scholarly journals The Determination of Miconazole and its Related Production Impurities Together with Basic Solution Stability Studies Using a Sub 2  m Chromatographic Column

2012 ◽  
Vol 50 (3) ◽  
pp. 199-205 ◽  
Author(s):  
N. O'Connor ◽  
M. Geary ◽  
M. Wharton ◽  
P. Sweetman
Keyword(s):  
Chromatographic Column ◽  
Solution Stability ◽  
Basic Solution ◽  
Stability Studies

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

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.

scholarly journals On factors affecting surface free energy of carbon black for reinforcing rubber

2020 ◽  
Vol 9 (1) ◽  
pp. 170-181 ◽  
Author(s):  
Shangyong Zhang ◽  
Ruipeng Zhong ◽  
Ruoyu Hong ◽  
David Hui
Keyword(s):  
Free Energy ◽  
Carbon Black ◽  
Surface Free Energy ◽  
Surface Activity ◽  
Gas Flow ◽  
Influential Factors ◽  
Chromatographic Column ◽  
Factors Affecting ◽  
Carrier Gas Flow

AbstractThe surface activity of carbon black (CB) is an important factor affecting the reinforcement of rubber. The quantitative determination of the surface activity (surface free energy) of CB is of great significance. A simplified formula is obtained to determine the free energy of CB surface through theoretical analysis and mathematical derivation. The surface free energy for four kinds of industrial CBs were measured by inverse gas chromatography, and the influential factors were studied. The results showed that the aging time of the chromatographic column plays an important role in accurate measurement of the surface free energy of CB, in comparison with the influences from the inlet pressure and carrier gas flow rate of the chromatographic column filled with CB. Several kinds of industrial CB were treated at high temperature, and the surface free energy of CB had a significant increase. With the increase of surface free energy, the maximum torque was decreased significantly, the elongation at break tended to increase, the heat generation of vulcanizates was increased, and the wear resistance was decreased.

scholarly journals PERENCANAAN BAHAN BAKU DAN HASIL PRODUKSI MENGGUNAKAN METODE LINIER PROGRAMMING SIMPLEK

2017 ◽  
Vol 12 (2) ◽  
Author(s):  
Monika Handayani ◽  
Eka Kusuma Dewi
Keyword(s):  
Linear Programming ◽  
Production Planning ◽  
Simplex Method ◽  
Raw Materials ◽  
Raw Material ◽  
Planning System ◽  
Testing System ◽  
Basic Solution ◽  
Linear Programming Method

<p>CV. Baja Utama Landasan Ulin is a business entity that manufactures various products using the basic ingredients of iron. In the management of raw materials for the production of common regulatory process raw materials into sections for further processing. This setting is often done manually without doing careful planning, so that at the end of each production process there are many remaining pieces of the raw materials that should be used in production. In addition to the determination of the production is necessary to reference how the product should be made for each type of existing products. This is often an important factor that pushed for the optimization of production planning in determining the number of products for each type of product and raw material consumption.Linear Programming is one of the methods used in production planning to regulate the use of raw materials is limited. Simplex method is part of the linear programming method that can be used in the production planning system implementation. Simplex method identifies an initial basic solution and then move systematically to other basic solution that has the potential to improve the value of the objective function.The calculation result of production planning using the simplex method can be used as a reference in the decision making production planning. By building an application using the simplex method can assist in the calculation of production peencanaan more efficiently and effectively. Accuracy testing system constructed show significant results with great value reached 94% level of accuracy.<br />Keywords: simplex, production planning, the maximum gain, linear programming</p>

scholarly journals Simultaneous Determination and Stability Studies on Diminazene Diaceturate and Phenazone Using Developed Derivative Spectrophotometric Method

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Ruaa Mohamed Akode ◽  
Shaza Wagiealla Shantier ◽  
Elrasheed Ahmed Gadkariem ◽  
Magdi Awadalla Mohamed
Keyword(s):  
Simultaneous Determination ◽  
Correlation Coefficients ◽  
Degradation Process ◽  
Stability Studies ◽  
Temperature Dependent ◽  
First Order Kinetics ◽  
First Derivative Spectrophotometry ◽  
Aqueous Mixture ◽  
Photo Stability

This work presents UV first derivative spectrophotometry as a precise, accurate, and feasible method for simultaneous determination of diminazene diaceturate and phenazone in bulk and dosage forms. The absorbance values of diminazene diaceturate and phenazone aqueous mixture were obtained at 398 nm and 273 nm, respectively. The developed method was proved to be linear over the concentration ranges (2–10) μg/mL and (2.496–12.48) μg/mL for diminazene diaceturate and phenazone, respectively, with good correlation coefficients (not less than 0.997). The detection and quantitation limits were found to be (LOD = 0.63 and 0.48 μg/mL; LOQ = 1.92 and 1.47 μg/mL, resp.). The developed method was employed for stability studies of both drugs under different stress conditions. Diminazene diaceturate was prone to degrade at acidic pH via first-order kinetics. The degradation process was found to be temperature dependent with an activation energy of 7.48 kcal/mole. Photo-stability was also investigated for this drug.

Determination of Tryptophan Using Nanocomposite-Based Sensor

2013 ◽  
Vol 829 ◽  
pp. 675-680 ◽  
Author(s):  
Akbar Islamnezhad ◽  
Esmaeil Farzaneh Jobaneh
Keyword(s):  
Catalytic Effect ◽  
Basic Solution ◽  
Carbon Paste ◽  
Experimental Conditions ◽  
Chemically Modified ◽  
Solvent Free Condition ◽  
Analytical Response ◽  
Paste Electrode ◽  
Effect Of The Composition

In this study, the nanoComposite Silica Perchloric Acid Poly (2-Methyl Aniline) (NSPPMA) was synthesized under the solvent-free condition and used as modifier in preparation of chemically modified electrode (CME). The effect of the composition of carbon paste electrode on its voltammograms were evaluated in basic solution with 5.0 × 105 M Trp. It was found that addition of NSPPMA to the carbon paste would generate the peak current of Trp because of its catalytic effect on redox process. The best analytical response was obtained at pH 12.0. The anodic peak currents were proportional to Trp concentrations in the range of 2.5 × 109 5.0 × 10-4 M under the optimized experimental conditions. The detection limit was 1.7 × 10-10 M. The correlation of the peak currents against v1/2 (v is the scan rate) is linear. The proposed method was applied to the determination of Trp in pharmaceuticals formulations successfully.

scholarly journals Stability Indicating RP-HPLC Method for Determination of Valsartan in Pure and Pharmaceutical Formulation

2010 ◽  
Vol 7 (1) ◽  
pp. 246-252 ◽  
Author(s):  
S. K. Patro ◽  
S. K. Kanungo ◽  
V. J. Patro ◽  
N. S. K. Choudhury
Keyword(s):  
Linear Response ◽  
Mobile Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Control Analysis ◽  
Solution Stability ◽  
Stability Indicating ◽  
Quality Control Analysis ◽  
Rp Hplc

A simple, rapid and accurate and stability indicating RP-HPLC method was developed for the determination of valsartan in pure and tablet forms. The method showed a linear response for concentrations in the range of 50-175 µg/mL using 0.01 M NH4H2PO4(pH 3.5) buffer: methanol [50:50] as the mobile phase with detection at 210 nm and a flow rate of 1 mL/min and retention time 11.041 min. The method was statistically validated for accuracy, precision, linearity, ruggedness, robustness, forced degradation, solution stability and selectivity. Quantitative and recovery studies of the dosage form were also carried out and analyzed; the % RSD from recovery studies was found to be less than 1. Due to simplicity, rapidity and accuracy of the method, we believe that the method will be useful for routine quality control analysis.

Gas Chromatographic Determination of Residual Hexane in Modified Hop Extract

1972 ◽  
Vol 55 (6) ◽  
pp. 1226-1227
Author(s):  
Mark A Litchman ◽  
Lewis A Turano ◽  
Ronald P Upton
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Chromatographic Determination ◽  
Methanol Solution ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Porapak Q ◽  
Residual Hexane ◽  
Head Space

Abstract A method is described for the quantitative determination of hexane in modified hop extract by head-space gas-liquid chromatography. A sample of extract is weighed into a serum vial and water-methanol solution is added. The vial is sealed tightly and heated 1 hr in a 70°C bath. A sample of the head-space gas over the solution is injected onto a Porapak Q gas chromatographic column for determination. Recovery of 2–29 ppm hexane added to potassium isohumulone was 95.5–114.8%. The method may be applicable to other hop extracts.

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