A Simple Rapid HPLC‐UV Method for Assessing C‐Terminal Arginine Content in Darbepoetin Alfa

Upon the development of biosimilar drugs, the structural, physical-chemical, and functional similarity to the original drug should be ensured. We have proposed a simple and rapid HPLC-UV method for assessing the content of C-terminal Arg¹⁶⁶ in darbepoetin alfa samples, in particular after their isolation from the culture fluid. All the stages of the described method (from the sample extraction to obtaining a chromatographic profile) take about 5 h. The proposed approach will be useful for laboratories developing a technology for producing recombinant darbepoetin alfa, to assess the quality of the product, and for subsequent optimization of the production process.