Programming of pressure and mobile phase composition at constant flow-rate using a self-adjusting valve in super-critical-fluid chromatography

1989 ◽  
Vol 475 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Stephan Küppers ◽  
Benno Lorenschat ◽  
Franz Peter Schmitz ◽  
Ernst Klesper
Keyword(s):  
Phase Composition ◽  
Flow Rate ◽  
Mobile Phase ◽  
Constant Flow ◽  
Mobile Phase Composition ◽  
Constant Flow Rate

scholarly journals A SIMPLE AND FAST RP-UHPLC-PDA METHOD FOR DETERMINATION OF ISRADIPINE FROM POLYMERIC NANOCAPSULES

2020 ◽  
pp. 225-229
Author(s):  
Fernanda Malaquias Barbosa ◽  
Guilherme dos Anjos Camargo ◽  
Amanda Martinez Lyra ◽  
Jessica Mendes Nadal ◽  
Paulo Vitor Farago
Keyword(s):  
High Performance Liquid Chromatography ◽  
Phase Composition ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Experimental Basis ◽  
Mobile Phase Composition ◽  
Polymeric Systems ◽  
Polymeric Nanocapsules

A simple and fast analytical method of ultra-high performance liquid chromatography (UHPLC) was developed and validated in order to assay isradipine in poly(ε-caprolactone) (PCL)/polyethylene glycol (PEG) nanocapsules. Experiments were performed by UHPLC on a C18 chromatographic column at 25°C using a mobile phase composed by methanol and water (85:15 v/v) with a flow rate of 0.5 mL.min−1 and UV detection at 327nm for achieving a total run time of 1.5 min. The UHPLC method was validated according to the guidelines set on The International Conference on Harmonisation. It proved to be selective, linear (r = 0.99962), precise (RSD < 4.1%), and accurate (recovery rates between 95.24 and 96.53%) at the range from 10 to 40 µg.mL−1. The performance was robust when slight changes in the flow rate, wavelength of detection, and mobile phase composition were tested. It was successfully applied to quantify isradipine from nanoparticulate polymeric systems, showing high loading efficiency rates, greater than 98.55%. These results provided an experimental basis to use this method for quantifying isradipine with reliable results, besides being very fast, easy to perform and cheaper.

Development and validation of high-performance liquid chromatography method for the simultaneous monitoring of pantoprazole sodium sesquihydrate and domperidone maleate in plasma and its application to pharmacokinetic study

2020 ◽  
Vol 32 (3) ◽  
pp. 157-165
Author(s):  
Ghulam Abbas ◽  
Malik Saadullah ◽  
Akhtar Rasul ◽  
Shahid Shah ◽  
Sajid Mehmood Khan ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Phase Composition ◽  
Flow Rate ◽  
Retention Time ◽  
Mobile Phase ◽  
High Performance ◽  
Mobile Phase Composition ◽  
Chromatography Method ◽  
Surface Design

A sensitive, inexpensive high-performance liquid chromatography–ultraviolet detection (HPLC–UV) method has been developed and validated for the simultaneous monitoring of pantoprazole sodium sesquihydrate (PSS) and domperidone maleate (DM) in rabbit plasma on a C18 column with UV detection at 285 nm. Box–Behnken design was used with 3 independent variables, namely, flow rate (X1), mobile phase composition (X2), and phosphate buffer pH (X3), which were used to design mathematical models. Response surface design was applied to optimize the dependent variables, i.e., retention time (Y1 and Y2) and percentage recoveries (Y3 and Y4) of PSS and DM. The method was sensitive and reproducible over 1.562 to 25 μg/mL. The effect of the quadratic outcome of flow rate, mobile phase composition, and buffer pH on retention time (p ˂ 0.001) and percentage recoveries of PSS and DM (p = 0.0016) were significant. The regression values obtained from analytical curve of PSS and DM were 0.999 and 0.9994, respectively. The percentage recoveries of PSS and DM were ranged from 94.5 to 100.41% and 94.77 to 100.31%, respectively. The developed method was applied for studying the pharmacokinetics of PSS and DM. The Cmax of test and reference formulations were 48.06 ± 0.347 μg/mL and 46.31 ± 0.398 μg/mL for PSS, and 15.11 ± 1.608 μg/mL and 12.06 ± 1.234 μg/mL for DM, respectively.

Sequential Injection Chromatography with Monolithic Column for Phenothiazines Assay in Human Urine and Pharmaceutical Formulations

2020 ◽  
Vol 16 (7) ◽  
pp. 967-975
Author(s):  
Abubakr M. Idris
Keyword(s):  
Phase Composition ◽  
Human Urine ◽  
Mobile Phase ◽  
Monolithic Column ◽  
Pharmaceutical Formulations ◽  
Pharmaceutical Formulation ◽  
Assay Method ◽  
Sequential Injection ◽  
Mobile Phase Composition ◽  
Sequential Injection Chromatography

Methods: Sequential injection chromatography (SIC) with monolithic column has been proposed with potential benefits for separation and quantification. Objective: To utilize SIC to develop a new assay method for the separation and quantification of some phenothiazines (promethazine, chlorpromazine and perphenazine) in human urine and synthetic pharmaceutical formulations. Methods: The 32 full-factorial design was adopted to study the effect of mobile phase composition on separation efficiency, retention time, peak height and baseline. The separation was conducted on a C18 monolithic column (100 × 4.6 mm) using a mobile phase composition of phosphate: acetonitrile:methanol (60:28:12) at pH 4.0. The detection was carried out using a miniaturized fiber optic spectrometer at 250 nm. Results: Satisfactory analytical features, including number of theoretical plates (1809-6232), peak symmetry (1.0-1.3), recovery (95.5-99.1% in pharmaceutical formulations and 91.6-94.7% in urine), intra-day precision (0.36-1.60% for pharmaceutical formulation and 2.96-3.67 for urine), inter-day precision (1.47-2.28% for pharmaceutical formulation), limits of detection (0.23-0.88 μg/ml) and limits of quantification (0.77-2.90 μg/ml), were obtained. Conclusion: The remarkable advantages of the proposed SIC method are the inexpensiveness in terms of instrumentation and reagent consumption.

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