The use of botanicals in personal care products has been a distinctive trend over the last decade and will continue growing as the demand for natural concepts is rising. Traditional European (such as chamomile) or Asian plants (such as green tea) are used in cosmetic applications, specifically in skin and hair care formulations.

Despite the extensive use of botanicals just for ingredient label claiming, there is a growing demand to use plant extracts with proven efficacy . On the other hand, traceability of active ingredients in cosmetic formulations starts to be a legal necessity in some European countries like Germany with the LMFG (the Law covering Food and Feedstuffs).

In this way, high quality botanical extracts with a high and constant content of active ingredients (standardized extracts) are becoming fundamental for both efficacy and traceability. Particular guidelines for the selection of raw materials, validated extraction procedures and quantitative analytical methods are needed to ensure their batch-to-batch consistency.

The aim of this paper is to show the traceability of botanicals from Cognis in several formulations thanks to their high active content and the development of specific analytical methods which allow their determination in both the extract and the final formulation.

1. Introduction

1.1 Trends

There is an increasing demand for the use of natural raw materials such as plant extracts or vegetable oils in cosmetics. In particular, botanicals are among of the top ten active ingredients in skin and hair care formulations. Every year the cosmetic industry uses around 2,000 tons of botanical extracts.

In recently launched international products many traditional plant extracts appear such as aloe vera, green tea, grape, soy or camomile. These extracts have been used for years and will continue to be used in the future, because consumers believe in their efficacy. The main claims are based on anti-aging, soothing and anti-microbial properties. For instance, there is a trend towards the use of green tea and grape extracts. Both are strong anti-oxidants due to their polyphenol content. To provide "well-being" ginseng or ginkgo are often included in cosmetic formulations. New trends are the introduction of plant derivatives with low estrogenic efficacy such as soy bean or red clover and anti-microbial extracts like green tea or olive leaf extracts. In addition, the skin lightening market is expanding towards Europe and includes for example actives based on licorice (glabridin) or bearberries.

1.2 High quality botanicals: Definition and main basic concepts

Newly launched market products cover a range of products from only plant labelling (e.g. shower gels including passionflower) to products with additional effects based on the plant extracts (e.g. soothing after sun formulations with aloe vera) to products, where the claim is based on the real efficacy of the extracts (skin lightening products with arbutin ). However, not every plant extract in the market fulfils the requirements for the use of real claim substantiation. Therefore, there is an increasing demand for high-quality plant extracts with a natural content of actives to provide the desired efficacy.

The botanical extracts are concentrated preparations usually obtained from dried-vegetable or plant materials. Extracts can be either liquid or solid. But the most important difference between plant extracts and (pure) single chemical substances is that plant extracts usually consist of many hundreds of components. Sometimes one or more of the active ingredients in the extract are known and described but the efficacy of all components or the whole composition is hardly known completely. The plant components work synergistically as an ensemble.

Therefore to secure a consistently high quality plant extract, guidelines for the selection of the raw material, validated production process (guaranteeing a consistent content of the active component) and appropriate analytical control parameters are necessary.

In the process of the raw material selection three items are of considerable importance. Firstly, it is necessary to make sure that the raw material used is always obtained from the same subspecies of the plant. For example there is a large number of different subspecies of white birch, e.g. betula alba and betula pendula. These subspecies differ in their composition and in the concentration of the components. The second point is that the raw material should always be of the same origin because climatic conditions have a strong influence on the composition and concentration of the plant components. The last point is that only the part of the plant which contains the identified actives should be used for the extraction process. For instance leaves contain other ingredients than the roots or the blossoms. For example only the blossoms should be used for a high quality camomile extract. If these particular guidelines are taken into consideration when selecting the native raw material for producing, the extract will have a more controlled composition.

Another important requirement when offering botanical extracts for efficacy is a validated production process that ensures a high content of the active component. The plant actives have different physical and chemical properties based on their structure. Therefore, it is not possible to use one extraction method for all plants. For every plant a specific extraction procedure has to be developed. The best solvent, the optimum temperature and the sufficient extraction time have to be optimized. To maintain a consistent quality in every batch no changes in the validated procedure are allowed.

The highest content of actives is obtained by complete extraction methods (percolation). In this case the solvent is added continuously to the raw material. Based on multiple diffusion steps and equilibrium points a very high content of the desired fraction of the plant component is obtained. In an additional step these extracts can be concentrated by using a mild spray-drying process. The spray-dried powder extracts have the advantage that they do not contain any preservatives.

The last stage of the production of a botanical extract is quality control. Traditionally, the quality of plant extracts is described with the "Extract: Raw material ratio". This means that the quality is referred to the quantity of raw material used. Despite this and thanks to the modern analytical methods it is possible to measure the concentration of one or more substances. When plant extracts contain a specific concentration of the active substances which are present at the same concentration in every batch, we refer to standardized extracts.

Thus, if the extract is used for real claim substantiation, the same quantity of the extract and of the active ingredients are used in every batch of the final cosmetic product. The producers of the retail product do not want to adjust the production process to varying qualities of the botanical extract. Therefore, only standardized extracts fulfill the requirements for the use of botanicals for efficacy. Different quality grades of standardized extracts are available such as standardized extracts, purified extracts or pure isolated plant actives.

For some plants, groups of actives are known. For example, grape extract contains the group of polyphenols. Polyphenols can be separated by chromatography and the result is a purified grape extract with 95 percent polyphenols. For highest efficacy, isolated plant actives are recommended. Isolation makes sense only if tests have shown that the single active has the same or a higher efficacy than the synergistically working extract. For example β-escin is the well-known active out of horse chestnut. It is isolated with different solvents, and the last step is crystallization. Pure natural plant actives provide high efficacy and are often lighter in color.

Many plant extracts on the market have not been toxicologically and dermatologically assessed. Product safety has been referred to in literature and from experience based on the traditional use of the plants. However, in high quality extracts, due to the high content of the plant ingredients this comparison is not always possible, and therefore toxicological and dermatological safety assessments are highly recommended.

On the other hand the absence of allergens must be proved with regard to the new Directive (7th Amendment of Council Directive 76/768/EEC). This directive added 26 substances to Annex III Part I due to their allergenic potential and so their presence must be indicated in the list of ingredients of finished product when the concentration exceeds 0.001 percent in leave-on and 0.01 percent in rinse-off products.

Once the botanical has been formulated in a shampoo or in an emulsion, it is often an interesting matter and not an easy task to show its traceability. Since in some European countries like Germany there are some laws such as the LMFG which regulate this, traceability of active ingredients in cosmetic formulations starts to be a key topic. This law, which is originally for food, has been transferred to cosmetics with the main target to protect consumers from deception and wrong expectations.

2. Traceability of botanicals in personal care formulations

2.1 Traceability of Herbalia® Camomile in a shampoo

2.1.1 Introduction

Camomile, chamomilla recutita, is one of the most widely used herbs in the kingdom of botanicals (Figure 1). Camomile has been used for centuries in teas as a mild, relaxing sleep aid and treatments for stomach, and as an anti-inflammatory agent, to name only some of its therapeutic applications.

Extensive scientific research over the past years has confirmed many of the traditional uses and established pharmacological mechanisms for the plant's therapeutic activity, including anti-bacterial, antifungal and antiallergenic activity. In addition to the medical use, camomile is used in numerous cosmetics as a mild ingredient, particularly in baby care. Furthermore, it is used in hair care to add highlights to blonde hair.

High quality camomile extracts are obtained from the beautiful blossoms as these contain the main active ingredients. The main constituents of camomile are essential oils, apigenins, bisabolene, alpha-bisabolol, chamazulene, chlorogenic acid, well over one hundred compounds.

Fig. 1: Camomile