Study on the Method Validation of Recombinant Factor C Endotoxin Testing Assay

Main Article Content

Kanitta Phuwanartnaranubarn
Assajun Amen
Ekalak Songtan
Surapon Sreemanta

Abstract

Background: Bacterial endotoxins, the pyrogens derived from gram-negative bacteria, are heat-stable and can contaminate vaccine, injectable drug, and medical device products for human and veterinary use during manufacturing. The Limulus Amebocyte Lysate (LAL) method for analyzing the endotoxin determination uses a lysate of horseshoe crab blood, which has a high post-bleeding mortality rate. In accordance with the 3Rs principle of animal welfare, there has been a global effort to find a replacement for the use of animals. A recombinant factor C (rFC) assay has been developed as a replacement for the horseshoe crab lysate assay. Currently, the European and United State Pharmacopoeias have recognized it as a standard method.


Objectives: To study the validation of the recombinant factor C method for analyzing the endotoxin determination for use as a standard method in quality control of biological products to cover all analytical methods in European and United Stated pharmacopoeias.


Methods: This experimental research was conducted from October 2022 to December 2023 for validation of the endotoxin determination using recombinant factor C method in the parameters such as linearity, accuracy and precision (repeatability and reproducibility by different days and analyst).


Results: The study found that the method demonstrated a linear relationship between the measured values and the concentration of the standard with a correlation coefficient of             ≥ 0.980. The accuracy was assessed by spiking known concentrations of endotoxin into samples, the % recovery was within the acceptance criteria of 50-200%. The precision was evaluated by repeatability and intermediate precision studies. The coefficient of variation (CV) of % recovery was less than 25%. It could be used as a standard method for conducting the endotoxin determination in human vaccine and monoclonal antibody products. However, plasma-derived or blood products could not be analyzed due to interference from the samples.


Conclusions: The recombinant factor C method, which has been studied for its accuracy, is suitable and reliable. It can be used as a standard method for analyzing the quality of vaccines and monoclonal antibodies sold in Thailand.

Article Details

How to Cite
1.
Phuwanartnaranubarn K, Amen A, Songtan E, Sreemanta S. Study on the Method Validation of Recombinant Factor C Endotoxin Testing Assay. TFDJ [internet]. 2025 Feb. 27 [cited 2026 Jan. 19];32(1):18-32. available from: https://he01.tci-thaijo.org/index.php/fdajournal/article/view/277535
Section
Research Articles

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