Identification of stress degradation products of iloperidone using liquid chromatography coupled with an Orbitrap mass spectrometer

An Overview of Advances in the Chromatography of Drugs Impurity Profiling

A systematic literature survey published in several journals of pharmaceutical chemistry and of chromatography used to analyze impurities for most of the drugs that have been reviewed. This article covers the period from 2016 to 2020, in which almost of chromatographic techniques have been used for drug impurity analysis. These chromatography techniques are important in the analysis and description of drug impurities. Moreover, some recent developments in forced impurity profiling have been discussed, such as buffer solutions, mobile phase, columns, elution modes, and detectors are highlighted in drugs used for the study. This primarily focuses on thorough updating of different analytical methods which include hyphenated techniques for detecting and quantifying impurity and degradation levels in various pharmaceutical matrices.

Identification and characterization of degradation products of indacaterol using liquid chromatography/mass spectrometry

Indacaterol (IND), 5-[2-[(5,6-Diethyl-2,3-dihydro-1H-inden-2-yl)amino]-1-hydroxyethyl]-8-hydroxyquinolin-2(1H)-one, is an active pharmaceutical ingredient (API) which is used to treat chronic obstructive pulmonary disease (COPD). We followed the International Council for Harmonization (ICH) guide lines to study the degradation behavior of IND under various stress conditions. Stressed degradation of the drug was performed under hydrolytic (alkaline, acidic and neutral), photolytic, oxidative and thermal conditions. Identification and characterization of IND and its forced degradation products (DPs) were demonstrated by using LC-HRMS and MS/MS method. A total of three DPs (DP1-DP3) were identified and characterized. The IND was found to be stable under photolytic, oxidative and thermal conditions, whereas it produced three DPs in acidic, basic and neutral hydrolytic stress conditions.

Development and Validation of a Stability Indicating LC-MS/MS Method for the Determination of Clenbuterol HCl

Clenbuterol hydrochloride (CLT), β₂ adrenergic agonist is used as a bronchodilator in the therapeutic treatment of asthma. It is important to know the stability behaviour of the drug in different degradation conditions as per ICH Q1A (R2) guidelines for safety and efficacy purpose. The main objective of the study is to develop and validate stability indicating LC-MS/MS method for the determination of Clenbuterol HCl. The separation was achieved using Phenomenex Gemini NX C18 (250*4.6 mm, 5 μ) column and the mobile phase consisting of ammonium acetate buffer (5 mM), 0.15% triethylamine (TEA), pH 7.5 with acetic acid: methanol (70:30, v/v) at flow rate 1 ml/min. The detection was done using PDA detector at 245 nm. The validation was performed as per ICH Q2 (R1) guideline. The drug was subjected to stress degradation conditions as per ICH Q1A (R2) guidelines. The significant degradation was observed in acidic (8.78%) and sunlight (liquid) (9%) condition while no degradation was observed in neutral, basic, oxidation and thermal condition. The drug and its degradation products were characterized using LC-MS/MS and the proposed degradation mechanism was communicated. The developed method was found to be stability-indicating, simple, specific, selective, sensitive, linear, accurate, robust and precise and used as a routine analysis in quality control laboratory.

Study of degradation behavior of besifloxacin, characterization of its degradation products by LC-ESI-QTOF-MS and their in silico toxicity prediction

Knowledge and understanding of the stability profile of a drug is important as it affects its safety and efficacy. In the present work, besifloxacin, a new, fourth-generation fluoroquinolone antibiotic, was subjected to different forced-degradation conditions as per International Conference on Harmonization (ICH) guidelines such as hydrolysis (acid, base and neutral), oxidation, thermal and photolysis. The drug degraded under acidic, basic, oxidative and photolytic conditions while it was found to be stable under dry heat and neutral hydrolytic conditions. In total, five degradation products (DPs) were formed under different conditions-DP1 and DP2 (photolysis), DP3 (oxidation), DP4 (acidic), DP3 and DP5 (basic). The chromatographic separation of besifloxacin and its degradation products was achieved on a Sunfire C₁₈ (250 mm × 4.6 mm, 5 μm) column with 0.1% aqueous formic acid-acetonitrile as a mobile phase. The gradient RP-HPLC method was developed and validated as per ICH guidelines. The degradation products were characterized with the help of LC-ESI-QTOF mass spectrometric studies and the most likely degradation pathway of the drug was proposed. In silico toxicity assessment of the drug and its degradation products was carried out, which indicated that DP3 and DP4 carry a mutagenicity alert.

Characterization of degradation products of macitentan under various stress conditions using liquid chromatography/mass spectrometry

RATIONALE

Stress testing of a drug candidate is an important step in the drug discovery and development process. The presence of degradation products in a drug affects the quality as well as the safety and efficacy of drug formulation. Hence, it is essential to develop an efficient analytical method which could be useful for the separation, identification and characterization of all possible degradation products (DPs) of a drug. Macitentan (MT) is an endothelin receptor antagonist (ERA) drug used to treat high blood pressure in the lungs. Comprehensive stress testing of MT was carried out as per ICH guidelines to understand the degradation profile of the drug.

METHODS

MT was subjected to various stress conditions such as acidic, basic, neutral hydrolysis, oxidation, photolysis and thermal conditions; and the resulting degradation products were investigated using liquid chromatography/diode-array detection/electrospray ionization high-resolution mass spectrometry (LC/DAD/ESI-HRMS) and tandem mass spectrometry (MS/MS) techniques. An efficient and simple ultra-high-performance liquid chromatography (UHPLC) method has been developed using an Accucore C18 column (4.6 × 150 mm, 2.6 μm) using a gradient elution of 5 mM ammonium formate and acetonitrile as mobile phases.

RESULTS

MT was found to degrade under acid and base hydrolysis stress conditions; whereas it was stable under oxidation, neutral hydrolysis, thermal and photolytic conditions. MT formed nine DPs (DP1 to DP9) and one DP (DP10) under acidic and basic hydrolytic conditions, respectively. All the degradation products (DP1 to DP10) were identified and characterized by LC/MS/MS in positive ion mode with accurate mass measurements.

CONCLUSIONS

MT was found to be labile under hydrolytic conditions. The structures of the DPs were characterized by appropriate mechanisms. The proposed method can be effectively used for the characterization of MT and its DPs.

Characterization of forced degradation products of canagliflozine by liquid chromatography/quadrupole time-of-flight tandem mass spectrometry and in silico toxicity predictions

RATIONALE

Forced degradation studies are useful for better understanding of the stability of active pharmaceutical ingredients and drugs and to generate information about drug degradation pathways and formation of degradation products (DPs). Identification of DPs plays a vital role in establishing the safety and therapeutic benefit of a drug.

METHODS

Canagliflozin (CAN) was subjected to different stress conditions as per International Conference on Harmonization guidelines (Q1A R2). All the DPs and the drug were well separated on an Aquity CSH C₁₈ (100 × 2.1 mm, 1.7 μm) column using acetonitrile-methanol (70:30, v/v) and formic acid in gradient mode. The same UPLC method was employed for LC/HRMS for the characterization of DPs. In addition, in silico toxicity was predicted for all the DPs by using TOPKAT and DEREK software tools.

RESULTS

CAN was found to degrade under oxidative stress condition and formed DP1 and DP2. This is a typical case of degradation where co-solvents acetonitrile-water (50:50, v/v) and methanol-water (50:50, v/v) react with CAN under acid hydrolytic conditions leading to the formation of pseudo-DPs, DP3 and DP4, respectively. Among these, DP2 and DP3 showed ocular irritancy whereas DP1 showed skin sensitization.

CONCLUSIONS

The drug was labile under oxidative stress condition. CAN reacted with co-solvent under acid hydrolytic conditions and gave pseudo-DPs. All the DPs were separated using UPLC and characterized by LC/QTOF/MS/MS. Toxicity of DPs was evaluated using TOPKAT and DEREK software tools.