USP Class VI Testing – What is it?

Dec 9, 2020

In order to identify the biocompatibility of materials, USP Class VI testing is required. As one of the most widely used methods, VI forms part of six different classes with this being the most thorough. This form of testing is developed to certify that no harmful reactions or long-term issues are caused to the body by chemicals that are released or leached from plastic materials. The United States Pharmacopeia and National Formulary (USP-NF) determine the USP Class Testing standards, and so, this organisation is responsible for ensuring that medical devices and foods are safe. The testing is carried out frequently, especially those plastic materials that are regularly in contact with injectable drugs as well as a range of other fluids that are seen during the many steps involved in the drug manufacturing process.

What Are the USP VI Testing Methods?

Testing is carried out through producing an extract of the product using different extraction fluids which can include Polyethylene Glycol and vegetable oil. This is then injected into a specimen that is alive in order to see how it responds. This is carried out regularly and requires three forms of testing including systematic injections, intracutaneous and implantation.

Systemic Injection Test – During this test, test specimens are injected with the extract intravenously and monitored for 72 hours. They are monitored to identify any reactions that relate to abnormal toxicity level.

Intracutaneous Test – This test is carried out to identify whether any local skin reactions take place. The specimen is injected intracutaneously with the extract before being monitored for 72 hours. Any reactions are scored and averaged.

Implantation Test – The product materials implanted into the specimen to identify whether a reaction in the live tissue takes place after coming into direct contact with the product over a period of around five days.

What’s the Reason for Products Being USP Class VI?

Class testing is needed when manufacturing drugs to identify its low toxicity compliance while ensuring it meets all biocompatibility standards. Therefore, it is crucial to identify that any fluid contact surfaces will not leach harmful chemicals into the fluid during manufacturing. Class VI testing vigorously investigates where there is a reaction in the skin, body and living tissue, ensuring that a product is safe for use.