RU1837213C - Method for quantitative determination of piperazine adipinate - Google Patents

Abstract

SUMMARY OF THE INVENTION: An assayed sample of photomac .- dock nfiipyRji sodium tungstate in the presence of 2, 5, hydrochloric or sulfuric acid. 7 tab.

Description

(E

b) Murallkrlshna M. et al. Analytical uses of

change transfer complexes. Determination of pure and dosege forms piperarln Analyst, 109 Io. R. 1277 (1984).

l

The invention relates to methods for the qualitative determination of piperazine adipate, which may find application in the control and analytical laboratories.

The purpose of the invention is to increase sensitivity, simplify the method by reducing analysis time.

This is achieved by dissolving the analyzed sample in water and acidifying it with hydrochloric or sulfuric acid to a content of 2, 0 M (, 1-4.5) and photometrically titrated with sodium tungstate,

 It was found that photometric titration of piperazine adipate with sodium tungstate can be carried out at pH 3.1-4.5 with a relative error in the analysis of Tf), 76-1.0f% (Tables 1,2, 5).

Table 3 shows the analysis of piperazine adipate beyond the optimum pH of the solution at pH 2.8 (acid concentration 6, M). It was found that in this case, the relative analysis error increases to 2.67% and

in many cases overestimated or underestimated results are obtained.

When creating a solution pH greater than 4.5, the reaction product of piperazine adipinate with sodium tungstate has low optical density values, i.e. the reaction practically does not proceed.

When studying piperazine adipate beyond the concentration limits of a titrated sodium tungstate solution, it was found that at a titrant concentration less than 0.015 M, the equivalence point on the titration curve is fixed much later than theoretically calculated or a straight line is obtained without a pronounced equivalence point. At a reagent concentration greater than 0.025 M, there is no clearly defined equivalence point on the titration curve.

Thus, a 0.015-0.25 M titrated sodium tungstate solution can be used to quantify piperazine adipate.

Table 4 presents the results of the analysis of piperazine adipate at a concentration of the analyte in

(L

WITH

00 O)

H

the test sample is less than 6.50 mg. It has been established that the relative error in the quantitative determination increases up to 5.54% and the results of the analysis are overestimated.

With a piperazine adipate content of more than 9.29 mg in the analyzed sample, finding the equivalence point on the titration curve is difficult.

Example 1. The exact weight of piperazine adipate (about 0.10 g) was added to a 50 ml volumetric flask, the contents were dissolved in water and the volume of the flask was adjusted to the mark with water. 4 ml of the prepared solution was placed in a titration beaker, 10 ml of a 0.01 M solution of hydrochloric (sulfuric) acid were added, and water was adjusted to a total solution volume of 30 m. Titration was carried out with a 0.02 M sodium tungstate solution using a titrator T -107 (blue filter) with the magnetic stirrer switched on. 0.5 ml of a 0.02 M sodium tungstate solution was added from the microburette and after 2 minutes the light transmission was measured. Further addition of the titrated solution was carried out in 0.1 ml portions after 1 minute. About 0.9 ml of sodium tungstate solution is spent on the reaction with piperazine adipate. From the data obtained, a titration curve is constructed in the coordinates: g,% -; Vp-Ba,. Ml, where: g is the percent light transmission; V is the volume of sodium tungstate solution in ml. The equivalence point is found graphically by extrapolating two straight lines of the titration curve.

The concentration of the test drug in percent is calculated by the formula:

%

V T Ya 100 N Vi

where H is the mass of the drug taken for analysis, g;

T is the titer of the standard solution for the test substance, g / ml;

V is the volume of the standard solution spent on titration, ml;

Vi is the volume of the test solution taken for analysis, ml;

V2 - volumetric volumetric flask, ml.

1 ml of a 0.02 M sodium tungstate solution corresponds to 0.009291 g of piperazine adipate.

The results of the analysis and their statistical processing are given in table 5.

From Table 5 it can be seen that the relative error in the determination of piperazine adipate by the proposed method is: 0.76%. A quantitative determination of a drug with this relative error can be carried out with the content of piperazine adipate in the analyzed sample from 6.50 mg to 9.29 mg.

Thus, the lower limit for piperazine adipate is 6.50 mg / 30 ml, and the upper limit is 9.29 mg / 30 ml.

PRI me R 2. Analysis of piperazine adipate in tablets of 0.2 g and 0.5 g.

Exact mass (about 0.10 g) of powder

5 crushed tablets are placed in a 50 ml volumetric flask. Piperazine adipate is dissolved in water, the volume of the flask is adjusted to the mark with water, and the solution is filtered. 5 ml are placed in a titration beaker

0 filtrate and then proceed similarly to the analysis of piperazine adipate (example 1). The content of piperazine adipate in tablets is calculated according to the formula V T Vi P

5

WITH

M V2

where P is the average weight of a piperazine adipinate tablet, g;

M is the mass of powder of ground tablets, g.

0 The results of the analysis of piperazine adipate in tablets are shown in table.6.

From table 6 it is seen that the content of piperazine adipate, in tablets, found by the proposed method, is within 5 acceptable tolerance standards.

To compare the analysis data of piperazine adipate, we quantitatively determined it by the method of the proposed method and prototype. Comparative data on the time spent, the test substance on one analysis and sensitivity. Are given in table.7.

From table 7 it is seen that the proposed method can significantly increase the sensitivity, reduce the analysis time of piperazine adipate by 10 times, and reduce the cost of a particular drug by 3.5 times.

Claims (1)

SUMMARY OF THE INVENTION A method for the quantitative determination of piperazine adipate by treating an analyzed sample with a color reagent and photometry, characterized in that sodium tungstate is used as a color reagent and photometric titration is carried out in the presence of 2,3.10 - 5, M hydrochloric or sulfuric acid. Quantification of piperaein from adipate iri pH 3.1 / 5.0 10 M / Quantitative determination of piperazine adipate at pH 4.5 / SK-you 2.3 M / Table 1 hey from t table 2 Quantitative determination of piperazine adipate at a pH of 2.8 / SK-you 6.6 M / Quantification of piperazine adipate when it is contained in the analyzed a sample of less than 6.50 mg / SK-you 3.3 M; Stranta 0.02 M / Table 3 Table 4