Skin Care Delivery Systems
From liposomes to microsponges, advances in delivery systems have improved the efficacy of skin care products. But sometimes new ingredients and area of application require formulators to take a closer look at which delivery system is the best method for a particular product.
By Christine Canning
W hether they improve moisturization, decrease fine lines or smooth texture, skin care products promise to revamp dry, aging and stressed out skin. Although consumers expect their skin care products to deliver on these promises, they aren't as interested in the product's delivery system.
But luckily for them, cosmetic formulators are. Companies are continually searching for new delivery technologies that will improve skin treatment products. From liposomes to lipids to microsponges, advances in skin care delivery systems have enabled marketers to launch more effective and targeted treatments that contain more powerful ingredients.
One of those ingredients is retinol, which helps to diminish fine lines and wrinkles. Creating stable formulations that include retinol has been a major challenge for cosmetic companies, according to John Duffy, technical director, skin care, Avon Worldwide. But Avon has successfully harnessed the power of retinol by entrapping the ingredients in a special delivery system called micro-sponges, and next month will launch Anew Retinol Recovery Complex PM Treatment.
"Using microsponges offers two advantages," said Mr. Duffy. "First, it slowly releases retinol once it's applied, and it also protects and stabilizes the retinol." According to Mr. Duffy, Avon's researchers have found that by entrapping the retinol in the microsponge, the Anew Retinol Recovery Complex PM Treatment formulation remains stable for as many as three years.
When it came to selecting the best system for delivering the retinol, Avon ruled out liposomes, even though it had previous success with the technology in other products. "Liposomes can be tricky to work with," Mr. Duffy said. "When it comes to protecting fragile ingredients, like retinol, microsponge technology is the one that is truly effective."
The microsponge system also enabled the company to use a higher concentration of retinol, although Mr. Duffy would not reveal the exact amount. "The microsponge allows you to deliver a higher concentration of retinol, and because of the time release delivery, you avoid irritation."
Microsponge technology also caught the eye of Lander, an Englewood, NJ-based marketer of mass market personal care products with annual sales of $55 million. The company in January acquired Premier Inc., the consumer products arm of Advanced Polymer Systems-the firm behind the Microsponge technology used in Avon's retinol treatment.
"A key factor helping us make this purchase decision was the incorporation of the patented microsponge delivery system in Premier product formulations," Mike Zeher, Lander president said in a statement. Premier brands include ExACT acne preparation, Everystep foot deodorant, Take-Off cosmetic remover and Neet depilatory.
The acquisition allows Advanced Polymer Systems (APS), Redwood City, CA, to concentrate on its core activities, according to Gordon Sangester, vice president, finance and comptroller. "Licensing the consumer products to Lander lets us focus on research and development."
Formulators agree new developments in delivery systems have improved skin care products, but industry veterans happi spoke with offered different opinions on which one has made the biggest difference.
The evolution of liposomes is one the most important advancements in skin care delivery systems, said Debbie D'Aquaino, executive director, product development for treatment at Clinique. "There are so many ways that vendors are extrapolating this. There has been a lot of work that has improved on the liposomes." Systems last longer and provide more targeted and time-released delivery, according to Ms. D'Aquaino.
Clinique uses liposomes in several of its products, including Turn Around treatment. The formulation contains Salisome, a patented liposome that contains salicylic acid. According to Ms. D'Aquaino, the salicylic acid is impregnated into the core of the liposome rather than the outer layers.
"In our opinion, the biggest advance in delivery systems is in the area of silicone emulsion technology," said Jim Ayres, manager, Artistry research and development, Amway. Traditional water-in-oil systems, Mr. Ayres added, "are good performers when it comes to treating skin, but they typically have poor aesthetics and very poor stability." By using silicone emulsions, Mr. Ayres added, "Today's formulator can produce a wide variety of product types including makeup, creams, lotions, and gels which have exceptional aesthetics and performance characteristics."
Since 1983, Artistry has used a Hydrolipid matrix in its moisturizers. The matrix is a combination of humectant materials -- glycerine, hyaluronic acid and panthenol -- and phospholipids, sphingolipids and cholesterol, which according to Jim Mayne, research scientist, global skin care products, Amway, make up the bulk of lipids in the outer layer of skin. The goal, Mr. Mayne added, is to "mimic nature's way of retaining moisture."
Initially Amway used lipids derived from animal extracts, however the company has worked with its suppliers to come up with non-animal alternatives including natural ingredients such as milk as well as sources developed using bio-technology. "The functionality hasn't changed, but the sources have," said Mr. Mayne.
Cary Sartin, president of Janet Sartin, a New York-based, prestige skin care company, singled out phospholipids as a key development in delivery technology. Phospholipids are abundant in younger skin, but as skin ages and is exposed to the environment, phospholipids decrease, Mr. Sartin said. "The skin accepts phospholipids into the stratum corneum. You can truly see and feel the benefits."
Two of Janet Sartin's new skin care products incorporate phospholipids -- Replenishing bath and shower gel, which contains Sartinizing phospholipid complex (derived from plant extracts), and Replenishing milk hand and body lotion, which is formulated with Sartinizing milk phospholipid complex. Both products hit counters in February.
Milk is also the focus of Nutritious Bio-Protein Moisture Complex, a new skin care treatment from Estée Lauder. The product was developed with Lauder technology that extracted proteins, ceramides and lipids from milk and enhanced them with vitamins, minerals and enzymes, according to the company. "We worked with milk-derived ingredients," said Daniel Maes, vice president, Estée Lauder research and development. The formulation contains lecithin, a phospholipid that Dr. Maes described as a "mild emulsifier."
Watch Where You Use Them
Not all delivery systems work in all products, of course. Clinique in January launched Skin Calming Moisture mask, which uses a polymer delivery system to help retain moisture. "When formulated correctly, polymers work to pull moisture back into the skin when rinsing the mask off," said Ms. D'Aquaino. The product also contains a trio of lipids-wheat sphingolipid, linoleic acid and cholesterol.
But when it came to the new Exceptionally Soothing cream and lotion, Clinique took another route. "Delivery systems are really good for some ingredients, and not for others," she said. The Exceptionally Soothing line, which hit counters in February, contains 0.5% hydrocortisone, an active OTC level. "There's no particular delivery system, alá liposomes or microsponges. If we had put hydrocortisone in an active delivery system," Ms. D'Aquaino said, "We would have to apply for new drug application."
Instead Exceptionally Soothing cream uses a traditional base system, but Clinique left emulsifiers out of the mix. "When skin is upset, emulsifiers can drive ingredients through damaged skin,"said Ms. D'Aquaino. Exceptionally Soothing lotion and cream calm irritated skin by reducing itch and redness so skin can heal itself. The product contains linoleic acid, cholesterol and hydrogenated lecithin, lipids which, Ms. D'Aquaino said, aid in barrier repair, slow transepidermal water loss, increase moisture retention and help prevent penetration of irritating substances.
But why spend $30 for a 1.7-oz. supply of Clinique's treatment when hydrocortisone creams cost less than $5 at the local drug store? Ms. D'Aquaino added that to boost the activity of the hydrocortisone, Clinique also added green tea extract, sucrose and oat extract to soothe the skin, as well as vitamin E and shea butter- ingredients that are much more elegant than generic hydrocortisone cream. Furthermore, Exceptionally Soothing is offered in a lotion, which many consumers prefer for facial skin care products.
Dr. Maes contends that emulsifier-free technology, like that used in Clinique's Exceptionally Soothing line and Lauder's Verité line, will play a larger role in future skin care applications.
Alpha hydroxy acid is another ingredient which limits a delivery system. "You want to keep hydroxy acid on the skin's surface," commented consultant Walter Smith, who also serves on the Nu Skin advisory panel. Nu Skin's latest skin care launch, the MHA (Multi Hydroxy Acid) Product system, does just that. The products, which contain alpha and beta hydroxy acids, include MHA Revitalizing lotion, MHA Revitalizing lotion with SPF 15, MHA Revitalizing body lotion and MHA Diminishing gel. They must be used in a short regimen. During weeks one to four, a woman must use the diminishing gel and the lotion SPF 15 followed by nightly applications of gel and the non-SPF lotion. During weeks five to eight, only the diminishing gel is used. The MHA lotion (without SPF) includes ethoxydiglycol which interacts with the hydroxy acid and forms a reservoir on the skin's surface. "It holds on to the material, and slows down the penetration for better exfoliation," said Dr. Smith.
Nu Skin has avoided using a lot of delivery systems, according to Dr. Smith. "It created an issue in terms of flexibility of (product) forms." The company instead relies on ingredients that are penetration enhancers or modifiers, such as silicone, which is used in the MHA diminishing gel formulation.
The Eyes Have It
With aging baby boomers becoming the cash cows of cosmetics companies, more marketers are launching eye treatments that target the tell-tale signs of aging-crows feet, dark circles and puffiness. Often these products require delivery systems that differ from regular facial treatments.
"There are special considerations," Ms. D'Aquaino said about eye treatment products. "That area of skin is half as thick (as facial skin). You need to minimize penetration."
Mr. Sartin, whose company recently launched new Eye Care Serum for Sensitive Eyes, agreed with Ms. D'Aquaino's assessment. "The skin is most delicate in the eye area. That's why we chose kalaya oil and ceramide [for delivery]." The company worked on the combination for two years, according to Mr. Sartin. Kalaya oil, he said, helps "bring moisture to the stratum corneum and ceramide, another skin penetrating ingredient, hydrates the skin and enhances moisture binding capabilities."
Amway this month unveils Artistry Advanced Daily eye cream, which the company bills as a "much improved version" of Artistry eye balm. The new product has a water-emulsion delivery system and its primary emollient is squalane, according Mr. Mayne. "We worked with large molecules. The eye is a thin area and we didn't want to penetrate or irritate the skin." The treatment also contains Amway's Hydrolipid complex.
More to Come?
As consumers look for more efficacious products, companies are forced to speed up research on new treatments, and it appears that some companies happi spoke with are tuning into delivery systems for future launches. Janet Sartin plans to launch three new products "with enhanced delivery systems in late 1997 or early 1998," according to Mr. Sartin. At Avon, Mr. Duffy noted that "there are some other delivery systems in the early stages." Neither gentlemen would be more specific, however.
Although the consumer may say "the faster the better" when it comes to improving her skin, Dr. Maes contends companies should exercise caution when formulating. "Let's be more careful and precise...It's more important to retard delivery than create irritation. The effect may be delayed, but it happens safely."