A reference standard is a highly purified and well characterized material suitable to test the identity, strength, quality and purity of substances for Chemical, pharmaceutical and medicinal products.
A Drug Substance or chemical material of established quality and purity as shown by comparison to the reference standard material and used as Reference Working Substance for routine quality control analysis.
An impurity is "any component of the product which is not the chemical entity defined as the active substance or an excipient in the product".
Isotope Labelled Compound is a chemical substance in which part of the molecules are labeled with an isotope so that observations the isotopic composition make it possible to follow the compound.
A metabolite is the intermediate end product of metabolism. The term metabolite is usually restricted to small molecules. A drug metabolite is a byproduct of break down, or “metabolizing,” a drug into a different substance.
Research chemicals are chemical substances used by scientists for scientific research and development purposes. Research Chemicals are produced by Custom Synthesis Methods.