Re: Product release vs. pyrogen test
Hi everybody,
I have some questions about product release (medical devices) concernig pyrogen test. So....After a years of pyrogen testing (rabbit) on each lot we will not be able to do it after the october pass. I search through Iso 13485, MDD and also ISO 10993 series of stand. and tried to find is it obligatory to do pyrogen test on each lot?
I red something about LAL test, do anyone knew how to perform it (pyrogen free water, pyrogen free equipment, laminar flow etc.)?
Thanks for any help!
Tomislav
Hi Tomislav,
Welcome to the Cove
The United States Pharmacopeia (USP) has recognized the Limulus Amebocyte Lysate (LAL) method as the official method for carrying out the Bacterial Endotoxins Test. The rabbit pyrogen test may be used only if a product is incompatible with the LAL test.
Limulus amebocyte lysate (LAL) is an aqueous extract of blood cells (amebocytes) from the horseshoe crab, Limulus polyphemus. LAL reacts with bacterial endotoxin or lipopolysaccharide, which is a membrane component of gram negative bacteria. This reaction is the basis of all three LAL test methodologies viz. gel-clot, turbidimetric, and chromogenic.
Gel-clot Method
The gel-clot method is the simplest and most widely used LAL test. The gel-clot test is the compendial method. It is the only endotoxin test fully described in the United States Pharmacopoeia (USP) and many other pharmacopeias. You could use other methods as alternatives also.
Turbidimetric Methods
As the concentration of insoluble coagulin increases during the LAL reaction, the turbidity of the reaction mixture increases. The rate at which turbidity increases is related to the endotoxin concentration in the sample and is the basis of the Turbidimetric methods.
Chromogenic Methods
Chromogenic methods utilize a synthetic substrate which is added to the lysate. When chromogenic LAL reagent reacts with endotoxin, the cascade is initiated and clotting enzyme is activated as in the other methods. The reactions proceed more rapidly at higher endotoxin concentrations.
Refer FDA document -
Validation of LAL Test as an end product Endotoxin Test for Human and Animal Parenteral Drugs, Biological Products and Medical Devices .
You could refer to USP General Chapter 85 < Bacterial Endotoxin Test > for more detailed methodology on how to perform this test.