Excipient 914572 222019847 2008-06-27T04:48:59Z SJP 2716074 Reverted edits by [[Special:Contributions/99.226.37.40|99.226.37.40]] (using [[WP:HG|Huggle]]) An '''excipient''' is an inactive substance used as a carrier for the [[active ingredient]]s 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, various excipients may be used. For oral administration, see [[Tablet]] and [[Capsule]]. For rectal administration see [[suppository]]. 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=== [[Antiadherent]]s are used to reduce the [[adhesion]] between the [[Powder (substance)|powder]] ([[granule]]s) and the punch faces and thus prevent tablet sticking to the tablet punches. ===Binders=== Binders hold the ingredients in a tablet together. Binders ensure that tablets and granules can be formed with required mechanical strength. Binders are usually [[starch]]es, [[sugar]]s, [[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 [[ethanol|alcohol]] and used in wet granulation processes. Examples are [[Gelatin]], [[Cellulose]], Cellulose derivatives, [[Poly vinyl pyrrolidone|Polyvinyl pyrrolidone]], [[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 are [[Cellulose]], [[Methyl cellulose]], [[Poly vinyl pyrrolidone|Polyvinyl pyrrolidone]], [[Polyethylene glycol]] ===Coatings=== 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 [[allergen]]s. Occasionally, other coating materials are used, for example synthetic polymers, [[shellac]], corn protein [[zein]] or other [[polysaccharide]]s. ====Changing the dissolution rates of active species==== Enteric coatings or slow release coatings control the rate of drug release, or determine where the drug will be released in the digestive tract. ===Disintegrants=== [[Disintegrant]]s 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 promoters They ensure that when the tablet is in contact with [[water]], it rapidly breaks down into smaller fragments, thereby facilitating [[solvation|dissolution]]. Examples of disintegrants include: [[starch]], [[cellulose]], crosslinked [[Poly vinyl pyrrolidone|polyvinyl pyrrolidone]], [[sodium starch glycolate]], [[sodium carboxymethyl cellulose]]methycellulose. ===Fillers/Diluents=== 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]], and, [[calcium carbonate]]. ===Flavors and Colors=== [[Flavoring|Flavors]] and [[Coloring|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=== [[Glidant]]s 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=== [[Lubricant]]s prevent ingredients from clumping together and from sticking to the tablet punches or [[capsule filling machine]]. Lubricants also ensure that tablet formation and injection can occur with low [[friction]] between the solid and die wall. Common minerals like [[talc]] or [[silica]], and [[fat]]s, e.g. vegetable [[stearin]], [[magnesium stearate]] or [[stearic acid]] are the most frequently used lubricants in tablets or hard gelatin capsules. ===Preservatives=== Some typical [[preservatives]] used in pharmaceutical formulations are * [[antioxidants]] like [[vitamin A]], [[vitamin E]], [[vitamin C]], retinyl palmitate, and [[selenium]] * the [[amino acid]]s [[cysteine]] and [[methionine]] * [[citric acid]] and [[sodium citrate]] * synthetic preservatives like [[methyl paraben]] and [[propyl paraben]]. ===Sorbents=== [[Sorbent]]s 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=== [[Sweetener]]s 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. ==See also== *[[Pharmaceutics]] *[[Active ingredient]] *[[Pharmacology]] - [[Placebo]] - [[Placebo effect]] - [[Quality system]] *[[Gluten-free diet]] [[Category:Excipients| ]] [[Category:Pharmacology]] [[Category:clinical research]] [[Category:Pharmaceutical industry]] [[ca:Excipient]] [[de:Pharmazeutischer Hilfsstoff]] [[es:Excipiente]] [[fr:Excipient]] [[it:Eccipiente]] [[pl:Substancja pomocnicza]] [[pt:Excipiente]]