In these days of advanced skin care technology, scientific breakthroughs are constantly evolving as they continue to enhance the efficacy of formulations for acne, brightening, and antiaging. Formulators can now coat large molecules in natural liposomes to ensure effective delivery. Microencapsulation allows multiple active ingredients to reach target sites and perform optimally. Vitamin C can be loaded into an encapsulated vesicle that maintains 100% stability and potency. Yet, the greatest breakthrough is the testing of delivery success by way of 3D and 4D imaging machines, which have recently culminated in 5D imaging machines. Only a few 5D machines are available in the entire world, and they literally have the capability to trace the delivery pathway of a molecule to see how it impacts underlying cells.
It is important to note that the biggest benefit a formulator can strive for is to produce an effective product as a whole, rather than just target a single delivery system. Not all ingredients or products need liposomal formulation. For example, cleansers are not designed to be delivered into deeper, targeted areas and ultraviolet filters should stay on the surface. Moisturizers that work by occluding skin moisture should also remain on the stratum corneum. However, hydration-based humectants need liposomes in order to penetrate the superficial layers of the skin and retain the water in deeper skin layers.
THE NEED FOR SPEED AND IMPACT
In the past, skin care formulators were experts in working with a synergistic combination of ingredients that impacted the surface of the skin, without testing how the molecules would be delivered to a target site underneath. After all, the stratum corneum of the skin is a protective barrier that defends against the external environment and keeps things out. Skin care might soothe, hydrate, or plump effectively, but those formulations do not have lasting effects if the molecules are too large to penetrate the skin’s natural protective barrier. Without the technology of a delivery system, formulators have always faced multiple challenges when working with ingredients to create an efficacious skin care product that impacts lower layers of the skin. Some of those roadblocks have to do with concentration and potency, stability and efficacy, and molecular size.
Concentration and Potency
Some ingredients need to be present in the maximum recommended percentages in order to achieve the desired benefit. However, more is not necessarily better, especially when it comes to certain ingredients. For example, while many clients may favor natural products, it is important to note that just because an ingredient is botanical-derived, like essential oils, it does not always mean that the natural ingredient will be 100% safe in large amounts, will be well-suited for the client’s particular skin type, or will not trigger an allergic complication.
Stability and Efficacy
After being extracted and isolated from their source, active ingredients may undergo stability issues. Due to sensitivity to light, oxidation, temperature, and pH levels, the molecules become unstable and break down, which reduces or even destroys their potency and effectiveness. For example, L-ascorbic acid (vitamin C) is a popular ingredient in skin care products to minimize melanin production, fade hyperpigmentation, ward off free radicals, and promote collagen synthesis, but when exposed to light and air, L-ascorbic acid and other forms of vitamin C oxidize, lose efficacy, and may negatively impact skin proteins and DNA.
The smaller the molecule, the more easily it is absorbed by the skin. Although large molecules cannot effectively pass through the stratum corneum, that is not necessarily a bad thing for achieving certain skin care benefits. For example, high molecular weight hyaluronic acid (1,000 kilodaltons and above) is too large to be absorbed by the skin, so it stays on the surface for a film-forming, plumping, and moisturizing effect. But, large molecules such as collagen, peptides, ceramides, and some vitamins might naturally be too unstable or too large to penetrate the skin barrier.
What is one of the biggest problems for formulators? It is that without an effective delivery system, large molecules cannot reach beyond the stratum corneum to reach targeted sites for desired results. Unstable ingredients lose their efficacy and highly active ingredients, like retinoids, that linger on the surface may irritate sensitive skin, lead to breakouts, or trigger other skin issues. So, how can formulators create skin care products that penetrate through this natural protective barrier, maintain stability, and cause the desired antiaging effect?
SERUMS: SUPERSTARS OF TRADITIONAL DELIVERY
A serum is one of the most necessary products for delivering stable actives to combat signs of aging skin. When creating serums, formulators do not have the same problems with concentration, stability, and molecular size. Serums are an ideal skin care formulation because, unlike creams and lotions, they are not heated to high temperatures, so high levels of actives can be added at a higher concentration. The actives in serums do not break down and instead remain concentrated and stable. Serums can also be formulated with small molecules that are easily absorbed, which allows active ingredients to reach targeted areas of the skin where they can do the most good. Serums can be oil-based or water-based and should be applied underneath a moisturizer, which helps lock in nutrients. But what about serums that are formulated with larger molecules, like long-chain peptides, stem cells, and growth factors? For those, liposomes provide the solution.
ENTER LIPOSOME DELIVERY
Initially used as effective and efficient delivery vehicles for drugs in the medical field, liposomes are now commonly used as skin care delivery systems. These hollow, sphere-shaped vesicles have one or more phospholipid layers, with a structure similar to that of cell membranes. These fluid-filled spheres transport the active ingredients deeper into the skin, where they are slowly released.
Phospholipid tails have a water-soluble end and a lipid-soluble end, which attach to the active ingredients. These ingredient-carrying phospholipids can then move into deeper layers of the skin, letting go of the active ingredient along the way. For example, essential fatty acids like omega-3 and omega-6 are the tails of phospholipids, which control what goes in and out of cell membranes. This makes them ideal carriers for driving skin care ingredients from the surface to the deeper targeted sites.
The latest technology incorporates bilayer liposomes. These bilayer microspheres smuggle in natural actives that are hydrophilic (water-soluble), as well as actives that are lipophilic (oil-soluble). As antiaging ingredients become more advanced, growth factors, plant-derived stem cells, peptides, retinol, vitamins, and hyaluronic acid can now be delivered to targeted sites by way of liposomes. Vegetable-derived liposomes act as water-soluble and oil-soluble carriers that easily penetrate the stratum corneum. Once absorbed, the skin is sealed with a micro-thin, flexible film to reduce dehydration, transepidermal water loss (TEWL), or the evaporation of moisture within skin.
MICROENCAPSULATION: SKIN CARE SHUTTLE
Microencapsulation provides the same benefits as liposomes, with the additional perk of timed-release technology. Like shuttles that deliver people to the correct destination, at the appropriate time and without losing their luggage, microencapsulated ingredients are absorbed through the skin’s protective layer, reach the targeted site, and maintain potency and stability. Microencapsulation technology starts with an outside spherical shell material (“encapsulant”) that blocks other material from entering and keeps the natural active (“core”) from escaping before it reaches the targeted area.
Commonly used encapsulation substances include wheat proteins, soy, phospholipids, liposomes, beeswax, egg lecithin, or polysaccharides, like carrageenan from algae and chitosan from sea crustacean shells. Multi-layered spheres can be used to enclose active ingredients, which helps prevent oxidization and discoloration of the formula while in the bottle.
On the way to the targeted site, the shell material prevents the active ingredient from degrading to the exposure of light or air, so it maintains the ingredient’s stability and efficacy. The shell’s core is released when there is a trigger such as heat, pH, moisture, enzymes, diffusion, or dissolution, and the molecule is delivered to targeted sites at its full potency. This type of delivery system has an extremely low potential for skin irritation, even as the active ingredient targets wrinkles, hyperpigmentation, atopic skin, rosacea, post-treatment skin, wound sites, and other skin issues.
LOW MOLECULAR WEIGHT HYALURONIC ACID
Size matters, especially with hyaluronic acid at medium and low molecular weights (under 1,000 kilodaltons), which is small enough to seep into skin. There, low molecular weight hyaluronic acid promotes elasticity and repair. How? To prevent collagen and elastin fibers from stiffening and deteriorating, much like aging rubber bands that crumble over time, low molecular weight hyaluronic acid keeps collagen and elastin fibers moist. This leads to a reduction in skin roughness and wrinkles, and an increase in skin suppleness and elasticity.
Still, there is an important distinction between varied sizes of hyaluronic acid at low molecular weights. For example, reputable scientific studies have shown that low molecular weight at 20 kilodaltons or below increases the risk of pro-inflammatory responses. However, low molecular weight hyaluronic acid at 50 kilodaltons is considered safe to use for strong antiaging and moisturizing properties with efficient skin penetration and without irritation.
Recent advancements have led to encapsulation of potentially irritating active ingredients such as retinols, so there is a very low potential for skin irritation. These new delivery methods allow cosmetic bio-actives to arrive at the targeted site at their full potential and potency, without triggering an inflammatory effect.
For example, coated microsponge microcapsules release retinol ingredients over an extended period without triggering irritation or allergic complications, while stimulating dermal proteins and growth factor synthesis.
Micronized oleosomes are another retinol encapsulation technology using vegetable-derived hydrophilic and lipophilic microspheres that are attracted to water and oils to propel the encapsulated actives to the targeted site where they are needed.
Retinol molecular film fluid is a relatively recent delivery system, created for retinol, to keep it stable, prevent oxidation, and facilitate product absorption, while lowering the risk of irritation to sensitive skin types.
Nanotechnology is a cutting-edge method for penetrating skin layers using extremely small particles. Each of these nanoparticles is approximately one-billionth of a meter, which is calculated to be about 100,000 times smaller than the diameter of a human hair. There is some controversy surrounding the safety of using nanotechnology in cosmetics and skin care, due to a concern that the particles may cross cell membranes and spill into the blood stream; however, scientific studies are still taking place to either confirm or disprove this.
MACHINES FOR EXPEDITED DELIVERY
Delivery of ingredients is not limited to chemical means. Ingredient penetration can also be achieved through certain handheld beauty devices that professionals can incorporate into spa facials. Clients can also use these tools for skin maintenance to enhance the benefits of their homecare products. When these devices are used after exfoliation or microdermabrasion treatments, the absorption rate of the nutrients and actives in skin care improves because ingredients are not blocked out by a layer of dead skin cells on the stratum corneum.
The use of ultrasonic waves, also referred to as sonophoresis, is a convenient and efficacious modality for infusing product. Low frequency ultrasonic waves (28,000 ultrasonic waves per second or 28 kilohertz) are responsible for creating cavitation, which is the sudden formation and collapse of bubbles. The impact of microbubbles collapsing on the skin’s surface creates micro-jets that increase the permeability of cell walls, enhancing the delivery of topical skin care products by propelling ingredients through the stratum corneum to the targeted sites.
Microcurrent devices sending off low electrical currents to the skin allow for iontophoresis, facilitating a greater infusion of charged molecules from appropriately formulated skin care products into the skin. Dual-tipped microcurrent probes, as opposed to single-tipped versions, can increase tissue saturation without increasing the current.
As technology bolsters the effects of skin care ingredients, skin care is always exponentially advancing. Skin care technology is finally starting to catch up with medical technology. It is, therefore, time for a new perspective on expectations of skin care ingredients that improve skin appearance and overall skin health. The technology of delivery systems married with the potential of new growth factors, stem cells, peptides, minerals, and therapeutic botanicals can redefine the face of the skin care industry.
The appropriate delivery system can maximize results for the client and solve multiple skin care issues, whether short-term or long-term. However, before choosing any device or product with a special delivery system, it is important to determine the specific goals of the treatment. Look for independent clinical studies and brand reputability. Now that delivery systems are becoming more of a trending buzz word, professional aestheticians and their clients should keep in mind that marketing claims and social media posts need to be validated by actual performance.
When used appropriately, delivery technology can enhance products in order to allow consumers to see instant, as well as long-term, results. Still, it is important to recognize that not every ingredient needs to be delivered. First and foremost, a seasoned formulator balances cutting-edge science, experience, and intuition in creating safe, effective skin care.
The formulator’s takeaway advice? Be discerning about the reason for choosing products that utilize encapsulation as a delivery system. Is it to make the product work better for sensitive skin? Is it to guide larger molecules where they need to go? Skin care experts should not be too enamored with delivery vehicles because, with some products, ingredients need to stay on the surface. Like the idea of the skin care shuttle getting to the right address, the important question is not was the ingredient delivered? Instead, the main issue should be did the ingredient have an impact on treating the skin condition? For professional aestheticians, this discernment will positively impact the health and appearance of their clients’ skin. For the formulator, this discernment makes the beaker the birthplace of beauty.
Founder, formulator, and CEO of Le Mieux Cosmetics and PurErb, Janel Luu has over 35 years of experience in the beauty industry as an educator, researcher, and formulator. She has taught over 37,000 skin care professionals and physicians on topics ranging from antiaging cellular technology to centuries-old Meridian techniques.