Carryover analysis by liquid chromatography mass spectrometry in a multiproduct resin reuse context

The reuse of the same chromatography resin to purify multiple products is of high economic and ecologic interest in the pharmaceutical industry. An effective cleaning program to ensure no product carryover from one product to the subsequent is key to enable a multi-product use strategy. The methods utilised to assess product carryover during resin lifetime studies for a given product are not specific enough to detect carryover to support multi?product use. Here the proposed use of liquid chromatography coupled to mass spectrometry (LC-MS) is the analytical method of choice due to its high sensitivity and selectivity. A proof-of-concept study using protein A resin and two distinct IgG product streams produced by CHO cell lines was conducted. The experimental design was developed to determine any carryover from previous products after a multiple product Protein A resin reuse process, using LC-MS and capillary electrophoresis (CE). The capability of LC-MS coupled with bioinformatic analysis to detect carryover where CE with UV detection was not able to detect any carryover was demonstrated. The findings from this approach suggest that the acceptance of chromatographic resin reuse for multiple products will be dependent on the development of analytical/bioinformatics tools such as those proposed in this work.