Cosmetics are products created for skin & hair care for the purpose of cleansing, beautifying and enhancing the attractive features 1. Skin care is not a modern trend. In fact, people in every civilization used cosmetics to protect and embellish their skin – which naturally leads us to conclude that this is a primordial need. Although cosmetic products have undergone many changes in modern times, the basic concept of using cosmetics to enhance the features of good health has not changed. Resurrecting and preserving a youthful complexion has been the holy grail of beauty since Cleopatra stepped into her legendary bath of milk more than 2,000 years ago. When Hitler tried to ban make-up in Germany, German women refused to work. Roman women used to dye their hair darker with a mixture of boiled walnuts and leeks. The first cold cream was developed by Galen, a Greek physician. People from all these cultures used herbal concoctions with components like henna, sage and chamomile to darken their hair. Up to the late nineteenth century, women in Western countries secretly wore make-up made from mixtures of household products, as make-up was then deemed the domain of celebrities. Cosmetics were for the first time openly put up for sale in the early part of the twentieth century. At the end of the Second World War when people celebrated the return of their loved ones, there occurred a true surge in cosmetic sale and it still continues.
1.1. SCIENCE BEHIND COSMETICS
While cosmetics can be fun to use, the work that goes behind-the-scenes for creating them involves highly advanced science 1. Cosmetics represent a highly diversified field involving many sub-sections of science and art, because even in an era of high technology, intuition continues to play an important role. So innovative raw materials and formulation techniques are the key factors to create products that can accomplish multiple tasks. To put just one new product on the shelves can take up to Many years, with immense research on synthesizing the active molecule, claim substantiation (efficacy, safety and toxicology) and formulation of the products. Improved knowledge of the biology of the skin and the development of innovative raw materials, and technologies help cosmetic chemists understand how to develop and evaluate the multifunctional personal care formulations desired by the consumer.
1.2. ADVANCEMENTS IN COSMETICS:
Cosmetics have advanced into Natural Cosmetics, Cosmeceuticals, Nutricosmetics & Probiotics 2.
1.2.1. NATURAL COSMETICS:
Fig. 1.1 Natural Cosmetics 2
History repeats itself – but for better benefits! For thousands of years, we have been using natural cosmetic products for skin care. Many of the chemical additives used in cosmetic products, that emerged out of modern science may do the job but at the price of our health. It has become apparent that many of these chemicals are detrimental to health and in the long run, can do more harm than good. Over the years, many inventions and discoveries were made that “improved” on nature’s power and today, the vast majority of cosmetic products contain additives including enzymes, hormones and herbal actives that, supposedly, can be more effective. In the 21st century natural cosmetic is about developing “New skin care concept based on the perfect synergy between nature and technology, between the purest bioactive ingredients and premium performance innovation.” Natural cosmetic Philosophy is “Believe in the synergy of nature, in its simplest form, along with the most complex technology.” Modern natural cosmetic products are free from potentially harmful substances and help promote our looks without damaging our skin. With the technology that exists today to produce natural cosmetic products, we no longer have to find a compromise between health and beauty.
Fig. 1.2 Cosmeceuticals 2
Cosmeceuticals are cosmetic products that have therapeutic benefits against degenerative skin conditions. The unique combination of cosmetic and pharmaceutical functionality makes them significant in enhancing skin health. “Cosmetics” hide the age and enhance the attractive features. “Cosmeceuticals” do not just hide the age, they slowdown ageing. “Cosmeceuticals” do not just enhance the attractive features, they keep them long lasting. In other words, “Cosmeceuticals” do not just benefit the skin condition, they impart therapetic usefulness too.
“Nutricosmetics” is all about eating ; drinking to attain health ; beauty from within. The term nutricosmetics refers to nutritional supplements which can support the function and the structure of the skin. Many micronutrients have this effect. For example, Vitamin C has a well-established anti-oxidant effect that reduces the impact of free radicals in the skin and also has a vital function in the production of collagen in the dermis. Other micronutrients like omega-3 fatty acids, carotenes and flavonoids protect the skin from the damaging effects of UV light exposure, which may lead to accelerated skin ageing and wrinkle formation. Nutricosmetics set to be the next big niche and have hit the world market with 100% food-based, organically certified products like “antioxidant-infused chocolate bar, tea, soups, health drinks and tablet-sized dietary supplements.”
Fig. 1.3 Nutricosmetics 2
Probiotics are ‘Live microorganisms which when administered in adequate amounts confer a health benefit on the host’ 2. Probiotics are beneficial bacteria in the intestinal flora that help aid digestive health, improve immunity and may prevent some allergies. Following the success of Probiotics in health care and extensive knowledge on the beneficial effects of Probiotics for human health, the latest research has been extended in “Probiotics for skin care to promote skin health and beauty”. Bacteria forthe skin: ageing and UV damage. Probiotics work from the inside out whenconsumed orally as a nutritional supplement. By keeping pathological bacteria at bay and preventing overproduction of toxins, Probiotics actually eliminate the root cause of skin damage. Probiotics can prevent in the body, Probiotics can create health-promoting substances that can circulate in the blood stream, activating skin’s natural immune defenses, which consequently help inhibit inflammatory responses and free radical generation eventually preventing skin ageing and sun damage. It has been clinically-proven that Probiotics have a positive effect on UV-exposed skin. Studies have shown that skin cell regeneration after UV exposure is accelerated by using Probiotics as a complement to sun protection cream. Many studies have underlined the importance and efficacy of the probiotic complex in cosmetic formulations as well. Regular use of cosmetics containing Tantalized probiotics (heat inactivated probiotic bacteria) undeniably re-established balance – and most particularly, it maintains this balance over time – of normal physiological conditions of the skin, such as pH and ceramide levels. Application of a cream containing Tantalized probiotic lactobacilli has shown a significant increase in ceramides, which translates into a better functioning of normal lipid barriers of the skin.
2. NATURAL COSMETIC PRODUCTS:
Soap is one of the oldest and most important cosmetic and personal care products. Soap is a product used in conjunction with water for washing and cleaning. It usually comes in a solid molded form (bar soap) but may also come in the form of liquids dispersed from dispensers. Soaps typically contain surfactants that, when applied to a soiled surface in combination with water wet the dirt and effectively holds particles in suspension so it can be rinsed off with clean water. Soap making can be very simple or you can make it as complicated as you like 3. The beauty of learning how to make soap is that you can make it with the ingredients that you choose and the fragrances that you like. Adjustments aren’t hard but take some practice. Most all soap recipes use ounces or grams and ingredients must be weighed to get good results.
2.1.1. KEY QUALITIES OF NATURAL SOAP:
Harder soap is generally better. Why? One reason is because a hard, dense bar lasts longer. Have you ever held an ooey-gooey glob that’s sat in a wet soap dish a bit too long? It’s not easy to hang onto, let alone use to lather up a washcloth. All you want to do is put it back down and hope it dries out a bit before you use it again 13.
The number one reason most folks use soap is to get clean, and though we usually don’t think of the chemistry behind this process, it’s an important factor in soap quality. A soap molecule is actually a chain of carbon atoms. One end of the chain attracts water and the other attracts oil. A soap must have the proper balance. If it has too much of a cleansing ingredient, the oil grabbing part can irritate the skin by washing away the top dirty layer as well as the protective layer of surface oils on the skin13.
People like a soap that lathers, too; the balance of fun bubbles and soothing, cleansing cream is what makes lather so satisfying. The best soap makers distinguish bubble lather and creamy lather, striving to create the perfect balance of each in their products. And to further complicate the issue is the matter of constancy. Have you ever noticed how some soaps start out lavishing you with lather and about halfway through the bar it fizzles out?
Soap conditioners refer to emollients — what’s left behind on the skin after you rinse, and they vary depending on the type of soap a person prefers. For example, if you have dry skin, you should look for a soap with moisturizing emollients which will prevent water evaporation 13.
One of the first things most folks do is pick up a bar and stick it under their nose. It’s an essential factor in the do-I-buy-it decision-making process. Fragrances are part of who we are; they are simple pleasures that enrich our daily life. They calm us, invigorate us, make us smile and, let’s be honest – they mask our body odors 13.
2.1.2. A WORD ABOUT LYE:
The one thing in homemade soap you can’t substitute is lye. You should always use 100% sodium hydroxide, or lye in crystal form. Don’t substitute liquid lye or drain cleaners such as Drano. These may cause inaccurate measurements or have bits of metal in them, you don’t want either. Lye is caustic. It can eat holes in fabric and cause burns on your skin. Always be extra careful when using lye. Use gloves and eye protection and a mask if desired. When you mix the lye with water, it will heat up and fume for about 30 seconds to a minute. It may cause a choking sensation in your throat. Don’t worry, it’s not permanent and will go away after a few minutes. Always add lye to water (not water to lye) and start stirring right away. If allowed to clump on the bottom, it could heat up all at once and cause an explosion. Even though lye is caustic and dangerous to work with, after it reacts with the oils in your soap (through saponification process), no lye will remain in your finished soap.
When making soap, use equipment that will not be used for cooking. While you could clean everything really well, it’s best not to take a chance. Stainless steel, tempered glass and enamel are all good choices for mixing bowls. Don’t use copper or aluminum, they will react with the lye. Some plastics may melt, so don’t use plastic bowls. For spoons, use styrene plastic or silicone. Other things are a pint and a quart canning jar, newspaper, a stainless-steel thermometer that reads between 90° and 200°. An old towel, and any additions you want to add to the soap.
2.1.4. PREPARATION OF SOAP:
15 gm coconut oil – to produce good lather.
05 gm Almond oil – which makes a hard and mild bar.
05 gm lye – also called 100% sodium hydroxide.
15 ml cool water – use distilled or purified
01 gm Common Salt (KCl)
Take a beaker and add 15gm coconut oil and 5gm almond oil.
Take another beaker and prepare lye by adding 5gm NaOH pellets to 15 ml of water (Rose water can be taken for essence).
Now add 1gm of common salt and mix it for 10 minutes.
Now keep the mixture several time (2 hrs) till it becomes solid/semisolid.
Now wash it with water to remove traces of NaOH.
Keep it for drying (2 days).
The soap becomes hard solid and ready for use.
Fig. 2.1 Soap Preparation (a) Side View (b) Top View
In the analysis of soap, it is necessary to determine 4:
Water contentpH (8-9)
Fig. 2.2 pH Measurement for Soap
2.2. LIP BALM:
Summer is one of the worst seasons for your lips 5. Despite the high humidity in much of the region, lips go through high heat, blazing sun, and just plain old wear and tear. They can get chapped, reddened, dried out, and can even peel. But if you know how to take care of them properly, they can be so soft.
Fig. 2.3 Various Types of Lip Balm 9
2.2.1. THINGS HARMFUL TO LIPS (NEED OF LIP BALM):
Some things are worse for your lips than you’d think 5. Here’s a list of things you should avoid:
Smoking can cause lack of circulation and wrinkles.
No SPF (sun protection factor) can lead to sun burn. A few natural oils that offer sun protection are carrot seed oil, raspberry seed oil, avocado oil, coconut oil, and sesame seed oil.
Para beans, which are present in most commercial lipsticks, can damage your skin.
Fragrance, also in some lipsticks, can dry out your skin.
Artificial sweeteners could cause health problems.
Camphor and menthol, while natural, are drying ingredients often found in lip care products.
Dry air, created when air conditioning is used, can dry out your lips.
There are some ingredients in lipsticks and lip balms that are good for you. Glycerin and aloe Vera are humectants. They pull moisture out of the air and attach it to whatever they are on, such as your lips. Water, in any form, is good for your lips, but will evaporate quickly without something to hold it there. Lip balms are made to hold the moisture in. But first, before you apply lip balm, exfoliation is the best thing to do. You can mix a little oil with granulated sugar or salt, and gently rub on lips in a circular motion.
2.2.2. PREPARATION OF LIP BALM:
6.5gm oil (coconut oil)
2.8 gm candle wax
Measured oil and wax into a heatproof glass measuring cup. Melted with the help of boiling water n vessel.
Take a stainless-steel spoon and mix everything together. Pull the spoon out and wait a few minutes until what’s left on the spoon hardens. Test this to see if it’s hard or soft enough for your liking. Make your adjustments now (adding more oil if you want it softer, or more wax if you like it harder).
Added little amount of turmeric powder.
Carefully poured into lip balm tubes or tins.
Fig. 2.4 Various Types of Lip Balm prepared
In the analysis of Lip Balm Following Parameters are required to check 6:
Preliminary study of stability
Normal stability test
Test of spreadability
You can use different oils for their individual qualities. Many have antioxidants, vitamins, and minerals that are good for your skin 7. You can do an infused oil with herbs such as calendula and use that for your base oil. You can add essential oils like tea tree or lavender to make a healing ointment that’s very portable – great for use on scrapes and bug bites. You can add a few drops of cinnamon or ginger essential oils. These oils increase circulation and can make your lips appear plumper. Don’t use too much as they can also be irritating.
You can make a stretch mark balm by omitting the oil and adding more butter. Nothing soothes dry, itchy skin like cocoa butter. Add some grapeseed oil and it makes it all that much more nourishing. You can add a small amount of zinc oxide or one of the oils with natural SPF listed above to act as a sunscreen. And if you want it a bit sweeter, add a small amount of powdered stevia. You’ll literally need just a pinch as this herb is very, very sweet
Shampoos are cleaning formulations used for a wide range of applications, including personal care, pet use, and carpets 14. Most are manufactured in roughly the same manner. They are composed primarily of chemicals called surfactants that have the special ability to surround oily materials on surfaces and allow them to be rinsed away by water. Most commonly, shampoos are used for personal care, especially for washing the hair.
In the early 1930s, the first synthetic detergent shampoo was introduced, although it still had some disadvantages 14. The 1960s brought the detergent technology we use today. Over the years, many improvements have been made to shampoo formulations. New detergents are less irritating to the eyes and skin and have improved health and environmental qualities. Also, materials technology has advanced, enabling the incorporation of thousands of beneficial ingredients in shampoos, leaving hair feeling cleaner and better conditioned.
2.3.2. RAW MATERIALS:
New shampoos are initially created by cosmetic chemists in the laboratory. These scientists begin by determining what characteristics the shampoo formula will have. They must decide on aesthetic features such as how thick it should be, what color it will be, and what it will smell like. They also consider performance attributes, such as how well it cleans, what the foam looks like, and how irritating it will be. Consumer testing often helps determine what these characteristics should be.
Once the features of the shampoo are identified, a formula is created in the laboratory. In the personal care industry, nearly all of the ingredients that can be used are classified by the Cosmetic, Toiletry, and Fragrance Association (CTFA) in the governmentally approved collection known as the International Nomenclature of Cosmetic Ingredients (INCI). The more important ingredients in shampoo formulations are water, detergents, foam boosters, thickeners, conditioning agents, preservatives, modifiers, and special additives.
2.3.3. MANUFACTURING OF SHAMPOO:
Dry Amla (Indian Goose Berry)
Dry Reetha (Soap Nut)
Take a Vessel and Add 50gm Methi Seeds to it.
Now add 50gm Shikakai to it.
Then add 50gm Reetha to it.
Now Add 50gm Dry Amla to it.
Now Soak them in Water for Overnight.
Now Heat it till the water starts boiling.
Now using a sieve transfer all the Liquid content to a bottle
Fig.2.5 Natural Shampoo
2.3.4. QUALITY CONTROL:
In addition to the initial checks to make sure the product meets specifications, other quality control checks are made 17. For example, line inspectors watch the bottles at specific points on the filling line to make sure everything looks right. They notice things like fill levels, label placement, and whether the cap is on correctly. The product is also routinely checked to see if there has been any microbial contamination. This is done by taking a bottle off the filling line and sending it to the QC lab. Here, a small amount of the shampoo product is smeared onto a plate and inoculated with bacteria and other organisms to see if they grow. Additionally, the packaging is also checked to see if it meets specifications. Things such as bottle thickness, appearance, and bottle weight are all checked.
2.3.5. THE FUTURE:
Consumer product corporations will continue to manufacture new types of shampoos. These new formulas will be driven by ever-changing consumer desires and developing chemical technology. Currently, consumers like multi-functional shampoos, such as 2-in-I shampoos, which provide cleansing and conditioning in one step, or shampoos that aid in styling. New shampoos will likely provide improved conditioning, styling, and coloring while cleaning the hair. Shampoo technology will also improve as new ingredients are developed by raw material suppliers. Some important advances are being made in the development of compounds such as polymers, silicones, and surfactants. These materials will be less irritating, less expensive, more environmentally friendly, and also provide greater functionality and performance.
2.4. HAIR DYE:
Hair dye is one of the oldest known beauty preparations, and was used by ancient cultures in many parts of the world 15. Records of ancient Egyptians, Greeks, Hebrews, Persians, Chinese, and early Hindu peoples all mention the use of hair colorings. Early hair dyes were made from plants, metallic compounds, or a mixture of the two. Rock alum, quicklime, and wood ash were used for bleaching hair in Roman times, and herbal preparations included mullein, birch bark, saffron, myrrh, and turmeric. Henna was known in many parts of the world; it produces a reddish dye.
Many different plant extracts were used for hair dye in Europe and Asia before the advent of modern dyes. Indigo, known primarily as a fabric dye, could be combined with henna to make light brown to black shades of hair dye. An extract of the flowers of the chamomile plant was long used to lighten hair, and this is still used in many modern hair preparations. The bark, leaves, or nutshells of many trees were used for hair dyes. Wood from the brazil wood tree yielded brown hair dyes, and another hair dye known in antiquity as fustic was derived from a tree similar to the mulberry. Other dyes were produced from walnut leaves or nut husks, and from the galls, a species of oak trees. Some of these plant-derived dyes were mixed with metals such as copper and iron, to produce more lasting or richer shades.
A French hairdresser, Gaston Boudou, first marketed a standardized range of hair dyes in 1910. Whereas earlier hair colors had been mixed on the spot by hair dressers, and the colors produced were variable, Boudou’s dyes produced a predictable color. Sold in a range of 18 colors, from black to light blond, these became very popular both in Europe and in the United States. The amino dyes, however, caused allergic reactions in a significant portion of users. Researchers in the United States are credited with creating a modified, less toxic amino-based hair dye, for standardizing the method of applying the dye, and for establishing strict specifications for the purity and strength of the raw materials. Further advances in hair dye chemistry were made by the makers of Clairol. Clairol produced the first one-step hair dye in 1950.
2.4.2. RAW MATERIALS:
Most commercial hair dye formulas are complex, with dozens of ingredients, and the formulas differ considerably from manufacturer to manufacturer. In general, hair dyes include dyes, modifiers, antioxidents, alkalizers, soaps, ammonia, wetting agents, fragrance, and a variety of other chemicals used in small amounts that impart special qualities to hair (such as softening the texture) or give a desired action to the dye (such as making it more or less permanent). The dye chemicals are usually amino compounds, and show up on hair dye ingredient lists with such names as 4-amino-2-hydroxytoluene and m-Aminophenol. Metal oxides, such as titanium dioxide and iron oxide, are often used as pigments as well.
Other chemicals used in hair dyes act as modifiers, which stabilize the dye pigments or otherwise act to modify the shade. The modifiers may bring out color tones, such as green or purple, which complement the dye pigment. One commonly used modifier is resorcinol, though there are many others. Antioxidants protect the dye from oxidizing with air. Most commonly used is sodium sulfite. Alkalizers are added to change the pH of the dye formula, because the dyes work best in a highly alkaline composition. Ammonium hydroxide is a common alkalizer.
Fig.2.6 Raw Materials Required for Dye Preparation
2.4.3. MANUFATURNG OF HAIR DYE FROM AMLA:
Dry Amla (Indian Goose Berry)
Take a Metal Pan and Add 50gm Dry Amla to it.
Roast it till it gets dark black.
Add Water after roasting it for sometimes.
Now Keep it for 4 hours
Now Grind it well in mixer-grinder available at home.
2.4.4. MANUFACTURING OF HAIRDYE USING MEHENDI:
Dry Amla (Indian Goose Berry)
Take a Metal Pan and Add 50gm Dry Amla to it.
Roast it till it gets dark black.
Add Water after roasting it for sometime.
Now Keep it for 4 hours
Now filter the water and add 50gm mehendi powder to it.
Now add 10gm curd to it.
Now add 10gm of coffee powder to it.
Mix it well and leave for 4 hours.
2.4.5. QUALITY CONTROL:
Government regulations control what ingredients may be used in hair dyes, as many of them are toxic. Industry researchers will have already tested a formula numerous times in the laboratory before it reaches the manufacturing stage, to make sure a formula is non-irritating, works well, performs consistently, etc. As part of the manufacturing process, workers check their chemicals before they go into a batch, to make sure only the correct chemicals at the correct potency are used. After the batch is mixed, samples are taken, and these are subjected to a series of standard tests. Lab technicians make sure that the batch is the required viscosity and pH balance, and they will also test the dye’s action on a swatch of hair. If a hair dye formula is being made for the first time, or if a formula has been altered, technicians will also test samples of the dye after the filling stage.
2.4.6. THE FUTURE:
Hair dye manufacturers are increasing their use of computers to control and automate the manufacturing process. Computers can be used to weigh and measure ingredients, to control reactions, and to regulate equipment such as pumps. The future may see more fully automated manufacturers and increased efficiency.
2.5. TALCUM POWDER:
Talcum powder is made from a mineral called “talc” that is ground to a fine consistency 16. Talcum powder is commonly used to care for rashes and chafing on children and adults, as well. The powder is sold in many grocery and drugstores and is fairly inexpensive. However, some individuals may wish to create their own talcum powder at home to reduce costs and control the substances used.
The cosmetic use of talcum based Baby Powder began in the early 1900’s, when Johnson & Johnson began marketing the product to women and young children. From this point forward, the manufacturer developed the Baby Powder brand by appealing primarily to women through multimedia advertisements. Now, Johnson & Johnson’s reported average revenue derived from the sale of talcum powder products exceeds $300 million per year.
2.5.2. MANUFACTURING OF TALCUM POWDER:
Rose Leaves/Rose Water
Fig.2.7 Ingredients for Preparation of Talcum Powder
Take 10gm of Arrowroot Powder and add it to a beaker.
Then add 2.5gm of Baking Soda to it.
Then add 7.5gm Rice Flour to it.
Now add rose water/rose petals to it and shake it well.
Keep it for drying (one day).
Fig.2.8 Talcum Powder
1 Janet WB, Regulatory developments in Canada Japan, Australia, China and India. In: Betton.CI.Editor. Global Regulatory Issues for the Cosmetic Industry, New York: William Andrew; 2007. P25-39.
2Kligman AM. The Future of Cosmeceuticals : An interview with Albert Kligman , MD, PhD. Interview by Zoe Diana Draelos. Dermatol Surg. 2005; 31:809-1.
3 How To Make Soap: Homemade Natural Hand and Body Bar Soap Recipe – https://www.diynatural.com/how-to-make-soap-2/
4 F Li, M Chen, W Zhang – Journal of surfactants and detergents, 2017 – Springer. Effect of Binary/Ternary Fatty Acids Ratio and Glycerin on the Phase Behaviors of Soap Solutions
5 Lip Care and a Homemade Lip Balm Recipe – https://www.diynatural.com/homemade-lip-balm-and-natural-lip-care/6 BAREL, A.O.; PAYE, M.; MAIBACH, H.I. Handbook of cosmetic science and technology. New York: Marcel Dekker, 2001. 904 p.
7 IFOAM. International Federation of Organic Agriculture Movements. 2008. Available at: http:www.ifoam.org. Accessed on: 19 apr. 2008.
8 https://www.vickerey.com/spp202-pre-de-provence-large-french-bath-bar-soap.html9 DIY: Lip Balm | doTERRA Essential Oils – https://www.doterra.com/US/en/blog/diy-essential-lip-balm10 Sankholkar, D.S. Current Indian Cosmetic Regulations and suggested way forward. Pharma Times.2009;41: 31-32.
11 CUNNINGHAN, J. Color cosmetics. In: WILLIAMS, D.F. Chemistry and technology of the cosmetics and toiletries industry. London: Chapman and Hall, 1996. cap.4, p.149-158.
12 BONO, A.; MUN, H.C.; RAJIN, M. Effect of various formulation on viscosity and melting point of natural ingredient based lipstick. Stud. Surf. Sci. Catal., v.159, p.693-696, 2006.
13 Soaps: The Five Key Characteristics of The Beat Soaps – https://blog.vermontcountrystore.com/best-soaps-5-key-qualities/14 Knowlton, John and Steven Pearce. The Handbook of Cosmetic Science and Technology. Elsevier Science Publishers, 1993.
15 Balsam, M.S. and Edward Sagarin. Cosmetics Science and Technology. John Wiley ; Sons, 1972.
16 A Brief History of Talcum Powder/ Law Offices of Peter Angelos, P.C. – https://www.angeloslaw.com/legal-blog/2016/07/a-history-of-talcum-powder/
17 Umbach, Wilfried. Cosmetics and Toiletries Development, Production, and Use. Ellis Horwood, 1991.