Analysis method for measuring and calculating dissolution amount of josamycin tablets in acid medium

Abstract

The invention discloses an analysis method for measuring and calculating the dissolution amount of josamycin tablets in an acid medium. According to the method disclosed by the invention, the josamycin and the degradation product of the josamycin are simultaneously determined by adopting a liquid chromatography, and a corresponding relation between the increased amount of the degradation product and the degradation amount of the josamycin is established by using a calculation formula, so that the dissolution amount of the josamycin tablet in an acid medium is accurately determined and calculated.

Description

Technical Field

[0001] The invention belongs to the technical field of drug analysis, and in particular relates to an analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium. Background Art

[0002] Josamycin is a macrolide antibiotic that has strong antibacterial activity against Gram-positive bacteria and is effective against some Gram-negative bacteria, mycoplasmas, chlamydia, rickettsiae, and spirochetes. The drug has been widely used in clinical practice. The Josamycin API was first developed and successfully marketed by Yamanouchi, Japan.

[0003] There are reports on the dissolution determination method in China, all of which use ultraviolet spectrophotometry. Since josamycin is extremely unstable and easily degraded in pH 1.2 medium, this method has poor specificity and cannot accurately detect the dissolution amount of josamycin tablets in this medium, which is the key to evaluating whether the homemade preparation is equivalent to the reference preparation. It is of certain significance to establish an analytical method that can accurately determine the dissolution amount of josamycin tablets in pH 1.2 medium. Summary of the invention

[0004] In view of this, the object of the present invention is to provide an analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium, which can accurately determine and calculate the dissolution amount of josamycin tablets in an acidic medium.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium comprises the following steps:

[0007] (1) dissolving josamycin tablets in an acidic medium with a pH value of 1.2 to obtain a josamycin tablet solution;

[0008] (2) determining the main peak area of ​​the main component and the impurity peak area of ​​the degradation impurities in the josamycin tablet solution by liquid chromatography;

[0009] (3) Calculate the corrected main peak area using the following formula:

[0010] Corrected main peak area = impurity peak area / correction factor + main peak area

[0011] Correction factor = 0.45;

[0012] (4) The dissolution amount of josamycin tablets in acidic medium was calculated using the corrected main peak area.

[0013] As a preferred technical solution, in step (1), the acidic medium with a pH value of 1.2 is a hydrochloric acid solution with a pH value of 1.2.

[0014] As a preferred technical solution, in the step (1), a phosphate buffer solution of pH 6.8 is added immediately after dissolution sampling.

[0015] As a preferred technical solution, in step (2), the liquid chromatography detection conditions are:

[0016] Chromatographic column: chromatographic column using octadecylsilane bonded silica gel as filler;

[0017] Mobile phase A: 0.1% trifluoroacetic acid solution;

[0018] Mobile phase B: acetonitrile;

[0019] Flow rate: 1.0ml / min;

[0020] Injection volume: 10 μl;

[0021] Detection wavelength: 231nm;

[0022] Column temperature: 30°C;

[0023] Gradient elution program:

[0024]

[0025] Sample pan temperature: room temperature.

[0026] The beneficial effects of the present invention are:

[0027] The invention adopts liquid chromatography to simultaneously determine josamycin and its degradation products, and establishes the corresponding relationship between the increase of degradation products and the degradation amount of josamycin by using a calculation formula, thereby accurately determining and calculating the dissolution amount of josamycin tablets in acidic medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0029] Figure 1 This is a typical chromatogram of test solution 2;

[0030] Figure 2 This is the linear graph of josamycin. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0032] Example 1 Corresponding relationship between the amount of degradation product increase and the amount of josamycin degradation

[0033] 1. Liquid chromatography detection conditions:

[0034] Chromatographic column: A chromatographic column using octadecylsilane bonded silica as a filler (MicroPulite Platinum C18 4.6mm×250mm 5μm or a chromatographic column with equivalent performance)

[0035] Mobile phase A: 0.1% trifluoroacetic acid solution

[0036] Mobile phase B: acetonitrile

[0037] Flow rate: 1.0ml / min

[0038] Injection volume: 10 μl

[0039] Detection wavelength: 231nm

[0040] Column temperature: 30°C

[0041] Gradient elution program:

[0042]

[0043] Sample pan temperature: room temperature.

[0044] 2. Preparation of solution

[0045] (1) Prepare pH 1.2 hydrochloric acid solution: Take 7.65 ml of hydrochloric acid, dilute to 1000 ml with water, and shake well.

[0046] (2) Preparation of pH 6.8 phosphate buffer: Weigh 34.02 g of potassium dihydrogen phosphate and 4.72 g of sodium hydroxide, add 1000 ml of water to dissolve, and adjust the pH value to 6.8 with phosphoric acid or 1 mol / L sodium hydroxide solution.

[0047] (3) Prepare diluent: pH 1.2 hydrochloric acid solution-pH 6.8 phosphate buffer (1:1).

[0048] (4) Preparation of test solution 1: Take one josamycin tablet, add 900 ml of diluent to dissolve and dilute to make a solution containing 56 μg of josamycin per 1 ml (josamycin tablets will degrade rapidly in a pH 1.2 medium. A certain amount of pH 6.8 phosphate buffer is added to inhibit the degradation of josamycin, so it is used as the 0 h test solution).

[0049] (5) Preparation of test solution 2: Take one josamycin tablet, add 900 ml of pH 1.2 hydrochloric acid solution to dissolve it and dilute it to make a solution containing 56 μg of josamycin per 1 ml.

[0050] 3. Liquid chromatography detection: Take the test solution 1 as the 0-hour test sample and inject the test solution 2 continuously for 8 injections.

[0051] The detection spectrum obtained in Example 1 is as follows Figure 1 As shown in Table 1, the relationship between the degradation rate of the main component (kitasamycin A3) and the increase of the degradation impurity (RRT is about 0.74) is shown in Table 1. The correction factor is calculated using Formula 1, and the peak area of ​​the main peak after correction is calculated using Formula 2.

[0052] Calculation formula 1:

[0053] Calculation formula 2: Corrected main peak area = impurity peak area / correction factor + main peak area.

[0054] Table 1 Relationship between the degradation rate of the main component (kitasamycin A3) and the increase of degradation impurities (RRT is about 0.74)

[0055]

[0056] According to the above test results, the correction factor of the impurity of josamycin tablets at RRT of about 0.74 for 8 consecutive injections in pH 1.2 medium is 0.45 on average within two hours, and the ratio of the main peak area after correction to the 0h peak area is between 99.02% and 100.91%. The sampling time of the pH 1.2 medium dissolution curve is within 2 hours, indicating that the correction factor of 0.45 for the impurity can accurately reflect the dissolution amount of josamycin.

[0057] Example 2 Linearity Test

[0058] The liquid chromatography detection conditions provided in Example 1 were used to examine the degree of linearity within the range of 20% to 120%.

[0059] Prepare linear solution:

[0060] (1) Take about 13.9 mg of josamycin reference substance, accurately weigh it, place it in a 50 ml volumetric flask, dissolve it in a diluent and dilute it to the mark, shake well.

[0061] (2) Linear solution 1 (20%): Accurately measure 1 ml of the linear stock solution, place it in a 50 ml volumetric flask, dilute to the mark with a diluent, shake well, and the solution is obtained (about 5.56 μg / ml).

[0062] (3) Linear solution 2 (50%): Accurately measure 1 ml of the linear stock solution, place it in a 20 ml volumetric flask, dilute to the mark with a diluent, shake well, and the solution is obtained (about 13.9 μg / ml).

[0063] (4) Linear solution 3 (80%): Accurately measure 2 ml of the linear stock solution, place it in a 25 ml volumetric flask, dilute to the mark with diluent, shake well, and the solution is obtained (about 22.24 μg / ml).

[0064] (5) Linear solution 4 (100%): Accurately measure 1 ml of the linear stock solution, place it in a 10 ml volumetric flask, dilute to the mark with a diluent, shake well, and the solution is obtained (about 27.8 μg / ml).

[0065] (6) Linear solution 5 (120%): Accurately measure 3 ml of the linear stock solution, place it in a 25 ml volumetric flask, dilute to the mark with diluent, shake well, and the solution is obtained (about 33.36 μg / ml).

[0066] The linear equation curve of josamycin is as follows Figure 2 As shown, the test results and linear equations are shown in Table 2:

[0067] Table 2 Josamycin linear solution test results and linear equation

[0068]

[0069] According to the test results in Table 2, with the peak area as the horizontal coordinate and the concentration as the vertical coordinate, in the range of 5.305μg / ml to 31.828μg / ml, the linear equation is y=0.0564x-0.5269; r=0.9999, which is greater than 0.995; the ratio of the absolute value of the intercept of the linear equation to the 100% concentration is 1.99%, which is less than 5%; the linear relationship is good.

[0070] Example 3 Accuracy Test

[0071] The preparation of each solution is as follows:

[0072] (1) Prepare pH 1.2 hydrochloric acid solution: Take 7.65 ml of hydrochloric acid, dilute to 1000 ml with water, and shake well.

[0073] (2) Preparation of H6.8 phosphate buffer: Weigh 34.02 g of potassium dihydrogen phosphate and 4.72 g of sodium hydroxide, add 1000 ml of water to dissolve, and adjust the pH value to 6.8 with phosphoric acid or 1 mol / L sodium hydroxide solution.

[0074] (3) Preparation of blank excipient solution: prepare blank excipient (excluding josamycin) according to the prescribed amount, mix well, weigh about 15 mg of blank excipient into a 200 ml volumetric flask, add diluent to dissolve and dilute to the scale, shake well, and obtain.

[0075] (4) Reference substance stock solution: Accurately weigh about 13.9 mg of josamycin reference substance into a 50 ml volumetric flask, add diluent to dissolve and dilute to scale, shake well, and obtain.

[0076] (5) Prepare 20% accuracy solution: Pipette 5 ml of blank auxiliary stock solution into a 50 ml volumetric flask, accurately add 1 ml of reference stock solution, dilute to scale with diluent, shake well, filter and obtain the filtrate. (Prepare 3 copies in parallel)

[0077] (6) Prepare 100% accuracy solution: Pipette 2 ml of blank excipient stock solution into a 10 ml volumetric flask, accurately add 1 ml of reference substance stock solution, dilute to scale with diluent, shake well, filter and obtain the filtrate. (Prepare 3 times in parallel)

[0078] (7) Prepare 120% accuracy solution: Pipette 3 ml of blank auxiliary stock solution into a 25 ml volumetric flask, accurately add 6 ml of reference substance stock solution, dilute to scale with diluent, shake well, filter and obtain the filtrate. (Prepare 3 copies in parallel)

[0079] Calculation formula

[0080]

[0081] Test results:

[0082] By testing the above three groups of accuracy solutions, the accuracy test results of josamycin are shown in Table 3 below:

[0083] Table 3 Josamycin accuracy test results

[0084]

[0085] According to the test results in Table 3, the recovery rates of 20%, 100%, and 120% accuracy solutions are all between 100.32% and 102.21%; the average recovery rate of 20% accuracy is 101.87, RSD = 0.58%; the average recovery rate of 100% accuracy is 101.38%, RSD = 0.15%; the recovery rate of 120% accuracy is 100.77%, RSD = 0.57%; the average recovery rate of 9 test samples is 101.34%, RSD = 0.63%. Therefore, it is shown that the method of using liquid chromatography to detect the dissolution curve of josamycin is accurate.

[0086] Example 4 Determination and calculation of the dissolution amount of josamycin tablets in acidic medium

[0087] 1. Detection method: The dissolution amount of josamycin tablets (batch number: 240205-BY2, specification: 50 mg) was detected using the liquid chromatography detection conditions provided in Example 1.

[0088] 2. Preparation of each solution

[0089] (1) Prepare pH 1.2 hydrochloric acid solution: Take 7.65 ml of hydrochloric acid, dilute to 1000 ml with water, and shake well.

[0090] (2) Preparation of test solution: Take 12 tablets of this product and use 900 ml of pH 1.2 hydrochloric acid solution as the dissolution medium. The rotation speed is 50 rpm and the temperature is 37°C. Sample after 60 minutes. Take 0.5 ml of the dissolution solution and immediately add 0.5 ml of pH 6.8 phosphate buffer and shake well.

[0091] 3. Liquid chromatography detection: The main peak area of ​​the main component and the impurity peak area of ​​the degradation impurities in the josamycin tablet solution were detected using the liquid chromatography detection conditions provided in Example 1.

[0092] 4. Use the following formula to calculate the corrected main peak area:

[0093] Corrected main peak area = impurity peak area / correction factor + main peak area

[0094] Correction factor = 0.45.

[0095] 5. Use the corrected main peak area to calculate the dissolution amount of josamycin tablets in acidic medium.

[0096] The detection and calculation results are shown in Table 4 below:

[0097] Table 4 Dissolution of josamycin tablets in acidic medium

[0098]

[0099] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. An analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium, characterized in that: The following steps are involved: (1) dissolving josamycin tablets in an acidic medium with a pH value of 1.2 to obtain a josamycin tablet solution; (2) determining the main peak area of ​​the main component and the impurity peak area of ​​the degradation impurities in the josamycin tablet solution by liquid chromatography; (3) Calculate the corrected main peak area using the following formula: Corrected main peak area = impurity peak area / correction factor + main peak area Correction factor = 0.45; (4) The dissolution amount of josamycin tablets in acidic medium was calculated using the corrected main peak area.

2. The analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium according to claim 1, characterized in that: In the step (1), the acidic medium with a pH value of 1.2 is a hydrochloric acid solution with a pH value of 1.

2.

3. The analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium according to claim 1, characterized in that: In the step (1), a phosphate buffer solution of pH 6.8 is added immediately after dissolution sampling.

4. The analytical method for determining and calculating the dissolution amount of josamycin tablets in an acidic medium according to any one of claims 1 to 3, characterized in that: In the step (2), the liquid chromatography detection conditions are: Chromatographic column: chromatographic column using octadecylsilane bonded silica gel as filler; Mobile phase A: 0.1% trifluoroacetic acid solution; Mobile phase B: acetonitrile; Flow rate: 1.0ml / min; Injection volume: 10 μl; Detection wavelength: 231nm; Column temperature: 30°C; Gradient elution program: Sample pan temperature: room temperature.

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