Review on Implementation of Multivariate Approach for Forced Degradation Study and Impurity Profiling with Regulatory Considerations

An Overview of Degradation Strategies for Amitriptyline

Antidepressant drugs play a crucial role in the treatment of mental health disorders, but their efficacy and safety can be compromised by drug degradation. Recent reports point to several drugs found in concentrations ranging from the limit of detection (LOD) to hundreds of ng/L in wastewater plants around the globe; hence, antidepressants can be considered emerging pollutants with potential consequences for human health and wellbeing. Understanding and implementing effective degradation strategies are essential not only to ensure the stability and potency of these medications but also for their safe disposal in line with current environment remediation goals. This review provides an overview of degradation pathways for amitriptyline, a typical tricyclic antidepressant drug, by exploring chemical routes such as oxidation, hydrolysis, and photodegradation. Connex issues such as stability-enhancing approaches through formulation and packaging considerations, regulatory guidelines, and quality control measures are also briefly noted. Specific case studies of amitriptyline degradation pathways forecast the future perspectives and challenges in this field, helping researchers and pharmaceutical manufacturers to provide guidelines for the most effective degradation pathways employed for minimal environmental impact.

Determination of Three Alkyl Camphorsulfonates as Potential Genotoxic Impurities Using GC-FID and GC-MS by Analytical QbD

Camphorsulfonic acid salts are commonly used in the manufacturing production of active pharmaceutical ingredients (APIs) and have the potential to form alkyl camphorsulfonates, which can be considered as potential genotoxic impurities (PGIs). Alkyl camphorsulfonates should be controlled using the Threshold of Toxicological Concern (TTC) when detected in APIs due to their genotoxicity. An in silico study utilizing the ICH M7 guideline was performed in order to classify the alkyl camphorsulfonates that can be produced from the reaction of camphorsulfonic acid salts with methanol, ethanol, and isopropyl alcohol, which are commonly used solvents in API manufacturing processes. Two sensitive, reproducible, and accurate analytical methods using GC-FID and GC-MS were developed using the analytical Quality By Design (QbD) approaches for the quantitation of three alkyl camphorsulfonates in APIs satisfying the control limit of PGIs according to the TTC. The detection limits of the GC-FID method were found to be between 1.5 to 1.9 ppm, and the detection limits of the GC-MS method were found to be between 0.055 to 0.102 ppm. The method was validated in terms of accuracy, linearity, precision, detection limit, quantitation limit, specificity and robustness.

QBD-driven HPLC method of eltrombopag olamine: Degradation pathway proposal, structure elucidation, and in silico toxicity prediction

Eltrombopag olamine is prescribed for chronic immune (idiopathic) thrombocytopenic purpura (ITP). This work aims to investigate the formation of potential degradants of the drug and determine their toxicity in silico. A stability-indicating high performance liquid chromatography (HPLC) method was developed to separate six oxidative degradation impurities and three thermal degradation impurities employing the quality by design (QBD) approach. The degradation impurities were resolved with minimum resolution of 1.5 using a phenyl column with 0.1 % trifluoroacetic acid (TFA) and acetonitrile as the mobile phase and quantified at 245 nm. The structure and degradation pathway for the degradants was proposed by employing liquid chromatography with tandem mass spectrometry (LC-MS/MS), among the identified degradation pathways demethylation and decarboxylation are common reactions observed during oxidation resulted in majority of degradation products. All the degradation products are characterized with help of the daughter ions and product ion obtained upon LC-MS/MS analysis. The HPLC method parameters such as column temperature, flow rate, TFA concentration and organic concentration are identified as critical method attributes (CMA), a design of experiments (DOE) mediated design space was established through use of design experts. The resolution between sets of adjacent peaks was identified as a critical quality attribute; among the investigated CMAs, column temperature and flow rate significantly affected the resolution. Furthermore, the toxicology of the degradation products was predicted with the help of in silico TOPKAT analysis, the carcinogenicity of the impurities was discussed.

Comprehensive stability-indicating method development of Avanafil Phosphodiesterase type 5 inhibitor using advanced Quality-by-Design approach

Avanafil (AV) is the phosphodiesterase (PDE) type 5 inhibitor drug used in erectile dysfunction, having pyrrolidine, pyrimidine, carboxamide, and chlorine as functional groups which can easily break by environmental changes and cause toxicity. Henceforth, in detail, HPLC stability study with the Quality-by-Design (QbD) approach is presented which leads to recommended storage conditions. The stability of AV was analyzed in hydrolysis, photolysis, and thermal and oxidative conditions. The application of the QbD approach during the stability method development comprises steps as screening and optimization. Quality target product profile (QTPP) was defined, and critical quality attributes (CQAs) were assigned to meet the QTPP requirements. Primary parameters obtained from the Ishikawa diagram were studied via Placket–Burman, and four critical factors were optimized through the central composite design (CCD). The finalized method includes mobile phase [10 mM ammonium acetate, pH 4.5 adjusted by acetic acid:ACN (60:40, v/v)] at 0.9-mL/min flow rate and 239-nm wavelength. A control strategy was set up to ensure that the method repeatedly meets the acceptance criteria. Overall, 16 degradation product peaks of AV in all conditions (solid and solution state) were identified with optimized method and evaluated by HPLC-PDA study. A comprehensive systemic optimization of AV stability study is stated for the first time, which reveals that AV is prone to degrade in sunlight, moisture, and temperature. Global regulators and manufacturers should take care of the packaging, handling, and labeling of AV. A fully validated LC–MS compatible stability method can be successfully applied to monitor AV stability from its formulation which can be wisely extrapolated to assess the AV from biological samples.