International Chemical Reference Substances (ICRS)
International Chemical Reference Substances (ICRS) are required to support the monograph specifications in The International Pharmacopoeia. They are established according to General guidelines for the establishment, maintenance and distribution of chemical reference substance, by the WHO custodian organization for ICRS, the European Directorate for the Quality of Medicines & HealthCare (EDQM), located in the Council of Europe, Strasbourg, France.
About WHO ICRS
Search the Online Database for the availability and price of ICRS by using substance name or Catalogue Code or Chemical Abstract Service (CAS) Registry Number.
Access to ICRS database and purchase of ICRS online at EDQM
ICRS are used by laboratories as primary standards for physical and chemical tests and assays described in The International Pharmacopoeia; or to calibrate secondary standards according to the General guidelines for the establishment, maintenance and distribution of chemical reference substance.
Intended use of ICRS
The International Pharmacopoeia constantly develops new monographs and revises existing ones to stay abreast of advances in analytical science and regulatory affairs. Along with these changes the intended use of already established ICRS often needs to be adjusted, for example, because an ICRS previously used for identification only shall newly also be employed in quantitative tests.
The user of The International Pharmacopoeia finds information on the actually established intended uses of an ICRS in the leaflet enclosed with the substance when distributed or accessible via the ICRS online database. The information found in current leaflets is applicable to all standards of the respective batch number.
Authorization of ICRS
ICRS are adopted by the WHO Expert Committee on Specifications for Pharmaceutical Preparations following a procedure aligned with the WHO General guidelines for the establishment, maintenance and distribution of chemical reference substances.