Cold Cream - Lecture notes 1-3 PDF

Preview

Summary

Cold Cream Lecture Notes....

Description

COLD CREAM

Introduction Cold cream is basically an emulsion of water and certain fats, usually including beeswax and various scented agents, designed to smooth skin and remove makeup. CATEGORY: Water in Oil (w/o) emulsion The name “cold cream” is derived because of the cooling sensation that the cream leaves on the skin. Cold cream is mainly used for skin treatment (such as a facial mask or lip balm), due to its moisturizing properties. Cold creams are multipurpose creams as they not just moisturize the skin but sometimes are also used to remove makeup and as shaving cream.

What is a cold cream? Historically cold cream was a mixture of a natural plant oil, beeswax and floral water used to nourish and cleanse the skin. The first cold cream is attributed to the Roman physician Galen who made a basic emulsion by mixing rose-water with beeswax and olive oil.

The first marketed Cold cream

2

Vegetable oils in these emulsions would deteriorate when mixed with water, so early forms were not long-lasting. Their short shelf life meant that cold creams were purchased in small quantities, freshly made up by a local pharmacist. For centuries, prominent society ladies, noted for their exquisite skin and complexions, used cold cream. In the second half of the nineteenth century cold cream was manufactured on an industrial scale. Natural oils were replaced with cheaper, more stable petrolatum and mineral oil and borax was added to ensure emulsion. By the 1920’s the all-purpose nature of the original cold cream, which had been its strength, was also its weakness. Natural plant oil based creams like the first cold cream, had long since disappeared. It wasn’t long before the recognition of the skin’s need for nutritive ingredients which petroleum products could not provide, lead to the proliferation of skin creams containing ‘beneficial additives’. Manufacturers began adding things like lanolin to cold creams, allowing them to make claims that these creams had ‘nutritive’ value. Additionally, the development and marketing of detergent based cleansers reduced the appeal of cold creams as facial cleansers and petroleum-based moisturizer, filled with ‘beneficial additives’ finally took their place completely.

How cold creams got their name? Cold creams were usually made as water-in-oil (W/O) emulsions. After the creams are applied to the skin much of the water evaporates leaving the remaining oil to act as a solvent which cleanses the skin of cosmetics and other grime. There may also be some surfactant activity. On application of the cream to the skin, as the water evaporated it cooled the skin which is why the creams are called ‘cold creams’. An alternative explanation is that in the days before mineral oil or petrolatum were used, the creams needed to be stored in a cool place to stop them going rancid. This made them cold to the touch and so gave them their name.

3

General Formulation

Formula 1 (With mineral oil) Ingredient Wt. % Beeswax 8.00 Mineral oil (paraffinumliquidum) 50.00 Lanolin 3.00 Borax 0.20 Water q.s. 100

Formula 2 (With vegetable oil) Ingredients

Quantity

Olive oil (118.29ml)

4 oz.

White wax (36.97ml)

1.25 oz.

Diluted rose-water (59.15ml)

2 oz.

A few drops of pure essential oil of roses.

4

Method of Preparation

Heat the mineral oil and bees wax in jacketed vessel at 75C and maintain heat .

In another container, dissolve borax and preservative in water and heat at 75C.

On cooling,

Cold cream is obtained.

Now, slowly add the aqueous phase to the oil phase and cool the mixture to 35C and add perfume.

5

Manufacturing Problems in Cold cream Preparation 1. Formation of water and oil pocket Causes: • Improper mixing • Difference of temperature of two phases. • Improper use of emulsifying agents. Prevention: • Maintaining optimum temperature of both phases. • Using proper emulsifying agents 2. Phase separation Causes: • • • •

Improper ratio of phase Presence of electrolyte. Improper mixing of borax by decreasing of mixing tie. Increase temperature.

Prevention: • Desired ratio should be maintained. • Proper mixing of borax slowly. • Maintaining optimum temperature 3. Presence of granules Causes: • Increased temperature of one phase than another. • Decreased cooling time. • Un-uniform and insufficient mixing.

6

Prevention: • Temperature of both phases should be equal. • Mixing should be uniform and sufficient. • Avoiding rapid cooling. 4. Consistency of cold cream Causes: • Evaporation of water from the preparation. • Large time difference between mixing and packaging. Prevention: • Prevention of water from evaporation. • Addition of some extra water than calculated amount. • Filling should be done immediately after mixing two phases. 5. Miscellaneous Causes: • Temperature fluctuation. • pH differences. Prevention: • Should maintain optimum temperature throughout the process. • Should maintain optimum pH

Application Cold creams that contained a high percentage of mineral oil (liquid paraffin) or petrolatum were regarded primarily as cleansers, to be spread on thickly, then removed with a cloth or tissues. However, depending on the formulation, they could be used for a variety of purposes and were often advertised as beauty creams or night creams. Dust, soot and other particulate matter collected on the face, making it an enduring problem. Early advertisements for cold cream stressed

7

the need to “cleanse your skin of all the dirt which lodges in the pores through the day, and which, more than anything else, injures the skin”. The Cold Cream, applied whenever convenient during the day, always after exposure to the open air and before retiring at night, brings to the surface particles of dust and dirt which can easily be removed with a soft towel. Its gentle oils will sink deep into the pores especially during sleep and cleanse the skin thoroughly.

Evaluation of the cold cream The cream is evaluated for the following physical parameters: § Formulation Properties: The formulation properties of the cream are to be studied by visual appearance and characteristics. The creams are studied for its texture appearance feel color and other organoleptic characteristics. § Presence of foreign particles/grittiness: Small amount of cream is to be taken and spread on a glass slide free from grease. The slide is then observed against diffused light to check for presence of foreign particles. § pH of the cream: The pH of cream is determined using digital pH meter after diluting about 1 g of the cream with 100ml of water. § Viscosity: Viscosity of the cream is determined by Brookfield Viscometer. §

Determination of type of emulsion Cold cream is basically a w/o emulsion. The type of emulsion formed is determined by the dilution test In this test the emulsion is diluted either with oil or water and checked for stability. 8

§

Stability studies Stability of the cream is determined by the following tests: o Globule size: 1 mL of cream is diluted to 10 mL with glycerin. A few drops of this is transferred onto a glass slide and observed under the microscope. o Phase separation: The formulated cream is to be kept intact in a closed container at 25 - 30°C not exposed to light. Phase separation is observed carefully every 24 hrs for 30 days. o Moisture absorption studies: About 50 mg of cream is taken on a watch glass and placed in a desiccators maintained at different humidity conditions for 24hrs. the cream is collected after 24hrs and reweighed. The difference in weights of the cream before and after gives an idea about the amount of moisture absorbed by the cream. o Shelf life: The shelf life of cream is determined as per the ICH guidelines

§ Extrudability: It is useful empirical test to measure the force required to extrude the material from a tube. The formulations are filled in standard caped collapsible tube and sealed. The tube is weighed and recorded. The tube is placed between two glass slides and is clamped. A 500 gm weight is placed over the glass slide and cap is opened. The amount of cream extruded is collected and weighed. The percent of cream extruded is calculated and graded as per the grading system (++++ Excellent, +++ Good, ++ Fair, + Poor).

9

§ Spreadability: Spreadability denotes the extent of area to which the formulation readily spreads on application to skin or hair. The bioavailability efficiency of a formulation also depends on its spreading value. The spreadability is expressed in terms of time in seconds taken by two slides to slip off from the cream, placed in between the slides, under certain load. Lesser the time taken for separation of the two slides, better the spreadability.

Cold creams today Although the use of cold creams has declined, they are still available. However, when more recent products are compared to original formulations marked differences are evident, primarily in the replacement of borax with modern surfactants. Some of the available cold creams in market today are listed below. 1. Pond’s Cold Cream Cleanser Ingredients: Mineral oil, Water, Ceresin, Beeswax, Triethanolamine, Ceteth-20, Fragrance, Behenic acid, Montan wax, Cetyl alcohol, Carbomer, DMDM hydantoin, Iodopropynylbutylcarbamate. Improvements in preservatives have also allowed some cold creams to eliminate mineral oil, a substance disliked by many consumers. 2. Weleda Cold Cream Ingredients: Water (aqua), Prunus amygdalusdulcis (sweet almond) oil, Arachis hypogaea (peanut) oil, Beeswax (cera flava), Glyceryl linoleate, Fragrance (parfum), Hectorite, Limonene, Linalool, Citronellol, Geraniol, Citral. Still others have such complex formulations that they appear to have little relationship with traditional cold creams.

10

3. Avene Cold Cream Ultra Rich Cleansing Gel Ingredients: Avene Thermal Spring Water (Avene Aqua), CarthamusTinctorius (Safflower) Seed Oil (CarthamusTinctorius Seed Oil), Mineral Oil (ParaffinumLiquidum), Cocos Nucifera (Coconut) Oil (Cocos Nucifera Oil), Cyclopentasiloxane, Sesamum Indicum (Sesame) Seed Oil (Sesamum Indicum Seed Oil), Sorbitan Stearate, Cyclohexasiloxane, Glyceryl Stearate, Peg-100 Stearate, Allantoin, Beeswax (Cera Alba), Benzoic Acid, Cetyl Alcohol, Citric Acid, Fragrance (Parfum), Phenoxyethanol, Sodium Hydroxide, Sodium Polyacrylate, Tetrasodium Edta, Water (Aqua).

Packaging There are different types of packaging available in market for the cold cream. They are shown as follows: Wide mouth pot bottles

Collapsible metal tubes

Collapsible plastic tubes

11...