Cream (pharmaceutical)

From ArticleWorld

A cream is a semi-solid topical preparation that is applied to the skin and can be a vehicle for the delivery of medications that can remain on the skin or be absorbed through the skin. Even unmedicated creams have therapeutic effects on certain skin conditions.

Preparations

Creams are more solid than are lotions, but like lotions, creams are emulsions (mixtures) of an oil-based substance and a water-based substance (or just water). There are two different types. Oil-in-water creams have small droplets of oil suspended in a primarily aqueous (water-based) substance. Water-in-oil creams involve water droplets suspended in oil. Oil-in-water creams are more cosmetically acceptable because they are less greasy. These are preferable for unmedicated creams as medicines often don’t absorb into these creams as well.

Water-in-oil creams are greasier but take up most medications better because medications are hydrophobic (water-hating) so they will take up medications better and release them into the skin better than oil-in-water creams. Because the water-in-oil creams are greasier, they tend to be more moisturizing and provide an oil barrier that keeps water inside the outer layers of the skin. Both kinds of creams are preferable to lotions for moisturizing as creams do not contain the degree of alcohol in them as do lotions so they do not dry out the skin.

Medical uses

Creams without medication can be used on skin conditions like psoriasis and eczema that require a moisture barrier and maximal moisturizing. Even those with only very dry skin would benefit from the use of unmedicated cream.

Hydrocortisone cream is available to treat rashes like poison oak or poison ivy. It also helps those with other skin conditions such as psoriasis and eczema. Antibiotic creams can be used on abrasions or small wounds to prevent or treat minor infections. Antifungal creams are used in those with patches of fungal infections, such as ringworm, Candida Intertrigo or Candida diaper rash. Zinc oxide cream is used for local sunblock activity and for infant diaper rash.

More recently, a cream called Emla was developed. Emla contains the drug, lidocaine, and is placed on intact skin for several minutes prior to starting an intravenous line or drawing blood in those people, like children, who don’t tolerate the pain of needle sticks.

Compounding pharmacists can make creams with hormones such as estrogen, progesterone and testosterone in them. Patients put a small amount of cream on the inside of their forearm or upper arm and rub the cream into the skin. This has been shown to be as effective (or more effective) than providing these hormones in oral form.