INTRODUCTION:

The function of a skin cream is to protect the skin against harshness from the environment and any dry conditions of the skin. A skin cream should aid the skin in carrying out its normal functions, that is, restoring moisture to dry skin, allowing the elimination of waste matter through the pores, and the cooling of the body by evaporation of water (perspiration) and radiation, thus aiding in the maintenance of the normal body temperature. If the cream clogs the pores of the skin with heavy, insoluble, inert material, it results in a thick sticky coating on the skin and prevents sufficient normal skin function, being detrimental to health. Skin creams contain a variety of ingredients that range from common, such as mineral oil, to the exotic, such as placenta extract.

Some skin creams may contain small amounts of vitamins or other “nutrients”. A basic and satisfactory skin cream can be prepared from stearic acid, lanolin, mineral oil, triethanolamine, and water. The purpose of this experiment to prepare a skin cream from these ingredients, and, then, by omitting one of the ingredients in subsequent preparations, to deduce the purpose of that particular ingredient. Skin creams contain ingredients for adding body, improving texture, emulsifying the oil and water components, raising the melting point, improving the spreadability, improving the odor, softening the skin, and providing various medicinal properties.^{[1, 2]}

Types of Skin Creams:

They are divided into two types: oil-in-water (O/W) creams which are composed of small droplets of oil dispersed in a continuous phase, and water-in-oil (W/O) creams which are composed of small droplets of water dispersed in a continuous oily phase. Whether the aqueous or the oil phase becomes the dispersed phase depends primarily on the emulsifying agent used and the relative amounts of the two liquid phases. Hence, an emulsion in which the oil is dispersed as droplets throughout the aqueous phase is termed an oil-in-water (O/W) emulsion. When water is the dispersed phase and an oil the dispersion medium, the emulsion is of the water-in-oil (W/O) type. Oil-in-water creams are more comfortable and cosmetically acceptable as they are less greasy and more easily washed off using water. Water-in-oil creams are more difficult to handle but many drugs which are incorporated into creams are hydrophobic and will be released more readily from a water-in-oil cream than an oil-in-water cream. Water-in-oil creams are also more moisturizing as they provide an oily barrier which reduces water loss from the stratum corneum, the outermost layer of the skin. It is important for pharmacists to know the type of emulsion they have prepared or are dealing with, because this can affect its properties and performance. Unfortunately, the several methods available can give incorrect results, so the type of emulsion determined by one method should always be confirmed by means of a second method. ^[4]

Classification of creams:

All the skin creams can be classified on different basis:

1. According to function, e.g. cleansing, foundation, massage, etc.

2. According to characteristics properties, e.g. cold creams, vanishing creams, etc.

3. According to the nature or type of emulsion.

Types of creams according to function, characteristic properties and type of emulsion:

1. Make-up cream (o/w emulsion):

a) Vanishing creams. b) Foundation creams.

2. Cleansing cream, Cleansing milk, Cleansing lotion (w/o emulsion)

3. Winter cream (w/o emulsion):

a) Cold cream or moisturizing creams.

4. All-purpose cream and general creams.

5. Night cream and massage creams.

6. Skin protective cream. Hand and body creams.

Vanishing creams:

They are called vanishing creams because they seem to disappear when rubbed onto the skin. These formulations are based on stearic acid. After application, the cream leaves a dry but tacky residual film which also has a drying effect on the skin. Because of this reason, these are used particularly in hot climates which cause perspiration on the skin.

Foundation creams:

These cream serve as a foundation base for make-up. It acts as an adherent base for application of make-up powders. They provide emollient action and a protective action against environment to the skin which is neither too greasy nor too dry. It is multi-coloured make up applied on the face to create an even, uniform colour similarto the complexion, to cover flaws and to change the skin tones.

Cleansing creams:

These creams are used for body cleaning purposes and it is used for personal hygiene and beautification which is important for cosmetics. Cleansing creams or lotions can be used for the removal of make-up, surface grim, oil mainly from the face and neck. Winter creams: These are w/o type of formulation and in this formulation oil content will be more than water content. These creams are mainly used for chapped and dry skin.

Cold cream:

It is known as moisturizer or moisturizing cream. Cold cream must have an emollient action. It should produce a cooling sensation in use and the oil film on the skin should be non-occlusive. All purpose creams and general creams: These creams are used more nowadays than before. These creams are somewhat oily but non-greasy type and can spread on the skin easily. This can also be used as a night creams, nourishing creams, protective creams for prevention or alleviation of sunburns or for the treatment of roughened skin areas.

Night cream or massage creams:

These creams are mainly used for the nourishing the skin or as a treatment to dry skin. Creams which are generally applied on skin and left for few or several hours over night are mainly known as night creams. Creams which acts as an emollient by rubbing the cream on the skin with massage is known as massage cream. Skin protective creams: These creams are smooth, thick bodied creams formulated to provide an invisible, uniformprotective film barrier to the skin. It helps to maintain the barrier between the skin and contaminants that may irritate the skin (contact dermatitis and occupational dermatitis). Strengthens the natural properties of the skin and maintains the balance of normal to combination skin. Hand and body creams: Hands are one of the first places to show signs of aging. We tend to wash our hand several times a day, stripping offmoisture. Applying cream softens and protects the skin and it keeps the skin looks younger. Since the skin on our palms and fingers needs oil to stay supple and to prevent it from chapping and cracking, it is sensible to use hand creams that puts plenty of oil back in. It is usedon the hands more than other parts of the body. ^[1]

Advantages:

· It is the easiest way to deliver a drug.

· Avoidance of first pass metabolism.

· Convenient and easy to apply.

· Avoid of risk.

· Inconveniences of intravenous therapy and of the varied conditions of absorption like Ph changes presence of enzymes gastric emptying time etc.

· Achievement of efficacy with lower total daily dosage of drug by continuous drug input.

· Avoid fluctuation of drug levels inter‐and intra-patent variations. (Surver et al, 2002).

Disadvantages:

· Skin irritation of contact dermatitis may occur due to the drug and / excipients

· Poor permeability of some drugs through the skin

· Possibility of allergic reactions

· Can be used only for drugs which require very small plasma concentration for action

· Enzyme in epidermis may denature the drugs

· Drugs of larger particle size not easy to absorb through the skin. (Mishr et al,1990). ^[3]

CONCLUSION:

The skin is the most accessible part of the body and as such is also highly vulnerable to injuries. In case of cuts, burns and wounds, topical formulations such as creams are the most preferred for treatment. As compared to other conventional systems, topical formulations have certain advantages including- ease of application, less chances of side effects, non-invasive process and higher patient compliance. Creams are semisolid formulations widely acceptable by the society Creams are meant for wider applications in the skin like beautification, regeneration, treatment and mmaintenance.

REFERENCES:

1. Rai R, Poudyl AP, Das S, Pharmaceutical Creams and their use in wound healing: A Review, Journal of Drug Delivery and Therapeutics. 2019; 9 (3-s):907-912

2. AK Mohiuddin. Skin Care Creams: Formulation and Use. American Journal of Dermatological Research and Reviews, 2019, 2:8

3. Tanesh Sahu, Tarun Patel, Sagar Sahu, Bina Gidwani. Skin Cream as Topical Drug Delivery System: A Review, Journal of Pharmaceutical and Biological Sciences 2016

4. Mohiuddin AK. Skin Care Creams: Formulation and Use. A Review, OSP Journal of Clinical Trials. 2019

Received on 04.10.2020 Modified on 11.12.2020

Research J. Topical and Cosmetic Sci. 2021; 12(1):1-3.

DOI: 10.52711/2321-5844.2021.00001