RU2332662C2 - Method of assay defining for pentalgin fs pills - Google Patents

Abstract

FIELD: pharmacology.

SUBSTANCE: invention concerns highly efficient fluid chromatography, particularly methods of defining assay of multicomponent medicines of antipyretic, analgesic, anticatarrhal effect, and can be applied in controlling and analytical laboratories of pharmaceutical enterprises and drugstore chains. To define assay of all drug components at one time the analysis is performed in reverse-phase isocratic mode with concentrations of acetonitryl and monosubstituted potassium phosphate in mobile phase within 4÷6% (volume) and 0.09÷0.12% (mass-volume) respectively.

EFFECT: improved repeatability of quantitative results of optimal peak separation for analgin, paracetamol, caffeine, Phenobarbital, analgin decomposition product and codeine by a single-stage method.

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Description

The invention relates to high-performance liquid chromatography (HPLC), and in particular to methods for determining the quantitative composition of multicomponent drugs with antipyretic, analgesic, anti-cold action, and can be used in the practice of control and analytical laboratories of pharmaceutical enterprises and the pharmacy network. The method belongs to the mass.

Multicomponent drugs are widely used in medical practice. Pentalgin FS, along with analgin (0.3 g), paracetamol (0.3 g), caffeine (0.05 g), narcotic and potent substances - codeine phosphate (0.008 g) are part of the antipyretic, analgesic, and anti-cold action drug. and phenobarbital (0.01 g). In this regard, the problem of ensuring and controlling the quality of this drug is extremely relevant, and its successful solution is impossible without effective ways to determine its quantitative composition. At the same time, the task of developing such methods is very complex, which is due to the complex composition of the analyzed drug, and a large difference in the content of some components. So, in Pentalgin FS tablets, the content of analgin exceeds the amount of codeine phosphate by 37 times, and phenobarbital - by 30 times. The analysis of tablets is also complicated by the instability of analgin in aqueous-organic solutions. For these reasons, the simultaneous detection and quantification of all active components of the drug is a difficult task. This may explain the fact that, despite the rapid development in recent years of the latest methods for the analysis of complex drugs and, above all, HPLC, the scientific literature does not describe the method of quantitative analysis of Pentalgin FS tablets.

A known method for determining the quantitative composition of complex drugs containing propiphenazone by reverse-phase HPLC (Vergeichik EN, Onegova N. S. HPLC in the analysis of complex drugs containing propiphenazone. Pharmacy. - 2001. - T.50, No. 3. - S.24-26). The authors of the publication offer a method for determining the quantitative composition of Kaffetin tablets containing 0.250 g of paracetamol, 0.210 g of propiphenazone, 0.050 g of caffeine and 0.010 g of codeine phosphate in one tablet. Since the content of codeine phosphate in relation to propiphenazone and paracetamol is 21-25 times lower in the analyzed tablets, the developers carry out the analysis in three stages. At the first stage, the solution of the test tablets and the solution of working standard samples (RSO) are chromatographed in isocratic mode using acetonitrile - water - diethylamine (3: 2.2: 0.2) as the mobile phase (PF) and paracetamol (retention time) is determined 3.08 min), caffeine (4.0 min) and propiphenazone (5.73 min). In the second stage, the solution of the test tablets in water is acidified with 10% sulfuric acid to a pH of 2.0, extraction is carried out in portions of 10 ml of ethyl acetate three times, and the extracts containing paracetamol, caffeine and propiphenazone are discarded. In the third stage, 25% ammonia solution is added to an aqueous solution containing codeine phosphate to a pH of 9-10 and the codeine is extracted three times with 10 ml of chloroform each. The combined chloroform extracts were evaporated, the dry residue was dissolved in acetonitrile, and codeine was determined in the resulting solution under the chromatographic conditions described above (retention time 4.41 min). The eluted substances are detected at 238 and 276 nm.

The disadvantages of the method are its multi-stage, and, as a result, the complexity, duration and unsatisfactory accuracy of determination of codeine phosphate (the degree of extraction of codeine from tablets, according to the authors of the method, 89-93%).

There is also a known method for determining the quantitative composition of Spazmoveralgin Neo tablets containing bromized (0.250 g), paracetamol (0.150 g), caffeine (0.050 g), papaverine hydrochloride (0.030 g), phenobarbital (0.020 g), codeine phosphate (0.008 g) , ephedrine hydrochloride and atropine sulfate (the content of the last two components in the tablet is not indicated in the publication), by reverse phase HPLC in an isocratic elution mode using a column filled with a sorbent with grafted nitrile groups, the mobile phase (PF) of the composition acetonitrile is 0.05 M phosph buffer solution (pH 4.0) in the ratio of 15:85 and detection at 230 nm (Larionova S.G., Dementieva N.N., Nechaeva E.B., Nazarenko P.V., Nesterova G.A. Optimization conditions for the analysis of tablets with a complex composition of analgesic and antispasmodic effects, Pharmacy. - 2002. - T.51, No. 1. - S.16-19). In this work, the authors simultaneously determined bromized, codeine phosphate (content ratio 31: 1), paracetamol, caffeine, phenobarbital and papaverine hydrochloride. The disadvantage of this method is associated with the peculiarities of isocratic elution and consists in the unsatisfactory resolution of the peaks of substances eluting from the column first (in the range of capacitance coefficients k from 0.4 to 1.4, 7 substances elute) and the relatively high retention of the peak of papaverine eluting last (k = 7 , 0). Poor separation of the peaks of the substances being determined negatively affects the accuracy of their quantitative determination.

The closest to the claimed invention in the composition of the analyzed drugs, the task, the technical solution and the achieved results is the "Method for the quantitative analysis of multicomponent drugs antipyretic, analgesic, anti-cold" (Golubitsky GB, Budko EV, Pokrovsky M.V. ., Pass EF and Zakharova EV Patent RU 2267115 C2, 12/27/2005), in which the analysis is carried out by reverse-phase HPLC in a linear gradient mode, the slope and duration of which are determined by the properties Components of the analyzed drug. Mixtures of acetonitrile with a buffer solution (0.025 M solution of potassium phosphate monosubstituted - KH ₂ PO ₄ , the pH of which is adjusted to 3.0 by adding concentrated phosphoric acid) is used as a PF; mixtures of acetonitrile with water; water. In this method, the improvement in the separation of analgin, codeine and caffeine is based on the chromatographic properties of codeine: with the Nova-Pak C 18 reverse phase used in the work, codeine is not eluted with acetonitrile-water mixtures. In accordance with this chromatographic property of codeine, a PF containing only acetonitrile and water is introduced at the initial stage of the gradient, and a phosphate buffer solution with a pH of 3.0 is introduced into the PF after all peaks except codeine are released. The disadvantage of this method is the instability of chromatographic conditions during one analysis, which is due to a change in the pH and ionic strength of the PF and reduces the reproducibility of quantitative results.

The objective of the present invention is to develop a one-step method for determining the quantitative composition of tablets "Pentalgin FS", free from this drawback.

The problem is achieved by reverse-phase HPLC using the proposed method, which consists in the fact that as a PF use a mixture of acetonitrile with a phosphate buffer solution, characterized in that the analysis is carried out in isocratic mode at concentrations of acetonitrile and potassium phosphate monosubstituted in the mobile phase 4 ÷ 6% (by volume) and 0.09 ÷ 0.12% (weight-volume), respectively.

The authors of this application experimentally established that such a composition of the PF provides the optimal separation of dipyrone, paracetamol, caffeine, phenobarbital, the decomposition product of dipyrone and codeine (figure 1). An increase in the content of potassium phosphate 1-substituted in PF to 0.17% (weight-volume) worsens the separation (Fig. 2), and its decrease to 0.08% (weight-volume) increases the retention time of the codeine peak with a simultaneous increase in it "Tail", which reduces the accuracy of calculating its area (figure 3). According to these data, the working range of concentrations of potassium phosphate 1-substituted in PF is 0.09 ÷ 0.12% (weight-volume), since it is inappropriate to increase the concentration above 0.12% (weight-volume) in order to save the reagent and reduce the negative the influence of salt on the chromatographic column and communication device.

The optimal concentration of acetonitrile was determined by resolving the “critical pair” of peaks: caffeine - phenobarbital. A decrease in concentration to 4% (by volume) impairs resolution (FIG. 4); when reduced to 3% (by volume), the resolution is even worse (figure 5). When increasing to 5% (by volume), the resolution improves (Fig. 6), but a further increase to 6% (by volume) practically does not improve the picture (Fig. 7). Thus, the working range of acetonitrile concentrations in PF is 4–6% (by volume).

In relation to the indicated results, it should be noted that the dependence of the retention of various classes of substances on the concentration of acetonitrile in the mobile phase has been widely studied and, therefore, the prediction of the corresponding patterns can be attributed to the obvious. However, in the system under consideration, this dependence is anomalous: as a rule, a decrease in the concentration of acetonitrile improves resolution, and in this case, vice versa. In addition, the dependence of the chromatographic properties of substances on the concentration of salts in the mobile phase, which we used in the development of the inventive methods, has been studied much worse than the effect of acetonitrile. This dependence is much more complex and has an individual character for each individual substance. So, with an increase in the concentration of potassium phosphate 1-substituted in PF, the retention of codeine decreases, in naproxen it increases. Therefore, the predictions in accordance with this dependence are not obvious, especially when it comes to the separation of a group of substances, as in the case under consideration.

These facts suggest that the proposed method has a novelty and an appropriate inventive step.

The method is as follows. The solution of the test drug and the solution of the working standard sample (RSO) are sequentially chromatographed on a liquid chromatograph with an ultraviolet (UV) detector and a reverse phase chromatographic column in isocratic elution with a mixture of acetonitrile (4 ÷ 6% by volume) with an aqueous solution of potassium phosphate monosubstituted (0 , 09 ÷ 0.12% weight-volume).

The method is illustrated by the following example.

Quantitative determination of analgin, paracetamol, caffeine, codeine phosphate and phenobarbital in tablets "Pentalgin FS"

For the preparation of the test solution, about 0.160 g (accurately weighed) of thoroughly ground tablets and 0.12 g of sodium sulfite xc are placed in a 100 ml volumetric flask, 10 ml of water are added, and stirred for 3 minutes. 5 ml of acetonitrile are added and stirred for another 3 minutes. The resulting solution was adjusted to the mark with water, stirred and filtered through a hydrophilic membrane filter with a pore size of 0.45 μm (for example, the company Millipor), discarding the first 5 ml of the filtrate.

To prepare a solution of POR, about 0.060 g of dipyrone, about 0.060 g of paracetamol (accurately weighed) and 0.12 g of sodium sulfite rh are placed in a 100 ml volumetric flask, 10 ml of water are added and stirred. Add 5 ml of acetonitrile and mix until the substances are dissolved. 5.0 ml of a solution of caffeine, codeine phosphate and phenobarbital are added, adjusted to the mark with water, stirred and filtered through a membrane filter with a pore size of 0.45 μm, discarding the first 5 ml of the filtrate.

To prepare the RCO-2 solution, about 0.2000 g of caffeine, about 0.0320 g of codeine phosphate, dried to constant weight at a temperature of 105 ° C, and about 0.0400 g of phenobarbital (accurately weighed) are placed in a volumetric flask with a capacity of 100 ml, 10 ml of water and 5 ml of acetonitrile are added and stirred until the substances are dissolved. Bring water to the mark and mix. The shelf life of the solution is 7 days.

5.0 μl of the test solution and the PCO solution are successively chromatographed on a liquid chromatograph with a UV detector and a 3.9 × 150 mm column with a Nova-Pak CN HP sorbent with a particle size of 4 μm in isocratic mode using acetonitrile 5 as a PF mixture % (by volume) and an aqueous solution of potassium phosphate monosubstituted with a concentration of 0.1% (weight-volume). Get at least 3 chromatograms of each solution.

The flow rate of the mobile phase is 1.0 ml / min. Detection wavelength of 212 nm.

Calculate the peak areas of the determined components and find the amount of each component in the analyzed tablets according to the formula

where S _to and S _article - the average values of the peak areas of the determined components in the chromatograms of the solutions of the test and RNO, respectively;

m _st , m _s and m _n are the masses of the standard of the analyte in the RNO solution, the average weight of the tablet and the weight of the weighed ground tablets taken to prepare the test solution, respectively, in grams.

The results of the analysis of tablets (industrial series) are presented in table 1. Table 2 presents the comparative results of the analysis obtained by gradient (prototype) and isocratic methods.

Table 1
The results of the analysis of tablets "Pentalgin FS" Components Content in one tablet, g (n = 9; P = 0.95) Norm on ND X _Wed S S _hsr ΔX ε,% p. 21052004 Analgin 0.28500-0.31500 0.29440 0,00294 0,00098 0,00235 0.80 Paracetamol 0.28500-0.31500 0.29609 0,00161 0,00054 0.00130 0.44 Caffeine 0.04675-0.05325 0,04965 0,00062 0,00021 0,00050 1.01 Codeine phosphate 0.00720-0.00880 0.00818 0.00006 0.00002 0.00005 0.61 Phenobarbital 0.00900-0.01100 0.01005 0.00013 0.00004 0.00010 1.00 p. 22052004 Analgin 0.28500-0.31500 0.28891 0,00182 0,00061 0,00146 0.51 Paracetamol 0.28500-0.31500 0.29118 0.00160 0,00053 0,00127 0.44 Caffeine 0.04675-0.05325 0,04869 0,00040 0.00013 0,00031 0.64 Codeine phosphate 0.00720-0.00880 0.00800 0.00006 0.00002 0.00005 0.62 Phenobarbital 0.00900-0.01100 0.00961 0.00010 0.00003 0,00007 0.73 p. 23052004 Analgin 0.28500-0.31500 0.28835 0,00157 0,00052 0.00125 0.43 Paracetamol 0.28500-0.31500 0.29021 0,00093 0,00031 0,00074 0.25 Caffeine 0.04675-0.05325 0.04903 0,00068 0,00023 0,00055 1.12 Codeine phosphate 0.00720-0.00880 0,00803 0.00009 0.00003 0,00007 0.87 Phenobarbital 0.00900-0.01100 0,00953 0.00002 0.00001 0.00002 0.21

table 2
The results of the analysis of tablets "Pentalgin FS" (industrial series 2004), obtained by a) gradient b) isocratic methods Components Content in one tablet, g (n = 9; P = 0.95) Norm on ND X _Wed S S _xav ΔX ε,% Analgin 0.2850-0.3150 a) 0.2933 0.0010 0,0003 0,0007 0.24 b) 0.2944 0.0029 0.0010 0.0024 0.82 Paracetamol 0.2850-0.3150 a) 0.2946 0,0003 0.0001 0,0002 0,07 b) 0.2961 0,0004 0.0001 0,0002 0,07 Caffeine 0.04675-0.05325 a) 0,05043 0,00045 0.00015 0,00035 0.69 b) 0.04965 0,00062 0,00021 0,00050 1.01 Phenobarbital 0.0090-0.0110 a) 0.00975 0.00017 0.00006 0.00014 1.44 b) 0.01005 0.00013 0.00004 0.00009 0.90 Codeine phosphate 0.0072-0.0880 a) 0.00825 0,00032 0.00011 0,00026 3.15 b) 0.00818 0.00006 0.00002 0.00005 0.61

Claims (1)

The method for determining the quantitative composition of a multicomponent antipyretic, analgesic, anti-cold action drug containing analgin, paracetamol, caffeine, codeine phosphate, phenobarbital, which consists in the fact that the determination is carried out by reverse phase HPLC with an ultraviolet detector in isocratic mode using as a mobile phase mixtures of acetonitrile with an aqueous solution of potassium phosphate monosubstituted at concentrations of acetonitrile and potassium phosphate monosubstituted in izhnoy phase 4 ÷ 6% (by volume) and 0.09 ÷ 0.12% (overall weight and volume), respectively.

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