目的 考察使用药用级磷酸盐试剂代替分析纯磷酸盐对脑膜炎球菌多糖疫苗稀释剂的关键质量属性的影响。 方法 采用中国药典2020年版四部方法，对分析纯与药用级的磷酸氢二钠和磷酸二氢钾的pH、水中不溶物、干燥失重等质量属性进行比对分析，然后对使用不同级别磷酸盐配制的疫苗稀释剂的pH和渗透压等关键质量属性进行比对，并考察其稳定性。 结果 2种磷酸盐各质量属性差异均无统计学意义（t=-1.38~1.67，P=0.126~0.954）。使用2种磷酸盐配制的稀释剂的质量差异也无统计学意义（t=0.09~0.26，P=0.376~0.524），均符合中国药典2020年版四部及企业注册质量标准；在25 ℃±2 ℃和60%±5%相对湿度下保存36个月，稳定性良好。 结论 药用级磷酸盐的质量符合法规要求，能保证脑膜炎球菌疫苗稀释剂质量的稳定、可控，可以替代分析纯磷酸盐。

Objective To investigate the effect of replacing analytically pure phosphate with pharmaceutical grade phosphate on critical quality attributes of diluent for meningococcal polysaccharide vaccine. Methods The quality attributes of analytically pure and pharmaceutical grade dibasic sodium phosphate and potassium dihydrogen phosphate, including pH, insoluble matter in water and drying weight loss, were compared and analyzed according to Chinese pharmacopoeia 2020 edition volume 4. The key quality attributes of vaccine diluents prepared with phosphates of different grades were compared and their stability was investigated. Results There was no statistically significant difference in the quality of two phosphates (t=-1.38-1.67，P=0.126-0.954) and diluents produced with two phosphates (t=0.09-0.26，P=0.376-0.524). The quality of both diluents complied with the requirements of Chinese pharmacopocia and standard of enterprise.Both diluents were stable within 36 months storage under 25 ℃±2 ℃ and 60%±5% relative humidity. Conclusion The quality of pharmaceutical grade phosphate meets the regulatory requirements, which can ensure the stable and controllable quality of meningococcal vaccine diluent, and analytically pure phosphate can be replaced.