Development of a Simultaneous Analytical Method for\nAmines Corresponding to 10 Typical Nitrosamines

Regulatory authorities\nin various countries have successively issued\nnotices and guidance to pharmaceutical manufacturers and distributors\nto evaluate the risk of contamination of nitrosamines in pharmaceutical\nproducts and to take appropriate measures. Analysis of nitrosamines\nin pharmaceutical products is not easy due to the large number of\nforeign substances, and the risk of contamination is determined by\nfirst conducting a desk investigation of the manufacturing process\nof the APIs or pharmaceutical products. However, a desk investigation\nmay miss the risk since this method is not based on actual measurements.\nTherefore, in addition to conventional desk-based investigation, a\nnew method is required to pick up risks that cannot be covered by\na desk investigation. Nitrosamines are known to be formed by the reaction\nof amines with nitrosating agents such as nitrite. In the case of\nsmall alkyl nitrosamines such as NDMA and NDEA, the origin of the\namines is mostly residual amines in the APIs. Residual amines in the\nAPIs are a potential nitrosamine contamination risk, although the\nextent of that risk has rarely been reported. In this study, we developed\nand validated a simultaneous analytical method for amines corresponding\nto 10 typical small alkyl nitrosamines. Good linearity was obtained\nin the range of 0.003 to 10 μg/mL for MPA, 0.003 to 2 μg/mL\nfor DIPA and DBA, 0.003 to 1 μg/mL for MeP, DEA, EIPA, and DPA,\nand 0.003 to 0.2 μg/mL for DMA, MOR, and MBA. The limits of\nquantitation and detection were 0.003 and 0.001–0.003 μg/mL,\nrespectively. The recovery rates ranged from 70 to 130% for 121 APIs\nand were more than 40% for 83 APIs. Repeatability was also good, with\n%RSD < 15%. Although the correlation between the amount of amines\ndetected in the APIs and the nitrosamines in the pharmaceutical products\nis under investigation, we expect that this analytical method will\nbe used to determine the residual amine contents in APIs and contribute\nto the risk assessment of the nitrosamine contamination.