Tapping pharmacological potential and assuring ingredients work most efficaciously on the skin are the prime aims of delivery systems for antiaging skin care. Informed consumers want to know that topical treatments are a viable alternative to invasive procedures, and technologically advanced delivery of highly functional ingredients is the major way to provide that assurance.
While the passage of the years can’t be stopped, technological advances in skin care have forestalled their imprint. Consumers are trying a variety of topical approaches, which in turn utilize a variety of delivery systems, and suppliers of functional ingredients are seeking the synergy of appropriate delivery systems to answer the demand.
Because a highly functional ingredient may be expensive, the proper delivery system will allow the ingredients to be metered out slowly without waste, and enable greater efficacy at a reduced overall cost. It also is important that system and formulation work together. Their compatibility aids in their efficacy.
Meyer Rosen, editor of Delivery System Handbook for Personal Care and Cosmetic Products(© 2005, William Andrew Publishing), cites the importance of functional actives, delivery system technology, applications and opportunities for technology licensing and differentiation. Numerous, innovative and in-demand, the systems are utilized in many products reaching consumers today.
“Delivery system technologies significantly enhance the power and flexibility of formulators by decreasing the amount of costly functional actives, protecting them from oxidation and reducing potential irritation due to undesirably rapid release,” says Rosen. “The delivery system, with its contained active, typically is put into many types of personal care and cosmetic formulations, and one must be mindful that the delivery system/active/formulation is a ‘new’ entity that must remain compatible and functional.”
As there are many systems, delivery of actives can be tailored to particular formulations to optimize functionality and stability.
Demand and Delivery
Savvy customers are aware of ingredient breakthroughs, and support the popularity of skin care preparations, especially those offering efficacy and aesthetics.
According to Johann Wiechers, principle scientist and skin care R&D manager, Uniqema Personal Care,
“When we talk about reversing the effects of aging on human skin, it becomes necessary to talk about the delivery capabilities of formulations at or very near the beginning of the conversation. In a word, formulating for efficacy is key to the success of any antiaging formula. A great number of active ingredients have been shown to be beneficial in antiaging formulations, but relatively few ever reach the market because formulators often cannot find a delivery mechanism that positions the right active (and not an inactive metabolite for instance) in the right location, at the right concentration, for the right period of time.”
Active ingredients often are abandoned if, after stability and clinical testing, no efficacy is shown in finished formulations. Wiechers says emulsion systems and emollients within formulas profoundly influence the efficacy to deliver the active from the formulation. Uniqema created the Relative Polarity Index (RPI) to help find optimal formulation conditions, and Wiechers says it is a novel way to custom-design the proper emollient system in conjunction with specific actives in order to make the active more efficient.
Improvement in delivery efficiency has profound implications for the personal care industry, and marketers can differentiate their products from others if their effectiveness is shown to be an improvement over historical formulations. “Another option, given the improvement in delivery efficiency, is to include less of an expensive active in a product reformulated for a lower price point without loss of efficacy, opening up new markets,” says Wiechers. “Another may be to reconsider the use of actives previously believed to be ‘undeliverable’ in skin care formulas.” In cases where the active ingredient is a small molecule with a hydrophilic profile, the company offers an adjuvant currently used in acne formulas which has a potential use in antiaging formulas to deliver antioxidants.
From the Lab
Arch Personal Care has developed a patent-pending method to encapsulate sensitive or labile bioactive skin care ingredients within a modified polyglucose matrix. “This method of encapsulation protects the sensitive ingredients during vigorous heating slowing both water-soluble and lipid-soluble active components to be prepared as anhydrous powders,” says Vince Gruber, Ph.D., director of research and market development, Arch Personal Care. “The unique modified polyglucose entraps the bioactive ingredients in a spiral-shaped cage, which acts somewhat like a spring, wrapping itself around the actives and holding them in the interior of the cage until release.”
As Gruber explains, the encapsulating polyglucose also helps bind moisture through extensive hydrogen bonding that can provide enhanced moisturizing benefits to anhydrous skin care formulations. The skin’s natural moisture causes the modified polyglucose to slowly uncoil and act as a time-release device that delivers the active ingredients to the skin. In lip care products, the encapsulant is particularly effective as the food-grade polysaccharide polymer is digested partially by the enzymes of the mouth, further enhancing release of the actives. After the polyglucose completes its time-release function, the functional encapsulant continues to hydrate the skin, providing increased moisturization to improve texture, tone and feel.
Salvona Technologies, Inc., offers a number of platforms to deliver antiaging actives onto the skin and hair and provide their release. They are said to improve the stability and efficacy of actives, reduce irritation and assist in formulating actives into conventional skin or hair care products. One such platform, with biodegradable solid hydrophobic nanospheres in the form of an aqueous dispersion, delivers a range of ingredients onto skin, hair and hair follicles, enhancing its efficacy and prolonging their release over an extended time period. Due to their lipophilic nature and small particle size, they are able to deliver actives into the deeper layers of the skin in a controlled manner and enhance their bioavailability and efficacy. “The nanospheres are loaded with the active, and can adhere to the skin, scalp and hair and sustain the release of the active for more than six hours,” said Sam Shefer, executive vice president. “The slow release of the functional ingredients allows the cells to incorporate the active within the physiological process, without leaving signs of irritation on the skin. Since they are composed of natural biodegradable materials, they are a safe and functional delivery system.”
Another technology from Salvona provides controlled delivery of multiple actives. “The multicomponent nanotechnology allows delivery of multiple actives that normally don’t mix well, and releases them in a consecutive manner, opening fields in product development for multiple actives,” Shefer adds.
When speaking of delivering actives to multiple layers of skin, Art Georgalas, director of new technologies, TRI-K Industries, cites a multicomponent, multifunctional actives complex—a concentrated herbal active developed from the traditional medicine of Australia’s Aborigines. The complex “acts on different layers of the skin. On the surface it retexturizes the visible cutaneous microrelief with film-forming properties that smooth the surface skin appearance. Below this, at the deeper layers, it reactivates skin metabolism and stimulates fibroblasts in the dermis to help plump the skin structure and reduce signs of wrinkles.”
“Delivery of the actives takes place through hydrated skin, which enhances penetration of these hydrophilic actives,” says Georgalas. “Fibroblasts in the dermis, as evidenced in cell culture, are stimulated to replicate and produce higher quantities of type 1 Collagen.” For the enhanced, controlled delivery of liposoluble actives, Georgalas notes the new nanoparticle dispersions. “Ingredients such as retinol, vitamin A alcohol (with skin-firming and rejuvenation activity) and tocopherol, vitamin E or coenzyme Q-10 with antioxidant properties can be incorporated at high levels in a variety of solid lipids to deliver as aqueous dispersions of nanoparticles in skin creams and lotions.” The high surface area of the nanoparticles, their natural adhesion to the skin and formation of a layer of contiguous particles allow them to systematically release actives to the skin in a controlled way, with enhanced penetration.
Delivery at Retail
SkinMedica TNS Recovery Complex with NouriCel-MD is said to improve skin health by rejuvenating aging sun damaged skin and softening lines. The products contain a delivery system built into NouriCel-MD, based on topical penetrants that simultaneously prepare the skin for delivery and carry the NouriCel-MD through the stratum corneum.
IS Clinical, by Innovative Skincare, launched a vitamin C collection with topical stabilized L-ascorbic acid as the key component. Antiaging, skin protection and treatment of pigmentation disorders are targeted, and ingredient delivery to the cells is key. “For any ingredient to be effective, it has to arrive at the site of its action, whether that is the cell’s DNA, collagen producing mechanism or cell membrane lipid layer,” says Charlene DeHaven, clinical director, IS Clinical. If applied topically, a cosmetic ingredient first must penetrate the stratum corneum. Considering that the skin is designed to keep substances out, this is more difficult than it sounds.” After penetration, the ingredient must travel through other layers or cellular structures to reach its site of action. Once there, it still must be in its active form, unmodified by its travels or changed in a way during its travels that it has become active.
A product using novel delivery is emerginC Multi Vitamin Serum + Retinol, which delivers active vitamins A (retinol), B, C, E, F, H and K in a green tea base to nourish skin and fight aging. The formula is encased in airtight millicapsules that ensure ingredient integrity and break on the skin for even delivery.
Innovation in delivery systems can breathe new life into abandoned active ingredients, and make more effective use of less expensive actives to open new markets at lower prices.