Establishment of Ph. Eur. Somatropin/desamidosomatropin resolution mixture Chemical Reference Substance batch 2

The control of somatropin products according to the monographs of the European Pharmacopoeia (Ph. Eur.) requires a system suitability preparation for the test for related proteins by liquid chromatography. A preparation consisting in a mixture of somatropin and desamidosomatropin, such as the Ph. Eur. Somatropin/desamidosomatropin resolution mixture Chemical Reference Substance (CRS), is to be used to ascertain adequate resolution of the chromatographic setup. Due to low stocks, the Biological Standardisation Programme (BSP) of the Council of Europe and the European Union ran a study to establish a new batch of this system suitability CRS. A freeze-dried candidate batch (cCRS2) was produced and tested at the European Directorate for the Quality of Medicines and HealthCare (EDQM, Council of Europe). The resolution between the peaks due to somatropin and desamidosomatropin was 1.7 and the symmetry factor for the somatropin peak was 1.2. The mean percentage area of the desamidosomatropin peak was 14.6 %. These results showed that cCRS2 is suitable for its intended purpose. Based on these data, in May 2020 the Ph. Eur. Commission established the candidate batch as Ph. Eur. Soma-tropin/desamidosomatropin resolution mixture CRS batch 2.