A method for testing residual solvents in nicotine resinate

Abstract

The invention belongs to the technical field of drug analysis, and specifically relates to a method for detecting residual solvents in nicotine resinate. In order to solve the problem of isopropanol adsorption by nicotine resinate, the diluent is adjusted during sample processing to solve the problem of inaccurate detection caused by residual solvent adsorption by nicotine resinate, thereby effectively ensuring drug safety and facilitating quality control of nicotine resinate. The method is convenient, efficient and accurate, and fully complies with the guiding principles of method verification of the Chinese Pharmacopoeia in terms of system applicability, repeatability and accuracy, and can be used for quality control of nicotine resinate.

Description

Technical Field

[0001] The invention belongs to the technical field of drug analysis, and particularly relates to a method for detecting residual solvents in nicotine resinate. Background Art

[0002] Nicotine resinate is mainly used in the production of nicotine chewing gum. Its main advantage is that it delays the release of nicotine, allowing nicotine to be released continuously for 10-20 minutes. At the same time, resinate also improves the stability of nicotine, making it more convenient to use in preparations. During the synthesis process of nicotine resinate, isopropyl alcohol is used, which will remain in the sample and be carried into the finished product.

[0003] Isopropyl alcohol, chemically known as 2-propanol, is a common organic compound with the chemical formula C3H8O. It is a colorless transparent liquid that is soluble in water, alcohol, ether, benzene, chloroform and most other organic solvents. The list of carcinogens published by the World Health Organization's International Agency for Research on Cancer is a preliminary reference. Isopropyl alcohol is on the list of three types of carcinogens. Isopropyl alcohol is also specified as a third-category solvent that requires restricted use in the 2010 edition of the Chinese Pharmacopoeia. Residual solvents in drugs refer to those used in the production of raw materials or excipients, as well as in the preparation of preparations. The residual limit of the third-category solvents commonly found in drugs is not higher than 0.5%.

[0004] When the content of residual solvent isopropyl alcohol in nicotine resinate was determined by gas chromatography, it was found that nicotine resinate adsorbed isopropyl alcohol, thereby affecting the recovery rate of the test results.

[0005] The invention discloses a method for determining the content of isopropanol, a residual solvent, in nicotine resinate by gas chromatography. In order to solve the problem that nicotine resinate produces adsorption effect on isopropanol and affects the detection recovery rate, the invention selects a suitable diluent to pre-treat the sample, thereby solving the problem that nicotine resinate produces adsorption effect on isopropanol and affects the detection recovery rate, ensuring the accuracy of the detection result, fully complying with the guiding principles of method verification of the Chinese Pharmacopoeia in terms of system applicability, repeatability and accuracy, and can be used for quality control of nicotine resinate. Summary of the invention

[0006] The present invention provides a gas chromatography method for determining the content of isopropanol, a residual solvent, in nicotine resinate. In order to solve the problem that nicotine resinate produces adsorption of isopropanol and affects the detection recovery rate, the present invention selects a suitable diluent to pre-treat the sample, thereby solving the problem that nicotine resinate produces adsorption of isopropanol and affects the detection recovery rate, ensuring the accuracy of the detection result and facilitating the quality control of nicotine resinate.

[0007] To achieve the above object, the present invention provides the following technical solutions: A method for testing residual solvents in nicotine resinate, wherein the residual solvent is isopropanol, and the testing method comprises the following steps: (1) Prepare solutions, including blank solution, reference solution and test solution; (2) Determination method: The residual solvent content in nicotine resinate is determined by gas chromatography. After the system is stable, blank solution, reference solution and test solution are added respectively, and the chromatogram is recorded; For the control solution: take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute to the mark with diluent; The test solution: take an appropriate amount of nicotine resinate sample, place it in a headspace bottle, make up to volume with diluent, seal it with a cap, and sonicate; The diluent is N,N-dimethylformamide:methanol in a volume ratio of 4:1; The blank solution is the diluent.

[0008] Furthermore, the ultrasonic time is 2-10 minutes.

[0009] Further, the chromatographic conditions of the gas chromatography are as follows: Instrument: Gas chromatograph equipped with FID detector and headspace injector, chromatographic column: Agilent DB-624, 30m×0.32mm, 1.8μm, column temperature: 45℃ for 6min, 50℃ / min to 250℃, hold for 5min, inlet temperature: 150℃, detector temperature: 250℃, N2, column flow rate: 2ml / min, split ratio: 20:1, hydrogen flow: 30ml / min, air flow: 300ml / min, tail gas flow: 25ml / min; HS headspace conditions: equilibrium temperature: 50℃, quantitative loop temperature: 60℃, transfer line temperature: 70℃, equilibrium time: 20min, GC cycle time: 20min, injection time: 0.5min, injection volume 1ml.

[0010] The invention discloses a method for determining the content of isopropanol, a residual solvent, in nicotine resinate by gas chromatography. In order to solve the problem that nicotine resinate produces adsorption effect on isopropanol and affects the detection recovery rate, the invention selects a suitable diluent to pre-treat the sample, thereby solving the problem that nicotine resinate produces adsorption effect on isopropanol and affects the detection recovery rate, ensuring the accuracy of the detection result and facilitating the quality control of nicotine resinate. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is the blank solution spectrum of the present invention; Figure 2is the reference solution spectrum of the present invention; Figure 3 This is the test solution spectrum of the present invention. DETAILED DESCRIPTION

[0012] The present invention is further illustrated by the following examples, but are not intended to limit the present invention.

[0013] Example 1: Determination of Residual Solvents in Nicotine Resinate (1) Preparation of solution: The blank solution was N,N-dimethylformamide-methanol (4:1); Control solution: Take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute it with diluent to make a solution with a concentration of 100 μg / ml; Test solution: Take an appropriate amount of nicotine resinate sample, place it in a headspace bottle, dilute it with diluent to make a solution with a concentration of 20 mg / ml, cover it and seal it, and ultrasonicate it for 5 minutes.

[0014] (2) Chromatographic conditions: GC chromatographic conditions: Chromatographic column: Agilent DB-624, 30m×0.32mm, 1.8μm or other column with equivalent performance Column temperature: 45℃ for 6 min, then increase to 250℃ at 50℃ / min, and keep for 5 min Inlet temperature: 150°C Detector temperature: 250°C N2, column flow rate: 2ml / min, split ratio: 20:1 Hydrogen flow rate: 30ml / min Air flow rate: 300ml / min Make-up gas flow rate: 25ml / min HS headspace conditions: Equilibrium temperature: 50°C Quantitative loop temperature: 60°C Transfer line temperature: 70°C Equilibration time: 20 min GC cycle time: 20 min Injection time: 0.5 min Injection volume 1ml (3) Steps After the system is stable, inject blank solution, control solution and test solution respectively and record the chromatograms.

[0015] calculate:

[0016] Where: At——peak area of ​​isopropanol in the test solution; As——the average peak area of ​​6 against isopropanol in the reference solution; Cs——concentration of isopropanol in the reference solution, mg / ml; Ct——concentration of test solution, mg / ml.

[0017] Example 2: System Applicability System suitability is achieved by measuring the RSD of the peak area of ​​isopropanol in the reference solution for 6 pairs. The RSD of the peak area of ​​isopropanol in the reference solution for 6 pairs should not be greater than 10.0%.

[0018]

[0019] Example 3: Limit of Detection and Limit of Quantitation The limit of quantitation and the limit of detection are achieved by measuring the ratio of the detection response signal to noise. The signal-to-noise ratio of the limit of quantitation is not less than 10:1, and the signal-to-noise ratio of the limit of detection is not less than 3:1. At the limit of quantitation concentration level, 6 minimum limit of quantitation solutions are repeatedly examined. The RSD of the peak area per unit concentration of isopropanol in the 6 LOQ solutions is required to be no greater than 10.0%, LOD≈1 / 3LOQ, and S / N≥3.

[0020]

[0021] Example 4: Accuracy Accuracy is achieved through the recovery rate and the RSD of the recovery rate between the measured concentration and the theoretical concentration of the measured component. The recovery rate at LOQ concentration should be between 70.0% and 130.0%, and the RSD of the recovery rate should be ≤20.0%; the recovery rate at 50% to 150% concentration should be between 80.0% and 120.0%, and the RSD of the recovery rate should be ≤10.0%.

[0022] Test solution: Take about 100 mg of nicotine resinate and place it in a 20 ml headspace bottle. Add 5 ml of isopropanol solution of different concentrations shown in Table 4 to obtain test solutions of various spiked concentrations.

[0023]

[0024] Example 5: Precision Repeatability is achieved by testing the RSD or absolute value of the change difference of the residual solvent isopropanol content in 6 test solutions. The impurity content in the 6 repeatability solutions must meet the requirement: RSD ≤ 10.0%.

[0025]

[0026] The following comparative examples illustrate the screening process of sample processing in this patent.

[0027] Comparative Example 1: GC chromatographic conditions: Chromatographic column: Agilent DB-624, 30m×0.32mm, 1.8μm or other column with equivalent performance Column temperature: 45℃ for 6 min, then increase to 250℃ at 50℃ / min, and keep for 5 min Inlet temperature: 150°C Detector temperature: 250°C N2, column flow rate: 2ml / min, split ratio: 20:1 Hydrogen flow rate: 30ml / min Air flow rate: 300ml / min Make-up gas flow rate: 25ml / min HS headspace conditions: Equilibrium temperature: 50°C Quantitative loop temperature: 60°C Transfer line temperature: 70°C Equilibration time: 20 min GC cycle time: 20 min Injection time: 0.5 min Injection volume 1ml The blank solution is N,N-dimethylformamide; Diluent: N,N-dimethylformamide; Control solution: Take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute it with diluent to make a solution with a concentration of 100 μg / ml; Test solution: Take about 100 mg of nicotine resinate and place it in a 20 ml headspace bottle. Add 5 ml of isopropanol solution of different concentrations shown in Table 6 to obtain test solutions of various spiked concentrations.

[0028] The accuracy of the solution was tested by measuring the concentration of the sample itself and the recovery rate of adding different concentrations of isopropanol;

[0029] The test results show that when nicotine resinate is treated with N,N-dimethylformamide as a diluent, the recovery rate varies greatly when isopropanol of the same concentration of 99.66 μg / ml is added to the test solution, and the recovery rate is unstable. When isopropanol of a higher concentration is added to the test solution, the recovery rate is close to 100%.

[0030] Comparative Example 2: The gas chromatography conditions were the same as those in Comparative Example 1.

[0031] The blank solution is N,N-dimethylformamide; Diluent: N,N-dimethylformamide; Control solution: Take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute it with diluent to make a solution with a concentration of 100 μg / ml; Test solution: Grind a batch of nicotine resinate, take about 100 mg of the ground nicotine resinate sample, place it in a headspace bottle, and add 5 ml of diluent to obtain the result of examining the residual solvent of nicotine resinate.

[0032]

[0033] Through this operation, it was found that there were still large differences in the test results of only grinding nicotine resinate samples, which requires further investigation.

[0034] Comparative Example 3: The gas chromatography conditions were the same as those in Comparative Example 1.

[0035] The blank solution is N,N-dimethylformamide; Diluent: N,N-dimethylformamide; Control solution: Take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute it with diluent to make a solution with a concentration of 100 μg / ml; Test solution: Grind nicotine resinate, take about 100 mg of the ground nicotine resinate sample, put it in a headspace bottle, add 5 ml of diluent, cover and seal, and sonicate.

[0036] The nicotine resinate was ground into powder and sealed with a cap, and the effect of different ultrasonic times on the residual solvent of the same batch of resinate was investigated.

[0037]

[0038] Through this operation, it was found that prolonging the ultrasonic time can increase the detection amount of isopropyl alcohol in nicotine resinate, and it is speculated that the abnormal recovery rate in Comparative Example 1 is related to the adsorption capacity of the resin for isopropyl alcohol.

[0039] Ultrasound can reduce the adsorbed isopropanol and improve the detection effect. However, the ultrasonic time is too long, which affects the detection efficiency, so we consider whether there are other methods.

[0040] Comparative Example 4: The enzymatic nicotine sample was mixed with polyclidinium and then spiked with isopropanol for testing. No isopropanol residue was found in the nicotine sample prepared by the enzymatic method. Nicotine resinate was obtained by mixing the enzymatic nicotine sample with polyclidinium. No isopropanol residue was found in the nicotine resinate obtained by mixing the enzymatic nicotine sample with polyclidinium. The recovery rate was tested by spiked nicotine resinate without isopropanol residue. The gas chromatography conditions were the same as those in Comparative Example 1.

[0041] The blank solution is N,N-dimethylformamide; Diluent: N,N-dimethylformamide; Control solution: Take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute it with diluent to make a solution with a concentration of 100 μg / ml; Test solution: Mix 20 mg of enzymatic nicotine sample with 80 mg of polyclidinium and add isopropanol, place in a headspace bottle, add 5 ml of diluent, seal with a cap, and sonicate.

[0042]

[0043] There is no isopropyl alcohol in the mixed sample of nicotine and polyclinic. Through this experiment, it is inferred that nicotine in the matrix has no effect on the detection of isopropyl alcohol.

[0044] Comparative Example 5: The gas chromatography detection conditions are the same as those of Comparative Example 1.

[0045] Ultrasound can improve the detection of residual solvents in nicotine resinate, but too long an ultrasonic time will affect the detection efficiency. The effect of changing the diluent on the results of residual solvents in the same batch of resinate was investigated.

[0046]

[0047] Through this operation, it was found that the diluent was N,N-dimethylformamide-methanol (4:1), ultrasonication was performed for 5 minutes, and the adsorption of residual solvent isopropanol on the sample was minimal. The residual solvent of nicotine resinate can be detected in a relatively short time. The system applicability, specificity, quantitative limit and detection limit, spike recovery rate and repeatability of this method are all good, and it is suitable for the detection of residual solvent of nicotine resinate.

Claims

1. A method for testing residual solvents in nicotine resinate, characterized in that: The residual solvent is isopropanol, and the inspection method comprises the following steps: (1) Prepare solutions, including blank solution, reference solution and test solution; (2) Determination method: The residual solvent content in nicotine resinate is determined by gas chromatography. After the system is stable, blank solution, reference solution and test solution are added respectively, and the chromatogram is recorded; For the control solution: take an appropriate amount of isopropanol, place it in a volumetric flask, and dilute to the mark with diluent; The test solution: take an appropriate amount of nicotine resinate sample, place it in a headspace bottle, make up to volume with diluent, seal it with a cap, and sonicate; The diluent is N,N-dimethylformamide:methanol in a volume ratio of 4:1; The blank solution is the diluent.

2. The method according to claim 1, characterized in that The ultrasonic time is 2-10 minutes.

3. The method according to claim 2, characterized in that The chromatographic conditions of the gas chromatography are as follows: Instrument: Gas chromatograph equipped with FID detector and headspace injector, chromatographic column: Agilent DB-624, 30m×0.32mm, 1.8μm, column temperature: 45℃ for 6min, 50℃ / min to 250℃, hold for 5min, inlet temperature: 150℃, detector temperature: 250℃, N2, column flow rate: 2ml / min, split ratio: 20:1, hydrogen flow: 30ml / min, air flow: 300ml / min, tail gas flow: 25ml / min; HS headspace conditions: equilibrium temperature: 50℃, quantitative loop temperature: 60℃, transfer line temperature: 70℃, equilibrium time: 20min, GC cycle time: 20min, injection time: 0.5min, injection volume 1ml.

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