linearity

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.

A simple, selective, rapid, precise and economical reverse phase HPLC method has been developed for the determination of Metoprolol Succinate in dosage formulation. The analyte was resolved by using a mobile phase (Acetonitrile, water and 1 % ortho phosphoric acid in the ratio 70:27:3 v/v/v) at a flow rate 2.0 ml/min on an isocratic HPLC system (Agilent 1100 series with Chemstation software) consisting UV lamp detector, Aligent C-8, RP column (4.6 mm i.d x250 mm) at a wavelength of 280 nm.  The linear dynamic range for Metoprolol Succinate was 10 g/mL–200µg/mL. The limit of detection [LOD]and Limit of quantification[LOQ] for Metoprolol Succinate  was 0.0284µg/mL  and 0.094µg/mL respectively.