concentration The amount of a particular substance in a given quantity of solution, usually stated as a percentage by weight or volume,
as weight per unit volume, as molarity (a molar solution contains one gram-mole of solute per liter of solution), or as normality
(a normal solution contains one gram-equivalent weight of solute per liter of solution).
conformation The shape of a molecule, produced by the specific spatial arrangement of the units that compose it.
contaminant A foreign agent or material that is not introduced as part of processing, such as airborne particulates or adventitious
controlled delivery Incorporation of one or more elements of control on the release of an active ingredient from a dosage form to obtain well-defined
convection A transfer of heat that occurs when a fluid flows inside a channel of a different temperature; heat is transferred through
the fluid because of the difference in motion between it and the flow boundary.
cryoconcentration When temperature is decreased at a sufficiently slow rate, ice formation occurs below the freezing temperature, which can
cause cryoinjury to the solution, and the ice crystals will function as an additional solute; a cryoprotectant is often used
to prevent this.
dalton (Da) A unit of mass very nearly equal to that of a hydrogen atom (precisely equal to 1 on the atomic mass scale), named after
John Dalton, who developed the atomic theory of matter. It is 1.660 3 10-24 gram. A kilodalton (kDa) is 1,000 daltons.
deamidation Removal of one or more amide groups from a polypeptide molecule.
deflashing The finishing procedure by which excess plastic (flash) is removed from a molding.
degradation Loss or reduction of quality, integrity, or character; a chemical reaction that breaks down a molecule into smaller parts.
degradants The smaller parts that are left over after a molecule or solution degrades.
delaminate To split apart into thin layers; the act of separating a laminate into layers.
delivery matrix A heterogeneous semisolid matrix (such as a biopolymer gel) for the sustained delivery of drug substances directly to the
tissues; a matrix can be modified to optimize the dosage or time period during which the drug is delivered.
denaturation A condition in which a protein unfolds or its polypeptide chains are disordered, rendering the molecule less soluble and
dendritic ice Ice that branches like a tree; if water is cooled slowly, it forms dendritic ice crystals.
differential scanning calorimetry (DSC) Analytical method that independently measures the rate of heat flow to a sample against a reference standard of the same
temperature. Data are obtained by monitoring the differential heat flow as a function of temperature. DSC can measure heat
capacities, phase transitions, dehydration, and decomposition reactions.
diluent A chemically inert substance added to a solution to increase the volume and reduce the concentration; a diluting agent.
disulfide bond A covalent bond formed between two sulfur atoms of different cysteines in a protein.
efficacy Usefulness; the power to produce an effect.
efficiency of delivery The relative effectiveness of a drug delivery system.
elastomeric closure A rubber or rubber-like closure or stopper; a packaging component that may come into direct contact with the enclosed drug,
which is usually an injectable.
electrophoresis Movement of suspended particles through a fluid or gel under the influence of an electrical charge.
emulsification A process that creates a stable mixture of two liquids that normally would not mix together (such as oil and water) by forcing
one to disperse in the other as droplets.