ABSTRACT
【Objective】 To investigate the changing pattern of polymer content in the manufacturing process of human immunoglobulin, especially the correlation between pH value and polymer content, so as to provide basis for the control of polymer in human immunoglobulin products. 【Methods】 IVIG and HBIG low pH intermediate samples were taken and their pH values were adjusted to different gradients with 0.5 or 0.1 mol/L HCl. The polymer content was detected by HPLC, and the influence of different pH values on polymer content was observed and analyzed. 【Results】 With low pH value, the polymer content of samples increased from <1% to 10% with the decrease of pH value. When pH value was in the range of 3.85~3.10, the polymer content in the samples increased from 0.38% to 15.5% exponentially with the decrease of pH value. The logarithm of polymer was linearly correlated with pH value. 【Conclusion】 When pH value is low, polymer content of human immunoglobulin is significantly affected by pH value. Keeping pH value above 4.0 during the whole manufacturing process of human immunoglobulin is suggested.