Recently, two departments of the China National Institute for Food and Drug Control (also a national key laboratory for drug regulatory science, a key laboratory for biotechnology product testing methods and standardization of the National Health Commission, and a key laboratory for quality research and evaluation of biological products of the National Medical Products Administration) jointly published experimental research articles in the second issue of the Journal of Pharmaceutical Research in 2025Determination of Particle Size of Human Papillomavirus like Particles by Resistance Method.

Researchers from the Central Inspection Institute adopted a method based onResistance methodResistance Pulse Induction (RPS) technologyNanoCoulter Particle Size AnalyzerMeasure and analyze the particle size of virus like particles (VLP) samples in the raw material of human papillomavirus (HPV) vaccine, and analyze them fromAccuracy, precision, and repeatabilityMethodological validation was conducted for each dimension separately. The author concludes through data validation that:

• The measurement results of the resistance method have good accuracy, and the instrument has good performance and stability.

• The resistance method measurement results have good precision (RSD=0.5%).

• The resistance method has good sample repeatability (RSD=1.74%).

• The particle size resolution of the resistance method is higher than that of the dynamic light scattering (DLS) method and is considered to be the highest resolution method.

• Compared with the DLS method, the results obtained by the resistance method are relatively stable with less fluctuation. The resistance method can maintain the stability of (particle size) detection results even at low sample concentrations.

• The DLS method detects the hydration particle size, but the result is relatively large; The results of measuring particle size using the resistance method are comparable to electron microscopy detection and also close to the actual virus particle size.

• By using the resistance method to detect the particle size changes of VLPs, the aggregation state of VLP particles can be detected, thereby monitoring their quality status.

Finally, the author concludes that the resistance based detection of VLP particle size using HPV vaccine particles as a model can achieveFast, simple, accurate, and with good reproducibility, its results are comparable to those of negative staining electron microscopy.Resistance can effectively control the quality of VLP particlesThat's right

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