In order to clearly observe the steps required by the formulation chemist in working with naturally derived ingredients, hereafter simply called naturals, one must begin not with the chemist but with the proposition of marketing request. So, where does the formulation chemist begin when facing a marketing request for a product stamped with a “natural” label claim? The first step is to identify the certifying organization or government under which the formulation is to be sold, to determine whose definition of natural should be considered. Since there is no globally unified definition for what constitutes natural, this information should be outlined and learned at the earliest stages of development to smooth the subsequent path toward intelligent formulation.
In an effort to illustrate the path to meet the challenges of formulating natural products, this article will concentrate on complying with the two primary authorizing organizations in the North American market—Whole Foods Markets (WFM) and the Natural Product Association (NPA). Though these two organizations will be the main focus, readers are reminded that any product sold in the United States must first comply with U.S. Food and Drug Administration (FDA) regulations and pass all necessary safety and regulatory-related tests. Considering this, a regulatory expert as well as a toxicologist should be involved in advising product developers of the necessary requirements, tests, costs and overall timeline to completion.
Composing Leave-on Products
The formulating process for leave-on naturals is, at its base, similar to that for conventional emulsions. However, one key difference is the choice of preservative system since most preservatives currently used are synthetic—yet the prevention of microbial growth is essential. The industry often uses parabens, methylchloroisothiazolinone and methylisothiazolinone in conventional products. These will typically not affect the physical properties or stability of formulations. In contrast, when natural preservatives are used, pH may play an important role in maintaining the efficacy of the preservatives since some preservatives will be effective only at a relatively narrow pH range. Therefore, it is recommended that when selecting ingredients for natural products, the formulator should begin by building from the preservative system; a suggested order of ingredient selection is as follows: 1) preservative or preservation system, chosen based on compliance with the natural association; 2) emulsifiers; 3) oil phase components; 4) antioxidants; 5) viscosity builders and stability modifiers; and 6) benefit ingredients to support intended claims. In addition, cost restrictions must be taken into consideration.