The process of developing a skin care product, as described here by Dr. Samuels, involves a complex formulation of science, marketing and packaging. The creation of a new cosmeceutical product involves the integration of available scientific information, chemistry and appropriate packaging, plus marketing. Here we describe our development of Rx Systems PF, which illustrates the product development process through the creation and launch of a unique L-ascorbic acid vitamin C serum.
Background on Vitamin C
L-ascorbic acid, or real vitamin C, is an essential vitamin. The body cannot synthesize L-ascorbic acid. Humans rely on dietary intake or a topical application to maintain vitamin C levels in the body and skin. The vitamin must be ingested from vitamin supplements, food sources like citrus fruits and dark-green leafy vegetables, or applied topically to the skin to replenish L-ascorbic acid in the body and skin, respectfully. Vitamin C is essential for normal cell growth and collagen synthesis. L-ascorbic acid serves as the most important and most powerful (aqueous phase) water soluble antioxidant in the body. Available scientific data indicates the topical preparation must be in a precise chemical form, with an appropriate pH, at an adequate concentration, and packaged in an oxidation-free container in order to penetrate the skin and replenish L-ascorbic acid in order to maintain normal collagen synthesis and antioxidant activity. Stated in a different way, the skin relies on antioxidants for protection against free radicals (reactive oxygen species). Since the skin receives the most free radical assault from ultraviolet light exposure, replenishing and increasing the antioxidant defense of the skin becomes an attractive strategy for photo-protection and photo-repair. Oral vitamin C cannot deliver an adequate amount of L-ascorbic acid to the epidermis. If antioxidants, particularly vitamin C, could be delivered into the skin with an adequate high concentration, with the precise bioactive chemical form of vitamin C, with an appropriate pH and packaging that avoids oxidation prior to application, then the antioxidant, protective reservoir in the skin could be increased, and photo-protection and skin cell repair would be enhanced. More importantly, skin cell rejuvenation, skin cell growth and collagen synthesis would be increased. Available scientific data has allowed the production of oral vitamin C in appropriate amounts to supplement our diet to maintain normal serum vitamin C levels required for normal systemic metabolic function. However, the challenge to determining the appropriate chemical form of vitamin C, the appropriate pH, the appropriate concentration of vitamin C, and the appropriate preparation/packaging has been elusive until the last few years.
Product Formulation and Packaging Issues
Formulation characteristics are critical for delivery, penetration and biologic activity of L-ascorbic acid into the skin to restore and enhance the skin’s natural antioxidant activity. The major formulation characteristics are related to: • Molecular structure of the vitamin C • The pH of the L-ascorbic acid serum • Concentration of the L-ascorbic acid • Proper packaging of the L-ascorbic acid Because the characteristics of the vitamin C serum are so important to the biologic activity and effectiveness of Rx System PF’s Age Defense Antioxidant Serum C, each formulation characteristic is addressed individually below. Molecular Structure. A study performed demonstrated that L-ascorbic acid is the chemical derivative that is chemically reactive and bioavailable. Other derivatives of vitamin C, including magnesium ascorbyl phosphate, ascorbyl-6-palmitate and dehydroascorbic acid, did not increase skin levels of L-ascorbic acid. These are vitamin C-related molecules, which moisturize the skin but have not been shown to penetrate the skin and do not increase L-ascorbic levels in the skin. L-ascorbic acid is the only molecular structure proven to penetrate into the skin and neutralize those damaging free radicals. Rx Systems PF’s Age Defense Antioxidant Serum C contains USP-grade L-ascorbic acid and is not buffered in order to insure maximum biologic activity. This highlights just one of the problems with existing vitamin C products on the market. The pH of the L-Ascorbic Acid Serum. Most vitamin C preparations are not pH adjusted for optimal biologic activity and penetration. The pKa for L-ascorbic acid is 4.2. The pKa of a product relates to how much free acid is available based on a certain pH. Tissue levels of L-ascorbic acid were enhanced only for formulations with a pH less than 3.5. Preparations with a pH higher than 4.0 will oxidize the L-ascorbic acid in the product, making it ineffective. Therefore, the L-ascorbic acid molecule must be un-ionized and formulated at pH levels less than 3.5 to enter the skin (penetration). This maximizes biologic activity, penetration and effectiveness while avoiding skin irritation with a product where the pH is too low (particularly less than 2.0). Concentration of the L-Ascorbic Acid. In addition, most preparations lack a sufficient concentration of free L-ascorbic acid for biologic activity and penetration. L-ascorbic acid concentrations were tested from 5% to 30%. Maximal tissue levels of L-ascorbic acid were obtained at L-ascorbic acid concentrations of 20% (graph available). Proper Packaging of the L-Ascorbic Acid — Single Use Packets. Lastly, and equally important for the penetration and benefits of a vitamin C product, is proper packaging. Not only did we want to produce an effective vitamin C preparation in an oxygen-free environment, but also to do it in such a way that the customer would appreciate the need for the unique packaging. When Rx Systems PF began to look at packaging, due to the highly unstable nature of L-ascorbic acid, the research quickly centered around the idea of single-use application packets. It was different, made a great deal of sense and no one had yet brought the idea to market. While researching vitamin C competitors, we determined the industry standard packaging size to be 30 ml, and soon after Rx Systems PF’s Age-Bloc Delivery System was born.
Oxidation. When filling the single-use applications, we used a temperature- and light- controlled room to expel as much free-oxygen from the single-use, individual serum packets as possible. When this process is complete, each packet contains 1 ml of L-ascorbic acid serum and is sealed in an air-tight fashion. The L-ascorbic acid with its optimal 20% free acid concentration and appropriate 2.6 pH can be kept in the Age-Bloc Delivery System almost without concern of oxidation since the packet offers permanent protection from light (UV) and air (oxygen). L-ascorbic acid exposed to light and air oxidizes hourly, and the so-called reduced-air exposure containers and liposome delivery systems only slow down the process to a few days compared to Rx Systems PF’s new, innovative Age-Bloc Delivery System with complete protection from light and air. This is a major problem with current topical vitamin C preparations. They lack stability when exposed to light and air, which causes oxidation of the L-ascorbic acid making it ineffective and potentially subject to the formation of free radicals. Temperature control during packing and storage is important with L-ascorbic acid, as well as other products. That is, high temperatures increase the rate of oxidation of L-ascorbic acid and other ingredients. Penetration. During the development process, we also examined the penetration of vitamin C. Studies show that Rx Systems PF’s new Age Defense Antioxidant Serum C (L-ascorbic acid) product with a pH of 2.6 and a free acid concentration of 20% in a light-protected package maximizes biologic activity and penetration into the epidermis (Figure 1). Research also demonstrates that the L-ascorbic acid penetrates the stratum corneum and upper cell layers of the epidermis. In addition, daily application increases the depth of epidermal and superficial dermal (papillary dermis) penetration producing L-ascorbic acid concentrations more than 20 times normal levels after three consecutive days of application and maintains these levels with daily use. From a scientific standpoint, these levels are maintained for 3 days if our Age Defense Antioxidant Serum C is stopped. This documents the reservoir effect of L-ascorbic and explains the preventative and reparative benefits seen with daily use. Once in the skin, studies show L-ascorbic acid stimulates collagen synthesis, provides sun protection, and protects the skin by reducing free radicals, which otherwise would destroy skin cells and its components. This enhances photo-protection and improves collagen synthesis.
Summary of Clinical Benefits
Rx Systems PF spent 2 years developing its vitamin C Serum, which it brought to market in July 2008. The cosmetic benefits of the antioxidant activity of our Age Defense Antioxidant Serum C include improvement in skin texture and tone, reduction in brown spots, and a decrease in the appearance of fine lines and wrinkles as well as helping to prevent their formation. In addition, Rx Systems PF’s Serum C contains the finest USP pharmaceutical grade L-ascorbic acid antioxidant available for skin cell growth and collagen production, which is necessary to repair tissues damaged by invasive breast cancer surgery and treatment. For this reason, Rx Systems PF donated a portion of its vitamin C Serum sales in September and October to the National Breast Cancer Foundation. Dr. Lawrence Samuels, MD is a board-certified dermatologist and the chief of dermatology at St. Luke’s Hospital in St. Louis. He is also an Instructor of Internal Medicine, Division of Dermatology, at Washington University School of Medicine. Disclosure: Dr. Samuels is the founder of Rx Systems PF (www.rxsystemspf.com). Products are availableonline and at select spas, doctors offices and salons nationwide.