With the latest in LCMS technology, Chemika has commenced testing of pharmaceutical materials for nitrosamines. Methods have been established for a number of critical small molecule nitrosamines and we have the capability to test for ingredient specific larger molecule nitrosamines.
This capability makes Chemika unique in Australia offering local nitrosamine testing to pharmaceutical manufacturers and researchers, with registrations with both the Australian TGA and US FDA.
Quantitative recoveries have been achieved at the ppb level for the 7 small molecule nitrosamines listed in the FDA Guidance Document “Control of Nitrosamine Impurities in Human Drugs” (NDMA, NDEA, NMPA, NDIPA, NIPEA, NDBA and NMBA). Targeted methods can be developed for nitrosamines which are specific to individual pharmaceutical ingredients, referred to as “nitrosamine drug substance related impurities” or NDSRI’s.
The cornerstone of our approach to nitrosamine testing is the acquisition of a Shimadzu LCMS 8060NX triple quadrupole mass spectrometer. During method development it was found that limits of detection were well below 1 ppb, easily meeting the sensitivity required for nitrosamine testing of pharmaceutical materials.
Example chromatograms of quantitative (black trace) and reference (blue and pink traces) transitions for the two CPCA potency category 1 nitrosamines tested, namely NDEA and NDBA, at concentrations of 1 ppb are shown below. The chromatograms clearly show that the nitrosamines are easily detected, highlighting the sensitivity of the technique.
NDEA
NDBA
A example chromatograms are included below showing NMBA in a 100 µg/L standard solution and a test preparation of laboratory grade ranitidine using the same intensity (y-axis) scale.
100 µg/L standard Solution
Ranitidine Test solution
The chromatogram clearly shows the extremely high level of N-nitroso-dimethylamine in the laboratory grade ranitidine sample. The area of the NDMA in ranitidine is approximately 25x higher than the 100 ppb reference standard, telling us that as expected, NDMA accumulates in ranitidine. The material tested was supplied only as a laboratory chemical so was not controlled for impurity formation as would be expected for a therapeutic good.
Maximum daily intakes for the small molecule nitrosamines are well known and published. Typically less information is available for NDSRIs both for the risk of their formation and their toxicity if formed.
Guidelines have been developed to address both of these unknowns; the risk of formation and risk of genotoxicity. Methods are published in the US FDA guidance document “Recommended Acceptable Intake Limits for Nitrosamine Drug Substance Related Impurities (NDSRIs)” and we welcome to opportunity to work with you to develop a set of maximum permissible limits for your pharmaceutical material.
With more than 25 years of experience in method validation for the pharmaceutical industry, Chemika is highly skilled in implementing validation protocols tailored to your specific needs. We are happy to collaborate with you to design a testing regime that meets the requirements of the TGA and overseas regulatory agencies. Depending on your objectives, methods can be validated for use as fully quantitative control measures or as limit tests to detect impurities in your material.