This article describes a new, accurate and highly specific high performance liquid chromatographic method with UV detection (HPLC-UV) for the simultaneous determination of cetirizine HCl (CZ), chlorphenamine maleate (CPM), loratadine (LTD), domperidone (DP), buclizine (BZ) and meclizine (MZ) in pharmaceutical dosage form and human serum, involving pyridoxine (PYD) as the internal standard. The mobile phase consists of heptane sulphonic acid salt buffer and acetonitrile, drawn at a flow rate of 1.0 mL min À1 using a symmetry C 18 column with UV detection at 230 nm. The intraday and inter-day precision measurements showed coefficients of variation always less than one. The calibration curve was tested in the range of 10-2150 ng mL À1 and the correlation coefficient of >0.9990 in all cases was obtained. The averages of the absolute and relative recoveries were found to be in the range of 98 to 102%. Up to six antihistamines were separated in the same chromatogram with good resolution. The proposed HPLC method has reasonable applications in pharmaceutical tablet dosage form and pharmacokinetics studies.

RP-HPLC ultraviolet detection simultaneous quantification of piracetam and levetiracetam has been developed and validated. The chromatography was obtained on a Nucleosil C18 column of 25 cm × 0.46 cm, 10 μm, dimension. The mobile phase was a (70 : 30 v/v) mixture of 0.1 g/L of triethylamine and acetonitrile. Smooth flow of mobile phase at 1 mL/min was set and 205 nm wavelength was selected. Results were evaluated through statistical parameters which qualify the method reproducibility and selectivity for the quantification of piracetam, levetiracetam, and their impurities hence proving stability-indicating properties. The proposed method is significantly important, permitting the separation of the main constituent piracetam from levetiracetam. Linear behavior was observed between 20 ng/mL and 10000 ng/mL for both drugs. The proposed method was checked in bulk drugs, dosage formulations, physiological condition, and clinical investigations and excellent outcome was witnessed.

A liquid chromatographic method is described for the quantification of prednisolone, benzimidazoles, and preservatives using a C 18 analytical column as stationary phase. The mobile phase was 30:70 methanol:pH 2.5 phosphate buffer at a flow rate of 1.0 mL min -1 with absorbance detection at 235 nm. The method was linear for concentrations from 40 to 10,000 ng mL -1 . Low values of coefficient of variance were obtained when samples were analyzed as replicates. Excellent recovery values were recorded in commercial products and fortified samples. International Conference of Harmonization protocols were employed to perform comprehensive method validation. The reported method has applications for pharmaceutical and serum samples.

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This paper demonstrates colorimetric visible spectrophotometric quantification methods for amino acid, namely, tranexamic acid and pregabalin. Both drugs contain the amino group, and when they are reacted with 2,4-dinitrophenol and 2,4,6-trinitrophenol, they give rise to yellow colored complexes showing absorption maximum at 418 nm and 425 nm, respectively, based on the Lewis acid base reaction. Detailed optimization process and stoichiometric studies were conducted along with investigation of thermodynamic features, that is, association constant and standard free energy changes. The method was linear over the concentration range of 0.02–200 µgmL−1 with correlation coefficient of more than 0.9990 in all of the cases. Limit of detection was in range from 0.0041 to 0.0094 µgmL−1 and limit of quantification was in the range from 0.0137 to 0.0302 µgmL−1. Excellent recovery in Placebo spiked samples indicated that there is no interference from common excipients. The analytical methods under proposal were successfully applied to determine tranexamic acid and pregabalin in commercial products. t-test and F ratio were evaluated without noticeable difference between the proposed and reference methods.