system suitability

In the present study a simple isocratic reverse phase HPLC method was developed for the estimation of rilpivirine in pharmaceutical formulation. The separation was carried out using a column of Zorbax Eclipse XDB-C18, 250x4.6mmi.d with 5micron particle size. The mobile phase comprises of 0.03M di potassium hydrogen orthophosphate with pH adjusted to 2.5 using dilute ortho-phosphoric acid (mobile phase solvent-A) and acetonitrile (mobile phase solvent-B) in the ratio of 15: 85 (v/v).The flow rate was 1.0 ml/min and the effluents were monitored at 284 nm. The retention time was 7.19 min. The detector response was linear in the concentration range of 100-300µg/ml. The respective linear regression equation being Y= 28817.742X-14741.2. The limit of detection (LOD) and limit of quantification (LOQ) for rilpivirine were found to be 0.05µg/ml and 0.15 µg/ml respectively. The assay was found to be 99.85%.The method was validated by determining its accuracy, precision and system suitability. The results of the study showed that the proposed RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of rilpivirine in its pharmaceutical dosage form.

The main aim of the present study was to develop and validate a simple, rapid and sensitive assay method for sildenafil citrate in pharmaceutical dosage forms by reverse phase high performance liquid chromatography method. Determination Of Sildenafil Citrate was determined by reverse phase HPLC using Potassium dihydrogen phosphate Buffer (pH 7.0):ACN(45:55) and column  Inertsil ODS-3V 5μ (150*4.6mm) as a stationary phase and  the chromatogram of Sildenafil Citrate has shown in figure 10 and peak was observed at 228 nm which was selected as a wavelength for quantitative estimation. After development of the method, it was validated for system suitability, specificity, linearity, precision, accuracy, robustness and solution stability studies. The results system suitability was found to be within the limits. The limit were not more than RSD