Fertilizers. Determination of flow rate

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

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Analytical methods for determination of aerosols by means of membrane ultrafilters. VIII. Determination of the mean pore size by gas flow rate measurements

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19661152 ◽

1966 ◽

Vol 31 (3) ◽

pp. 1152-1161 ◽

Cited By ~ 5

Author(s):

V. Hampl ◽

K. Spurný

Keyword(s):

Pore Size ◽

Flow Rate ◽

Analytical Methods ◽

Gas Flow ◽

Gas Flow Rate ◽

The Mean

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Box-Behnken Assisted Validation and Optimization of an RP-HPLC Method for Simultaneous Determination of Domperidone and Lansoprazole

Separations ◽

10.3390/separations8010005 ◽

2021 ◽

Vol 8 (1) ◽

pp. 5

Author(s):

Mohd Afzal ◽

Mohd. Muddassir ◽

Abdullah Alarifi ◽

Mohammed Tahir Ansari

Keyword(s):

Flow Rate ◽

Mobile Phase ◽

Limit Of Detection ◽

Hplc Method ◽

Box Behnken Design ◽

Rp Hplc ◽

System Suitability ◽

Method Optimization ◽

Key Variables

A highly specific, accurate, and simple RP-HPLC technique was developed for the real-time quantification of domperidone (DOMP) and lansoprazole (LANS) in commercial formulations. Chromatographic studies were performed using a Luna C8(2), 5 μm, 100Å, column (250 × 4.6 mm, Phenomenex) with a mobile phase composed of acetonitrile/2 mM ammonium acetate (51:49 v/v), pH 6.7. The flow rate was 1 mL·min−1 with UV detection at 289 nm. Linearity was observed within the range of 4–36 µg·mL−1 for domperidone and 2–18 µg·mL−1 for lansoprazole. Method optimization was achieved using Box-Behnken design software, in which three key variables were examined, namely, the flow rate (A), the composition of the mobile phase (B), and the pH (C). The retention time (Y1 and Y3) and the peak area (Y2 and Y4) were taken as the response parameters. We observed that slight alterations in the mobile phase and the flow rate influenced the outcome, whereas the pH exerted no effect. Method validation featured various ICH parameters including linearity, limit of detection (LOD), accuracy, precision, ruggedness, robustness, stability, and system suitability. This method is potentially useful for the analysis of commercial formulations and laboratory preparations.

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