Excipient

An excipient is an inactive substance used as a vehicle for medication, or an active ingredient. In addition excipients can be used to aid the process by which a product is manufactured. In general, the active substances (such as aspirin) may not be easily administered and absorbed by the human body; they need to be put in some appropriate form. The active substance is then dissolved or mixed with an excipient.

Depending on the route of administration, and medication form, various excipients may be used. For oral administration, see Tabletsand Capsules. For rectal administration see suppositories.

Once the active ingredient has been purified, it cannot stay in purified form for very long. In many cases it will denature, fall out of solution, or stick to the sides of the container. To stabilize the active ingredient, excipients will be added to ensure that the active ingredient stays active, and is stable for a long period of time to ensure that the shelf-life of the product makes it competitive with other products. The formulation of these excipients in many cases is considered a trade secret.

Although drugs are chosen primarily for their active ingredients, the other ingredients (excipients) needed to make the tablet, capsule or liquid are just as important. For this reason, excipients are only used when absolutely necessary and in the smallest amounts possible.

Types of exipients:

Binders

Holds the ingredients in a tablet together. One of three types of binders are used as required: Plant fiber known as cellulose, acacia gum from the stem of the Acacia tree or brazil wax from the leaves of a palm tree.

Fillers

Fills out the size and shape of a tablet or capsule making it practical to produce and convenient for the consumer to use. Plant cellulose (pure plant filler) is the filler of choice in tablets or hard gelatin capsules. Soybean or safflower oil is used in soft gelatin capsules.

Disintegrants

Expands when wet causing the tablet to break apart in the digestive tract releasing the nutrients for absorption.

Lubricants

Prevents ingredients from clumping together and from sticking to the tablet punches or capsule filler. Common minerals, silica, and forms of vegetable oils known as vegetable stearin, magnesium stearate or stearic acid are the most often used lubricants in tablets or hard gelatin capsules.

Coatings

Tablet Coating protects tablet ingredients from deterioration by moisture in the air and makes large tablets easier to swallow. For most coated tablets, a cellulose (plant fiber) film coating is used which is free of sugar and potential allergy-causing substances. Occasionally, other coating materials are used such as corn protein (zein) or an extraction from trees (pharmaceutical glaze).

Release Coating controls the rate of drug release, or controls specifically when the drug will be released in the digestive tract.

Sweeteners

Added to make the nutrients more palatable only in chewable tablets or liquids.

Flavors and Colors

Added to improve the taste or appearance of a formulation.

See also

• Pharmaceutical project- Pharmacology- Placebo- Placebo effect- Quality system
• Active ingredientca:Excipient

es:Excipiente fr:Excipient

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It uses material from the http://en.wikipedia.org/wiki/Excipient Wikipedia article Excipient.