An excipient is an inactive substance used as a carrier for the active ingredients of a medication. In many cases, an "active" substance (such as aspirin) may not be easily administered and absorbed by the human body; in such cases the substance in question may be dissolved into or mixed with an excipient. Excipients are also sometimes used to bulk up formulations with very potent active ingredients, to allow for convenient and accurate dosage. In addition to their use in the single-dosage quantity, excipients can be used in the manufacturing process to aid in the handling of the active substance concerned. Depending on the route of administration, and form of medication, different excipients may be used. For oral administration tablets and capsules are used. Suppositories are used for rectal administration.

Often, once an active ingredient has been purified, it cannot stay in purified form for 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 are added, ensuring that the active ingredient stays "active", and, just as importantly, stable for a sufficiently long period of time that the shelf-life of the product makes it competitive with other products. Thus, the formulation of excipients in many cases is considered a trade secret.

Pharmaceutical codes require that all ingredients in drugs, as well as their chemical decomposition products are identified and guaranteed to be safe. For this reason, excipients are only used when absolutely necessary and in the smallest amounts possible.

Types of excipients


Antiadherents are used to reduce the adhesion between the powder (granules) and the punch faces and thus prevent sticking to the tablet punches.


Binders hold the ingredients in a tablet together.

Binders ensure that tablets and granules can be formed with required mechanical strength. Binders are usually starches, sugars, cellulose or modified cellulose such as hydroxypropyl cellulose, lactose, or sugar alcohols like xylitol, sorbitol or maltitol.

Binders are classified according to their application:
*Solution binders are dissolved in a solvent (for example water or alcohol and used in wet granulation processes. Examples include gelatin, cellulose, cellulose derivatives, polyvinylpyrrolidone, starch, sucrose and polyethylene glycol.
*Dry binders are added to the powder blend, either after a wet granulation step, or as part of a direct powder compression (DC) formula. Examples include cellulose, methyl cellulose, polyvinylpyrrolidone, and polyethylene glycol.


Tablet coatings protect tablet ingredients from deterioration by moisture in the air and make large or unpleasant-tasting tablets easier to swallow. For most coated tablets, a cellulose (plant fiber) film coating is used which is free of sugar and potential allergens. Occasionally, other coating materials are used, for example synthetic polymers, shellac, corn protein zein or other polysaccharides. Capsules are coated with gelatin.

Changing the dissolution rates of active species

Enteric coatings control the rate of drug release and determines where the drug will be released in the digestive tract.


Disintegrants expand and dissolve when wet causing the tablet to break apart in the digestive tract, releasing the active ingredients for absorption. Disintegrant types include:
*Water uptake facilitators
*Tablet rupture promotersThey ensure that when the tablet is in contact with water, it rapidly breaks down into smaller fragments, thereby facilitating dissolution.Examples of disintegrants include: starch, cellulose, crosslinked polyvinyl pyrrolidone, sodium starch glycolate, sodium carboxymethyl cellulosemethycellulose.


Fillers fill out the size of a tablet or capsule, making it practical to produce and convenient for the consumer to use. By increasing the bulk volume, the final product has the proper volume for patient handling.

A good filler must be inert, compatible with the other components of the formulation, non-hygroscopic, soluble, relatively cheap, compactible, and preferably tasteless or pleasant tasting.

Plant cellulose (pure plant filler) is a popular filler in tablets or hard gelatin capsules. Dibasic calcium phosphate is another popular tablet filler. A range of vegetable fats and oils can be used in soft gelatin capsules.

Other examples of fillers include: lactose, sucrose, glucose, mannitol, sorbitol, calcium carbonate, and magnesium stearate.

Flavors and Colors

Flavors and Colors are added to improve the taste or appearance of a formulation. Color consistency is important as it allows easy identification of a medication.


Glidants are used to promote powder flow by reducing interparticle friction and cohesion. These are used in combination with lubricants as they have no ability to reduce die wall friction. Examples include colloidal silicon dioxide, talc, and etc.


Lubricants prevent ingredients from clumping together and from sticking to the tablet punches or capsule filling machine. Lubricants also ensure that tablet formation and ejection can occur with low friction between the solid and die wall.

Common minerals like talc or silica, and fats, e.g. vegetable stearin, magnesium stearate or stearic acid are the most frequently used lubricants in tablets or hard gelatin capsules.


Some typical preservatives used in pharmaceutical formulations are
* antioxidants like vitamin A, vitamin E, vitamin C, retinyl palmitate, and selenium
* the amino acids cysteine and methionine
* citric acid and sodium citrate
* synthetic preservatives like methyl paraben and propyl paraben.


Sorbents are used for tablet/capsule moisture-proofing by limited fluid sorbing (taking up of a liquid or a gas either by adsorption or by absorption) in a dry state.


Sweeteners are added to make the ingredients more palatable, especially in chewable tablets such as antacid or liquids like cough syrup. Therefore, tooth decay is sometimes associated with cough syrup abuse. Sugar can be used to disguise unpleasant tastes or smells.

ee also

*Active ingredient
*Pharmacology - Placebo - Placebo effect - Quality system
*Gluten-free diet

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • excipient — [ ɛksipjɑ̃ ] n. m. • 1747; lat. excipiens, de excipere « recevoir » ♦ Substance neutre qui entre dans la composition d un médicament, et qui sert à rendre les principes actifs plus faciles à absorber. Excipient sucré. ● excipient nom masculin… …   Encyclopédie Universelle

  • excipient — EXCIPIÉNT, Ă, excipienţi, te, adj., s.n. (Substanţă sau amestec de substanţe) care este inactiv faţă de organism şi în care se încorporează diferite medicamente. [pr.: pi ent] – Din fr. excipient. Trimis de ionel bufu, 16.06.2004. Sursa: DEX 98  …   Dicționar Român

  • Excipient — Ex*cip i*ent, a. [L. excipients, entis, p. pr. of exipere. See {Except}, v. t.] Taking an exception. [1913 Webster] …   The Collaborative International Dictionary of English

  • Excipient — Ex*cip i*ent, n. 1. An exceptor. [R.] [1913 Webster] 2. (Med., Pharmacy) An inert or slightly active substance used in preparing remedies as a vehicle or medium of administration for the medicinal agents. Chambers …   The Collaborative International Dictionary of English

  • excipient — [ek sip′ē ənt] n. [< L excipiens, prp. of excipere: see EXCEPT] Pharmacy any of various inert substances added to a prescription to give the desired consistency or form …   English World dictionary

  • Excipient — Un excipient désigne toute substance autre que le principe actif dans un médicament, un cosmétique ou un aliment. Son addition est destinée à conférer une consistance donnée, ou d autres caractéristiques physiques ou gustatives particulières, au… …   Wikipédia en Français

  • excipient — I. ikˈsipēənt, (ˈ)ek|s adjective Etymology: Latin excipient , excipiens, present participle of excipere to take out, make an exception of, take, receive more at except : taking exception II. noun ( s) Etymology …   Useful english dictionary

  • excipient — noun Etymology: Latin excipient , excipiens, present participle of excipere to take out, take up more at except Date: circa 1753 a usually inert substance (as gum arabic or starch) that forms a vehicle (as for a drug) …   New Collegiate Dictionary

  • excipient — /ik sip ee euhnt/, n. Pharm. a pharmacologically inert, adhesive substance, as honey, syrup, or gum arabic, used to bind the contents of a pill or tablet. [1720 30; < L excipient (s. of excipiens), prp. of excipere to take out, except, take up,… …   Universalium

  • excipient — [ɛk sɪpɪənt] noun an inactive substance that serves as the vehicle or medium for a drug or other active substance. Origin C18 (as adjective in the sense that takes exception ): from L. excipient , excipere take out …   English new terms dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”