LAL Test Procedure | What is Lal Test
The endotoxin test (LAL test Procedure ) checks the safety of sterile pharmaceutical products for human use.
Endotoxins are chemical compounds that are released by killed or lysed bacteria. These molecules are toxic to humans and / or animals and cause a pyrogenic reaction (increase in body temperature). For this reason, it is important that drugs and medical devices that are either injected or implanted are tested for their pyrogen and thus endotoxin content.
There are several methods available for performing the endotoxin test, including the in vivo pyrogen test and the in vitro Limulus amebocyte lysate test, LAL for short - the most common approach to endotoxin testing. Various methods are available for carrying out this test, such as the gel clot method, the kinetic-turbidimetric method and the kinetic-chromogenic method.
The method is also used for the evaluation of medical devices such as disposable devices and implants. For this purpose, the test product is extracted with pyrogen-free water (PFW) and tested for the presence of endotoxin in the extracts.
PRINCIPLE OF THE TEST:
Kinetic chromogenic process and kinetic turbid metric process
The chromogenic method is an enzymatic reaction between endotoxin and lysate, which leads to the generation of a yellow color in the presence of endotoxin. The intensity of the color production is directly related to the amount of endotoxin present in the sample. The time at which the color reaction begins is measured using the kinetic variation of the assay. We can therefore use endotoxin standards to calculate the value of the endotoxin present in or on the product. Some products have a color that would interfere with this form of testing, so the turbidimetric method can be used to avoid such interference. In this case, a different lysate is used and the reaction with endotoxin causes the solution to become cloudy and the endotoxin content can thus be quantified without being dependent on the color present. Both methods are equally effective in maintaining endotoxin levels in a product, but often one is more appropriate than the other. Both methods use objective measurements to determine the endotoxin content and are quantitative in nature. These tests can be performed relatively quickly and the results can be available within a week of receiving the sample. to maintain endotoxin levels in a product, but often one is more appropriate than the other. Both methods use objective measurements to determine the endotoxin content and are quantitative in nature. These tests can be performed relatively quickly and the results can be available within a week of receiving the sample. to maintain endotoxin levels in a product, but often one is more appropriate than the other. Both methods use objective measurements to determine the endotoxin content and are quantitative in nature. These tests can be performed relatively quickly and the results can be available within a week of receiving the sample.
Gel-clot assay
The gel clot assay was the original LAL test procedure . It is a qualitative or semi-quantitative test used to screen for the presence of endotoxins. The formation of a solid gel indicates the presence of endotoxins in the sample tested.
METHOD REFERENCE:
1. United States Pharmacopoeia (USP) <85>. Current
2.UnitedStates Pharmacopoeia (USP) <161>. Current
3. European Pharmacopoeia (EP) 2.6.14. Current
4. Japanese Pharmacopoeia (JP) 4.01. Current
SAMPLE REQUIREMENTS AND TURNAROUND TIMES:
Validation of the inhibition or improvement properties of the materials on the test system.
SAMPLE REQUIREMENTS [FDA and AAMI guidelines]:
Samples from three (3) production batches should be tested for inhibition and improvement before this test is considered valid for use with the test product. The number of samples required for each batch is the same as * below.
NOTE: Validation tests can be performed at the same time and on the same samples as the batch release (finished product test).
Quantitative determination of the endotoxin level for finished products or other materials.
* SAMPLE REQUIREMENTS [FDA guidelines]:
For batches of less than 30 units - 2 sample devices
For many 30-100 units - 3 sample devices
For lots of 101 units or more - 3% of the lot, up to 3%.
Endotoxin testing of water samples or other liquids.
SAMPLE REQUIREMENTS:
1 mL in a sealed, endotoxin-free polystyrene or glass container.
Routine test results and matrix validations can be completed within 7 days.
