The pharmacology dictionary, in two languages.

The substance in a medicinal product that is responsible for its pharmacological activity, as distinct from the excipients; in manufacturing terms it is the drug substance produced under GMP.

A scientific framework that classifies drug substances into four classes according to their aqueous solubility and intestinal permeability, the two main determinants of the rate and extent of oral absorption.

A parenteral preparation, usually given intramuscularly or subcutaneously, that forms a reservoir at the injection site from which the drug is released slowly over weeks to months.

The process by which a solid drug passes into solution in a solvent such as gastrointestinal fluid; for solid oral dosage forms it is a prerequisite for absorption and often its rate-limiting step.

The physical form in which a drug is manufactured and administered, combining the active substance with excipients, for example a tablet, capsule, solution, suspension, injection, cream, transdermal patch or inhalation powder.

A polymer coating on tablets, capsules or pellets that resists dissolution in acidic gastric fluid and dissolves at the higher pH of the small intestine, delaying drug release until the dosage form has left the stomach.

Any constituent of a medicinal product other than the active substance, added to enable manufacture, maintain stability, control release, improve acceptability or aid administration.

A dosage form designed to release the active substance promptly after administration, without deliberate modification of the release rate, so that absorption is governed mainly by dissolution and gastrointestinal physiology.

A spherical vesicle of one or more phospholipid bilayers enclosing an aqueous core, used as a drug carrier that holds hydrophilic drugs in the core and lipophilic drugs within the bilayer.

A dosage form in which the rate, timing or site of drug release is deliberately altered from that of a conventional product, as in prolonged-release, delayed-release and pulsatile preparations.

Administration of a drug by a route that bypasses the gastrointestinal tract, usually by injection or infusion (intravenous, intramuscular, subcutaneous, intradermal, intrathecal and others).

The path by which a drug is brought into contact with the body, such as oral, sublingual, rectal, intravenous, intramuscular, subcutaneous, inhaled, topical or transdermal.

A form of an ionisable drug substance combined with a pharmaceutically acceptable counterion, such as hydrochloride, sodium, maleate or mesilate, chosen to improve solubility, stability, crystallinity or manufacturability.

The period during which a medicinal product, stored under the specified conditions, is expected to remain within its approved quality specifications for identity, strength, purity and performance.

The maximum amount of a substance that dissolves in a given volume of solvent at equilibrium under specified conditions of temperature, pH and medium composition.

Administration of a drug under the tongue, where it dissolves and is absorbed through the oral mucosa directly into the systemic venous circulation, bypassing hepatic first-pass metabolism.

Delivery of a drug through intact skin into the systemic circulation, usually from an adhesive patch designed to release the drug at a controlled rate over one to several days.