RU1783391C - Method of detecting ludiamil - Google Patents

Abstract

The invention relates to analytical chemistry. The sample is pretreated with formaldehyde and concentrated sulfuric acid in a ratio of 0.25: 2.0, the treatment being carried out sequentially. The analysis is carried out by measuring the relative fluorescence intensity of the resulting solution of Table 6.

Description

The invention relates to analytical chemistry, in particular to methods for the qualitative and quantitative determination, and can be used in the analysis of preparations containing ludiomil.

A known method for the determination of ludiomil, based on the use of liquid chromatography of the drug in the UV region with absorption of l (nm.

The disadvantage of this method is its low selectivity, since compounds such as amitriptyline, imizine, carbamazepine, and a number of drugs containing a benzene ring in their structure are absorbed in this field.

The closest to the invention in technical essence and the achieved result is a method for the quantitative determination of ludiomil, based on the dissolution of the drug in acetone and the measurement of optical characteristics by spectrophotometric method.

The disadvantage of this method is its low sensitivity and selectivity.

The purpose of the invention is to increase the sensitivity and selectivity of the analysis in the presence of drugs containing a benzene ring in their structure.

To do this, the sample is successively treated with formaldehyde and concentrated sulfuric acid, taken in a volume ratio of 0.25: 2.00, and the intensity of the orange-yellow fluorescence of the solution is measured.

When studying the optimal conditions for the fluorescence reaction, it was found that the fluorescence intensity does not change for 24 hours. The time dependence of the fluorescence intensity is given in Table 1; on the ratio of the taken chemical reagents (formaldehyde and concentrated sulfuric acid) - in Table 2, on the type of solvent used to clarify the final effect of the reaction - in Table 3; from the sequence of addition of chemical reagents - in table 4; the selectivity of this reaction and

Yo

Xi 00

with

CA)

ABOUT

a comparison of the sensitivity reaction in relation to the prototype is shown in table 5.

From the obtained regression equation in stage VI:

Y - 45.31 - 13.94X1 + 8.06X2 + 0X3,

The optimal experimental conditions were found:

X1 0.5 0.465 0.43 0.395 0.36 0.325 0.290 0.256 0.221

X2 1.75 1.80 1.85 1.901 1.951 2.001 2.052 2.102 2.153

Thus, optimum ratios of 0.25: 2.0 formaldehyde-concentrated sulfuric acid reagents are the optimum conditions.

PRI me R 1. Qualitative determination of ludiomil in tablets (dragees).

Dissolve 4-5 tablets in distilled water (10-100 ml). After filtration, formaldehyde and concentrated sulfuric acid were added successively to the solution in a ratio of 0.25: 2.00. In UV light, an orange-yellow fluorescence is observed, indicating the presence of ludiomil.

PRI me R 2. Quantitative determination of ludiomil in tablets.

0.4 g (accurately weighed) of the powder of the crushed tablets was introduced into a volumetric flask with a capacity of 10 ml, 70-80 ml of warm distilled water was added, it was shaken for 1-2 minutes and the volume was adjusted to the mark with distilled water. The resulting solution was stirred and filtered through a pleated filter. The first 5-10 ml of the filtrate is discarded (solution A). 0.25 ml of formaldehyde, 2 ml of concentrated sulfuric acid, 6.75 ml of dioxane are added to 1 ml of solution A, mixed and fluorimetric relative to standard solutions of ludiomil. For this, 0.8: 0.9 are added to a number of tubes ; 1.0; 1.1; 1.2 and 1.6 ml of a standard solution of ludiomil with a concentration of 25 μg / ml, 0.25 ml of formaldehyde, 2 ml of concentrated sulfuric acid and dioxane up to 10 ml. Received

the solutions are mixed and fluorimetric at the same time as the test solutions. The calculation of the amount of ludiomil found in Ludiomil tablets in g is carried out according to the formula

X

AhRhS

H x1000000 where X is the content of ludiomil, g;

C is the average weight of the tablet, g;

P is the volume to which the initial sample is diluted, ml;

N - initial sample, g;

1,000,000 - transfer of micrograms to

The quantitative results of ludiomil in tablets on model mixtures were statistically processed and are presented in Table 6.

The analysis of ludiomil by the described method does not interfere: anafranil, azaleptin, imizine, pyrazidol, befol, carbamazepine, damylene maleate and other antidepressants, which indicates a high degree of selectivity of this reaction.

By steep climbing, the optimum ratios of formaldehyde and concentrated sulfuric acid were determined.

Claims (1)

SUMMARY OF THE INVENTION A method for determining ludiomil, including treating an analyzed sample with chemical reagents, irradiating the resulting solution with ultraviolet light, recording optical characteristics of the solution, which are determined by the method, characterized in that, in order to increase the sensitivity and selectivity of the analysis in the presence of drugs containing in its structure, the benzene ring, the sample is sequentially treated with formaldehyde and concentrated sulfuric acid, taken in bulk with ratio of 0.25.2.00. and measure the intensity of the orange-yellow fluorescence of the solution. Table 1 Dependence of the fluorescence intensity on the reaction time (with a ratio of formaldehyde and concentrated sulfuric acid 0.25: 2.0). P 7 Note XI - Formaldehyde volume, ml; X2 - volume of concentrated sulfuric acid, ml. Table 3 The dependence of the fluorescence intensity on the type of solvent used to clarify the final effect, p 7 Solvent Distilled water Dioxane Butanol Dimethylformamide Propanol Hexane Methanol Carbon tetrachloride Chloroform Toluene Acetone Acetic acid ethyl ester Continuation of table 1 table 2 Fluorescence intensity. % 45 96 94 33 17 32 20 15 No reaction Table 4 Dependence of the fluorescence intensity on the sequence of addition of formaldehyde and concentrated sulfuric acid Comparison table Table 6 The results of the quantitative determination of ludiomil in tablets Ludiomil (model samples); p 7, P 95% Table 5