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 Arg 166 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.