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The origin of the word cosmetic lies in the ancient Greek word Kosmein, which means decoration. The desire of people to decorate themselves, be it for hunting, sexual attraction, social status, ritual purposes, special occasions, or just for simple expression of beauty, are probably as old as humanity itself. From adornments to paints, ointments, tattoos and perfumes, the array of materials and fashions not only seems endless but is also changing with time and culture. Although occasionally very damaging ingredients have been used,, e.g. lead (Pb) and mercury (Hg) for whitening in the Middle Ages in Europe and until today in parts of Africa, hygiene and the care of the body have usually been an essential part of such decoration.
While care for the body and hygiene flourished during the Roman Empire, were deplored as something sinful during the Dark and Middle Ages in Europe. The use of cosmetics was punished in much the same way as witchcraft was punished in Puritan England and soap was considered a sinister curiosity threatening the health of the human soul. Not until the end of the sixteenth century did the use of perfumes, powders, creams and colours, and in some European countries even baths, slowly become acceptable. Other cultures, particularly those in tropical climates, had a much more practical and healthy relationship to body care and hygiene. The continued disdain for baths in Europe, at least into the nineteenth century, made the developing cosmetic industry a necessity.
Today's cosmetic products however include in addition to perfumes, a vast and ever increasing range of products from simple skin creams, soaps and shampoos to special lotions, base creams, moisturizers, nourishers, cleansers, protectors, rejuvinators and conditioners for body, face, hands, eyes, lips, mouth, hair, nails and so on (see Figure 9.1).
As our knowledge of various afflictions of different parts of the body, particularly skin and hair, has increased, as well as our understanding of the action and interaction of various chemicals and plant extracts with different parts of the body, cosmetology has developed into a highly complex and specialized field of its own. The cosmetics industry has combined knowledge of pharmacology and dermatology, with traditional herbology, modern processing technology and most advanced marketing psychology in order to exploit one of the strongest instincts or needs of human-kind, namely that of being considered attractive and healthy in his/her narrower or wider social environment.
Though bee products are not essential to cosmetics, their characteristics add to the various care products in a way no other single product can. Many of today's commercial multichemical formulations are designed for marketing needs such as storage, or better appearance and consistency, rather than for the actual benefits of all these chemicals for the intended cosmetic application. At the same time, scientific and technological advances have reached a state of sophistication in which formulations can have real beneficial action on the skin, for preventative or restorative treatments. Thus, the distinction from pharmaceutical products, well defined by law, becomes less obvious.
Figure 9.1 : Display of various cosmetic products containing one or more primary bee products.
Using simpler formulations usually influences the consistency or durability of a product. However, a choice of simpler formulations and more natural products, variously considered an improvement or a regression, does not necessarily include a loss of benefits or quality. Many of the technological and scientific advances of the last decades can also be applied to such simpler formulations
Both high technology cosmetics and natural cosmetics have their drawbacks and benefits. High technology cosmetics are too expensive to produce on a small scale and many ingredients are too difficult and expensive to obtain, especially in many tropical countries. Natural products usually do not have as long a shelf-life as highly processed and preserved products, and are therefore also limited in their access to long distance markets. On the other hand, natural products can often be obtained locally - which often means lower prices with no need for foreign currency - their freshness may be easy to confirm and people are already familiar with such ingredients and know how to appreciate them. The freshness of such materials and of the final product, as well as their easier adaptation to local preferences can be additional selling points.
In order to produce products based on natural materials and to give them the appearance and consistency of high quality products, using a minimum of technology, high quality ingredients and specialised knowledge are required. Home-made, small scale production is possible, but will not usually achieve the same technical quality as products processed with better facilities.
Considering quality in the sense of effectiveness, it is possible that home-made products can be of superior quality, particularly if most or all of the ingredients such as herbal extractscan be produced under controlled conditions at home as well. Again, however, a basic understanding of the different ingredients is necessary, in order to treat each in an appropriate way and maintain those characteristics for which they were selected in the first place.
Going back to the basic benefits derived from cosmetics, a much simpler approach than the high technology, high sales "make believe" approach, is possible. The purpose of this chapter is to present some basic ingredients and formulations for the different cosmetic applications in today's market, selecting more natural ingredients and providing the choice of substitutes available in various countries. Emphasis is given to understanding fundamental production principles. Very simple basic techniques are presented and contrasted with some intermediate technologies available to improve product quality. Finally, some marketing aspects will be discussed in order to present the formulated products on a competitive basis.
The cosmetology presented here is adapted to cold climates and white Caucasian skin. Other cultures prefer different colours and products - even requirements for skin or hair change between different climates and human races. However, it is assumed that such basic functions as moisturizing, nourishing, protecting, soothing and cleaning are similar enough to permit similar formulations. This is felt to be true particularly since the specific addition of bee products for such purposes adds a much broader spectrum of action than is possible with synthetic ingredients.
Discussion of the quality and other characteristics of various bee products as ingredients has been included in the individual chapters on each primary product. Other details necessary for the final products are included in the recipes. Every cosmetic product class is discussed briefly. General considerations on the actual manufacturing process are discussed in a separate section, detailing each production process and outlining the utility of appropriate equipment.
While there are many books and articles published on the various cosmetic formulations using beekeeping products, only a few recipes can be selected for this bulletin. More emphasis is given to methodology, technology and the understanding of basic needs, thus allowing replacement of various hard-to-come-by ingredients and encouraging experimental adaptation to suit local requirements.
9.2 Description of product types
A lotion is a fairly liquid, i.e. acqueous, formulation with a high water or alcohol content, but still having many similarities with creams. In general, lotions are used for cleaning and for adding moisture to the skin or the hair. Many of the aromatic waters of the past were used like lotions. As lotions, however, they may also contain substantial amounts of emulsified oil, fat or wax (see Figure 9.2).
Figure 9.2 : Various lotions containing primary bee products and packed in dispensers for easy use.
An astringent lotion is useful for oily skin and causes pores to contract. The astringent ingredients can be one or more alcohols, witch hazel, citric acid (lemon juice), vinegar, alum, or a large choice of synthetic products. Friction lotions and skin fresheners (containing up to 50% and 15% of alcohol, respectively) may also contain astringents, but they mainly serve to cleanse and moisturize the skin. Suntan lotions and after-shave lotions, for example, have very specific purposes and therefore specific ingredients. Various lotion formulations are listed in the recipe section.
Ointments and lipogels are not really creams because they consist of a single phase (for example, only oil). The classic preparation, using Vaseline, lanolin (wool grease) beeswax, mineral oils and/or vegetable oils, has been "modernized" by incorporating modified vegetable and animal oils, preservatives and stabilizers (e.g. hydrogenated ricinus oil). The addition of stabilizers to ointments leads to the formation of lipogels.
New choices of oils, fatty acids and triglycerides can make ointments less greasy and easier to absorb, but they are not very common in modern cosmetics. Some are employed in pharmaceuticals, and the use of beeswax carries additional benefits in these. However, it must be pointed out again that by law, cosmetic products cannot contain any pharmacologically active substances, or claim any medicinal effects.
In technical terminology, there are clear and not so clear distinctions between a large number of different types of creams. They are classified by the nature of the emulsion (clear) and the purpose of application (not so clear, since very similar or equal formulations can have different applications).
The most common type of emulsion is oil emulsified (dispersed) in water (o/w) and water emulsified in oil (w/o) (see also section 9.4.3). Cold creams require beeswax and are the most basic, yet possibly the most important cosmetic creams. Being w/o or w/o/w (water in oil in water) emulsions, cold creams are oily or greasy to the touch and produce a cooling effect on the skin, as the water slowly evaporates. Incorporating new synthetics, water in oil emulsions have been developed for nutritive, restorative, protective, water-repellent and sun-protecting purposes, for all types of skins, baby care and massage. Modern cosmetics however, tend to replace these less stable w/o emulsions with w/o/w emulsions, on magnesium sulphate bases, or even with o/w emulsions with high lipid contents. The appearance and feel of a cream, its effectiveness as a moisturizer and carrier and adhesive for colours depends on the emulsion type and pH as well as the type of oils, fats, alcohols and esters used.
Some of the more generic creams currently in use include cold creams, emollient creams (for soothing and skin softening), hand creams (for moisturizing and protecting), face creams (for more gentle moisturizing, nourishing and cleansing), bath creams (slightly astringent, for moisture sealing and replacing lost lipids), moisturizing creams (for providing moisture, moisture sealing and soothing), nourishing creams (containing vitamin and protein complexes, oils and other nutrients) and cleansing creams. Creams for more specific applications include depilatory creams, foundation creams for use under make-up, night creams, rejuvenating creams, antiwrinkle creams, sun-protection creams, shaving creams and medicated creams (for applications in dermatological disorders, inflammations and wound healing).
The selection of ingredients depends very much on the final purpose and the desired consistency (creamy, hard, soft, greasy or dry) of the product. Changing one ingredient may require changes in many others if the physical characteristics of the product are to be maintained. The diversity of applications and the choice of ingredients (mostly synthetic or modified natural products) is simply too large and too complex to be discussed here in detail. As a general guideline, the different oils, fats and waxes are chosen for their consistency and absorption characteristics, their mixability with other ingredients and for their function in protecting and providing moisture to the skin. Some oils may also be nourishing for the skin, give it special elasticity and br readily absorbed. Different types of applications often require only slight changes in the proportions of ingredients, but sometimes, more specific ingredients have to be added to achieve the desired effect. Classifications often overlap and definitions are not used by everyone in exactly the same way (see Figure 9.3).
The aqueous (water) phase of the emulsion provides moisture to the skin, serves as a solvent or carrier for other ingredients including dyes, allows the use of gels or polymers and, in general, helps to determine the consistency and shelf life of the product.
Figure 9.3 : Various types of creams containing primary bee products.
Emollient creams in particular are used to soothe and soften the skin by providing substances the body normally produces through its skin gland secretions. Among these sebum, secreted by the sebaceous glands, is important for its protective function. Fatty acid glycerides are abundant components of human sebaceous secretions (50%) and skin surface lipids constitute 5.5 to 37.5 %. These can be provided through incorporating one or several of many vegetable oils such as peanut, safflower, olive, avocado, corn, castor, cottonseed, sesame, peach, apricot kernel, palm kernel, coconut and hydrogenated vegetable oils and cocoa butter. One problem is the rapid degradation of these oils - they quickly become rancid if they are not refrigerated. Addition of antioxidants such as propolis extract can retard such decay. Industrial synthetic substitutes exist and are continuously being improved. In addition to the above-mentioned fatty acids and lipids, sebum also contains 14% waxes, 2% free cholesterol, 2.1 % cholesterol esters, 5.5 % squalene, 8.1 % branched paraffins, 2% alkane diols and 5.1 % of unidentified substances (Wheatley, 1950).
Shampoos are liquid, creamy or gel-like, depending on the inclusion of traditional soaps saturated with glycerides and natural or synthetic fatty alcohols or on the thickening agents (e.g. gum, resins and PEG-600D5) that are used.
In general, a shampoo is a colloidal dispersion of surfactants (substances which reduce the surface tension of a liquid) in water. Shampoos can have other substances incorporated which have a restoring and protecting effect on hair, such as natural and modified lipids, amino acids and silicones, or have a reconstituting effect on the integrity and health of the hair and scalp - such as preventing dandruff and excessive sebaceous secretion.
The actual procedures and equipment to be used must be adapted to the type of product required. Some shampoos can be mixed at room temperature simply by adding the ingredients one after the other and mixing them well. In other shampoos, the dissolution of various components will require the use of heat.
The demands for mixing are similar to those for other preparations. The product should be mixed well, in a blender which leaves no "dead", i.e. non-agitated, spaces. Since shampoos are not emulsions, speed is not very important, but a mixture prepared slowly and reaching a uniform consistency without excessive inclusion of air, is better than one prepared quickly, with a lot of included air. If the product is very liquid, has a reliable anti-oxidant and there is enough time and storage space to wait until the air bubbles have separated and the air has escaped, there should be no problem with such aeration. Alternatively, if there is insufficient time or space, or the product is fragile, the following precautions can be taken to avoid inclusion of air. The product should be:
- mixed slowly by hand or at very slow speed with a blender, if the blades are not fully and continuously immersed in the liquid;
- thickened only after mixing and settling of air bubbles;
- heated to 30° or 35° C before draining.
Almost all primary bee products can be added to shampoo or after-shampoo balsams and conditioners, because of their beneficial effect on both the hair and scalp. Aqueous extracts of propolis however, mix better than those extracted with concentrated alcohol.
Soaplike substances, usually extracts of special plants, have been used since ancient times. The Gauls of northwestern France prepared soap using animal fats, wood ash and calcium hydroxide (burned limestone plus water). However, they used it as a cosmetic. Galenus, a physician in the second century of the Roman Empire, apparently for the first time in Europe, indicated the use of this type of soap as a detergent in place of the lyes used previously. Until today, traditional soapmakers use the same three basic ingredients as the Gauls. Progress in the nineteenth century advanced the scientific understanding of soaps and led to industrial production and significant modification of the basic recipes. Today there are liquid soaps, bar soaps, powdered soaps, bath soaps, shampoos and medical soaps in all colours, shapes, consistencies and odours.
Making soap is fairly simple, but making coloured and perfumed soaps for various cosmetic applications is a little more complicated. Soaps made from animal fats rather than glyceric acids, are of higher quality. These soaps are re-melted several times to clean them and are finally dried to obtain a high content (72%) of fatty acids.
Industrial soaps for further processing are usually available in small pellets. Toilet soaps with a low glycerol (= glycerin) content (less than 1 %) are opaque, while those containing about 6% are translucent. This provides scope for the use of different pigments to achieve various colour effects. For large scale production, the pigments are mixed or tumbled with the soap chips before or after the addition of glycerol, fragrance, moisturizers and other additives. The mix is refined in a three-roller mill or "plodder", a special soap extruder and pelletizer. This is repeated several times if necessary. Refining is the dispersal of all the ingredients throughout the body of the soap. After refining, the soap is extruded and pressed into moulds.
For small scale production without extrusion, the soap should be melted for mixing with other ingredients and then be poured into moulds. Decorative moulds of different shapes (rather than the conventional square chunks) will look much more attractive (see Figure 9.4). This is particularly important if the soap is to be sold as a special beauty soap, and has to compete with others on the market. Adding pleasant fragrances will improve the attractiveness even further.
Most of the soap recipes given in this chapter begin with a prepared soap base. For small quantities, clean bar soap can be used. For medium and larger scale production, soap chips can be obtained from a local soap producer. For the addition of fragrances and colours, the most basic white or clear soap available should be obtained. However, white soap may already contain titanium oxide pigments, which may reduce the effectiveness of other added pigments. For simplicity, the colouring may be omitted or pre-coloured soap can be used.
Figure 9.4 : Various attractive and decorative shapes of soap formed in special moulds.
9.2.6 Toothpastes and mouth rinses
Toothpastes, by definition and common usage, are mild cosmetic detergents for cleaning teeth. Initially intended to freshen the breath and remove deposits from teeth, evolution of toothpaste has also made it a vehicle for the protection of teeth from caries and gum diseases.
The base recipe for toothpaste contains an abrasive, a detergent, a non-drying liquid, a binder, flavour, colouring and a few other additives such as preservatives, antiseptics and astringents. Formulations are relatively complex and poorly made pastes will separate, harden or liquefy.
Bennett (1970) describes the ideal abrasive as one that will not scratch the tooth enamel and yet will exert sufficient scouring action to clean and polish teeth. It should not react with the other ingredients, spoil the taste or appearance of the toothpaste nor segregate or lump with aging. Suitable abrasives include precipitated calcium carbonate, magnesium carbonate, bentonite, kaolin, chalk, silica, talc and tin oxide. Any abrasive that is used must be very finely ground. Because of the undesirable action of soaps on saliva, regular hard and soft soaps have largely been replaced by glycol, diglycol stearate and synthetic surfactants. Synthetic surfactants are usually also better emulsifiers, with better cleaning powers and lower alkalinity. Carriers and softeners, used to suspend the abrasive and prevent drying of the toothpaste, include alcohol, honey, glucose, invert sugars, mineral oil, water and calcium chloride. Binders, also incorporated as carriers and colloiding agents, include acacia, locust bean, India and Karaya gums, agar, colloidal clays, pectin, petrolatum, silica gel and starch. If binders are plant products, they must be adequately preserved.
Bad breath, caries and gum diseases are mostly a consequence of bacterial growth in the mouth. Therefore, an effective toothpaste should have an antiseptic component which preferably, should not destroy the beneficial mouth flora. Propolis is a mild antiseptic, well suited for this purpose and honey is a good sweetener, since it was demonstrated that artificial sweeteners have been shown to have non-beneficial side effects such as, for emample, the promotion of caries. The addition of fluoride for protection against caries, has been and still is controversial, but it is widely practised anyhow.
Mouth washes are mostly alcohol-based mixtures, with antiseptic, astringent, flavour and colour additives. While their purpose is primarily to freshen breath, they can only be effective if they destroy some of the bacterial flora of the mouth which caused the bad breath in the first place. Hence, propolis is an obvious and mildly flavoured choice ingredient.
Deodorants are designed to absorb, change, mask or prevent any unpleasant odours. Those used for cosmetic purposes are presented in soap, aerosol, cream and roll-on gel forms. The active ingredients comprise fragrances (or aromatic extracts), astringents, antibacterial agents and drying agents which interrupt the normal functions of sweat glands. A deodorant should dry quickly without leaving a greasy film. The solvents and thickening agents are selected for the method of application. One-time aerosol applicators using various driver gases should be avoided; they not only require expensive containers and filling equipment, but can also present an environmental risk. Mechanical dispensers for spray application work well and can be refilled by the customer or retailer.
Though less radical than most synthetic microbiocides, propolis extract is well suited as a deodorant ingredient, because of its bacteriostatic characteristics and for its pleasant smell.
9.2.8 Facial masks
Facial masks serve as many purposes as skin creams. Many preparations for easy application or home use are available on sale, but face masks are frequently prepared by beauticians themselves, just prior to use. Many of them have their own preferred recipes since it is possible to prepare them with a very wide variety of ingredients, particularly fresh ingredients which otherwise are too perishable. Less stringent restrictions in certain performance standards such as consistency and shelf-life, allow much freer use of primary bee products, all of which can be beneficially included in face masks. Thus, although it may be difficult to market the ingredients on a large scale, certain beauty salons and cosmeticians can prepare some of the formulas from the recipe section and all could include honey, royal jelly, propolis and pollen extracts in their own preferred formulas. However, precautions should be taken against any possible allergic reactions in customers.
Honey in these formulations serves as a moisturizing, cleansing and nourishing agent. For similar reasons, any of the other bee products can be included in those masks intended to refresh, nourish or cleanse the skin. Selection of the right be product for the right application can be made with the help of Table 9.1. Since the actual consistency or stickiness of many preparations is not very important, the precise proportion of bee products are not important either and there is plenty of scope for experimentation.
Summary of the cosmetic functions of five primary bee products (modified from Proserpio, 1981 and 1988)
|Honey||Sweetener, emollient, moisturizer, humectant, tonic, refresher, anti-irritant, skin softener, epithelial reconstitution and soothing agent|
|Wax||Excipient, protectant, film formant, water repellent, sebum restorant, depilatory, anti-irritant and emollient|
|Propolis||Antidandruff and anti-wrinkle agent, hair conditioner, deodorant, purifier, tonic, disinfectant, antioxidant, preservative and UV screen|
|Pollen and royal jelly||Anti-wrinkle, anti-stretchmarks, elastifier, nutrifier, firmer, revitalizer, hair conditioner, tonic and sebum equalizer, tanning aid (pollen only)|
The use of make-up includes a wide variety of applications and can be understood in a very wide sense as referring to all facial cosmetics, including actors' face paints. The make-up referred to here however, will be those facial preparations which temporarily change the appearance of part or all of the face, such as rouges, mascara and eye shadow. Lipsticks and various facial creams are considered separately.
Mascara is usually a black, sometimes bluish or dark brown paste or fast drying liquid, which is applied to eyelashes and eyebrows. Being one of the oldest make-ups, it was once prepared with oil and lampblack (from oil and later gas lamps). A sample formulation using beeswax is provided. Mascara is frequently packed with an applicator such as a special brush. Eyebrow sticks are generally simple in composition, but usually need to be heated and pressed into the right shape.
A good foundation cream protects the skin from the colouring of the make-up and makes it easier to apply, adhere and remove. Eye colouring can be applied in cream, stick (pencil) and powder form, each requiring essentially different formulations and processing. Creams use rather complex wax and oil mixtures to produce a durable, non-smearing, easy- to-apply colour. Pencils and sticks may be extruded, or poured into forms and dried, and powders are usually pressed with high pressure into pallets or containers.
As discussed in slightly more detail below (see section 9.4.5) pigmentation of cosmetics is quite complicated. The choice is also limited to a few types of permitted pigments and dyes. Pigment choice will depend on the type of formulation, i.e. a dry powder, cream or pressed cake. The preparation of make-up colours also requires a base which adheres well to the skin and spreads easily. There are innumerable patents for different formulations, some of them including low levels of beeswax (1 to 5 %) or other waxes which could be replaced by beeswax. One eye colouring cream formulation is described below (section 9.13.11), but its effectiveness in adhering to skin is based on two special chemicals. Pigment producers can sometimes help with certain formulation and production problems.
It is known from archaeological discoveries that even before Egyptian times, people used red dyes to stain their lips. During the time of the Roman and Greek Empires, these stains were applied as lip pastes and liquids. Only after the beginning of this century did solid lipsticks come into limited use. Yet, only after colouring became more effective and allowing more permanent stains, but most of all permitting more natural colours than the bright carmine red, did lipsticks become socially acceptable. Since then, fashion and pigment development have determined the colours (even conspicuous ones again) which have led to today's lustrous, pearlescent and frosted shades.
Lipsticks are made of a relatively complex mixture of waxes and oils. Some of the ingredients are modified in order to obtain a soft lipstick which maintains its form even at warmer ambient temperatures and which forms a good base for the pigments. A modified beeswax (PEG-8) is used in one of the selected recipes, where the gel-forming characteristics of the modified beeswax is increased with triglycerides from fractionated coconut oil. The lipstick formulations given in the recipe section (9.13.12) involve base formulations with different degrees of complexity. The simplest are soft and creamy lip glosses, for which one recipe is given in section 9.13.12. Mixing these formulations is not very difficult and they can be poured into forms and mounted in typical lipstick dispensers. To market a product successfully however, the colour of the lipstick should be constant from batch to batch.
Mixing the correct amount of pigments every time and getting the desired colour is an art of its own and requires good laboratory equipment. There are colour chemists who specialize in only this aspect. Expensive measuring devices can be used to compare all aspects of a colour and to ensure exact correspondence between batches. Since lipstick or its ingredients must be non-toxic, not just any pigment can be used (see section 9.4.5).9.2.11 Perfumes
Perfumes will not be discussed here as they do not normally contain beekeeping products and since they require production technologies and knowledge very different from those described here.
9.3 Sources of ingredients9.3.1 Local sources
Extracts from many plants can be used as emollients which soften and soothe the skin, such as from cattail root (Typha) fig fruit (Ficus) Jimson weed seeds (Datura) locust flowers (Robinia) lotus root, leaves and seeds (Nelumbo) Hibiscus seeds (also used as an as astringent and various others (Krochmal, 1973). Synthetic emollients are extremely common, but beeswax, other waxes, vegetable oils, and animal fats and oils also perform very well.
Pigments and dyes, powdered or extracted from local plant resources can be included in coloured preparations, if they are soluble in at least one of the phases of the formulation. Natural dyes, while very attractive on their own, can hardly compete with the brilliance and variety of synthetic pigments. However, natural dyes and pigments are generally, though not always safer to use.
The European Union (EU) and the US Food and Drug Administration (FDA) have published lists of natural pigments and dyes which are allowed in food, pharmaceuticals and cosmetics. Care has to be taken that local dyes and pigments are not toxic and do not cause allergies or other irritations. Pigments should be of a sufficiently small size so that they do not separate in the final product. Dyes which are soluble in the liquid phase (unlike insoluble pigments) should not stain permanently. But, as in lipsticks, some lasting colouration of the skin is desired to achieve a minimum of durability. It is probably the easiest to find out which of the locally available natural dyes and pigments have already been tested for compatibility by the larger producers, and use these.
One of the problems associated with using natural plant or animal extracts is their often inconsistent composition or quality, together with the possibility of contamination and interactions of the complex ingredients. Side-effects on skin are rare, except for fragrances, there are also several plants known for their irritant reaction. Dorato (1987) gives a short discussion of various water-soluble plant extracts, though mostly of temperate climate origin. He describes the current trend in phytocosmetics (those using plant extracts) towards the use of standardized extracts or pure compounds for the simple reasons of more constant performance and less difficult analysis and quality control.9.3.2 Imported
Although an attempt has been made here to provide some alternative formulations using commonly available products, specially refined raw materials are better for high quality production. Synthetic materials in particular need to be of a purity superior to that required for most other applications, so it is often best to obtain supplies from special cosmetic suppliers. Food quality products can usually be used safely in cosmetics.
A list of international suppliers of special ingredients, equipment and books should be consulted. The CTFA (Cosmetic, Toiletry and Fragrance Association) publishes the International Cosmetic Ingredient Dictionary with common, scientific and commercial names together with a list of suppliers. Information on "Emulsifiers & Detergents, Functional Materials" is published by McCutcheon's Division. The Cosmetic Bench References published by Cosmetics and Toiletries Magazine have a long list of suppliers of natural and synthetic and specialized materials, testing and formulation laboratories and equipment suppliers. Their addresses can be found in Annex 2. Other sources are the commercial attaches of various embassies, who can give information on suppliers from their respective countries. Many international suppliers have subsidiaries around the world. Purchases through these subsidiaries will eliminate most importation problems.
The first few importations will take a lot of time and effort to obtain all the necessary permits, letters of credit and of course the foreign exchange necessary has been obtained. Insurance of expensive shipments may not cover the merchandise after arrival in the local port harbour. These transactions might become smoother and quicker with experience and after regular trade with the suppliers. Orders for supplies should be timed carefully, in order to avoid unproductive periods because of the delayed arrival of one or more ingredients and spare parts.
The simpler the formulation used, the less need there should be for importation of ingredients. If the quality of the local ingredients is not adequate, the user should work with the producer to improve his quality of production.
9.4 Technical requirements9.4.1 Raw materials
In general, only the cleanest and freshest products should be used. Vegetable oils, vitamins, proteins, royal jelly, pollen, some plant extracts and aromatic oils have limited shelf-lives, and need special storage (refrigeration) or should be used quickly. To save work when using only very small quantities, the oil and water phases of a product may be prepared in advance, minus the aromatic oils, herb extracts and royal jelly. The different phases are then mixed only when more product is needed. Once mixed, the emulsions provide a much better medium for bacterial or fungal growth. The addition of propolis extract to the water phase acts as a mild preservative and antioxidant.
Water should be distilled or soft (with insignificant levels of bicarbonates or sulphates) and clean, rain water is preferable. Under most circumstances the water should also be boiled prior to use. In cities with piped drinking water, such water is often treated with chlorine, fluoride and other additives which can react negatively in some preparations. Even after boiling and filtering, this water would be second choice to rain water. Rainwater collected in heavily polluted areas should not be used. Distilled or deionized water is used in many industrial products.9.4.2 Equipment
For simple home made production, little more than normal cooking utensils are necessary. The following list describes the essential items of equipment, some of which are illustrated in Figure 9.5. An example of a small area devoted to cosmetics production is shown in Figure 9.6.
For slightly larger operations better mixing equipment is most essential, as is a refrigerator. A water jacketed mixer (see Figure 9.7) would be very helpful, providing better emulsions and mixing of creans during cooling. Better bowls and glass containers for measuring and mixing would also be required eventually (see Figure 9.6). Litmus paper for controling the pH will be needed for checking quality standards. A mortar and pestle are always useful, particularly for grinding pigments. Once serious marketing is considered, bottles and vials have to be selected in which each product type is adequately preserved and presented. Additional equipment (mills, driers and bottling machines) depending on the particular products to be produced may be needed. A battery heated wire or normal current operated machine to seal clear polyethylene bags may be useful for packing products such as individual doses of soaps, shampoos or bath foams and many other value added bee products.
Figure 9.5 : Basic kitchen equipment necessary for preparing simple cosmetic products.
Figure 9.6: a) Working area with heating plates, mixing and weighing equipment for medium-scale operations.
Figure 9.6: b) Convenient containers, beakers and other wares for medium-scale operations.
An emulsion is a suspension of one material finely dispersed in another, but without the formulation of a conventional solution. Milk and royal jelly are natural emulsions in which an oil phase is dispersed in water. In cosmetic preparations with at least two non-mixable phases, such as oil and water, the two phases are mixed at very high speed with special blades (see Figure 9. 9d). In an oil/water emulsion, the internal phase (the oil) is broken by the high speed mixer or turbine into droplets so small that they remain suspended without uniting again to form larger droplets. This emulsification is facilitated by the addition of emulsifiers. The smaller these droplets are and the better they are mixed, the longer the two phases remain emulsified, i.e. the more stable the emulsion is. Industry standards generally require an emulsion to be stable for at least 1 or 2 years.
Such stability and the success of emulsification depends on a variety of factors such as the quantity and efficiency of the emulsifier (such as borax) temperature (during and after emulsification) the sequence of addition of other ingredients, mixing techniques and the design of the equipment.
Borax is a traditional emulsifier for oil-based creams and works best for all smaller operations and simple recipes. There is a very large number of other emulsifiers available, both synthetic and natural. For further information, Emulsifiers & Detergents, Functional Materials or other basic cosmetic textbooks should be consulted.
Figure 9.7: A simple, small to medium size paddle mixer with water jacketed bowl for temperature control of the mix. During operation, the paddles are equipped with plastic scrapers which allow very close contact between paddle and vessel, thus avoiding any "dead" spaces.
The emulsification processis one of the major difficulties encountered with small-scale production. Simple hand stirring may appear to be sufficient to disperse the two phases, but such emulsions are often unstable and can separate after a short period of time (see Figure 9.8). If parameters such as temperature of the two phases, choice of emulsifier and storage temperature are optimized carefully, product stability should be sufficient for local marketing. Numerous small batches, rather than one big one will reduce requirements for emulsion stability, but might raise marketing and distribution costs.
Figure 9.8 : On the left, a vaseline-propolis ointment which was not properly emulsified. Droplets of propolis extract are separating from the vaseline and give the cream a defective appearance. On the right, a well-emulsified cream (o/w) with emulsifier and proper processing, shows no sign of separation after more than one year of storage.
There are basically four types of emulsions: o/w, w/o, w/o/w and o/w/o:
In an o/w emulsion, oil droplets are dispersed in water and the water is referred to as the external phase. An o/w emulsion does not necessarily consist of more water than oil. The sensation of such an emulsion is "lighter", thinner and fresher, although the final sensation can be influenced by other ingredients such as resins, triglycerides, silicone oils and biological polymers. It is said that the finely dispersed oils and waxes, with their very large increased surface area, can penetrate the skin surface more effectively.
A w/o emulsion consists of droplets of water emulsified in oil. The oily or greasy external phase comes into contact with the skin first, resulting in the "richer" sensation given by such creams. However, today's cosmetic chemistry has evolved far from the classical Vaseline or petrolatum base, and fatty acid esters, triglycerides and oils can now be modified so much that the sensation and absorption by the skin can be accurately controlled. Evaporation of the water from w/o emulsions is slower and it is possible that some is absorbed into the outer layers of the skin.
The w/o/w and o/w/o emulsions are basically combinations of the previous two types. Such multiple emulsions are sometimes required to mix otherwise incompatible ingredients together.
A general problem with emulsions is that the more water they contain, the more susceptible they are to contamination with microorganisms. Very hygienic working conditions and in most cases, the addition of anti-microbial ingredients, are required to protect the emulsions from degradation by such organisms. Adding bee products such as royal jelly, pollen and honey, which cannot be effectively sterilized without losing their beneficial characteristics, also adds a wide array of microorganisms. Beeswax and propolis extracts however, provide some protection. Even royal jelly and honey have some antimicrobial activity, which are unfortunately, weakened by extensive dilution. A multitude of synthetic preservatives are available.9.4.4 Mixing
Proper mixing of the ingredients is of the utmost importance in the production of stable cosmetic products. Whether it consists of an emulsion or not, the product should be homogeneous. This is often not easy and may require expensive equipment for medium to large scale operations. The sequence of adding ingredients to each other is, in many cases, also very important because of differences in their compatibility. Adding thickeners, gels and resins affects the mixability and choice of equipment. Sometimes, the order of mixing ingredients must be changed to suit the type of equipment available.
Thus it is, for example, important to mix the various ingredients with their respective solvents prior to emulsification, particularly if the solvent is the dispersed (suspended) phase in the emulsion. Solubility is important for all ingredients, but particularly for ingredients such as fragrances, which have to be added after the emulsion has been formed.
For batches too large to handle efficiently in available mixers, smaller batches can be premixed and then combined. This is particularly useful for hand mixing or paddle mixing of viscous materials which require thorough emulsification.
The inclusion of air during stirring can cause problems, in the appearance and oxidation of the product. Slower stirring, assuring complete submersion of paddles, longer storage or expensive vacuum agitators are the solutions discussed in section 9.2.4 and below. Under high-speed mixing for emulsification, air inclusion is a serious problem than for liquid, non-emulsified, slow-stirred shampoos. Air enclosed in viscous creams will not easily settle out. Special mixer designs and mixing under vacuum are the primary means by which air inclusion is avoided without compromising the efficiency of mixing or emulsification. Mixers must not allow any "dead" spaces where the product receives no agitation. For this reason, mixing containers are usually bowl-shaped and mechanical mixers have plastic spatulas on the outer paddles to scrape the vessel wall with each rotation.
It should be apparent that choosing the right mixer for the right type of product is important, since it influences product performance, appearance and stability. A few alternative mixing systems are described:
Hand stirring with a spatula is the simplest form of mixing. For hand stirring, a formulation providing easy dispersion is required. The ease of dispersion is not necessarily related to the stability of the product.
Aeration or stirring by means of bubbling gas or air through the formulation is not much more efficient than hand stirring, unless extremely large volumes of gas are used. The use of air (or steam) is more practical in low-fragile, low-viscosity systems.
Mechanically rotated paddles or anchor type agitators are a suitable way of stirring. Mechanical rotation of paddles is usually slow and the efficiency of agitation is good only for very viscous emulsions, like those containing soap gells, resinous materials and large amounts of solids.
In a planetary stirrer, the paddles rotate around their own axiswhile that same axis follows a circular movement around the container. In this way, a large batch may be mixed more thoroughly. The planetary stirrers, similar to the simple paddle stirrer, is especially suitable for the highly viscous fluids (honey) frequently also used in the food industry.
One or more propellers are mounted on a common shaft in a mixing tank. Modifications include variation in the location of the propellers in the tank, the use of two or more propeller shafts and the use of complex propellers. The inclusion of fixed baffles on the tank wall or adjacent to a propeller increases the efficiency. Propeller agitation is more commonly used for low and medium viscosity liquids. The system is also suited for small scale laboratory equipment.
Turbine type agitators are available in various sizes and designs, with different speeds and various rotor-stator clearances. Turbine type systems may be designed to give a very high degree of shearing action. Turbines may be used with higher viscosity fluids than propellers, but in high viscosity batches, the gross agitation may be insufficient and a combination mixer of various systems would be more effective.
Turbine-propeller combination agitator
A more complex mixer for producing better emulsions is pictured in Figure 9.9. In a water-jacketed bowl, several blades or paddles are slowly mixing the mass while a special high speed turbine at the base of the central axis agitates the mix at the bottom. The high speed rotor of the turbine hits the droplets of the internal phase and breaks them into much finer droplets for better emulsification. Droplet size is influenced by the turbine design, the rotor-stator clearance and the rotor speed.
Colloid and roller mills
Both types of mill are usually used for pigment dispersion and not for grinding or reducing pignment size. In the colloid mill, the product is forced past a fast spinning rotor. Clearance between the stator (the non-moving part) and moving rotor is usually a few hundredths of a millimetre. A roller mill often consists of three rollers which move against each other at different speeds. Clearance between these rollers is extremely small as between the rotor and the stator of a colloid mill. Today, this type of milling is avoided where possible for o/w emulsions, mascara and make-up foundations because of the relatively high moisture loss during processing. In such situations, a colloid mill or a turbine agitator are preferred, in combination with a mixer. If, for example, the latter attempts at mixing are not satisfactory, the pigments can be dispersed by hand or in one of the available mills in a small fraction of the oil phase, and then added to the res tof the mass shortly before or after the emulsification.
In a homogenizer, emulsification is effected by forcing the two phases tpast a spring-seated value.
Pebble and ball mills
Pebble mills, ball mills and other grinding equipment are frequently used for pigment suspension. They represent a class of relatively low speed equipment both for emulsification and for mixing dry materials. A cone-shaped container containing the product and several ceramic or metal balls is agitated. The action of the balls breaks up the pigment agglomerations and disperses them.
Stirring under vacuum
Sometimes, mixtures are agitated under vacuum. This largely avoids inclusion of air bubbles which may themselves become emulsified in the liquid and therefore become very difficult to remove. As discussed in section 9.2.4 under shampoos, slower and more careful stirring and longer storage of low viscosity fluids can provide cheap alternatives for small operations.9.4.5 Colouring
The US Food and Drug Administration has classified organic colours as Food, Drug & Cosmetic colours (FD&C) Drug & Cosmetic colours (D&C) and External Drug & Cosmetic colours (Ext D&C). Only FD&C and D&C certified colours can be used for lipsticks. Inorganic colours only need to conform to purity specifications. The EC uses the prefix E for all colours approved for food, pharmaceuticals and cosmetics which might come in contact with, or enter the digestive system. The Cosmetic Directive of the European Community (76/768/EEC) sets industry standards in Europe. The CTFA keeps updates on newly admitted dyes and pigments and their permitted uses. Some speciality suppliers of cosmetic pigments of all kinds can be found in Annex 2. Each country though, may have its own regulations and list of permitted substances. Before using any colouring, be it natural or synthetic, accurate information should be sought regarding the permissable uses. This is true for all ingredients and in particular for anti-microbial agents or other preservatives.
Figure 9.9: a) a large complex propeller and turbine vacuum mixer, removed from the vessel. The outer frame rotates to remove material from the vessel wall. The three horizontal propellers provide the main agitation and at the bottom is a high speed turbine mixer. These mixers come for batch sizes of 5 to 6000 litres.
Figure 9.9: b) Small desktop model of a vacuum mixer.
Figure 9.9: d) The rotor (left) and stator (right) of a turbine mixer (All photographs courtesy of Pressindustria S.p.A.).
Since colouring cosmetics, particularly lipsticks and makeup is very difficult, experiments should first be made with very simple mixtures of dyes and pigments. A due is a colouring agent which dissolves in the base solvent of the product whiled a pigment remains partly, or completely, insoluble in the respective base material. Lipsticks, for example, require dyes or pigments which stain the skin, i.e. interact with the skin to form longer lasting colouring effects. Such interactions sometimes also change the colour. The degree of solubility of a dye or the dispersion characteristics of a pigment in the various solvents, are very important and have to be considered for any formulation.
Toners are pure, organic pigments, undiluted and without a substratum. Lakes are dyes precipitated onto a substratum which then becomes an integral part of the new pigment. Lakes are frequently used in lipsticks while both lakes and toners are commonly used in makeup.
Pigment powders range in size from 4 to 150 microns (~m); those above 90 microns, however, are considered large. These small particles often agglomerate, i.e. clump together. To improve dispersion, wetting agents and dispersants are used. Roller or colloid mills are used to break up agglomerations (rather than to reduce the size of the particles themselves) and thereby improve dispersion. Thinner oils are more effective in wetting the pigments, but if thickeners need to be added to the product, they are best added prior to milling.
Synthetic colours can be organic or inorganic pigments or dyes. Many of the inorganic colours are metal oxides and occur naturally. Their purification, however, at least in the case of the ubiquitous iron oxides, is very difficult. While some of these oxides can be easily manufactured and are the same as in regular paints (e.g. titanium oxide) cosmetic pigments have to be particularly pure, without the contamination by arsenic and lead found in industrial grade pigments. Carbon blacks and ultramarine blues are examples of colorants that are not metal oxides. Mica is used as a base for many pearlescent pigments. Alumina (aluminum hydroxide) is used as an extender for cosmetic pigments where opacity is not needed. Calcium carbonate, talc and various clays are also used as extenders.
Water-soluble dyes once in solution change colour when contacting certain metals such as zinc, tin, aluminum, iron and copper. Accordingly, only stainless steel, enamel or glass containers should be used. If not used immediately, water soluble dyes, such as natural dyes should be carefully preserved, using cold storage or preservatives.
Organic colours are much more complex and are often derived from plants or animals. Worldwide, natural colours are extracted from numerous plant and animal species, but only a few are approved by the FDA and EC for cosmetic use. For exports of finished products such regulations have to be strictly adhered to. Since they are safety guidelines, they should really be observed by all manufacturers. If there is local knowledge about compatibility and reactions to local natural colours, they can be confirmed with experiments. Extreme care in tests with small amounts is recommended.
Speciality suppliers for cosmetic pigments of all kinds are listed in Annex 2. Suppliers will also help with certain formulations of products; otherwise specialized cosmetic literature should be consulted.
To achieve colour consistency from one batch to the next, extremely precise measurements and formulations are necessary. Objective colour comparison according to international standards is possible with colourmeters.
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