In the present study, a sensitive and fully validated liquid chromatography with mass spectrometry method was developed for the quantification of three potential genotoxic impurities in rabeprazole drug substance. The separation was achieved on Symmetry C18 column (100 × 4.6 mm, 3.5 μm) using 0.1% formic acid in water as mobile phase A and acetonitrile as mobile phase B in gradient elution mode at 0.5 mL/min flow rate. Triple quadrupole mass detection with electrospray ionization was operated in selected ion recording mode for the quantification of impurities. The calibration curves were demonstrated good linearity over the concentration range of 1.0-4.5 ppm for O-phenylenediamine, 1.8-4.5 ppm for 4-nitrolutidine-N-oxide and 1.0-4.5 ppm for benzyltriethylammonium chloride with respect to 10 mg/mL of rabeprazole. The correlation coefficient obtained in each case was >0.998. The recoveries were found satisfactory over the range between 94.22 and 106.84% for all selected impurities. The method validation was carried out following International Conference on Harmonization guidelines, from which the developed method was able to quantitate the impurities at 1.0 ppm for O-phenylenediamine, 1.8 ppm for 4-nitrolutidine-N-oxide and 1.0 ppm for benzyltriethylammonium chloride. Furthermore, the proposed method was successfully evaluated for the determination of selected impurities from bulk drug and formulation samples of rabeprazole within the acceptable limits.
Drug discovery is a highly complicated, tedious and potentially rewarding approach associated with great risk. Pharmaceutical companies literally spend millions of dollars to produce a single successful drug. The drug discovery process also need strict compliance to the directions on manufacturing and testing of new drug standards before their release into market. All these regulations created the necessity to develop advanced approaches in drug discovery. The contributions of advanced technologies including high resolution analytical instruments, 3-D biological printing, next-generation sequencing and bioinformatics have made positive impact on drug discovery & development. Fortunately, all these advanced technologies are evolving at the right time when new issues are rising in drug development process. In the present review, we have discussed the role of genomics and advanced analytical techniques in drug discovery. Further, we have also discussed the significant advances in drug discovery as case studies.
Potential genotoxic impurities in pharmaceuticals at trace levels are of increasing concern to both pharmaceutical industries and regulatory agencies due to their possibility for human carcinogenesis. Molecular functional groups that render starting materials and synthetic intermediates as reactive building blocks for small molecules may also be responsible for their genotoxicity. Determination of these genotoxic impurities at trace levels requires highly sensitive and selective analytical methodologies, which poses tremendous challenges on analytical communities in pharmaceutical research and development. Experimental guidance for the analytical determination of some important classes of genotoxic impurities is still unavailable in the literature. Therefore, the present review explores the structural alerts of commonly encountered potential genotoxic impurities, draft guidance of various regulatory authorities in order to control the level of impurities in drug substances and to assess their toxicity. This review also describes the analytical considerations for the determination of potential genotoxic impurities at trace levels and finally few case studies are also discussed for the determination of some important classes of potential genotoxic impurities. It is the authors' intention to provide a complete strategy that helps analytical scientists for the analysis of such potential genotoxic impurities in pharmaceuticals.
A sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the simultaneous determination of darunavir, ritonavir and tenofovir in human plasma. Sample preparation involved a simple liquid-liquid extraction using 200 μL of human plasma extracted with methyl tert-butyl ether for three analytes and internal standard. The separation was accomplished on an Acquity UPLC BEH C18 (50 mm x 2.1 mm, 1.7 μm) analytical column using gradient elution of acetonitrile/methanol (80:20, v/v) and 5.0 mM ammonium acetate containing 0.01% formic acid at a flow rate of 0.4 mL/min. The linearity of the method ranged between 20.0 and 12 000 ng/mL for darunavir, 2.0 and 2280 ng/mL for ritonavir, and 14.0 and 1600 ng/mL for tenofovir using 200 μL of plasma. The method was completely validated for its selectivity, sensitivity, linearity, precision and accuracy, recovery, matrix effect, stability, and dilution integrity. The extraction recoveries were consistent and ranged between 79.91 and 90.04% for all three analytes and internal standard. The method exhibited good intra-day and inter-day precision between 1.78 and 6.27%. Finally the method was successfully applied for human pharmacokinetic study in eight healthy male volunteers after the oral administration of 600 mg darunavir along with 100 mg ritonavir and 100 mg tenofovir as boosters.