Determination of Residual Proteins in Sodium Disodium Cantharidinate Injection
Objective:To establish a method for the determination of residual proteins in sodium disodium cantharidinate injection by 2,2,-biquinoline-4,4,-dicarboxylic acid(BCA).Methods:Based on the fact that protein molecules reduce Cu2+to Cu+in alkaline solution,and that 2,2'-biquinoline-4,4'-dicarboxylic acid(BCA)combines with Cu+to form a violet color complex,and that the color depth of BCA is directly proportional to the concentration of proteins in certain range,the results were determined by UV-spectrophotometry with protein control solution as standard curve.The protein content in the test material was determined by UV-spectrophotometry using the protein control solution as the standard curve.The results showed good linearity(R=0.997 9)in the range of 20~100 pg for protein,with a precision RSD of 1.6%,a stability RSD of 3.2%,a reproducibility RSD of 3.2%,and an average recovery of 93%with an RSD of 1.3%(n=9).Conclusion:This method has strong specificity,good precision and stability,high accuracy,and can be used as a method for the determination of protein content in sodium disodium cantharidinate,to ensure the safety of medication and to pay attention to whether the manufacturer's process is reasonable and to establish a standard for the detection of protein residues in sodium disodium cantharidinate in order to carry out the quality control of sodium disodium cantharidinate in a more scientific way.