Abstract: Objective To interpret the revised guidelines for bacterial endotoxin testing (9251) in Chinese Pharmacopoeia 2025 in order to help make the related testing more precise and feasible. Methods The modifications in the guidelines for bacterial endotoxin testing specified in Chinese Pharmacopoeia 2025 were analyzed. The background for the revision and implications were studied in depth. Results The major revisions included① specifications of endotoxin limits for ophthalmic medications; ②refined limit-setting requirements for raw materials, excipients, and packaging materials; ③ common interferents and ways of removal; ④ detailed descriptions of pretreatment methods for poorly soluble samples and packaging materials; ⑤ descriptions of low endotoxin recovery; ⑥ the specification of the recombinant factor C method as a complementary approach. Conclusion These revisions reflect better standards for pharmaceutical quality control in China and provide more practical technical guidance for professionals, which are of vital importance for quality control of pharmaceuticals.

Key words: Chinese Pharmacopoeia, Bacterial Endotoxin Testing, Guidelines, Revision, Low Endotoxin Recovery, United States Pharmacopeia