Oral Delivery of Proteins and Peptides and Carrier-Based Strategies
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Development Team Principal Investigator Prof. Farhan J Ahmad Jamia Hamdard, New Delhi Dr. Vijaya Khader Former Dean, Acharya N G Ranga AgriculturalDr. Javed AliUniversity Paper Coordinator Jamia Hamdard, New Delhi Content Writer Dr. Sanjula Baboota Jamia Hamdard, New Delhi Content Reviewer Prof. (Mrs.) Kamla Pathak Professor, Pharmaceutics Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 0 Shaving products and After Shave Preparations 2016 CONTENTS . Introduction Beard Softening Skin lubrication Characteristics of good shaving product . Basic ingredients of shaving products . Shaving soaps . Shaving creams . Brushless shaving cream . Shaving gels . After shave preparation After-shave lotion Crackling foam aerosol after-shave lotion After-shave gel After-shave cream . Packaging of shaving products . Evaluation of shaving products . Summary . Suggested reading Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 0 Shaving products and After Shave Preparations 2016 1.0 Introduction Each day men removes 20000-25000 of terminal hair protruding 250-500 µm from the skin at angles of 30-60 degrees and covering a facial area of 250 cm2. To minimize the trauma of shaving, a wide range of preparations are now available that prepare the beard and face for shaving, increase speed and comfort during shaving and confer a feeling of well-being after shaving. The choice of selecting shaving product depends upon the individual that which type of preparation is required for shaving. 1.1 Beard softening Beard softening results from the variations in the mechanical properties of hair by the absorption of water. At 100 % relative humidity hair absorbs about 31% of its dry weight of water. The hydration of hair is improved by increase in temperature; however, views differ on the time taken by the hair to hydrate completely. This ranges from 2 minutes at room temperature, as measured by the force required to cut beard hair, to 2.5 to 3 minutes at 49°C, as measured by the creep of scalp hair extrapolated to the thicker beard hair, to 6 minutes at 43°C as measured by the changes in the elasticity of hair. The established view on beard softening is based on measurements of the creep and elasticity of hair, supported by practical shaving tests. This suggests that the rate of softening of the beard can be increased by the addition of a wetting agent to the water, by increasing the pH of the aqueous phase and by the removal of sebum from the hair. 1.2 Skin lubrication There is little literature on the contribution of skin lubrication to the speed, comfort and closeness of shaving. It has been demonstrated that plastic material exhibit lower friction on dry, greasy or very wet skin, however more friction is required if skin is simply moist. Moreover, skin friction is decreased by mineral oil, surfactant and silicone fluids. One can only consider the mechanism of lubrication by the products as it depends on load applied to the razor, the area of Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 1 Shaving products and After Shave Preparations 2016 contact with the face, the velocity of razor across the face and the viscosity of preparation. At high load per unit area and low shaving speed, boundary lubrication is likely to predominate so that for a coefficient of friction the shaving preparation should have a high viscosity and should form a condensed film. At low load per unit area and high shaving speed, hydrodynamic lubrication is likely to predominate. The viscosity of the shaving preparation should be high enough to give a film thickness sufficient to prevent rough contact, but thereafter the viscosity should be as low as possible. The various kinds of shaving products that are commonly used are mentioned below: 1. Shaving soaps 2. Shaving creams 3. Shaving foams 4. Shaving gels 1.3 Characteristics of good shaving product The main characteristic features of shaving product are to support the beard hair, to soften the beard, and to lubricate the passage of the blade over the face. In addition: 1. It should be capable to produce a rich copious lather. 2. It should be non-irritant. 3. It should exhibit good wetting properties. 4. It should be soft, smooth and free from lumps. 5. It should easily adhere to both face and brush. 6. It should get easily removed from face and blade on rinsing. 7. It should exhibit satisfactory consistency and texture, which should be maintained at normal storage conditions. 8. It should assist in removal of shaving debris. 9. It should be stable over a range of temperature. Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 2 Shaving products and After Shave Preparations 2016 10. It should be resistant to rapid collapse and drying out. 11. It should be non-corrosive to blade. 2.0 Basic ingredients of shaving products The following are the main ingredients present in the formula of a shaving product: 2.1 Bases/saponification agent Triethanolamine, sodium hydroxide and potassium hydroxide are the example of saponification agent, which saponify the fatty acids. Sodium hydroxide facilitates creation of harder soap. On other hand softer soap is produced by potassium hydroxide which could be easily loaded on brush. Mono and diethanolamines are used occasionally because they may cause skin irritation. Triethanolamines soaps creates closer-knit foams than potassium soaps. 2.2 Fatty acids Saturated long-chain fatty acids (12 to 18 carbon atoms) are key ingredients of soap. Lower- molecular weight fatty acid such as coconut oil leads to skin irritation. To produce lather with different physical properties, the content of fatty acid is varied accordingly. Stearic acid is an example of fatty acid which is commonly used. If used in high content it gives a stiffer and more stable dense lather. Lauric acid provides softer foam and improves the expulsion properties. 2.3 Surfactants Surfactants are usually added with the aim to improve the emulsion stability, wetting properties and emolliency. A wide variety of nonionic and anionic surfactants are employed including laureth sulphates, betaine, sodium lauryl ether sulphate, lauric diethanolamide and ethoxylated lanolins. 2.4 Emollients Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 3 Shaving products and After Shave Preparations 2016 These are the ingredients used as moisturizers to soften the skin. They are usually added to relieve skin dryness, wrinkling, irritation and scaling of the skin. Few examples of emollients are polyoxyethylene (PEG-7) glyceryl cocoate, glycerine, lanolin derivatives and fatty acid esters. Lanolin derivatives are also used to mix immiscible substances and to retain moisture in skin. 2.5 Humectants Glycerine, sorbitol and propylene glycol are polyols which are commonly added to shaving preparations, which renders skin softer. The level of these agents is about 2-3% in preparation. These agent acts as moisturiser and lubricant. They also help in reducing the tendency of foam to dry out on the face. 2.6 Lubricants Mineral oil, vegetable oils (like palm oil, and coconut oil, lanolin and isopropyl myristate) are generally added to shaving preparations in order to assist the passage of blade over the face and to provide lubrication. Moreover, sodium carboxymethyl cellulose, polyvinyl pyrrolidone and polyacrylic acid are used to improve the lather stability and to provide lubrication. 2.7 Perfume Soap compatible perfumes are generally used in order to avoid any deterioration in the final product. The level of perfume to be used in the preparation ranges between 0.15 -0.65%. 2.8 Cooling agents Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 4 Shaving products and After Shave Preparations 2016 These agents are used to counteract the “after-glow” associated with shaving. Menthol is commonly used for cooling effect in the concentration range of 0.05-0.2%. The cooling effect can last for 5-15 minutes after the application. A group of chemicals from carboxamides to ureas to phosphine oxides exhibit physiological cooling action. 2.9 Pilomotor agents Pilomotor activity is the potential to cause the contraction of the arrectores pilorum (hair follicle muscles). The contraction of hair follicle muscles cause hair to be pushed farther above the skin by about 0.2-0.3 mm so that it is easy to cut hair in the elevated position which will retract below the skin surface as the follicle muscle gets relaxed. Such substances include morpholines, 2- amino-imidazolines, 2-(phenylamino)-1,3-diazacyclopentenes, 2-(2’5’-dimethoxy 4’6’- dimethylbenzyl)-2-imidazoline. It is claimed that a closer shave can be obtained by incorporating pilomotor agents into the shaving product. 2.10 Additional ingredients Opacifying agents (titanium dioxide), plant extracts (neem), proteins, vitamins, antioxidants, preservatives (methyl and propyl p-hydroxybenzoate), colours, etc are also added to shaving products. 3.0 Shaving soaps These are water-soluble sodium or potassium salts of fatty acids. These are formulated by using fats and oils, or their fatty acids, by reacting them with a strong alkali. Lather produced by soap is spread on the face by using brush. Lather provides protection from blade/ razor and generate lubrication at the same time. The main objective of using shaving soap is to wet and soften the hair to be shaved, and to decrease the skin irritation during shaving. Pharmaceutical Cosmetics sciences Shaving Products and After Shave Preparations 5 Shaving products and After Shave Preparations 2016 Formulation In table 1the general composition of a shaving soap is given. Table 1: Composition of shaving soap Ingredients Maximum level (%w/w) Soap (eg. potassium and sodium stearates, laureates) 60 Humectants (eg. glycerine, propylene glycol) 30 Viscosity controlling agents, emulsifying agents (eg. 15 fatty acids, glycol esters) Emollients (eg. oils, lanolin derivatives) 15 Surfactant (eg. sodium laureth sulfate) 5 Menthol 1 Perfume 2 4.0 Shaving creams Shaving creams are applied on hair face to prevent skin irritation and to provide lubrication.