An excipient is a substance formulated alongside the
active ingredient
An active ingredient is any ingredient that provides biologically active or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or any function of the body of humans or animals. T ...
of a
medication
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...
,
included for the purpose of long-term stabilization, bulking up solid formulations that contain potent active ingredients in small amounts (thus often referred to as "bulking agents", "fillers", or "diluents"), or to confer a therapeutic enhancement on the active ingredient in the final dosage form, such as facilitating
drug
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...
absorption, reducing viscosity, or enhancing solubility. Excipients can also be useful in the manufacturing process, to aid in the handling of the active substance concerns such as by facilitating powder
flowability
Flowability, also known as powder flow is a property that defines an ability of a powdered material to flow, related to cohesion.
Powder flowability depends on many traits:
* the shape and size of the powder particles due to intermolecular force, ...
or non-stick properties, in addition to aiding ''
in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...
'' stability such as prevention of
denaturation or aggregation over the expected shelf life. The selection of appropriate excipients also depends upon the
route of administration
A route of administration in pharmacology and toxicology is the way by which a medication, drug, fluid, poison, or other substance is taken into the body.
Routes of administration are generally classified by the location at which the substance i ...
and the
dosage form
Dosage forms (also called unit doses) are pharmaceutical drug products in the form in which they are marketed for use, with a specific mixture of active ingredients and inactive components (excipients), in a particular configuration (such as a ca ...
, as well as the
active ingredient
An active ingredient is any ingredient that provides biologically active or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or any function of the body of humans or animals. T ...
and other factors. A comprehensive classification system based on structure-property-application relationships has been proposed for excipients used in parenteral medications.
Pharmaceutical regulations and standards require that all ingredients in drugs, as well as their
chemical decomposition
Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. Chemical decomposition is usually regarded and defined as t ...
products, be identified and shown to be safe. Often, more excipient is found in a final drug formulation than active ingredient, and practically all marketed drugs contain excipients.
As with new drug substances and
dosage forms
Dosage forms (also called unit doses) are pharmaceutical drug products in the form in which they are marketed for use, with a specific mixture of active ingredients and inactive components (excipients), in a particular configuration (such as a cap ...
thereof, novel excipients themselves can be
patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...
ed; sometimes, however, a particular formulation involving them is kept as a trade secret instead (if not easily
reverse-engineered
Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompli ...
).
Relative versus absolute inactivity
Though excipients were at one time assumed to be "inactive" ingredients, it is now understood that they can sometimes be "a key determinant of dosage form performance";
in other words, their effects on
pharmacodynamics
Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or combinations of organisms (fo ...
and
pharmacokinetics
Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...
, although usually negligible, cannot be ''known'' to be negligible without
empirical confirmation and sometimes are important. For that reason, in
basic research
Basic research, also called pure research or fundamental research, is a type of scientific research with the aim of improving scientific theories for better understanding and prediction of natural or other phenomena. In contrast, applied resear ...
and
clinical trial
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...
s they are sometimes included in the
control substances in order to minimize
confounding
In statistics, a confounder (also confounding variable, confounding factor, extraneous determinant or lurking variable) is a variable that influences both the dependent variable and independent variable, causing a spurious association. Con ...
, reflecting that otherwise, the absence of the active ingredient would not be the only variable involved, because absence of excipient cannot always be assumed not to be a variable.
Such studies are called excipient-controlled or
vehicle
A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wa ...
-controlled studies.
Types
Adjuvants
Adjuvants are added to vaccines to enhance or modify the immune system response to an immunization. An adjuvant may stimulate the immune system to respond more vigorously to a vaccine, which leads to more robust immunity in the recipient.
Antiadherents
Antiadherents reduce the
adhesion
Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another).
The forces that cause adhesion and cohesion can be ...
between the
powder
A powder is a dry, bulk solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and ''granular'' are sometimes used to distin ...
(
granules) and the
punch
Punch commonly refers to:
* Punch (combat), a strike made using the hand closed into a fist
* Punch (drink), a wide assortment of drinks, non-alcoholic or alcoholic, generally containing fruit or fruit juice
Punch may also refer to:
Places
* Pun ...
faces and thus prevent sticking to tablet punches by offering a
non-stick surface
A non-stick surface is engineered to reduce the ability of other materials to stick to it. Non-stick cookware is a common application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer ...
. They are also used to help protect tablets from sticking. The most commonly used is
magnesium stearate
Magnesium stearate is the chemical compound with the formula . It is a soap, consisting of salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Magnesium stearate is a white, water-insoluble pow ...
.
Binders
Binders hold the ingredients in a tablet together. Binders ensure that tablets and granules can be formed with required mechanical strength, and give volume to low active dose tablets. Binders are usually:
*
Saccharide
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may ...
s and their derivatives:
**
Disaccharide
A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, lact ...
s:
sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula .
For human consumption, sucrose is extracted and refined ...
,
lactose
Lactose is a disaccharide sugar synthesized by galactose and glucose subunits and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by mass). The name comes from ' (gen. '), the Latin word for milk, plus the suffix '' - ...
;
**
Polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
s and their derivatives:
starch
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...
es,
cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...
or modified cellulose such as
microcrystalline cellulose Microcrystalline cellulose (MCC) is a term for refined wood pulp and is used as a texturizer, an anti-caking agent, a fat substitute, an emulsifier, an extender, and a bulking agent in food production. The most common form is used in vitamin sup ...
and
cellulose ethers such as
hydroxypropyl cellulose
Hydroxypropyl cellulose (HPC) is a derivative of cellulose with both water solubility and organic solubility. It is used as an excipient, and topical ophthalmic protectant and lubricant.
Chemistry
HPC is an ether of cellulose in which some of t ...
(HPC);
**
Sugar alcohol
Sugar alcohols (also called polyhydric alcohols, polyalcohols, alditols or glycitols) are organic compounds, typically derived from sugars, containing one hydroxyl group (–OH) attached to each carbon atom. They are white, water-soluble solids ...
s such as
xylitol
Xylitol is a chemical compound with the formula , or HO(CH2)(CHOH)3(CH2)OH; specifically, one particular stereoisomer with that structural formula. It is a colorless or white crystalline solid that is freely soluble in water. It can be classifie ...
,
sorbitol
Sorbitol (), less commonly known as glucitol (), is a sugar alcohol with a sweet taste which the human body metabolizes slowly. It can be obtained by reduction of glucose, which changes the converted aldehyde group (−CHO) to a primary alcohol g ...
or
mannitol
Mannitol is a type of sugar alcohol used as a sweetener and medication. It is used as a low calorie sweetener as it is poorly absorbed by the intestines. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to lower ...
;
* Protein:
gelatin
Gelatin or gelatine (from la, gelatus meaning "stiff" or "frozen") is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also ...
;
* Synthetic
polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
s:
polyvinylpyrrolidone
Polyvinylpyrrolidone (PVP), also commonly called polyvidone or povidone, is a water-soluble polymer made from the monomer ''N''-vinylpyrrolidone. PVP is available in a range of molecular weights and related viscosities, and can be selected accor ...
(PVP),
polyethylene glycol
Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular we ...
(PEG)...
Binders are classified according to their application:
*Solution binders are dissolved in a solvent (for example
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
or
alcohol
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
can be 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.
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 ether
hydroxypropyl methylcellulose (HPMC) film coating is used which is free of sugar and potential
allergen
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
In technical terms ...
s. Occasionally, other coating materials are used, for example synthetic polymers,
shellac
Shellac () is a resin secreted by the female lac bug on trees in the forests of India and Thailand. It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and ...
, corn protein
zein
Zein is a class of prolamine protein found in maize (corn). It is usually manufactured as a powder from corn gluten meal. Zein is one of the best understood plant proteins.Momany, Frank A.; Sessa, David J.; Lawton, John C.; Selling, Gordon W.; H ...
or other polysaccharides.
Capsules are coated with gelatin.
Enteric
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
s control the rate of drug release and determine where the drug will be released in the digestive tract. Materials used for enteric coatings include fatty acids, waxes, shellac, plastics, and plant fibers.
Colours
Colours
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associ ...
are added to improve the appearance of a formulation. Colour consistency is important as it allows easy identification of a medication. Furthermore, colours often improve the aesthetic look and feel of medications. Small amounts of colouring agents are easily processed by the body, although rare reactions are known, notably to
tartrazine
Tartrazine is a synthetic lemon yellow azo dye primarily used as a food coloring. It is also known as E number E102, C.I. 19140, FD&C Yellow 5, Yellow 5 Lake, Acid Yellow 23, Food Yellow 4, and trisodium 1-(4-sulfonatophenyl)-4-(4-sulfonatop ...
.
[ Commonly, titanium oxide is used as a colouring agent to produce the popular opaque colours along with azo dyes for other colors. By increasing these ]organoleptic
Organoleptic properties are the aspects of food, water or other substances that create an individual experience via the senses—including taste, sight, smell, and touch.
USDA uses
In traditional U.S. Department of Agriculture meat and poul ...
properties a patient is more likely to adhere to their schedule and therapeutic objectives will also have a better outcome for the patient especially children.
Disintegrants
Disintegrants expand and dissolve when wet causing the tablet to break apart in the digestive tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...
, or in specific segments of the digestion process, releasing the active ingredients for absorption
Absorption may refer to:
Chemistry and biology
* Absorption (biology), digestion
**Absorption (small intestine)
*Absorption (chemistry), diffusion of particles of gas or liquid into liquid or solid materials
*Absorption (skin), a route by which ...
. They ensure that when the tablet is in contact with water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
, it rapidly breaks down into smaller fragments, facilitating dissolution
Dissolution may refer to:
Arts and entertainment Books
* ''Dissolution'' (''Forgotten Realms'' novel), a 2002 fantasy novel by Richard Lee Byers
* ''Dissolution'' (Sansom novel), a 2003 historical novel by C. J. Sansom Music
* Dissolution, in mu ...
.[
Examples of disintegrants include:
* Crosslinked polymers: crosslinked ]polyvinylpyrrolidone
Polyvinylpyrrolidone (PVP), also commonly called polyvidone or povidone, is a water-soluble polymer made from the monomer ''N''-vinylpyrrolidone. PVP is available in a range of molecular weights and related viscosities, and can be selected accor ...
( crospovidone), crosslinked sodium carboxymethyl cellulose
Carboxymethyl cellulose (CMC) or cellulose gum is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used as its sodi ...
(croscarmellose sodium Sodium croscarmellose is an internally cross-linked sodium carboxymethylcellulose for use as a superdisintegrant in pharmaceutical formulations.
E468 is the E number of crosslinked sodium carboxymethyl cellulose, used in food as an emulsifier.
...
).
* sodium starch glycolate, a modified starch
Modified starch, also called starch derivatives, are prepared by physically, enzymatically, or chemically treating native starch to change its properties. Modified starches are used in practically all starch applications, such as in food produ ...
Flavours
Flavours can be used to mask unpleasant tasting active ingredients and improve the acceptance that the patient will complete a course of medication. Flavourings may be natural (e.g. fruit extract) or artificial.[
For example, to improve:]
* a bitter product–mint
MiNT is Now TOS (MiNT) is a free software alternative operating system kernel for the Atari ST system and its successors. It is a multi-tasking alternative to TOS and MagiC. Together with the free system components fVDI device drivers, XaA ...
, cherry
A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit).
Commercial cherries are obtained from cultivars of several species, such as the sweet ''Prunus avium'' and the sour ''Prunus cerasus''. The nam ...
or anise
Anise (; '), also called aniseed or rarely anix is a flowering plant in the family Apiaceae native to Eurasia.
The flavor and aroma of its seeds have similarities with some other spices and herbs, such as star anise, fennel, licorice, and ta ...
may be used
* a salty product–peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fu ...
, apricot
An apricot (, ) is a fruit, or the tree that bears the fruit, of several species in the genus ''Prunus''.
Usually, an apricot is from the species '' P. armeniaca'', but the fruits of the other species in ''Prunus'' sect. ''Armeniaca'' are also ...
or liquorice
Liquorice (British English) or licorice (American English) ( ; also ) is the common name of ''Glycyrrhiza glabra'', a flowering plant of the bean family Fabaceae, from the root of which a sweet, aromatic flavouring can be extracted.
The liqu ...
may be used
* a sour product–raspberry
The raspberry is the edible fruit of a multitude of plant species in the genus ''Rubus'' of the rose family, most of which are in the subgenus '' Idaeobatus''. The name also applies to these plants themselves. Raspberries are perennial with w ...
or liquorice may be used
* an excessively sweet product–vanilla
Vanilla is a spice derived from orchids of the genus ''Vanilla (genus), Vanilla'', primarily obtained from pods of the Mexican species, flat-leaved vanilla (''Vanilla planifolia, V. planifolia'').
Pollination is required to make the p ...
may be used
Glidants
Glidant
A glidant is a substance that is added to a powder to improve its flowability. A glidant will only work at a certain range of concentrations. Above a certain concentration, the glidant will in fact function to inhibit flowability.
In tablet manuf ...
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 wall friction. Examples include silica gel
Silica gel is an amorphous and porous form of silicon dioxide (silica), consisting of an irregular tridimensional framework of alternating silicon and oxygen atoms with nanometer-scale voids and pores. The voids may contain water or some other l ...
, fumed silica
Fumed silica (CAS number 112945-52-5), also known as pyrogenic silica because it is produced in a flame, consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles which then agglom ...
, talc
Talc, or talcum, is a Clay minerals, clay mineral, composed of hydrated magnesium silicate with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thi ...
, and magnesium carbonate
Magnesium carbonate, (archaic name magnesia alba), is an inorganic salt that is a colourless or white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals.
Forms
The most common magnesium carbonate forms are ...
. However, some silica gel glidants such as Syloid(R) 244 FP and Syloid(R) XDP are multi-functional and offer several other performance benefits in addition to reducing interparticle friction including moisture resistance, taste, marketing, etc.
Lubricants
Lubricant
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...
s 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
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of t ...
between the solid and die wall.[
Common minerals like ]talc
Talc, or talcum, is a Clay minerals, clay mineral, composed of hydrated magnesium silicate with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thi ...
or silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
, and fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers spec ...
s, e.g. vegetable stearin
Stearin , or tristearin, or glyceryl tristearate is an odourless, white powder. It is a triglyceride derived from three units of stearic acid. Most triglycerides are derived from at least two and more commonly three different fatty acids. Like o ...
, magnesium stearate
Magnesium stearate is the chemical compound with the formula . It is a soap, consisting of salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Magnesium stearate is a white, water-insoluble pow ...
or stearic acid
Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a waxy solid and its chemical formula is C17H35CO2H. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. ...
are the most frequently used lubricants in tablets or hard gelatin capsules. Lubricants are agents added in small quantities to tablet and capsule formulations to improve certain processing characteristics. While lubricants are often added to improve manufacturability of the drug products, it may also negatively impact the product quality. For example, extended mixing of lubricants during blending may results in delayed dissolution and softer tablets, which is often referred to as "over-lubrication". Therefore, optimizing lubrication time is critical during pharmaceutical development.
There are three roles identified with lubricants as follows:
*True lubricant role:
:To decrease friction at the interface between a tablet’s surface and the die wall during ejection and reduce wear on punches and dies.
*Anti-adherent role:
:Prevent sticking to punch faces or in the case of encapsulation, lubricants.
:Prevent sticking to machine dosators, tamping pins, etc.
*Glidant role:
:Enhance product flow by reducing interparticulate friction.
There are two major types of lubricants:
*Hydrophilic
:Generally poor lubricants, no glidant or anti-adherent properties.
*Hydrophobic
:Most widely used lubricants in use today are of the hydrophobic category. Hydrophobic lubricants are generally good lubricants and are usually effective at relatively low concentrations. Many also have both anti-adherent and glidant properties. For these reasons, hydrophobic lubricants are used much more frequently than hydrophilic compounds. Examples include magnesium stearate.
Preservatives
Some typical preservatives
A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by ...
used in pharmaceutical formulations are
* Antioxidants
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...
like vitamin A
Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably bet ...
, vitamin E
Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitami ...
, vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...
, retinyl palmitate
Retinyl palmitate, or vitamin A palmitate, is the ester of retinol (vitamin A) and palmitic acid, with formula C36H60O2. It is the most abundant form of vitamin A storage in animals.
An alternate spelling, retinol palmitate, which violates the - ...
, and selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...
* The amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
s cysteine
Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile.
When present as a deprotonated catalytic residue, sometime ...
and methionine
Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical ro ...
* Citric acid
Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in t ...
and sodium citrate Sodium citrate may refer to any of the sodium salts of citric acid (though most commonly the third):
* Monosodium citrate
* Disodium citrate
* Trisodium citrate
The three forms of salt are collectively known by the E number E331.
Applications
F ...
* Synthetic preservatives like the paraben
Parabens are a class of widely used preservatives in cosmetic and pharmaceutical products. Chemically, they are a series of parahydroxybenzoates or esters of parahydroxybenzoic acid (also known as 4-hydroxybenzoic acid). Parabens are effective p ...
s: methyl paraben and propyl paraben
Propylparaben, the ''n''-propyl ester of ''p''-hydroxybenzoic acid, occurs as a natural substance found in many plants and some insects, although it is manufactured synthetically for use in cosmetics, pharmaceuticals, and foods. It is a member ...
.
Sorbents
Sorbent
A sorbent is a material used to absorb or adsorb liquids or gases. Examples include:
*A material similar to molecular sieve material, which acts by adsorption (attracting molecules to its surface). It has a large internal surface area and good t ...
s are used for tablet/capsule moisture-proofing by limited fluid sorbing (taking up of a liquid or a gas either by adsorption
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a f ...
or by absorption
Absorption may refer to:
Chemistry and biology
* Absorption (biology), digestion
**Absorption (small intestine)
*Absorption (chemistry), diffusion of particles of gas or liquid into liquid or solid materials
*Absorption (skin), a route by which ...
) in a dry state. For example, desiccant
A desiccant is a hygroscopic substance that is used to induce or sustain a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water. Desiccant ...
s absorb water, drying
Drying is a mass transfer process consisting of the removal of water or another solvent by evaporation from a solid, semi-solid or liquid. This process is often used as a final production step before selling or packaging products. To be considered ...
out ( desiccating) the surrounding materials.
Sweeteners
Sweetener
{{Wiktionary, sweetener
A sweetener is a substance added to food or drink to impart the flavor of sweetness, either because it contains a type of sugar, or because it contains a sweet-tasting sugar substitute. Many artificial sweeteners have been ...
s are added to make the ingredients more palatable, especially in chewable tablets such as antacid
An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach. Some antacids have been used in the treatment of constipation and diarrhea. Marketed antacids contain salts of alumi ...
or liquids like cough syrup
Cold medicines are a group of medications taken individually or in combination as a treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The term encompasses a broad array of drugs, including a ...
. Sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...
can be used to mask unpleasant tastes or smells, but artificial sweeteners tend to be preferred, as natural ones tend to cause tooth decay.[
]
Vehicles
In liquid and gel formulations, the bulk excipient that serves as a medium for conveying the active ingredient is usually called the vehicle
A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wa ...
. Petrolatum
Petroleum jelly, petrolatum, white petrolatum, soft paraffin, or multi-hydrocarbon, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25), originally promoted as a topical ointment for its he ...
, dimethyl sulfoxide
Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula ( CH3)2. This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds a ...
and mineral oil
Mineral oil is any of various colorless, odorless, light mixtures of higher alkanes from a mineral source, particularly a distillate of petroleum, as distinct from usually edible vegetable oils.
The name 'mineral oil' by itself is imprecise, ...
are common vehicles.
See also
*Active ingredient
An active ingredient is any ingredient that provides biologically active or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or any function of the body of humans or animals. T ...
*Pharmaceutics
Pharmaceutics is the discipline of pharmacy that deals with the process of turning a new chemical entity (NCE) or old drugs into a medication to be used safely and effectively by patients. It is also called the science of dosage form design. The ...
*Pharmacology
Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemica ...
*Placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures.
In general ...
*Placebo effect
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures.
In general ...
*Quality system
A quality management system (QMS) is a collection of business processes focused on consistently meeting customer requirements and enhancing their satisfaction. It is aligned with an organization's purpose and strategic direction (ISO 9001:2015). I ...
References
External links
{{Commonscat, Excipients
FDA database for Inactive Ingredient Search for Approved Drug Products
Excipient selection for injectable / parenteral formulations
IPEC-Americas
UCSF-CERSI Excipient Browser
Pharmaceutical industry
Pharmacy