RP-HPLC method for simultaneous estimation of amlodipine and valsartan in tablet formulation and validation as per ICH guidelines

A simple, specific, sensitive and validated RP-HPLC method for the simultaneous estimation of amlodipine (AMB) and valsartan (VAL) in marketed tablet formulation was developed. The analysis was carried out on a phenomenex C18 (250 x 4.6 mm, 5 µm) column using a mobile phase of 0.1% ortho phosphoric acid solution: acetonitrile (35:65 v/v, pH 3.0). The flow rate of the mobile phase was adjusted to 1.0 ml/min and was detected at 238 nm. The retention time obtained from the analysis was 1.995 min and 4.910 min for AMB and VAL respectively. The developed method was validated as per ICH guidelines. In order to find out the linearity, the concentrations ranging 2-10 µg/ml for AMB and 64-320 µg/ml for VAL was used. The squared correlation co-efficient (r 2 value) derived from the equation for AMB and VAL was 0.9979 and 0.9994, respectively. The percentage recoveries calculated for AMB and VAL ranges from 96.93 to 99.63 %. The estimated drug in the tablet formulation was 100.13 % and 99.99 % for AMB and VAL respectively. The results of analysis shows that method can be used for the estimation of AMB and VAL in the tablet dosage form without further separation in the quality control laboratories.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Development and validation of a RP-HPLC method for determination of citicoline monosodium in human plasma

A sensitive and specific high performance reversed phase liquid chromatographic method was developed for quantification of citicoline monosodium (CTM) in human plasma. The active drug was isocratically eluted at a flow rate of 1 ml/min at ambient temperature in a nucleosil C18 analytical column with a mobile phase composed of tetrabutyl ammonium hydro gen sulfate buffer (0.005 M, pH5.0): methanol (95:05, v/v). Photodiode array (PDA) was performed at 270 nm and the retention time of the drug was found to be 6.64 min. The lowest limit of quantification (LLOQ) and of detection (LOD) were found to be 30 and 10 ng/ml, respectively. The method was validated and the response was found to be linear in the drug (CTM in spiked plasma) concentration range 150-900 ng/ml. The method was found to be accurate, with ranging from 96.38 to 98.65 % and precise, with intra-day, inter-day as well as analyst-toanalyst precision. The total recoveries of the method ranged between 95.69 and 97.89 %. Stability data revealed that the drug is stable in human plasma under various test conditions and the method can be successfully used for analysis of CTM in human plasma and in pharmacokinetic studies.Colegio de Farmacéuticos de la Provincia de Buenos Aire