Procedure for the Quantitative Determination of Mixtures of Nucleic Acid Components Based on Multivariate Spectrophotometric Acid−Base Titrations

1999 ◽  
Vol 71 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Javier Saurina ◽  
Santiago Hernández-Cassou ◽  
Romà Tauler ◽  
Anna Izquierdo-Ridorsa
Keyword(s):  
Nucleic Acid ◽  
Quantitative Determination ◽  
Acid Base

Chromatographic Procedure for Determination of Reserpine in Tablets. II. Collaborative Study

1969 ◽  
Vol 52 (1) ◽  
pp. 113-115
Author(s):  
Susan Barkan
Keyword(s):  
Quantitative Determination ◽  
Collaborative Study ◽  
Chromatographic Column ◽  
Colorimetric Analysis ◽  
Acid Base ◽  
Water Layers ◽  
Suitable Amount ◽  
Chromatographic Procedure ◽  
Tablet Formulations

Abstract A method is described for the quantitative determination of reserpine in tablet formulations. A suitable amount of tablet material is triturated with dimethylsulfoxide (DMSO), incorporated onto Celite, and transferred to a chromatographic column containing acid, base, and water layers. The reserpine is eluted with chloroform and quantitated spectrophotometrically. Duplicate results from 16 collaborators averaged 100.7% recovery as determined by UV, 98.8% recovery determined by colorimetric analysis. The method is recommended for adoption as official first action.

scholarly journals EXPLORING OF ACID-BASIC PROPERTIES, DEVELOPMENT AND VALIDATION OF THE METHOD OF QUANTITATIVE DETERMINATION OF ORIGINAL PHARMACEUTICAL SUBSTANCE

2019 ◽  
Vol 8 (1) ◽  
pp. 66-71
Author(s):  
G. M. Alekseeva ◽  
V. F. Apraksin ◽  
Yu. E. Generalova
Keyword(s):  
Quantitative Determination ◽  
Active Compound ◽  
Dissociation Constants ◽  
Acid Dissociation ◽  
Bromocresol Green ◽  
Acid Base ◽  
Indicator Method ◽  
Pharmaceutical Substance ◽  
Basic Properties

Introduction. The object of analysis was a newly synthesized organic substance, a derivative of 4-aminobenzoic acid and malonic ester  – 4,4’-(propandiamido) sodium dibenzoate, which has an antisteatotic effect. For the quantitative determination of pharmaceutical substances, it is preferable to use titrimetric methods of analysis, since they are absolute and allow us to estimate the content of the active compound in the substance without using standard samples. Aim. The objective of this work was to develop and validate a quantitative determination method for 4.4’-(propandiamido) sodium dibenzoate. Materials and methods. The analyzed compound is a salt of a weak dibasic acid, which exhibits basic properties in an aqueous solution; therefore, for its quantitative determination, a direct acid-base titration method (acidimetry) was proposed. The method of quantitative determination of the active compound in the substance 4,4’-(propandiamido) sodium dibenzoate will be used in future studies for routine analysis, therefore a visual (indicator) method for determining the end point of the titration has been chosen. To prove the suitability of the developed method and the possibility of obtaining reliable results of the quantitative content of the active compound in the newly synthesized pharmaceutical substance the used analytical method was validated. Results and discussion. The study of the acid-base properties of the newly synthesized substance was carried out using the method of potentiometric titration, on the basis of which the values of the dissociation constants were calculated. Using spreadsheets, the pKa1 and pKa2 values were calculated using a titration model of a multi-basic acid, the pKa values of which are 7.2 and 5.0. The titration curve that was constructed from the experimental data and the curve constructed from the calculated values of the dissociation constants almost completely overlapped with each other. Based on the data obtained, a 0.1% water-alcohol solution of bromocresol green (blue) with pT=4.6 was selected for titration, the color transition interval of which falls into the titration jump of the analyte. The developed methodology was validated according to the requirements of the XIV edition State Pharmacopoeia of the Russian Federation by the following indicators: specificity, linearity, accuracy, precision (convergence and internal reproducibility), robustness, analytical domain. Conclusion. As a result of the performed studies, the values of acid dissociation constants of the newly synthesized pharmaceutical substance 4,4’-(propandiamido) sodium dibenzoate were determined, and a method for quantitative determination was developed and validated using acidbase titration.

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