RESUMO
Objective To analyze and compare two potency assay methods of protamine sulfate.Methods Heparin titration method was according to foreign pharmacopoeia,while biological assay method was according to China pharmacopoeia(2015).Results The absorbance at the end-point was stable at 0.10 mg/mL and 0.15 mg/mL test solutions.The relative standard deviations(RSDs)of potency results were all less than 5%.Three test solutions and volumes of the titrant had a good linear relationship(R2 =1.000).The results of titration method were significantly related to those of biological assay(P=0.013),with similar RSD(P>0.05).However,the potency of titration method were significantly lower than those of biological assay (P=0.045).Conclusion Heparin titration method is good-using,convenient,and need to be applied widely at home.