Development of identification test methods for triptorelin acetate and goserelin acetate substances using NMR spectroscopy

The work is a continuation of the research on the use of NMR spectroscopy in the quality control of natural peptide hormone-based active substances and their synthetic analogues. The aim of the paper was to develop identification test methods for triptorelin acetate and goserelin acetate substances using NMR spectroscopy that does not require reference standards ‒ with the aim of using the newly developed test methods in pharmacopoeial analysis. Materials and methods: the procedure was developed using two-dimensional NMR spectroscopy (1H-1H gCOSY, 1H-13C gHSQC, 1H-13C gHMBC). Results: thestudy made it possible to assign 1H and 13C NMR signals to a specific molecular fragment, and to determine the amino acid composition of each oligopeptide. Conclusions: the authors drew up a table showing structural assignment of NMR signals, which makes it possible to use the NMR method for identification testing of triptorelin acetate and goserelin acetate substances without the use of pharmacopoeial reference standards. The study helped to determine the optimal temperature conditions for recording 13C NMR spectra (27 °С and 50 °С for triptorelin acetate and goserelin acetate, respectively). It was demonstrated that 13C NMR spectroscopy could be used for identification testing in pharmacopoeial analysis.