Delivery Technology

Because one of the functions of the skin is as a barrier to protect the internal environment of the body, this barrier function must be overcome to enable the external penetration of beneficial cosmeceuticals. Transdermal delivery systems have been developed to modify this barrier function of skin and can be categorized in two mechanism groups, chemical and physical. Electric current, thermal, light, and ultrasound energy are all examples of physical penetration enhancement systems that have been used in the medical and esthetic fields successfully for decades. However, cost is prohibitive for home care use. Also, concerns regarding the uniformity of current, distribution of energy, destruction of the skin and the ability to control ionic properties require trained practitioners.

The impracticality of physical enhancers makes chemical based delivery systems far more attractive and viable for pharmaceutical, cosmeceutical and skincare purposes. Commonly referred to as “penetration enhancers”, chemical delivery systems used for cosmeceutical uses must ideally be safe, non-toxic, pharmacologically inert, non-irritating, and non-allergenic, which unfortunately many are not. Additionally, once the active ingredients are allowed to penetrate through the stratum corneum (SC), the penetration agent should disperse and allow the skin to quickly revert back to its normal barrier properties. Some chemical enhancers such as alcohol are effective as penetration enhancers, but will ultimately dissolve skin lipids, irritating and drying out the skin, thus working against the benefits of the active ingredients. Such safety and tolerability issues greatly reduce the tolerability of many chemical enhancers for long-term topical use.

One suitable formulation method for chemically enhanced penetration delivery is the use of biodegradable polymeric matrices that deliver cosmetic molecules through the stratum corneum (SC, epidermal barrier layer) for deeper penetration. In these complex matrix formulations, a combination of cosmetic actives are formulated within polymeric matrices containing natural penetration enablers and then released into the skin via hydrolysis or enzymatic degradation. These polymeric cosmetic conjugates can be designed to target specific treatment areas providing substantially improved results. This approach is particularly suited to the delivery of large molecular weight substances such as peptides, amino acids, lipids, vitamins, hormones and other bio-actives.

Conrex’s PET™ delivery technology employs this type of polymeric matrix in its approach to cosmeceutical skincare. PET™ works by solubilizing active ingredients within the polymeric matrices and temporarily modifying the permeability of the skin. This enables large active ingredient molecules to pass between and through the skin cells of the stratum corneum, stratum lucidum, stratum granulosum ultimately also reaching the deeper layers of the skin (stratum spinosum, stratum basale). Proven effective for pharmaceutical applications through Auxilium Pharmaceutical’s FDA-approved Testim gel, PET™ is also ideal for cosmeceutical applications because it very effective, well tolerated and derived from natural materials. PET™ is also designated by the FDA to be GRAS (Generally Recognized As Safe), meaning it is non-toxic, non-irritating, and non-allergenic. PET™ is also extremely versatile, compatible with formulations containing a large range of peptides, vitamins, antioxidants and amino acids enabling deep controlled penetration of the SC in a single formulation.