Identification Of Major Degradation Products Research Articles

Identification of major degradation products of Clorsulon drug substance including its degradation pathways by high resolution mass spectrometry and NMR

Clorsulon is an effective anthelmintic drug substance extensively used in the treatment of parasitic infestations in both cattle and sheep. An in-depth investigation of Clorsulon’s degradation products (DPs) was carried out through forced degradation study to comprehend its degradation path. A total of eight degradation products were separated under various stress degradation conditions. Structural elucidation of these DPs was conducted using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS), and their fragmentation patterns were compared to that of the parent compound. Adequate amount of DP-4 was isolated and purified by semi-preparative high-performance liquid chromatography (HPLC) methods. Subsequently, it was examined in detail using both 1D and 2D NMR (nuclear magnetic resonance spectroscopy). Most probable mechanistic pathways for the formation of degradation products under various stress degradation conditions were proposed to better understand the degradation profile. Based on the results of the stress study, Clorsulon drug substance was found to be unstable under photolytic and oxidative conditions. Understanding Clorsulon's degradation pathway is essential for determining shelf-life prediction of the finished product, safety and efficacy assurance, and guiding the development of stable, high-quality formulations.

LC-MS-Compatible Chromatographic Method for Quantification of Potential Organic Impurities of Elagolix Sodium in Tablet Dosage Form with Identification of Major Degradation Products.

Elagolix is a gonadotropin-releasing hormone (GnRH) modulator and used for pain relief from endometriosis. The present research was performed to develop and validate a simple, novel, fast, sensitive, and cost-effective LC-MS-compatible chromatographic method for quantification of all prominent organic impurities of elagolix sodium in tablet formulation with identification of major degradation products. The optimum separation of the organic impurities of elagolix sodium was achieved on an ACE C18-PFP (250 mm × 4.6 mm, 5 µm) column by employing pH 5.6 acetate buffer-acetonitrile (95 + 5, by volume) as mobile phase A, and acetonitrile-methanol (90 + 10, by volume) as mobile phase B. UV detection of the drug and impurities was carried out at 210 nm. A forced degradation study was carried out by employing acid, alkali, oxidative, thermal, and photolytic stress conditions on elagolix sodium drug substance and its drug product. The major degradation products observed during the stress study were identified by using mass spectrometry. Elagolix sodium and its prominent organic impurities were resolved in the developed method through a gradient elution program of 46 min at a flow rate of 1.3 mL/min. Significant degradation was observed during alkali hydrolysis and oxidative stress conditions with a mass balance of more than 97.0%. The method was validated in line with present International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Q2(R1) guidelines. The forced degradation study suggested that the developed method is specific and stability-indicating and can be used for related substance analysis of elagolix drug substance and its dosage forms. This is the first research paper which describes a simple and sensitive (LOD 0.08 µg/mL) HPLC method for quantification of all probable impurities of elagolix in tablet dosage forms. The noticeable feature of the developed method is resolution of impurities of similar structures in a short time using routine solvents which are easily available in the QC laboratory.

Study on the forced degradation behaviour of ledipasvir: Identification of major degradation products using LC–QTOF–MS/MS and NMR

Ledipasvir, a novel NS5A inhibitor is used in the management of hepatitis C virus infections. The drug was subjected to forced degradation studies as per the conditions prescribed in ICH Q1 (R2) guideline. Ledipasvir degraded in hydrolytic (acid, alkaline and neutral) and oxidative stress conditions. The drug was found to be stable in thermal and photolytic conditions. Eight novel degradation products were obtained and were well separated using an HPLC C18 stationary phase (150×4.6mm, 5μm) and mobile phase composed of formic acid/acetonitrile in gradient elution mode. All the degradation products were characterised using tandem mass spectrometry with a time-of-flight analyser and the major degradation products of hydrolytic and oxidative stress were isolated and their structural confirmation was studied using 1H and 13C NMR. A well resolved chromatographic method proposed in this study suggests that the proposed analytical method finds its application as a stability indicating assay method for the drug and can be used in routine analysis.

Identification of Major Degradation products of Ketoconazole

Analytical methods were developed for the identification of major degradation products of Ketoconazole, an antifungal agent. The stressed degradation of Ketoconazole drug substance was performed under acid, base, thermal, photo and oxidative stress conditions. The major degradation was observed under acid, base and oxidative stress conditions. The degradation study was performed on Inertsil ODS-3V, length 100 X diameter 4.6 mm, particle size 3 μm column using gradient method. These degradants were identified by LC-MS technique.

Identification of major degradation products of 5-aminosalicylic acid formed in aqueous solutions and in pharmaceuticals

The formation of four major degradation products of 5-aminosalicylic acid (5-ASA) in buffered solutions at pH 7.0 was demonstrated by gradient HPLC analysis. The isolation and structural elucidation of the resulting degradation products showed that the degradation of 5-ASA led to the formation of polymeric species by oxidative self-coupling of 5-ASA moieties. These results indicate that the degradation of 5-ASA follows the same mechanism as observed for the autooxidation of 4-aminophenol and 1,4-phenylenediamine. Some of the identified degradation products were found in 5-ASA-containing pharmaceuticals, which had not been stored as prescribed, but in diffuse daylight for up to 2 years.