LC-MS

A new, simple, accurate and sensitive method was developed for the quantification of two potential genotoxic impurities 1-(2-methyl-5-nitro-phenyl)guanidine nitrate and  N-(2-methyl-5-nitro-phenyl)-4-(3-pyridyl)pyrimidin-2-amine at low level (2 ppm) in Imatinib using liquid chromatographic mass spectrometry. The chromatographic separation was achieved on Kromasil 100-3.5-C18 (150 x 2.1) mm column with gradient programme and elution was monitored by mass spectrometer in selective ion monitoring mode using electrospray ionization. The LOD and LOQ values found to be 0.2 ppm and 0.6 ppm for both the impurities with respect to the test concentration 5 mg/ml. The method was linear (r2>0.99), precise (RSD

A novel, simple and rapid reversed-phase liquid chromatography mass spectrometric method (LC-MS) was developed and subsequently used for the characterization of Drotaverine hydrochloride (DRH) and its impurities. The separation was achieved in 22 minutes on Merck Purosphere STAR RP-18e (250 x 4.6) mm, 5 µm column in gradient mode with flow rate 1.5 mL/min. 0.05 M ammonium acetate buffer pH 3.0 and a mixture of acetonitrile and methanol 85:15 v/v  was used as mobile phase A and mobile phase B, respectively. Detection was carried out at the optimum wavelength of 280 nm using a photodiode array/triple quadrupole mass detectors. The retention time of Drotaverine was found about 7 minutes. Specificity of the method was established by blank solution and the extreme degraded sample was used for the detection of impurity masses. The impurities detected under mass detector were further ionized for their daughter ions.

This paper deals with the development and validation of stability indicating an isocratic high performance liquid chromatographic method for the quantitative determination of memantine hydrochloride. The method is simple, highly sensitive, selective and is capable of quantitative determination of memantine hydrochloride. The chromatographic separation is achieved by injecting 20µL standard solution of memantine hydrochloride into HPLC system with refractive index detector using a YMC ODS-AQ, 5µm (150 x4.6)mm column. The mobile phase consists of 10 mL Triethylamine in 1L water(pH 5.5 adjusted with glacial acetic acid):MeOH in the ratio of  40:60 v/v. The flow rate was set at 0.9 ml/min with column and cell temperatures at 40˚C and 50 ˚C respectively and runtime was optimized to 10 min. Forced degradation studies were performed on bulk sample of memantine hydrochloride using acid (5.0Nhydrochloric acid) ,alkali (1.0N sodium hydroxide),oxidation (30% hydrogen peroxide),thermal(105 ˚C),photolytic and humidity conditions. The peak purity was checked with LC-MS and LC-MS/MS. The developed LC method was validated with respect to specificity, precision, linearity, ruggedness, stability of analytical solution and robustness.