An accurate, precise, robust and sensitive method was developed for residual solvents determination by fast static headspace gas chromatography (HSGC) with flame ionization detector in Imatinib Mesylate API. Residual solvents in drug substances are quantified using gas chromatography with headspace. As per regulatory guidelines, residual solvents must be controlled for release any batches of active pharmaceutical ingredients (API). This paper includes the development and validation of HSGC method for the determination of residual solvents specifically methanol, acetone, dichloromethane, n-hexane, ethyl acetate and pyridine in Imatinib Mesylate API. Imatinib Mesylate is a specific inhibitor of BCR-ABL tyrosine kinase. DB-624 capillary column, 30 m long × 0.53 mm internal diameter, the 3 µm film thickness was used for analysis. To minimize degradation, injector temperature was set at 170 °C. The initial oven temperature was kept at 35 °C for 2 min and used ramp 1 at a rate of 4 °C min −1 to temperature of 80 °C hold for 0 min and used ramp 2 at a rate of 40 °C min −1 to a final temperature of 230 °C for 12 min hold time. Nitrogen was selected as a carrier gas. 1-Methyl-2-Pyrrolidinone (NMP) was used as a sample solvent. The method can be readily used to determine defined residual solvents present in a various range of APIs, intermediates, excipients and drug products.

An accurate, fast, precise and economic gradient reverse phase high performance liquid chromatographic (RP-HPLC) method was developed for quantitative determination of process and degradation related impurities in the solid dispersion of dasatinib drug substance. The optimum separation was achieved by Sunniest C18, 250 x 4.6 mm, 5 µm column at 35 °C. The mobile phase A was 20 mM ammonium acetate buffer (pH 5.0) and mobile phase B was composed of methanol:buffer:acetonitrile (90:5:5) (%, v/v/v); the chromatographic analysis was performed with gradient condition detecting the related substances at wavelength 310 nm at flow rate of 1.2 mL/min. The resolution for dasatinib and six related components was found to be greater than 2.0 for any pair of impurities. The stability indicating nature of the method was demonstrated by performing force degradation studies. Significant degradation was observed when the solid dispersion of dasatinib was subjected to oxidation, thermal and photo degradation, while the drug substance was stable in acid and alkali degradation. Relative standard deviation obtained for the system precision and method precision studies was less than 5%. The accuracy of the method was demonstrated by performing recovery studies through spiking studies. The developed method was validated for linearity, specificity, accuracy, precision, limit of detection, limit of quantitation and robustness studies; it can be used in quality control for commercialization of solid dispersion of dasatinib drug substances and performing stability studies.

Forced degradation study is a systemic characterization of degradation products of active pharmaceutical ingredient (API) at conditions which posses more harsh environment that accelerates degradation of API. Forced degradation and stability studies would be useful in selection of proper, packaging material and storage conditions of the API. These are also useful to demonstrate degradation pathways and degradation products of the API and further characterisation of the degradation products using mass spectrometry. TGR5 is a G protein-coupled receptor, activation of which promotes secretion of glucagon-like peptide-1 (GLP-1) and modulates insulin secretion. The potent and orally bioavailable TGR5 agonist, ZY12201, shows activation of TGR5 which increase secretion of GLP-1 and help in lowering blood glucose level in animal models. Hence it is necessary to establish and study degradation pathway and stability of API for better handling and regulatory approval. Force degradation studies of ZY12201 have shown presence of one oxidative impurity during oxidative degradation in HPLC analysis. The oxidized product is further characterized by LC–MS to elucidate structure of impurity and characterize its degradation pathway.

Hydrazine hydrate has genotoxic effect in nature and so it should be controlled down as Potential Genotoxic Impurity (PGI). Being polar molecule, hydrazine hydrate (N2H4.H2O) has no chromophores present in structure which can follow Lambert beer law, thus it is difficult to analyze. The present work described an accurate and highly sensitive reversed-phase liquid chromatography-UV derivatization method for determination of hydrazine in imatinib mesylate drug substance. The method of quantification was developed by attaching chromophores to hydrazine with derivatization, which helped to increase sensitivity. The derivatization of hydrazine hydrate was performed using 1% methanolic solution of benzaldehyde which acts as derivatizing agent. The derivatized product 1,2-dibenzylidenehydrazine gives maximum absorbance at 300 nm and at this wavelength no interference of solvents and other impurities are noted. Limit of detection for developed method was 0.002 μg/g. The developed method was validated to determine hydrazine content and can be used in quality control for commercial batch release of imatinib mesylate drug substances with a genotoxic specification limit level 1.87 μg/g by HPLC.