Typical Approaches For the Development of Topical Formulations
When developing topical products, there are three development phases that must be undertaken to ensure that the finished product will perform optimally when applied to the skin. .
Phase 1: Ingredient Characterization
As discussed elsewhere, the first step in any product development is to identify safe and effective ingredients that can be well characterized in terms of their effects on skin cells. Skin care products contain numerous ingredients including moisturizers, emulsifiers, humectants, antioxidants, exfoliants, and with all of these ingredients it is important to know what their effects on skin cells are. Through the use of screening programs discussed elsewhere it is possible to identify both the positive and negative effects (if any) of any ingredient on cultured skin cells. That type of screeing allows one to determine:
- The skin cell types affected by the ingredient.
- The specific molecular and cellular processes in each cell type that are regulated by a particular ingredient.
- The optimal amount of each ingredient to use in the product.
Phase 2: Development of Topical Formulations to Optimize Skin Delivery
Even though an ingredient may be found to have beneficial effects in cell culture models, that ingredient will only be beneficial when applied topically if it is delivered across the dead skin cells comprising the stratum corneum efficiently.
The delivery of any ingredient across the skin's surface can be verified by laboratory tests that use actual human skin. The test is called Skin Percutaneous Absorption Analysis.
Phase 3: Clinical Studies to Determine Product Efficacy
For any product to meet customer expectations for improving skin appearance, it must first be tested clinically using an independent testing site to evaluate the product's effectiveness. There are typically two types of clinical studies run on skin care products. The simplest study is to simply give the product to patients (an "open label study") and have the clinical investigator assess the effect of the product in improving such parameters as skin redness, smoothness, or lines and wrinkles after one to two months. If a product contains a proprietary ingredient that the company feels is superior in improving skin appearance, then a blinded, placebo controlled clinical study is run in which two patient groups are enrolled. One group is given the test formulation that contains the proprietary ingredient while the other group receives exactly the same formulation that does not contain the proprietary ingredient. Obviously the second type of study is the only study that should be run to evaluate the efficacy of a proprietary ingredient.