UA151559U - Method for potentiometric determination of flurbiprofen - Google Patents

Abstract

A method for the potentiometric determination of flurbiprofen by a selective method involving the use of a potentiometric sensor based on polyvinyl chloride. An ionic association of flurbiprofen and rhodamine 6ZH was used as an electrode-active substance.

Description

A useful model belongs to analytical chemistry, namely, it concerns the selective determination of flurbiprofen by the potentiometric method, and can be used for its determination in dosage forms.

Quantitative determination of organic compounds is an important task of chemistry, pharmaceutical industry, medical and biological practice. Such methods of analytical chemistry as chromatography, spectrophotometry, luminescence, electrochemical methods of analysis are widely used for this purpose. Among the latter, a worthy place is occupied by ionometry - direct potentiometry using ion-selective electrodes (CE).

Flurbiprofen (Flur) is a derivative of propionic acid from the group of nonsteroidal anti-inflammatory drugs (NSAID33), which acts by inhibiting the synthesis of prostaglandins. In humans, flurbiprofen has a powerful analgesic, antipyretic and anti-inflammatory effect.

Flurbiprofen can be determined by gas chromatography with mass spectrometric detection. Mita?, E. AIkap. YuOeieptipaiop oi Pybirgoitep ip rpaptasetsshiisa! rgeragayop5 ru

С2О-М5 // Agabiap udoshtpai oi Spetivighu. - 2019. - M. 12, Mo. 8. - R. 2077-2083). A significant drawback of this method is that flurbiprofen must be derivatized before chromatography. It is not always possible to ensure the quantitative yield of the product of this reaction, which can lead to incorrect results.

The basis of a useful model is the task of developing a method for potentiometric determination of flurbiprofen by a selective method using a potentiometric sensor.

The problem is solved by the fact that the method of potentiometric determination of flurbiprofen is a selective method, which involves the use of a potentiometric sensor based on polyvinyl chloride. The ionic associate of flurbiprofen and rhodamine bZh was used as an electroactive substance.

The ionic associate of flurbiprofen with rhodamine bZh was synthesized according to the following method.

First, a 107 mol/l solution of this basic dye and flurbiprofen was prepared. A solution of flurbiprofen was added dropwise to the rhodamine EJ solution with constant stirring and left at room temperature for 2 hours. for advocacy. The precipitate was filtered off and washed several times with cold distilled water for washing

From the ionic associate from the remains of the main dye, after which it was dried at room temperature in the air for 48 hours.

Plasticized polyvinyl chloride membranes were prepared as follows: 0.1 g of polyvinyl chloride, the appropriate amount of the selected ion associate (so that its concentration in the membrane was 5 95 of the total weight of the membrane) were weighed, and then the mixture was thoroughly mixed for homogenization. After that, 0.1 ml of tricresyl phosphate plasticizer, 0.5 ml of tetrahydrofuran solvent were introduced. The resulting solution was transferred to a round glass mold with a diameter of 1.7 cm, which was previously polished, and glued to a glass substrate and dried in air for 1-2 days.

To make an electrode for the determination of flurbiprofen, after evaporation of the solvent from the obtained films, discs with a diameter of 0.5-1.0 cm were cut out with a cutter for rubber plugs and glued to the end of a polyvinyl chloride tube 1095 with a solution of polyvinyl chloride in cyclohexanone. The tube was filled with the appropriate concentrated standard solution of flurbiprofen (102 mol/l) and a copper wire was immersed in it. After that, the electrode was used for research.

To regulate and maintain the ionic strength of the solution, 0.1 mol/l KSI was used.

Potentiometric measurement was performed with an AI-123 ionometer; a ZVL-1M3Z silver chloride electrode was used as a reference electrode at room temperature.

The proposed new sensor based on an ion associate with rhodamine b6Zh can be used to determine flurbiprofen in pharmaceutical preparations, technological solutions, etc.

The linearity of the electrode function is observed within the range of 8.0105-5.0107 mol/l of flurbiprofen, the slope of the electrode function is 53252 mV/pC, the detection limit of flurbiprofen is 8.0-105 mol/l. The response time of the sensor to a change in flurbiprofen concentration is 5-15 s. Life time of the electrode From the month from the date of its manufacture. The value of the electrode potential of the flurbiprofen-sensitive sensor depending on the change in the concentration of flurbiprofen, as well as on the change in the acidity of the medium, is presented in Tables 1 and 2, respectively.

Table C shows the characteristics of the sensor based on the ionic associate of rhodamine b6Zh and flurbiprofen for the determination of flurbiprofen.

The developed flurbiprofen-sensitive electrode based on the ionic associate of flurbiprofen bo and rhodamine EJ for the determination of flurbiprofen has satisfactory characteristics (see Table 3).

The sensor proposed by us quickly reacts to changes in flurbiprofen concentrations (response time is only 5-15 s). Another significant advantage is that the developed sensor is sufficiently selective in relation to various ions and substances (Table 4).

Example of determination of flurbiprofen in gel.

For analysis, gels are prepared as follows. 1 g of gel is weighed, dissolved in a mixture of 25 ml of buffer solution pH 9.5 and ethyl alcohol, filtered. The solution and washing water are collected in a 50 ml flask, 5 ml of a pH 9.5 buffer solution of 0.1 mol/l KSI are added, and the volume of the solution is brought up to the mark with distilled water. Analyze 5 parallel samples.

Analysis progress. A membrane electrode and a silver chloride reference electrode are immersed in the solution to be analyzed for flurbiprofen content. Measure the potential of the indicator membrane electrode. The content of flurbiprofen is found by the method of a calibration graph constructed under similar conditions.

The claimed method provides high selectivity for the determination of flurbiprofen.

Table 1

Dependence of the electrode potential on the concentration of flurbiprofen pSelurbpofeui | 7 | 6 | 5 | 4 | With | 2 | 1

Table 2

The influence of pH of the solution on the pH response of the flurbiprofen-sensitive electrode (pOSzolurbiprofen-2.0). 11770 | 80 | 90 | 100 | 170 | 120

Table C

Characteristics of the flurbiprofen-sensitive electrode

Steepness, Linearity, 8.0-12.0 8.0105-5.0107| 8,005

Note: iv (s) is the response time of the electrode, her (weeks) is the life time of the electrode

Table 4

Comparative characteristics of ISE potentiometric selectivity coefficients for the determination of flurbiprofen

The logarithm of the selectivity coefficient on, substance -: flurbiprofen-sensitive electrodes v

Table 4 (continued)

The logarithm of the selectivity coefficient

Ion, substance - ; flurbiprofen-sensitive electrodes benzoate glucose

Claims (1)

USEFUL MODEL FORMULA The method of potentiometric determination of flurbiprofen by a selective method, which involves the use of a potentiometric sensor based on polyvinyl chloride, which differs in that the ionic associate of flurbiprofen and rhodamine bZh is used as an electroactive substance.