C. Rambabu

A simple, rapid, sensitive reverse-phase high-performance liquid chromatography method was developed and validated for simultaneous estimation of ofloxacin and ornidazole, at single wavelength of 343nm.chromotographic separation was performed on an enable aligent zorabax(thermo) column(250nmx4.6mm ID particle size 5 um) and a  mobile phase consisting of acetonitrile and buffer (600:4300v/v) at a flow rate of 1.0ml/min. the calibration curve was linear(r2≥0.0999) over the concentration range. 400-1200μg/mL of ofloxacin and 1000-3000μg/mL of ornidazole. the limit of detection 0.00246µg/ml  for ofloxacin  0.00508µg/ml for ornidazole and no interference was found by the excipients in the synthetic mixture. The proposed methods were validated for international conference on harmonization guideline for linearity, accuracy, precision, and robustness for estimation of ofloxacin and ornidazole in bulk and synthetic mixture, and The results were found to be satisfactory

The present paper describes the development and validation of novel chiral HPLC method for the enantiomeric separation of S-Levosimendan from R-Levosimendan and quantitative determination of S-Levosimendan enantiomer in Levosimendan bulk drugs. The enantiomers of levosimendan were baseline resolved on normal phase chromatographic separation on Amylose tris (3,5-dimethylphenylcarbamate) immobilized on 5μm silica-gel-Based Chiral Stationary Phase, Chiral pak IA column (250mm ×4.6mm i.d.; particle size,5μ) at a temperature of 30°C using a mobile phase consisting of MTBE:Ethanol:TFA (650 : 350 : 1.0, v/v/v) at a flow rate of 1.0mLmin-1 with an injection volume of 10μL. Quantitation was achieved with UV detection at 383nm based on peak area with linear calibration curves. The elution times of S-Levosimendan and R-Levosimendan were 6.8 min and 11.0 minutes respectively. In this proposed chiral HPLC method, the resolution between S-Levosimendan and R-Levosimendan was found to be greater than 8.0. The developed method was validated with respect to linearity, accuracy, precision, solution stability, ruggedness, robustness, limit of detection and limit of quantification. The recovery obtained for S-isomer was in between 99.1 % and 107.9%. The detection limit obtained for S-isomer was 0.025μg.mL-1 and the quantification limit was 0.075μg.mL-1 respectively. Linearity was performed for the S-isomer from LOQ to 150%. The correlation coefficient obtained for S-isomer was more than 0.999. The solution stability of Levosimendan bulk drug was determined and the compound was found to be stable up to 48 hrs. As the method has less run time (20 min), it can be useful in quality control laboratories for routine analysis.

A simple, accurate and precise HPLC method for the estimation of memantine in bulk and pharmaceutical dosage form has been reported. Chromatography was performed with Shimadzu HPLC equipment comprising an LC-10A VP quaternary pump, a variable-wavelength programmable UV–visible detector, an SPD-10AVP column oven, and an SCL 10AVP system controller. A Rheodyne injector fitted with a 20μL loop was also used and data were recorded and evaluated using Class-VP 5.032 software. The Compound was separated, at ambient temperature (25 ± 2°C), on a  BDS C18, ( 4.6 mm i.d x 250 mm, 5μm reversed phase column with 100% methanol as mobile phase at a flow rate of 1.0mL.min−1. Before use, the mobile phase was filtered through a 0.22-μm Nylon filter. UV detection was performed at 274nm. A linear response was observed in the concentration ranges of 5-25μg/ml with a regression coefficient of 0.9999. The method was then validated for different parameters as per the ICH guidelines. This method can be used for the determination of memantine in quality control of formulation without interference of the excipients.