Microneedles are a promising and minimally invasive transdermal delivery technique effective in promoting peptide permeation through the skin.

The needles have a size ranging from 100 to 1500 μm, which makes them able to pass through the stratum corneum (thickness between 10 and 30 μm).

Furthermore, they are responsible of forming pores in the skin, which are large enough to allow macromolecules to pass through, simply and painlessly.

Despite the advantages of this notable approach, microneedles have an obstacle when it comes to the delivery of substances: the elasticity of the skin. This parameter may hinder the penetration of microneedles in the stratum corneum, since the skin, can deform with the pressure exerted by the needle, without breaking its barrier. Consequently, pore formation and substance permeation are compromised.

There are some studies suggesting that different microneedles allow successful permeation of peptides into the skin. An in vitro study was performed by Zhang et al., to investigate the efficacy of solid microneedle arrays (consisting of 121 needles, attached to an applicator) in delivering hydrophilic peptides, namely acetyl hexapeptide-3, into pig ear skin. The results of the study exhibited not only that this physical system was effective in forming pores, but also in the delivery of the peptides through the skin, since the passive flow of acetyl hexapeptide 3 through the skin, when microneedles were applied was 0.44 ± 0.12 μmoL/cm/h, which was much higher than the passive flow of this peptide in untreated skin (0.014 ± 0.002 μmoL/cm/h).

Source: Journal of Drug Delivery Science and Technology - Anti-aging peptides for advanced skincare: Focus on nanodelivery systems

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Skin aging is largely due to the accumulation of oxidative damage, resulting from the insufficient bioavailability of antioxidants regarding the increased amount of ROS produced, by the mitochondrial aerobic metabolism or solar UV radiation.

Consequently, ROS accumulate and activate several signaling pathways, responsible for the reduction of collagen synthesis; production and activation of MMP and release of the senescence-associated secretory phenotype (SASP).

Studies with Tel-E6E7 human stem cells suggested that ROS induced by UV radiation, promote MMP-1 activity in keratinocytes and fibroblasts of the dermis.

Thereby, to prevent oxidative stress, antioxidant peptides are used owing to their ability to transfer an electron or hydrogen atom to stabilize radicals, or to their capability to complex ions, such as copper, essential for the functioning of enzymes involved in the inflammation and aging process, inhibiting them. Moreover, antioxidant activity is still dependent on their molecular weight, as low molecular weight peptides have a greater ability to donate hydrogen or electrons; their hydrophobicity that improve the accessibility to hydrophobic cellular targets, e.g. biological membranes; and their amino acid sequence.

Hydrolyzed collagen or collagen peptides results from the denaturation of collagen protein by enzymatic hydrolysis. In the cosmetic industry, hydrolyzed collagen is widely used, owing to their biocompatibility, easy biodegradability, and very low toxicity when topically applied. Hydrolyzed collagen has been identified as a good moisturizer for the stratum corneum of the epidermis, though, as far as its anti-aging benefits, its mechanism of action is not fully identified.

The antioxidant activity of peptides is related to its molecular weight, thus smaller peptides up to 10 KDa (equivalent to 2 to 10 amino
acids) show higher antioxidant activity. To assess the relationship between the molecular weight of collagen hydrolysates from sheep skin (which is dependent on the time of hydrolysis of the collagen) and its antioxidant activity, L´eon-Lopez et al. conducted a study in which two free radicals were used: ABTS (suitable to evaluate hydrophilic and hydrophobic antioxidants) and DPPH. The results of the study showed that the highest radical scavenging activity was seen after 4 h of hydrolysis of the collagen protein, 67.6 % for ABTS and 52.75 % for DPPH. Thus, collagen hydrolysates of small size and composition in antioxidant amino acids e.g., glutamic acid (due to the high hydrolysis time), guarantee a considerable antioxidant activity, and may be valid options in combating skin aging caused by oxidative stress.

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Copper tripeptide-1 (Cu-GHK) was the first peptide used in cosmetics for skin application, and resemble the alpha chain of collagen.
This carrier peptide is very versatile concerning several skin functions, including stimulation of collagen, glycosaminoglycans, elastin and proteoglycans synthesis by fibroblasts, as well as anti-inflammatory response. Cu-GHK comprises numerous cosmetic applications, being used in products for its efficacy in reducing wrinkles, hyperpigmentation and photo damage, in stimulating keratinocyte proliferation and improving the skin barrier.
A study conducted by Huang et al., demonstrated that Cu-GHK when used with therapeutic light-emitting diode (light therapy to prevent aging and aid the healing process) led to an increase in pro collagen type I synthesis (about 230.0 %), as well as in basic fibroblast growth factor production (about 30.0 %). Therefore, it is concluded that Cu-GHK may be an ally in combating skin aging, since it promotes fibroblast growth and collagen synthesis, as well as epidermal repair.

Source: Journal of Drug Delivery Science and Technology - Anti-aging peptides for advanced skincare: Focus on nanodelivery systems

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Palmitoyl tripeptide-1 is a signal peptide that results of the conjugation of palmitic acid with tripeptide-1 which performs two functions: signal peptide and carrier peptide when complexed with copper. Palmitoyl tripeptide-1 act on the TGF-β, which is responsible for stimulating dermal fibroblasts to produce ECM proteins, which will reinforce the epidermis, but also reduce wrinkles.

Source: Journal of Drug Delivery Science and Technology - Anti-aging peptides for advanced skincare: Focus on nanodelivery systems

Anti-aging peptides are applied to the skin to obtain a local effect, acting on the factors that cause changes in the structure, appearance, functionality, and homeostasis of the skin. According to their mechanism of action, anti-aging peptides can be categorized as bioactive peptides, which act on the skin repair and renewal systems, stimulate collagen synthesis, cell proliferation, and reduce melanogenesis; antioxidant peptides, capable of eliminating ROS from the body and antimicrobial peptides (AMPs) that are involved in the maintenance of a healthy skin microbiome.
Despite its beneficial effects, these peptides are hydrophilic substances, thus may have difficulty crossing the epidermal barrier, so conjugation with fatty acids, such as palmitic acid, is frequently used to increase protection of the peptides against enzymatic action, and their lipophilic character improve delivery through the skin.
Anti-aging peptides are therefore appealing ingredients for the cosmetic industry because of their wide applicability and also owing to their higher safety profile.

Source: Journal of Drug Delivery Science and Technology - Anti-aging peptides for advanced skincare: Focus on nanodelivery systems

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Adansonia Digitata Seed Oil is the oil expressed from the seeds of the Monkey Bread Tree or the Baobab, Adansonia Digitata L., Bombacaceae. Baobab oil (Mbuyu in Swahili) is derived from the seeds of the baobab tree, a tree that is native to Eastern and Southern Africa. Baobab oil has been part of African skin care for centuries. This rich, golden oil has a sligtly nutty smell. It has a high content of vitamins A, D, E and F (essential fatty acids). Baobab oil is said to provide impressive moisturizing benefits to the skin and hair. It absorbs quickly, improves elasticity, encourages regeneration of skin cells and does not clog the pores.

Saponification value: 205.
Iodine value: 80.
Average carbon number: 17.379.

Traditional use: An African tree steeped in mystery, legend and religious significance. The fruit provides an exquisite oil that is a rich and substantive moisturizer. The traditional method of oil extraction is by pounding the seeds. The oil thus produced is used as a rub to relieve aches, pains and rheumatism, but more especially, to treat skin complaints such as eczema and psoriasis. Baobab oil is extremely stable against rancidity. No adverse effects are reported or expected from the topical application to the skin.

(CAS: 91745-12-9; EINECS: 294-680-8)

Function: Emollient / hair conditioning / skin conditioning.

The actual or estimated LD₅₀ value: 5,000 mg/kg body weight. AICS status (NICNAS Australia): Number and description not found.

Source: Handbook Of Natural Ingredients - Anthony C. Dweck

Peppermint. Country: South Africa/Malawi. Part used: fresh leaves. Traditional use: Typical minty fragrance with mentholic undertones. It has a clean, clearing, penetrating odor. Invigorating; ideal travel companion, calms the stomach. Used to bathe tired and sweaty feet. A good insect repellent. Has a cooling effect on the body. Stimulating, used for headaches and nausea, very cooling. Breath freshener.

Source: Handbook Of Natural Ingredients - Anthony C. Dweck

Resveratrol  is a phytoalexin (trans-3,5,4’-trihydroxystilbene), an antioxidant polyphenol from red wine and recent evidence has supported the assumption that is largely responsible for red wine’s protective effects on blood vessels, by inhibiting lipid peroxidation of low density lipoprotein (LDL). It is found in the skin of red grapes, and is synthesized by the plant in response to attack by pathogens such as bacteria or fungi (especially by the Botrytis fungus). It has been the subject of intense interest in recent years due to a range of unique antiaging properties. The role of resveratrol in prevention of photoaging was reviewed and compared with other antioxidants used in skin care products. It has been clinically proven to have a two-step anti wrinkle activity and also has antiaging activity based on Sirtuin-1 activation.

Source: Handbook Of Natural Ingredients - Anthony C. Dweck

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Retinol is the primary naturally occurring form of vitamin A. It is a pale yellow crystalline material or a thick liquid. Retinyl Palmitate is a yellow to yellow-red solid or oily substance. Retinyl Palmitate is the ester of Retinol and palmitic acid. In cosmetics and personal care products, Retinol and Retinyl Palmitate are used primarily in the formulation of hair, facial make-up and skin care products. Internally it counteracts night blindness, weak eyesight and in the treatment of many eye disorders. It permits the formation of visual purple in the eye. Helps in the removal of age spots.Promotes healthy skin, hair, teeth and gums. Helps treat acne, impetigo, boils.

Source: Handbook Of Natural Ingredients - Anthony C. Dweck

Collagen is a natural protein found in the connective tissue of the skin (where it accounts for 70% of its content), as well as in the organs, muscles, bone and cartilage. In fact, there are more than 25 different types of collagen in our bodies. In the skin, it adds suppleness, plumpness, flexibility and spring, and, together with elastin, adds texture and structure. However, as skin ages or is exposed to sun damage, its collagen content is reduced, making skin progressively drier, thinner, flatter, less flexible and more wrinkle-prone. Since animal-derived and plant- derived pseudo-collagen also retains many times its own weight in water, these substitutes are used as conditioning, hydrating and suppleness-boosting ingredients in anti-aging products.

Source: Handbook Of Natural Ingredients - Anthony C. Dweck

Sea mustard, Wakame, Japanese Kelp. The algae has resistance against harsh environmental stress (UV light, water movements and abrasions) that is related to its content of a special sulphated polysaccharide called fucodian that protects the algae's body wall from losing integrity and stability. It contains proteins, lipids microturients, vitamins and sugar that lead to a revitalizing and energizing action on skin cells. It has been reported that fucodian has radical scavenging and hyaluronidase inhibitory properties. It is these properties that make Wakame a useful antiaging active ingredient in cosmetics.

Source: Handbook Of Natural Ingredients - Anthony C. Dweck

Microplastics are tiny pieces of plastic that measures less than five millimeters in size. Some microplastics are formed by breaking away from larger plastics that have fragmented over time. Others are made intentionally small, otherwise known as microbeads. These are also used in cosmetics products such as face scrubs, as well as detergents, paints, medicines, nappies and pesticides. The use of microbeads in cosmetics is banned in the EU.

The act of misleading consumers regarding the environmental practices of a company or the environmental benefits of a products or service.

Source: TerraChoice Group Inc, 2009

Bioplastics constitute a broad range of materials and products that are biobased, biodegradable/compostable, or both.

What is injection moulding?

Injection moulding is the process of manufacturing highly accurate plastic components such as closures, overcaps, and reducing plugs. Plastic resin is fed into a heated barrel and screw which is then injected at high pressure into a water-cooled mould which may consist of various moving parts.

Due to the high injection pressures, this cavity will be held together by the use of a clamping unit. While the plastic is held inside the mould, the plastic will freeze off to the desired shape. After the plastic has cooled sufficiently, the mould and clamping unit will open and allow the finished component to be ejected so that the process can be repeated.

Which materials can be injection moulded?

Polypropylene (PP) is the most common resins used in injection moulding and can be divided into three sub categories:

• Homo polymer: For general use of moulding closures
• Co Polymer (Random): Gives excellent clarity when used for overcaps and when closures are used with active hinges as with 'flip top' closures
• Co Polymer (Block): These components will generally have poorer clarity and are therefore generally coloured components but offer greater impact resistance

Generally PP is advantageous when being used in conjuction with a dissimilar bottle materials such as HDPE, PVC or PETG as it will improve any binding issues between the two components.

When choosing your bottle you will need to decide which neck best suits your products and choice of cap. This number is the neck finish.

The neck finish is normally signified by two numbers - for example 20/410, 20/415, 24/410 ans 24/415. These two numbers represent the outer diameter of the neck opening (mm), the thread configuration and height of the neck.

Injection Stretch Blow Moulding (ISB) is a process that manufacturers high quality containers in PET to produce a clarity similar to glass.

ISB can also produce materials that are less clear such as polypropylene (PP).

Production process

Production begins with the injection process, where molten polymer flows into an unjection cavity to produce a preform, a hollow test tube shaped plastic object that has a neck and a thread on the open end.

When the preform is conditioned to the correct temperature, it is ready for stretching and blowing to the desired shape using a mould. Once in the mould, a rod is introduced to stretch the preform using two levels of air pressure, the preform is then blown circumferentially. After a set cooling time, the moulds open and the preformed bottle is removed. The process is carried out concurrently using a revolving carousel of moulds.

ISB is an environmental alternative to glass

Because plastics are soft and boast lower melting points, PET bottles require less energy to manufacture than glass. Easier to recycle, PET can also be made in PCR in levels up to 100%.

It is also possible to make PET products using a range of biopolymers, including sugarcane based PET. With no sign of difference in both appearance or performance, out PET biopolymer can be recycled in the same stream as conventional PET and PCR PET, for a truly sustainable solution.

What are the advantages of this process?

Offering dimensionally accurate bottle shapes, when molded, PET (Polyethylene Terephthalate) provides an excellent alternative to glass for a number of reasons

These include:

• Clarity similar to glass
• Lighter in weight
• More cost effective to transport products
• Higher breakage resistance to avoid risk and injury
• More durable than glass
• Excellent barrier characteristics against carbon dioxide and oxigen
• Requires less energy to produce
• Can be easily recycled
• PET can be decorated with silk screen printing and hot foil blocking

Extrusion Blow Moulding is the process of manufacturing plastic bottles by melting plastic resin and extruding a tube which is them clamped inside two halves of a water-cooled mould.

This tube of plastic is then inflated using pressurized air to the shape of the cavity. While inside, the plastic will freeze off to the shape as it is forced against the inside. The mould will then open, releasing the bottle so that the process can be repeated.

One of the many benefits of the extrusion blow moulding process is the flexibility to change the necks without having to change the entire mould. This customizable solution enables customers to use differing neck fitments on the same bottle mould, eliminating the need for a completely new mould each time, which can prove more cost effective.

What are the advantages of this process?

Extrusion blow moulding is a highly versatile process that can provide unique shapes, sizes and neck types, using a variety of plastics. This versatility gives an overwhelming advantage over the bottle manufacturing processes.

One of the most common resins used in blow moulding is HDPE (high density polyethylene). Although opaque in its natural state, a high gloss feel and appearance can be achieved too.

For a squeezable feel, MDPE (medium density polyethylene) can be used for products such as creams and lotions.

Key advantages:

• Offers good resistance to alcohol, acids and alkalis
• Produces bottles with high stiffness
• Allows forn interchangeable neck moulds
• Easily recycled
• Can be moulded to produce complex shapes and sharp contours

PCR stands for Post Consumer Recycled materials. These plastics are popular with customers looking to reduce the amount of virgin plastic in their product packaging.

Generally produced from discarded plastic milk and drinks bottles, PCR materials are environmentally sustainable solution for reusing single-use materials that would otherwise be disposed of landfill sites.

PCR materials can be recycled again for new manufacturing to provide genuine sustainability.

Improves the feel of hair and skin. For example, hair conditioners leave hair smooth, soft and static-free.

Benefits of conditioning agents

Conditioning agents offer a number of benefits for hair and skin, including:

Reduce frizz: Conditioning agents smooth the hair shaft and fill in gaps between the cuticles, which helps to reduce frizz and make the hair look more manageable.

Increase shine: Conditioning agents add a layer of lubrication to the hair shaft, which helps to reflect light and make the hair look shinier.

Improve detangling: Conditioning agents make the hair slippery and easier to comb, which can help to prevent breakage and split ends.

Protect from damage: Conditioning agents help to seal in moisture and protect the hair from environmental damage, such as heat styling, sun exposure, and chlorine.

Hydrate the skin: Conditioning agents can help to hydrate the skin and make it feel soft and supple.

What is a nanomaterial?

A nanomaterial is a material in which at least one external dimension is in the nanoscale range (1-100 nanometers). Nanomaterials exhibit unique properties that are different from their bulk counterparts due to their small size. These properties arise from the increased surface area, quantum confinement, and enhanced reactivity of nanomaterials.

Despite the many potential benefits of nanomaterials, there are also some concerns about their safety. Nanomaterials can be inhaled, swallowed, or absorbed through the skin, and they may pose a risk to human health. More research is needed to assess the potential risks and benefits of nanomaterials.

Nanomaterials in cosmetics

In the context of cosmetics, a nanomaterial is defined as an intentionally manufactured material with at least one external dimension or an internal structure in the nanoscale range (1-100 nanometers). This means that the material is so small that it can only be seen with an electron microscope.

Nanomaterials are being increasingly used in cosmetics due to their unique properties, such as their ability to:

• Improve the efficacy of cosmetic products: Nanoparticles can be used to deliver active ingredients deeper into the skin, making them more effective.
• Increase the stability of cosmetic products: Nanoparticles can help to stabilize active ingredients and protect them from degradation.
• Enhance the aesthetic properties of cosmetic products: Nanoparticles can be used to improve the texture, color, and fragrance of cosmetic products.

Definition of nanomaterials:

Regulation (EC) No 1223/2009 specifically covers the use of nanomaterials in cosmetic products. The Regulation provides a definition of nanomaterial, as well as a mechanism for notification, labelling, and safety evaluation of cosmetic products containing nanomaterials. Under Article 2 (1) (k), “nanomaterial” means an insoluble or bio persistent and intentionally manufactured material with one or more external dimensions, or an internal structure, on the scale from 1 to 100 nm”. In view of the EU Chemicals Strategy for Sustainability (Ares, 2021), it is likely that the definition for a nanomaterial in the Cosmetic Regulation will be aligned with the recently published 2022/C 229/01 Commission Recommendation of 10 June 2022 on the definition of nanomaterial. The Regulation therefore mainly covers those nanomaterials that are intentionally produced and are insoluble/poorly-soluble or bio persistent (e.g., metals, metal oxides, carbon materials, etc.), and not those that are either completely soluble or degraded and are not persistent in biological systems (e.g., liposomes, oil/water emulsions, etc.). When dealing with the question of solubility, as provided in the current definition, it is important to note that any nano-specific risk may change (even diminish) when a nanomaterial is dissolved. But it is the time period during which the dissolution happens that determines the considerations for risk assessment based on either particle risk or soluble substance risk. Partial dissolution over a long period of time may lead to the mistaken claim that the material is 'soluble', and therefore not a nanomaterial under the scope of the current definition provided in the Cosmetic Regulation (EC) No 1223/2009.

Potential safety issues of nanomaterials

The use of nanomaterials in cosmetics is subject to a high level of protection of human health under the EU Cosmetics Regulation. This is because nano forms of some substances may differ from their conventional (bulk) forms in terms of physicochemical properties, biokinetic behaviour, and/or biological effects. Any intended use of nanomaterials (other than colourants, preservatives and UV filters and not otherwise restricted by the EUCosmetics Regulation) in cosmetic products must be notified to the Commission by the RP through the Cosmetic Product Notification Portal (CPNP) at least six months prior to placing them on the market, except if they were already on the market before 11 January 2013.In case of a safety concern over a nanomaterial, the Commission shall request the SCCSfor a scientific Opinion on the safety of the nanomaterial for use in relevant categories of cosmetic products in consideration of the reasonably foreseeable consumer exposure.The SCCS was recently mandated by the Commission to provide scientific advice to facilitate the identification of any safety concerns relating to the nanomaterials intended for use in cosmetic products, so that they can be prioritised for safety assessment. The advice has recently been published (SCCS/1618/2020), which provides the key scientific aspects of a nanomaterial that should trigger consumer safety concerns, and therefore the need for further evidence-based safety assessment.Although there are currently no hard and fast rules for identifying the safety concerns for nanomaterials, as a general principle, each of the following attributes should add a further degree of safety concern. For example, where:

i. The nanomaterial has constituent particles that have sizes in the lower range of the nanoscale.

ii. The nanomaterial is insoluble, or only partially soluble.

iii. The chemical nature of the nanomaterial suggests the potential for a toxicological hazard.

iv. The nanomaterial has certain physical/morphological features (e.g. needle shape, rigidlong fibres) that are associated with a higher potential for harmful effects. The nanomaterial has surface reactivity in terms of catalytic (including photocatalytic)activity, potential for radical formation, or other surface properties (e.g. potential allergenicity due to proteinaceous surface).

v. The nanomaterial has a different bio kinetic behaviour than the conventional equivalent.For example, a surface modification/coating (e.g. hydrophobic coatings, encapsulation)has been applied to core nanoparticles to alter their ADME properties and as a result make them more accessible systemically, compared to the neat nanoparticles and/or their conventional chemical forms.

vi. The nanomaterial is used as vehicle to carry other substances that have not been assessed for safety as individual components, or together in the form of nano-scale entity.

vii. There is a likelihood of systemic exposure of the consumer to nanoparticles through the use of final products. The frequency of use, and/or the amounts of the relevant consumer product are relatively high.

viii.There is evidence for persistence/accumulation of nanoparticles in the body.

ix. Nanoparticles have other distinctive properties not present in conventional form of the same material, or have a new activity/function (e.g. a smart/functional nanomaterial).

x. The nanomaterial is so novel that it does not have a conventional comparator to allow assessment of changes in properties, behaviour or effects.

xi. The nanomaterial is used in a product that is inhalable (taken up by inhalation into respiratory tract and lung), and the particles are respirable (can reach respiratory epithelium i.e. alveoli).

xii. The assessment of genotoxicity is performed inadequately, e.g. in vitro studies are without information on stability of the test suspension, or evidence of cell exposure(internalisation).

While this section only provides a brief guidance on nanomaterials in cosmetics, the SCCS has published a more detailed specific Guidance on Risk Assessment of Nanomaterials( SCCS/1611/19, under revision), which is an update of a previous guidance published in2012 (SCCS/1484/12), a Memorandum on the Relevance, Adequacy and Quality of theData Expected in Safety Dossiers on Nanomaterials (SCCS/1524/13), and a checklist for the applicants submitting dossiers on nanomaterials as cosmetic ingredients(SCCS/1588/17). Safety assessors need to consult these documents to ensure that any testing to generate evidence on the safety of nanomaterials is carried out with special considerations of the nano-size related characteristics of the materials, and in compliance with the ban on animal testing of cosmetic ingredients. In this regard, it is important to note that, as indicated in the memorandum (SCCS/1524/13), the SCCS will only consider data that are relevant to the nanomaterial(s) under evaluation, are sufficiently complete, and are of appropriate quality to support the safety assessment. The SCCS has also published a number of scientific Opinions in the past few years on the nano-form of different materials. Each of the Opinions can be consulted via the EuropeanCommission website. SCCS Opinions can provide further information on the type o fscientific evidence needed in a safety dossier on nanomaterials intended for use as cosmetic ingredients.In general, a number of reviews have concluded that the existing risk assessment paradigm, in use for conventional chemicals, should in principle be also applicable to engineered nanomaterials. However, it has also been pointed out that the current testing methods may need certain adaptations to take account of the special features of nanomaterials (Rocks et al., 2008; SCENIHR, 2009; SCCS, 2012; EC, 2012; ECHA, 2017; EFSA, 2018;EFSA, 2021a, EFSA 2021b, EC 2022).

Special features of nanomaterials:

- Due to high surface energies, nanoparticles have a tendency to stick together to form agglomerates and aggregates, and/or bind with other moieties on the particle surface.This particle behaviour can change in the presence of certain stabilising/dispersing agents. Characterisation of nanomaterials, prior to and during a test, is therefore a key to ensuring that results obtained are valid.

- Most of the currently available test methods were developed for conventional substances that can be solubilised. In contrast, nanomaterials generally comprise insoluble or poorly soluble nanoparticles that are dispersed in a test medium in the form of a nano-suspension rather than a solution. The applied concentration of a nanomaterial may therefore drop during the test due to particle agglomeration, sedimentation, binding with other moieties in the medium, or sticking to the sides ofthe glass/plastic ware. This could lead to only a partial or no exposure of the test systems during the test. Nanomaterials are known to adsorb or bind different substances on their surfaces, including proteins (Šimon and Joner, 2008; Lynch andDawson, 2008; Monopoli et al., 2012; Moore et al., 2015). They may also bind other substances in the test medium and carry them into the exposed test systems, leading to artefacts in the results.

- The toxicological hazards of chemical substances are currently measured and expressed in terms of weight or volume units (such as mg/kg, or mg/l). These conventionalmetrics may not be fully adequate to account for nanomaterial toxicity. It is thereforeimportant that tests on nanomaterials are not only evaluated in terms of weight/volume concentration, but that results are also expressed in other dose-describing metrics, such as particle number concentration, surface area etc.

- Due to the insoluble particulate nature, and the nano-dimensions, nanomaterials may show an altered uptake and bio kinetic profile in a biological system compared to equivalent conventional forms, e.g. transport of insoluble particles across biological membrane barriers is not driven by concentration-gradient based diffusion partitioning, but by other mechanisms such as endocytosis and/or active (energy-driven) uptake and transport.

- Currently, there are uncertainties in regard to whether the endpoints identified by the current testing methods will be sufficient to identify and characterise all the hazards that may be associated with a nanomaterial.

Source: SCCS Notes of guidance for the testing of cosmetic ingredients and their safety evaluation

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Cosmetic products play a significant role in our daily lives, helping us look and feel our best. Ensuring the safety of these products is of greatest importance and one crucial aspect of the process is the assessment of Systemic Exposure Dose (SED).  

What is the Systemic Exposure Dose (SED)?

The Systemic Exposure Dose, abbreviated as SED, is a fundamental concept in toxicology and risk assessment and it refers to the amount of a cosmetic substance expected to enter the bloodstream. It is obtained by combining the external exposure (mg/kg bw/day) with the absorption rate (typically expressed in % or μg/cm2), frequency of application and retention factors and it is expressed in mg/kg body weight/day.

Why does SED matter in cosmetic safety evaluation?

In the context of cosmetics, the SED helps determine the potential health risks associated with the use of certain ingredients. It is essential to assess the SED of cosmetic ingredients to ensure they do not pose any harm when applied to the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or the teeth and the mucous membranes of the oral cavity.  

Factors Influencing SED in Cosmetics

The following factors can influence the SED of cosmetic ingredients, including:

Ingredient physicochemical properties: The chemical composition, size, and solubility of an ingredient can affect its ability to penetrate the skin and enter the bloodstream.  
Frequency and duration of use: The more often a cosmetic product is used and the longer it stays on the skin, the greater the potential for increased SED.
Ingredient concentration: The concentration of an ingredient in a cosmetic product plays a significant role in SED assessment. Higher concentrations are more likely to result in greater systemic exposure.

Source: SCCS Notes of guidance for the testing of cosmetic ingredients and their safety evaluation

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The sunflower originally came from Peru in the 16th century, where a number of varieties grow in the wild. It was a plant highly prized by the people, who adorn their temples with sunflowers made of pure gold. A substantive oil produced from sunflower seeds. It is pure enough to eat. It contains a rich blend of glycerides and fatty acids, which will moisturise and protect the skin.

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In the old English Leechbook of Bald it was recommended to boil tender ivy twigs in butter and apply the results to ease sunburn. Culpeper recommended the leaves for ulcers, boils and ulcers. Today, the leaves are sometimes used by herbalists to treat slow healing wounds, abscesses and burns. The plant contains a component called hederagenin, which at high plant concentrations is effective in treating cellulitis and oedema.

Function: Anticaking, antimicrobial, astringent, skin conditioning, soothing, tonic.

(CAS: 84082-54-2/EINECS: 282-000-2)

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A simple but effective natural edible oil, the Chinese have been growing soya for more than 4,000 years. Soya oil is light, odourless and contains a valuable source of nutritious fatty acids, and is a versatile emollient and skin moisturiser. This plant has been known and used by the Chinese for more than 4,000 years, though today most of the oil comes from the USA. This oil is a cost-effective base on which to prepare hair and body products where good honest moisturisation is required at a budget price. Soybean is listed as a major starting material for stigmasterol, once known as an anti stiffness factor. Sitosterol, also a soy byproduct, has been used to replace diosgenin in some antihypertensive drugs.

(CAS: 8001-22-7/EINECS: 232-274-4)

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Glycerin or glycerol is one of the oldest and most respected skin moisturisers. It has been proven in many trials (both clinicals and instrumentals) to increase the moisture content of the skin and protect it from becoming dry and scaly. Glycerin is listed in all of the major pharmacopoeias and is used extensively for the treatment of the skin. 

(CAS: 56-81-5/EINECS: 200-289-5)

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Gluconolactone, also called glucono delta-lactone, is an ester of Gluconic Acid. Pure gluconolactone, is an ester of Glucanic Acid. Gluconolactone is formed by the removal of water from Gluconic Acid. Gluconic Acid is a carboxylic acid. In cosmetics and personal care products, Gluconic Acid and its derivatives may be used in the formulation of mouthwashes, bath products, cleansing products, skin care products and shampoo.

(CAS: 90-80-26/EINECS: 202-016-5)

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Ferulic Acid (4-hydroxy-3-methoxycinnamic acid) is a natural UV-absorber (maximum absorbance between 300 and 320 nm) derived and extracted from rice bran. Ferulic acid is available as an odourless and pale yellow crystalline powder. It is also a powerful antioxidant. Ferulic acid, unlike p-cinnamic acid and caffeic acid, scavenges superoxide anion radicals and also inhibits lipid peroxidation induced by superoxides. In 1886 Hlasiwetz and Barth in Innsbruck, Austria isolated a dibasic acid from Ferula foetida and named this compound ferulic acid. Five years later, it was isolated again from Pinus laricio Poir by Bamberger. It is now often extracted from rice bran (Oryza sativa).

(CAS: 1135-24-6/EINECS: 214-490-0)

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