P.V.V.Satyanarayana

A simple, accurate and stability indicating high performance liquid chromatographic (HPLC) method was developed for the simultaneous estimation of Torsemide and Spironolactone in combined dosage form. Isocratic RP-HPLC separation was achieved on Kromasil RP- C18 column (250mm×4.6mm; 5µm) using methanol: acetonitrile: water in the ratio of 50:30:20 (v/v), pH6.8, at flow rate of1.0ml/min at ambient temperature. Quantization was achieved by UV detection at 235nm over the concentration range of 10-60μg/ml for torsemide and 25-150μg/ml for spironolactone with percentage recoveries of range 99.688-101.792 and 98.282-101.811for torsemide and spironolactone respectively. Different stress degradation studies like acidic, alkaline, peroxide, thermal etc were measured for both standard drugs and results found that the stress degradation conditions doesn’t affect the elution of the both the drugs and hence the developed method was found to be stability indicating method.

An accurate, simple and precise RP-HPLC method for the simultaneous estimation sulfadiazine and trimethoprim in pharmaceutical formulations was developed and validated. Chromatographic separation of two drugs was achieved on PEAK 7000 isocratic HPLC with rheodyne manual sample injector by using the mobile phase consisting of methanol, water and aceticacid in the ratio 70:25:05 (v/v/v) at a flow rate of 1mL/min and the wavelength of detection was at 237 nm. The retention time for sulfadiazine and trimethoprim were found to be 4.24 and 7.25 min respectively. The linearity of the method was tested over a concentration range of 41-287 µg/mL for sulfadiazine and 9-63 µg/mL for trimethoprim and the correlation coefficient was 0.999 for sulfadiazine and 0.998 for trimethoprim which is almost equal to 1. The limit of quantification was 3.5 μg/mL for sulfadiazine and 1 μg/mL for trimethoprim and the limit of detection was 1 μg/mL for sulfadiazine and 0.3 μg/mL for trimethoprim. The percentage recoveries were ranged from 98.64-101.64 for sulfadiazine and 98.56-100.86 for trimethoprim.

An isocratic, reversed phase-HPLC method was developed and validated for the quantitative determination of Ofloxacin and Ketorolac Tromethamine in combined-dosage form. A thermo hypersil BDS C18 (250mmx4.6mm, particle size 5µm) column with mobile phase containing water (pH - 2.8 adjusted with ortho phosphoric acid) and methanol in the ratio of 60: 40, v/v was used. The flow rate was 1.0 mL/min, column temperature was 30°C and effluents were monitored at 241 nm. The retention times of ofloxacin and ketorolac tromethamine were 4.671min and 5.751 min respectively. The correlation co-efficient values for both the ofloxacin and Ketorolac tromethamine were found to be 1. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness. Recovery of ofloxacin and Ketorolac tromethamine in formulations was found to be 100% confirms the non-interferences of the excipients in the formulation. Due to its simplicity, rapidness and high precision, the method can be successfully applied to the estimation of Ofloxacin and Ketorolac tromethamine in combined dosage form.