Method Validation of Cell Proliferation Assay for Filgrastim Potency Testing

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Sompong Sapsutthipas
Jiradej Patchim
Saywarul Jadoonkittinan
Supaporn Phumiamorn


Nowadays, biosimilar filgrastim is being to produce in domestic, quality control of filgrastim products is therefore necessary. The strength examination by using a cell proliferation method is common used in many countries. The study aimed to measure the accuracy of the methods in various parameters which include: specificity, accuracy, precision, linearity, and robustness. The results showed that this method revealed specificity to only filgrastim standard and samples. They were able to trigger the proliferation of adapted M-NSF-60 cells when compared with the formulation buffer. For the accuracy, the relative potency of filgrastim standard at 50, 100, and 150% was analyzed and showed that the %recovery were within the acceptance criteria from 80 to 125%. The precision of the method was less than 25% of GCV. Linearity and range exhibited the r2 = 0.9979 in the suitable range at 50-200% of relative potency. The robustness of the method was tested by modifying the passage numbers of cells and the incubation time. The robustness indicated that the 4 to 20 passage numbers of cells was able to use and incubation time by 27 and 29 hours, whereas %GCV was less than 25% at 95% confidence level (p = 0.11). All of the results confirmed that the cell proliferation method had the specificity, accuracy, precision, and
robustness. It is clear that this method is suitable to use as a standard method for the potency test of filgrastim products.


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