Establishment of validated stability indicating purity method based on the stress degradation behavior of gonadotropin-releasing hormone antagonist (ganirelix) in an injectable formulation using HPLC and LC-MS-QTOF

Abstract

Stress study of a drug substance or pharmaceutical drug product provides a vision into degradation pathways and degradation products of the active pharmaceutical ingredient and helps in interpretation of the chemical structure of the degradation impurities. In the current study, Ganirelix active ingredient presented in the Orgalutran® was stressed with acidic and alkali hydrolysis, photolysis, thermal and oxidation conditions as per the guidelines of International Conference on Harmonization (ICH) Q1A (R2). Ganirelix was found to be labile under thermal and alkali hydrolytic stress conditions, while it was stable to acid hydrolytic, oxidative and photolytic stress. All degradation products were separated with a resolution > 1.5 on a C18 column (2.6 µm, 25 cm×4.6 mm) using a hydrophilic ion pair such as sodium perchlorate, at a concentration <0.04 M. In total, four major degradant impurities were found during stress study. These impurities were fractionated and desalted by flash chromatography for identification of chemical structures. LC-MS-QTOF analysis revealed that two degradation products are diastereomers of Ganirelix, one degradation product is a deamination compound and other degradation product result from the insertion of a new amino acid residue in the Ganirelix peptide sequence. The developed method is sensitive enough to quantify the related substances of Ganirelix at the 0.04% level with that of Ganirelix test concentration.

Identification, synthesis, and characterization of an unprecedented N‐(2‐carboxyethyl) adduct impurity in an injectable ganirelix formulation

“…Hence, GA appeared to be an attractive drug for generic applications, which led us to develop a formulation of GA acetate and subsequently carry out its impurity profiling. Multiple impurities have been previously reported for GA formulations, a majority of which constitute C‐terminal alanine modifications 11–13 . However, during impurity profiling of our formulated GA acetate, a hitherto unknown highly unusual impurity (>0.1%) was generated in the post‐formulation process, which increased in concentration on standing at room temperature.…”

“…Generic formulation mandates impurity profiling of the final product on standing over extended periods at room temperature. After the formulation steps (Figure 1A), we observed two major impurities generated in our formulation, besides other known synthetic impurities, [11][12][13] within a few months. These two major impurity fractions, corresponding to RRT (relative retention time to the GA API) $0.64 and $0.70, were collected using a developed HPLC method (STM-0340) (Figure 2A, Supporting Information Section Ic).…”

“…Multiple impurities have been previously reported for GA formulations, a majority of which constitute C-terminal alanine modifications. [11][12][13] However, during impurity profiling of our formulated GA acetate, a hitherto unknown highly unusual impurity (>0.1%) was generated in the postformulation process, which increased in concentration on standing at room temperature. A trace amount (<0.05%) of this impurity was also found in the mass spectrometry of an RLD sample of GA (batch: U002393, Merck), which escaped previous screening.…”

A New Method for Quantifying Aluminum in Antiperspirant Lotion Using a Differential Refractometer and an HPLC Column Containing a Maleate Functional Group Kumarswamy Ummiti1*, Narayana Reddy Godi2 , Hanimi Reddy Bapatu2

“…The utilization of stress testing can facilitate a more comprehensive comprehension of the degradation products of a medicinal product and the intrinsic stability of its molecule [13][14][15][16][17][18][19][20][21][22][23]. Therefore, both the sample and the placebo were subjected to varying levels of stress, as elaborated upon thereafter.…”

Synthesis and characterization of two potential impurities (des‐ethyl‐Ganirelix) generated in the Ganirelix manufacturing process

“…Generic application of Ganirelix demands chemical and biological profiles of impurities if present in a commercial source. However, synthesizing these two impurities (GA‐I and GA‐II) is relatively more challenging than the other reported common Ganirelix impurities 14 because the Fmoc‐ N ‐ω 1 ‐ethyl‐L/D‐homoarginine (hArg(Et)) and Fmoc‐ N ‐ω 1 , ω 2 ‐diethyl‐L/D‐homoarginine (hArg(Et) 2 ) building blocks (Figure 1C) are not easily accessible from commercial sources. In addition, these derivatives are highly expensive in the market (>600$/g).…”