nm, and the US extends this to 1000 nm. 

The EC, CFDA and NICNAS require a report of the complete cosmetic profile before placing it on the market. The USFDA on the other hand, has “no premarket clearance” as manufacturers are responsible for the safety of products.

Between the four regulatory bodies, labeling of nanomaterials and toxicological profile and analysis remain unquestionable. 

In terms of animal testing, the EC has banned the prctice since 2013 and the USFDA prefers validated in-vitro studies over animal testing. CFDA is trying to mitigate animal testing for imported cosmetics and banned it locally in 2014. NICNAS is “not specified” on this requirement. 

“So far, the EC has approved the use of nanosized ZnO, TiO2, trisbiphenyl triazine, and methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) in UV filters. It has also allowed carbon black (nano) for use as a colorant in cosmetic products,” note the researchers. 

“USFDA and EC are continuously warning and regulating the human health related risks of nanocosmetics.” 

Moreover, recent reviews have discussed the safety concerns of nanoplastic, polymeric nanoparticles, graphene, amorphous nanosilica and other nanomaterials, they add.

Potential ways of exposure
Exposure to nanoparticles can occur via inhalation when spraying perfumes, powders or aerosol-based products. These may be deposited in the respiratory tract depending on the properties and can interact with the epithelium lining of the respiratory system, flag the researchers.

“The nanoparticles which are soluble may get dissolved, metabolized and transported to blood and subsequently other organs, whereas the insoluble nanoparticles may be either retained in the airways and induce pulmonary effects. These nanomaterials may also be ingested particularly when cosmetic formulations are applied on lips or mouth like lipsticks, lip balms, lip gloss, etc,” they continue.

Why the hype?
The authors say: “Nanomaterials act as carrier agents and easily penetrate in the deeper layer of skin where they enhance the bioavailability of the substance.”

It provides advantages compared to micro-scale cosmetics by enhancing the stability of the end product, improving skin permeability for efficient transport of the nanoconstruct loaded active ingredients, elegant color coding (e.g., in lipstick, face powder, nail polish), UV protection and transparency in sunscreens, they underscore. 

“As revealed from different surveys, almost all the world’s leading cosmetic brands use nanotechnology in their products,” share the authors.

“Lancome was the first company to launch nanomaterial-based cosmetic formulations. L’Oréal, has patented the use of dozens of ‘‘nanosome particles.’’ Estee Lauder is using nanomaterials in various products since 2006. Procter & Gamble, Henkle, Unilever, and Johnson & Johnson are some other cosmetic manufacturers utilizing these nanomaterials in their products.”The authors note that there has been a rising trend in using nanoscale materials to develop nanocosmetics. 

Cubosomes, liposomes and dendrimer
One type of nanomaterial is cubosomes. Its merits are that it is non-toxic, less viscous, biocompatible, has enhanced skin permeation and has a high drug loading due to its crystalline structure. Its demerits include a low entrapment of soluble drugs due to a large amount of water and is difficult to produce at large scales. 

Another type is liposomes. Its merits are its biocompatibility, biodegradability, non-toxicity and how it enables efficient drug penetration. Its demerits include high production costs, drug leakage and that it may get hydrolyzed or oxidized. It is in products such as Dermosome Decorte Moisture, Liposome Face Cream, Decorte Moisture and Liposome Eye Cream. The proposed use of Liposomes is for skin moisturizers.

Dendrimer provides versatility due to ease of functionalization, biocompatibility, numerous binding sites and enhanced skin permeation. Its demerits are that it is difficult to synthesize pure forms in bulk and the toxicity is unclear in-vivo. 

Nanoemulsions, solid lipid nanoparticles, nanocrystals, nanocapsules
Another nanomaterial is nanoemulsion which is optically transparent, provides hydration, has efficient penetrating ability, is non-toxic and nonirritant. Its demerits include instability which is influenced by pH and temperature. Moreover, it is expensive to produce. 

It is marketed products such as Nanocreams, Bepanthol-Protect Facial Cream Ultra, Coni Hyaluronic Acid & Nanoemulsion Intensive Hydration Toner. Nanoemulsion is proposed to be used for wet wipes, moisturizing, antiaging, and anti-pollutant skin hydration. 

Solid lipid nanoparticles increase bioactivity and provide a controlled release of carrier molecules, improves skin hydration, is biocompatible and provides stability to unstable ingredients. Its demerits are that it has a low drug loading capacity to hydrophilic drugs, drug expulsion during storage. It is marketed in formulations such as Allure Body Cream, Allure Parfum Bottle, Allure Eau Parfum Spray. The proposed use is for body moisturizers and perfumes.

Furthermore, nanocrystals are nontoxic and they increase the solubility and bioavailabilty of substances. However, its demerits and market use are unreported. Further studies should be conducted to provide customers with accurate and scientific information on the benefits, safety, toxicity and regulatory aspects of nano-technology based cosmetics. 

Nanocapsules protect drugs during storage, increase bioavailability and have a controlled and sustained release. Its demerits include a difficult and costly production at an industrial scale and has a less ability to adjust the drug dose. It is marketed in Hydra Flash Bronzer and Daily Face Eye Contour Nanolift. The proposed use is for moisturizing, anti-wrinkle and anti-aging products. 

Nanogold and silver and niosomes
Another type of nanomaterial is Nanogold. Its merits are its biocompatibility, easy penetration, dermo protection and it is photostable. Its demerits are not reported. It is marketed in formulations such as Chantecaille Nano Gold Energizing Cream, Ameizii Nano Gold Foil Liquid, LR Nano Gold Day & Silk Day Cream. The proposed use is for cell regeneration, collagen production, sun damage repair, skin firming, skin repair, moisturizers, skin whitening and UV ray protection.

Moreover, nanosilver has skin healing properties and is also dermo protective and antimicrobial. Its demerits are not reported. It is found in Cosil Whitening Mask. The suggested use is in facemasks for removing germs from the face, compressing pores, and keeping the skin radiant and soft.

Lastly, niosomes enhance dermal permeation, have a controlled and targeted drug release, are stable to oxidation or hydrolyzation, increase entrapping efficacy and are suitable for poorly absorbed drugs. Its demerits are drug leakage, physicochemical instability (sedimentation, fusion, aggregation) and it is time-consuming to prepare. It is in Niosome + Perfected Age Treatment. The proposed use is for removing wrinkles, foundation creams and for clear and white skin tones. 

By Venya Patel