C.Rambabu

A stability indicating RP-HPLC method was developed for the simultaneous determination of Spironolactone (SRL) and Hydroflumethiazide (HFM) in pharmaceutical dosage form. Inertsil ODS - C18 (250 mm x 4.6 mm, 5 µm) column and mobile phase of methanol: acetonitrile : phosphate buffer in the ratio of 55:40:05 v/v at a flow rate of 1.0 mL/min was used for separation of the components. The components were detected at a wavelength of 221nm using UV detector. The Spironolactone and Hydroflumethiazide were separated at retention time 4.67 and 6.74 min respectively. The developed method was validated in terms of precision, accuracy, linearity, specificity, limit of detection, limit of quantitation. The range of linearity was found to be 5-30 µg/mL for Hydroflumethiazide and 5-30 µg/mL for Spironolactone. The proposed method was applied to study the stability of the drugs under different degradation conditions such as acid, alkali, peroxide, thermal and photo light. The developed method was found to be simple, sensitive and rapid and hence, It can be adopted in any laboratory for quality control analysis.

A simple, rapid, sensitive reverse-phase high-performance liquid chromatography method was developed and validated for simultaneous estimation of Cefixime and linezolid ,at single wavelength of 263nm.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 water(70:30v/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 cefixime and 1200-3600μg/mL of linezolid. the limit of quantification was 9.709µg/ml for Cefixime and  9.482µg/ml  for linezolid no interference was found by the excipients in the synthetic mixture. The proposed methods were validated for international conference on harmonization guidelines for linearity, accuracy, precision, and robustness for estimation of Cefixime and linezolid in bulk and synthetic mixture, and the results were found to be satisfactory

Rapid, accurate, precise and economical UV-Visible spectrophotometric methods were developed for the determination of Oxalamine phosphate (OMP) in bulk and pharmaceutical formulations. These methods (Method-A and Method-B) were based on the formation of colored complexes with Iron (III), o-Phenonthroline (M-A) and Cobalt thiocyanate (M-B). The absorbance concentration of plots were linear over the concentration range 10-60µg/ml (Method-A) and 4-24 µg/ml (Method-B) respectively for both methods with a minimum detection limit (LOD) of 2.059 µg/ml (Method-A) and 0.106 µg/ml (Method-B), limit of quantification (LOQ) of 6.240 µg/ml (Method-A) and 3.240 µg/ml (Method-B) respectively. The absorbance was measured at 482 and 620 nm with use of the cited reagents, respectively. The reactions were extremely rapid at room temperature and absorbance values remain unchanged up to 18hrs. Recoveries were 97.90-102.06%. Interferences of the other ingredients and excipients were not observed. The proposed methods are simple and sensitive and this is the first reported complexometric methods for the determination of Oxalamine phosphate (OMP) in commercial tablets.