iological therapeutics, also referred to as Biologicals, are those class of medicines which are grown and then purified from large-scale cell cultures of bacteria or yeast, or plant or animal cells. Biologicals are a diverse group of medicines which includes vaccines, growth factors, immune modulators, monoclonal antibodies, as well as products derived from human blood and plasma. What distinguishes biologicals from other medicines is that these are generally proteins purified from living culture systems or from blood, whereas other medicines are considered as ‘small molecules’ and are either made synthetically or purified from plants.

Due to the differences in their nature and how they are produced, biological therapeutics are regulated, tested, and controlled differently than other medicines. To help ensure their quality, safety, and efficacy, each batch of a biological therapeutic product must be tested extensively at each stage of production in order to ensure consistency with prior batches.  The use of WHO international reference standards helps to further ensure the consistency of a product across many batches as well as to allow the comparability of biologicals between manufacturers and/or countries.  The establishment of general requirements applicable across a diverse range of product classes governing starting materials, manufacturing and regulatory oversight is an essential aspect of this process. Whereas guidelines may be established for specific biologicals to help .