Method for detecting dissolution rate of sucralfate suspension

Abstract

The invention relates to a method for detecting the dissolution rate of sucralfate suspension. Specifically, the invention provides the method for detecting the dissolution rate of the sucralfate suspension, which is small in sampling amount, simple and convenient to operate, high in accuracy and high in sensitivity.

Description

Technical Field

[0001] The present invention belongs to the field of drug analysis and relates to a method for detecting the dissolution of a sucralfate suspension. Background Art

[0002] The second part of the 2020 edition of the Chinese Pharmacopoeia records the determination method of aluminum content in sucralfate oral suspension: take an appropriate amount of this product (approximately equivalent to 1g of sucralfate), accurately weigh it, put it in a 200ml volumetric flask, add 10ml of dilute hydrochloric acid, shake it to dissolve the sucralfate, dilute it to the scale with water, and shake it well; accurately measure 20ml and determine it according to the aluminum method under sucralfate. Calculate according to the relative density of this product. Each 1ml of disodium ethylenediaminetetraacetic acid solution (0.05mo / L) is equivalent to 1.349mg of Al.

[0003] The method for determining aluminum content under the item of sucralfate in Part II of the 2020 edition of the Chinese Pharmacopoeia is as follows: take about 1.0g of this product, accurately weigh it, place it in a 200ml volumetric flask, add 10ml of dilute hydrochloric acid to dissolve it, dilute it with water to the scale, and shake it well; accurately measure 20ml, add the test solution to neutralize it until a precipitate is precipitated, then add dilute hydrochloric acid until the precipitate is just dissolved, add acetic acid-ammonium acetate buffer (pH 6.0) 20ml, and then accurately add 25ml of disodium ethylenediaminetetraacetic acid solution (0.05mol / L), boil for 3 to 5 minutes, cool to room temperature, add 1ml of xylenol orange indicator solution, and titrate with zinc titration solution (0.05mo / L) until the solution changes from yellow to red, and the titration result is corrected with a blank test. Each 1ml of disodium ethylenediaminetetraacetic acid solution (0.05mol / L) is equivalent to 1.349mg of Al.

[0004] However, in the actual production operation process, EDTA and aluminum complexation is slow, and there are many side reactions. Therefore, the back titration method is used to boil the aluminum solution to be tested and a certain amount of excess EDTA standard solution for several minutes, and then add a buffer solution and use a standard zinc solution to back titrate the excess EDTA. At the same time, the above pharmacopoeia method requires a lot of dissolution solution (20ml for each sampling), sampling and filtration are difficult, and the operation timeliness is poor during the dissolution curve process, and the method is not simple.

[0005] There is also an 8-hydroxyquinoline fluorescent reagent-HPLC detection method to detect the aluminum ion content to measure the dissolution of sucralfate suspension. Using this detection method, the aluminum ion in the dissolution solution of sucralfate oral suspension is detected. The complex tailing is serious and the integral parameter will affect the accuracy of the test result. Summary of the invention

[0006] The present invention discloses a method for detecting the dissolution of sucralfate suspension with small sampling amount, simple operation, high accuracy and high sensitivity, and can also be used for the detection of aluminum ions in acidic dissolution media.

[0007] The present disclosure provides a method for detecting the dissolution of a sucralfate suspension, the method comprising the following steps:

[0008] Step a. It comprises: preparing a color developing solution;

[0009] Step b. comprising: preparing an aluminum standard curve solution using a color developing solution;

[0010] Step c comprises: using a color developing solution to prepare a blank preparation dissolution solution and a test solution;

[0011] Step d comprises: measuring the solution obtained in step b by ultraviolet spectrophotometry to obtain a response value and drawing a standard curve;

[0012] Step e. comprising: measuring the solution obtained in step c by ultraviolet spectrophotometry to obtain a response value, and

[0013] Step f. It includes: substituting the response value obtained in step d into the standard curve obtained in step d to calculate the aluminum dissolution content.

[0014] The steps a, b, c, d, e or f described in the present disclosure are not limited in order. For example, the order of step a and step b can be interchanged, and step c using ultraviolet spectrophotometry can be performed after steps a and b, or between steps a and b, and so on.

[0015] In some embodiments, the color developing solution includes a color developing agent, a pH adjusting agent, and a solvent.

[0016] In some embodiments, the color developing agent is selected from 8-hydroxyquinoline.

[0017] In some embodiments, the pH adjuster is selected from ammonium acetate.

[0018] In some embodiments, the solvent is selected from one or more of water, ethanol, dichloromethane, chloroform, acetonitrile. In some embodiments, the solvent is selected from acetonitrile. In some embodiments, the solvent is selected from water.

[0019] In some embodiments, the pH of the color developing solution is between 6.5 and 9.5.

[0020] In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step a includes the step of mixing 8-hydroxyquinoline acetonitrile solution with ammonium acetate test solution; in some embodiments, step a includes the step of mixing 8-hydroxyquinoline acetonitrile solution with ammonium acetate test solution in a ratio of 1:1 (V / V); in some embodiments, the concentration of 8-hydroxyquinoline acetonitrile solution used to prepare the color developing solution is 3 g / L; in some embodiments, the concentration of ammonium acetate test solution used to prepare the color developing solution is 0.2 mol / L.

[0021] In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: respectively taking different volumes of aluminum standard solution, and quantitatively diluting with a color developing solution to obtain a standard curve solution; in some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: respectively taking different volumes of aluminum standard solution, and quantitatively diluting with a color developing solution to a solution with a concentration range of 0.4 to 6 μg / ml, to obtain a standard curve solution; in some embodiments, the concentration range of the solution after quantitative dilution with the color developing solution in step b is 0.8 to 8 μg / ml; in some embodiments, the concentration range of the solution after quantitative dilution with the color developing solution in step b is 2 to 7 μg / ml; in some embodiments, the concentration range of the solution after quantitative dilution with the color developing solution in step b is 2 to 6 μg / ml.

[0022] In some embodiments, the concentration of the aluminum standard solution is 1000 μg / ml.

[0023] In some embodiments, the concentration of the aluminum standard solution is 20 μg / ml.

[0024] In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 0.4 μg / ml with a color developing solution. In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 0.8 μg / ml with a color developing solution. In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 2 μg / ml with a color developing solution. In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 3.2 μg / ml with a color developing solution. In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 4 μg / ml with a color developing solution. In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 5 μg / ml with a color developing solution. In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step b comprises: pipetting 20 μg / ml of aluminum standard solution, and quantitatively diluting it to 6 μg / ml with a color developing solution.

[0025] In some embodiments, the method for preparing the aluminum standard solution in step b further includes a standing step.

[0026] In some embodiments, the method for preparing the aluminum standard solution in step b further comprises the step of standing for 20 minutes after quantitative dilution.

[0027] In some embodiments, the dissolution medium comprises 0.1 N HCL / 0.067 M KCl, pH 1.0.

[0028] In some embodiments, the method for preparing a blank preparation comprises: subjecting the preparation containing sucralfate to a high-speed centrifugation step.

[0029] In some embodiments, in the method for preparing the blank preparation, the high-speed centrifugation speed is selected from 8000 r / min.

[0030] In some embodiments, the method for detecting the solubility of sucralfate suspension, wherein step c includes: mixing a blank preparation with a dissolution medium, and diluting it with a color developing solution. In some embodiments, step c also includes: mixing the blank preparation centrifugal supernatant with a dissolution medium, and diluting it with a color developing solution. In some embodiments, step c also includes: mixing the blank preparation centrifugal supernatant with a dissolution medium, and diluting it with a color developing solution, and then filtering it with a filter membrane. In some embodiments, step c also includes: mixing the blank preparation centrifugal supernatant with a dissolution medium, and diluting it with a color developing solution, and then filtering it with a filter membrane, and then further diluting it with a color developing agent.

[0031] In some embodiments, the method for preparing the blank preparation dissolution solution in step c further includes a standing step.

[0032] In some embodiments, the method for preparing the blank preparation dissolution solution in step c further comprises the step of standing for 20 minutes after quantitative dilution.

[0033] In some embodiments, the method for preparing the test solution in step c includes the steps of taking the sample dissolution solution and diluting it with a color developing solution.

[0034] In some embodiments, the method for preparing the test solution in step c includes taking 1 ml of the sample solution and diluting the volume to 50 ml with a color developing solution.

[0035] In some embodiments, the method for detecting the dissolution of the sucralfate suspension, wherein step d comprises: measuring the solution obtained in step b by ultraviolet spectrophotometry, and drawing a standard curve. In some embodiments, the method for detecting the dissolution of the sucralfate suspension, wherein step d comprises: measuring the solution obtained in step b by ultraviolet spectrophotometry at 385-420nm, and drawing a standard curve. In some embodiments, measuring the solution obtained in step b by ultraviolet spectrophotometry at 390-415nm, and drawing a standard curve. In some embodiments, measuring the solution obtained in step b by ultraviolet spectrophotometry at 393nm, and drawing a standard curve.

[0036] In some embodiments, the step of drawing a standard curve includes: drawing a standard curve with aluminum ion concentration (μg / ml) as the horizontal coordinate x and the response value (OD) after deducting the blank preparation dissolution solution as the vertical coordinate y, and performing linear regression.

[0037] In some embodiments, the method for detecting the solubility of the sucralfate suspension, wherein step e comprises: measuring the solution obtained in step c by ultraviolet spectrophotometry, and substituting the response value into the standard curve obtained in step d to calculate the aluminum dissolution content. In some embodiments, the method for detecting the solubility of the sucralfate suspension, wherein step e comprises: measuring the solution obtained in step c by ultraviolet spectrophotometry at 385-420nm, and substituting the response value into the standard curve obtained in step d to calculate the aluminum dissolution content. In some embodiments, the solution obtained in step c is measured by ultraviolet spectrophotometry at 390-415nm, and the response value is substituted into the standard curve obtained in step d to calculate the aluminum dissolution content. In some embodiments, the solution obtained in step c is measured by ultraviolet spectrophotometry at 393nm, and the response value is substituted into the standard curve obtained in step d to calculate the aluminum dissolution content.

[0038] The present disclosure provides a method for detecting the dissolution of a sucralfate suspension, the method comprising the following steps:

[0039] Step a. It comprises: mixing 3 g / L 8-hydroxyquinoline acetonitrile solution with 0.2 mol / L ammonium acetate aqueous solution in a volume ratio of 1:1 to obtain a color developing solution;

[0040] Step b. It comprises: taking different volumes of aluminum standard solution respectively, and quantitatively diluting the solution with the color developing solution in step a to a concentration range of 2 to 6 μg / ml to obtain a standard curve solution;

[0041] Step c comprises: taking 1 ml of the centrifuged supernatant of the blank preparation and mixing it with 90 ml of the dissolution medium, filtering it through a filter membrane, taking 1 ml of the mixed solution, and diluting it to 50 ml with a color developing solution;

[0042] Step c. further comprises: taking 1 ml of the sample solution and diluting the volume to 50 ml with a color developing solution;

[0043] Step d comprises: measuring the solution obtained in step b at 393 nm by ultraviolet spectrophotometry, and drawing a standard curve;

[0044] Step e. It includes: using ultraviolet spectrophotometry to measure the solution obtained in step c at 393nm, and substituting the response value into the standard curve obtained in step d to calculate the aluminum dissolution content. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 .The standard curve drawn by the detection method of sucralfate suspension dissolution in Example 1.

[0046] Figure 2 .The standard curve of the 8-hydroxyquinoline fluorescence reagent detection method in Comparative Example 1.

[0047] Figure 3 .HPLC spectrum of 8-hydroxyquinoline fluorescence reagent detection method in Comparative Example 1.

[0048] Figure 4 .The standard curve drawn by the aluminum reagent detection method in Comparative Example 2. DETAILED DESCRIPTION

[0049] Example 1

[0050] 1.1 Sucralfate dissolution measurement method:

[0051] Sample to be tested (test product): Use a paddle apparatus (USP type 2) at 75 rpm in 900 ml 0.1 N HCL / 0.067 M KCl solution (pH 1.0) at 37.5°C ± 0.5°C to dissolve sucralfate oral suspension. The added amount is 10 g (10 ml, containing approximately 1 g of sucralfate). Samples are taken at 10 min, 20 min, 30 min and 45 min, respectively, and filtered through a 0.45 μm filter membrane to obtain the filtrate.

[0052] 1.2 Sucralfate dissolution test method:

[0053] 1.2.1 Sample preparation

[0054] Preparation of color developing solution: Take 6 g of 8-hydroxyquinoline, dissolve it in 2000 ml of acetonitrile, filter, measure 2000 ml of 8-hydroxyquinoline acetonitrile solution and 2000 ml of 0.2 mol / L ammonium acetate solution (take 30 g of ammonium acetate, dissolve it in 2000 ml of water, filter, and obtain), mix well, and ultrasonicate to obtain.

[0055] Reference solution stock solution (20 μg / ml): Take 2 ml of aluminum standard solution (aluminum content 1000 μg / ml), place in a 100 ml volumetric flask, dilute to the scale with color developing solution, shake well, and leave for 20 minutes.

[0056] Preparation of reference substance limit concentration solution: dilute the reference substance stock solution according to Table 1 below to obtain different reference substance limit concentration solutions.

[0057] Table 1

[0058] limit concentration Dilution process 45% limit solution 2μg / ml 2ml→20ml 72% limit solution 3.2μg / ml 4ml→25ml 90% limit solution 4μg / ml 5ml→25ml 113% limit solution 5μg / ml 5ml→20ml 135% limit solution 6μg / ml 3ml→10ml

[0059] Pretreatment of blank preparation: Take sucralfate oral suspension and centrifuge at high speed (8000r / min) for at least 5 times (10min / time) until there is no obvious precipitation at the bottom of the centrifuge tube, and combine the centrifuge fluid.

[0060] Preparation of blank preparation dissolution solution: accurately measure 1 ml of blank preparation, place in a 100 ml volumetric flask, add 90 ml of 37°C medium, shake well, and filter through a 0.45 μm filter membrane to obtain the solution.

[0061] Preparation of blank preparation dissolution solution for test sample solution: Take 1 ml of blank preparation dissolution solution, place it in a 50 ml volumetric flask, add color developing solution to dilute to the scale, shake well, and let it stand for 20 minutes.

[0062] Preparation of test solution: Take 1 ml of sucralfate oral suspension dissolution solution, place it in a 50 ml volumetric flask, add color developing solution to dilute to the scale, shake well, and let it stand for 20 minutes.

[0063] 1.2.2 Establishing a standard curve

[0064] Using ultraviolet spectrophotometry, the solutions shown in Table 2 below were injected in sequence, and the absorbance (OD) value of the reference solution was measured at 393 nm.

[0065] Table 2

[0066]

[0067] Linear regression was performed with aluminum ion concentration (μg / ml) as the horizontal axis x and the absorbance of the sample solution (OD) as the vertical axis y. Figure 1 The standard curve is shown.

[0068] 1.2.3 Determination of aluminum ion content in samples

[0069] The absorbance of the blank preparation dissolution solution, the test solution and the test solution at different sampling time points were measured by ultraviolet spectrophotometry at a wavelength of 393 nm using a 1 cm cuvette.

[0070] Substitute the absorbance of the test solution after deducting the blank preparation dissolution solution into the regression equation obtained from the above standard curve: y=0.1968x-0.0074 to obtain the aluminum ion concentration of the sample solution.

[0071] 1.3 Dissolution curve results

[0072]

[0073] Example 2 Methodology Verification

[0074] 2.1 System Applicability

[0075] System suitability requirements:

[0076] The 90% reference limit solution was measured 5 times in succession, and the RSD of the absorbance should be no greater than 2.0%;

[0077] Within the limit concentration range, the absorbance has a good linear relationship with the limit solution concentration, the correlation coefficient (r) should be greater than 0.990, and the absolute value of the y-axis intercept should be less than 5% of the absorbance at the 100% limit concentration point. Report the linear equation y=ax+b, slope a and variance, and draw a linear graph.

[0078] Solution preparation:

[0079] Preparation of color developing solution: Take 6 g of 8-hydroxyquinoline, dissolve it in 2000 ml of acetonitrile, filter, measure 2000 ml of 8-hydroxyquinoline acetonitrile solution and 2000 ml of 0.2 mol / L ammonium acetate solution (take 30 g of ammonium acetate, dissolve it in 2000 ml of water, filter, and obtain), mix well, and ultrasonicate to obtain.

[0080] Reference solution stock solution (20 μg / ml): Take 2 ml of aluminum standard solution (aluminum content 1000 μg / ml) → 100 ml, add colorimetric solution to dilute to the scale, shake well, and leave for 20 minutes.

[0081] Dilute the reference substance stock solution with the color developing solution according to the table below to obtain reference substance solutions with different limit concentrations.

[0082] Table 3

[0083] limit concentration Dilution process 45% limit solution 2μg / ml 2ml→20ml 72% limit solution 3.2μg / ml 4ml→25ml 90% limit solution 4μg / ml 5ml→25ml 113% limit solution 5μg / ml 5ml→20ml 135% limit solution 6μg / ml 3ml→10ml

[0084] At a wavelength of 393nm, use a 1cm cuvette to measure the absorbance of reference solutions with different limit concentrations using the colorimetric solution as a reference.

[0085] like Figure 1As shown, within the limit concentration range, the absorbance has a good linear relationship with the limit solution concentration, the correlation coefficient (r) is 0.9998, which is greater than 0.990, and the absolute value of the y-axis intercept is less than 5% (0.85%) of the absorbance at the 100% limit concentration point, which meets the expected standard.

[0086] Table 4 System suitability results

[0087]

[0088] Conclusion: The 90% reference limit solution was measured 5 times in succession, and the RSD of absorbance was 0.1%, which was less than 2.0% and met the expected standard.

[0089] 2.2 Linearity

[0090] Solution preparation: Prepare in the same manner as in 2.1 “System suitability”.

[0091] Linearity criteria: r ≥ 0.990, intercept less than or equal to 5% of the 100% level response value

[0092] Conclusion: (r) was 0.9998 and the intercept was 0.85% of the 100% level response value, which met the expected standards.

[0093] 2.2 Exclusivity

[0094] Solution preparation:

[0095] Preparation of dissolution medium test solution: Take 1 ml of dissolution medium, place it in a 50 ml volumetric flask, add color developing solution to dilute to the scale, shake well, and leave it at room temperature for 20 minutes.

[0096] Test solution: Weigh 123 mg of sucralfate raw material, place it in a 100 ml volumetric flask, add 1 ml (about 1 g) of blank preparation, shake to disperse evenly, add an appropriate amount of dissolution medium, ultrasonicate for 20 minutes to fully dissolve the sucralfate raw material, dilute to the scale with the dissolution medium, shake well, filter, discard 3 ml of the initial filtrate, take 1 ml of the subsequent filtrate, place it in a 50 ml volumetric flask, add solvent to dilute to the scale, shake well, and leave at room temperature for 20 minutes.

[0097] Expected standard: The absorbance of the dissolution medium is less than 2% of the absorbance of the test solution.

[0098] The experimental results are shown in Table 5 below.

[0099] Table 5 Specificity results

[0100]

[0101] Conclusion: The absorbance of the dissolution medium (0.004) is 0.5% of the absorbance of the test solution (0.845), which is less than 2% and meets the expected standard.

[0102] 2.3 Repeatability

[0103] Solution preparation

[0104] Color development solution: 8-Hydroxyquinoline acetonitrile solution (6g to 2000ml)-0.2mol / L ammonium acetate test solution (1:1)

[0105] Repeatability test solution: weigh 123 mg of sucralfate raw material, place in a 100 ml volumetric flask, add 1 ml of blank preparation (about 1 g), shake to disperse evenly, add appropriate amount of dissolution medium, ultrasonic for 20 minutes to fully dissolve the sucralfate raw material, dilute to scale with dissolution medium, shake well, filter, discard 3 ml of the initial filtrate, take 1 ml of the subsequent filtrate, place in a 50 ml volumetric flask, dilute to scale with color solution, shake well, and leave at room temperature for 20 minutes. Prepare 6 copies in parallel.

[0106] Repeatability standard: The RSD of aluminum concentration test results shall not exceed 2.0%.

[0107] The experimental results are shown in Table 6 below.

[0108] Table 6 Repeatability results

[0109]

[0110]

[0111] Conclusion: The RSD of the aluminum concentration test results was 0.9%, which was less than 2.0% and met the expected standard.

[0112] 2.4 Accuracy

[0113] Blank preparation test solution: Take 1 ml (about 1 g) of blank preparation, place it in a 100 ml volumetric flask, dilute to scale with dissolution medium, shake well, filter, discard 3 ml of primary filtrate, take 1 ml of subsequent filtrate, place it in a 50 ml volumetric flask, add color development solution to dilute to scale, shake well, and place at room temperature for 20 minutes. Prepare 3 copies in parallel.

[0114] 45% accuracy sample: weigh 55 mg of sucralfate raw material, place in a 100 ml volumetric flask, add 1 ml of blank preparation (about 1 g), shake to disperse evenly, add appropriate amount of dissolution medium, ultrasonic for 20 minutes to fully dissolve the sucralfate raw material, dilute to scale with dissolution medium, shake well, filter, discard 3 ml of the initial filtrate, take 1 ml of the subsequent filtrate, place in a 50 ml volumetric flask, add color solution to dilute to scale, shake well, and leave at room temperature for 20 minutes. Prepare 3 copies in parallel.

[0115] 100% accuracy sample: weigh 123 mg of sucralfate raw material, place in a 100 ml volumetric flask, add 1 ml of blank preparation (about 1 g), shake to disperse evenly, add appropriate amount of dissolution medium, ultrasonic for 20 minutes to fully dissolve the sucralfate raw material, dilute to scale with dissolution medium, shake well, filter, discard 3 ml of the initial filtrate, take 1 ml of the subsequent filtrate, place in a 50 ml volumetric flask, add color solution to dilute to scale, shake well, and leave at room temperature for 20 minutes. Prepare 3 copies in parallel.

[0116] 135% accuracy sample: weigh 166 mg of sucralfate raw material, place in a 100 ml volumetric flask, add 1 ml of blank preparation (about 1 g), shake to disperse evenly, add appropriate amount of dissolution medium, ultrasonic for 20 minutes to fully dissolve the sucralfate raw material, dilute to scale with dissolution medium, shake well, filter, discard 3 ml of the initial filtrate, take 1 ml of the subsequent filtrate, place in a 50 ml volumetric flask, dilute to scale with color solution, shake well, and leave at room temperature for 20 minutes. Prepare 3 copies in parallel.

[0117] Expected standard: The recovery rate should be between 95.0% and 105.0%, and the RSD should not exceed 5.0%.

[0118] The recovery rate experimental results are shown in Table 7 below.

[0119] Table 7 Accuracy results

[0120]

[0121] Conclusion: The recovery rate was between 97.4% and 102.5%, and the RSD was 2.1%, which was in line with the expected standard.

[0122] 2.5 Solution stability

[0123] Place the 90% limit reference solution and the test solution at room temperature for 0 h, 1 h, 2 h, 4 h, and 6 h, measure the absorbance, and calculate the relative deviation of the absorbance at each time period.

[0124] Solution stability standard: When the absolute value of the relative deviation of the absorbance at each time point from the starting point is ≤2.0%, the solution is considered stable.

[0125] The results of the stability test are shown in Table 8 below.

[0126] Table 8 Solution stability results

[0127]

[0128] Conclusion: The 90% limit reference solution and the test solution were placed at room temperature for 6 hours, and the relative deviation of the absorbance at each time point from the starting point was less than 2.0%, and the solution was stable within 6 hours.

[0129] Comparative Example 1 8-Hydroxyquinoline Fluorescence Reagent-HPLC Detection Method

[0130] Chromatographic conditions:

[0131] Chromatographic column: Agilent ZORBAX SB-Phenyl 4.6×250mm, 5μm

[0132] Detector: Fluorescence detector (excitation wavelength: 380nm, emission wavelength: 520nm)

[0133] Column temperature: 40°C

[0134] Mobile phase: 8-Hydroxyquinoline acetonitrile solution (3g to 1000ml): 0.2mol / L ammonium acetate test solution = 1:1

[0135] Flow rate: 1.0ml / min

[0136] Injection volume: 20 μl

[0137] Injection time: 15min

[0138] Each solution was prepared by UV determination method.

[0139] Linear

[0140] Solution preparation: Prepare in the same manner as in 2.1 “System suitability”.

[0141] The reference substances with different limit concentrations were subjected to HPLC-fluorescence detection according to the above chromatographic conditions to detect the peak area of ​​8-hydroxyquinoline-aluminum complex. A linear regression was performed with aluminum ion concentration (μg / ml) as the abscissa and peak area as the ordinate y to draw the following graph: Figure 2 The standard curve is shown.

[0142] Linearity criteria: r ≥ 0.990, intercept less than or equal to 5% of the 100% level response value

[0143] Conclusion: The standard curve obtained using the fluorescence detection method is as follows Figure 2 As shown in Figure 2, (r) is 0.9998, and the intercept is 2.0% of the 100% level response value, which meets the expected standard.

[0144] Repeatability

[0145] Solution preparation: Prepare in the same manner as in 2.3 “Reproducibility”.

[0146] Perform HPLC-fluorescence detection according to the above chromatographic conditions and determine the peak area of ​​the test solution.

[0147] Substitute the peak area of ​​the test solution into the regression equation obtained from the above standard curve: y=89.7926x-7.7241 to obtain the aluminum ion concentration of the sample solution.

[0148] Repeatability standard: The RSD of aluminum concentration test results shall not exceed 2.0%.

[0149] The experimental results are shown in Table 9 below.

[0150] Table 9 Repeatability results

[0151]

[0152] Conclusion: The RSD of the aluminum concentration test results was 0.9%, which was less than 2.0% and met the expected standard.

[0153] Accuracy

[0154] Solution preparation: Prepare in the same way as in 2.4 “Accuracy”.

[0155] Expected standard: The recovery rate should be between 95.0% and 105.0%, and the RSD should not exceed 5.0%.

[0156] The recovery rate experimental results are shown in Table 10 below.

[0157] Table 10 Accuracy results

[0158]

[0159] Conclusion: The recovery rate is between 92.8% and 97.2%, with an RSD of 1.7%, which does not meet the expected standard (between 95.0% and 105.0%). Figure 3 The HPLC results shown show that the complex has severe tailing (tailing factor 2.82), and the complex tailing affects the accuracy of this method.

[0160] Solution stability

[0161] The 90% limit reference solution and the test solution were placed at room temperature for 0 h, 2 h, 4 h, and 6 h, respectively, the peak areas were measured, and the relative deviation of the peak areas in each time period was calculated.

[0162] Solution stability standard: When the absolute value of the relative deviation of the peak area at each time point from the starting point is ≤2.0%, the solution is considered stable.

[0163] The results of the stability test are shown in Table 11 below.

[0164] Table 11 Solution stability results

[0165]

[0166] Conclusion: The relative deviation of the peak area at each time point and the starting point is greater than 2.0%, and the solution stability is poor.

[0167] Comparative Example 2 Aluminum Reagent Detection Method

[0168] Solution preparation

[0169] 1. Ammonia solution (0.1 mol / L): dilute 1 ml of ammonia solution to 150 ml with purified water.

[0170] 2. Hydrochloric acid solution (0.1 mol / L): dilute 1 ml of hydrochloric acid to 120 ml with purified water.

[0171] 3. p-Nitrophenol indicator (1g / L): Weigh about 0.10g of p-nitrophenol, place it in a 100ml volumetric flask, add purified water to dissolve and dilute to the scale.

[0172] 4. Aluminum reagent (0.5g / L): Weigh about 0.25g of aluminum reagent (ammonium salt of gold tricarboxylate), add 250ml of purified water, warm until dissolved, add about 72g of ammonium acetate, after dissolving, add 30.0ml of glacial acetic acid, dilute to 500ml with purified water. Filter if necessary, place in a brown bottle, and store in a dark place.

[0173] 5. Aluminum standard working solution (10.0 μg / ml): Accurately measure 1 ml of aluminum standard solution (1000 μg / ml), place it in a 100 ml volumetric flask, dilute to the scale with purified water, and shake well.

[0174] 6. Preparation of standard solution: Accurately measure 3ml, 4ml, 5ml, 6ml, 7ml, and 8ml of aluminum standard solution respectively, place in a 50ml volumetric flask, add appropriate amount of purified water, add 3 drops of p-nitrophenol indicator, add 4.0ml of aluminum reagent solution, dilute to the scale with purified water, shake well, and let stand for 15 minutes.

[0175] 7. Preparation of repeatable test solution:

[0176] Accurately measure 3 ml of the dissolution solution, place it in a 20 ml volumetric flask, dilute it to the mark with purified water, shake it well, and use it as the test solution; accurately measure 4 ml of the test solution, place it in a 50 ml stoppered colorimetric tube, add purified water to 25 ml, and add 3 drops of p-nitrophenol indicator. If the test tube does not show color, first add ammonia solution until it turns yellow, and then add hydrochloric acid solution until the yellow color just disappears. Add 4.0 ml of aluminum reagent solution, dilute it to 50 ml with pure water, shake it well, let it stand for 15 minutes, and prepare 6 copies in parallel.

[0177] Establishing a standard curve

[0178] Using ultraviolet spectrophotometry, the standard solutions were injected in sequence and the absorbance was measured at a wavelength of 528 nm. The test results are shown in Table 12 below. Linear regression was performed with the aluminum ion content (μg) of the standard tube as the abscissa x and the absorbance (OD) of the reference solution as the ordinate y. Figure 4 The standard curve is shown.

[0179] Table 12

[0180] name Standard tube aluminum content (μg) Absorbance LR-3ml 30.00 0.215 LR-4ml 40.00 0.279 LR-5ml 50.00 0.341 LR-6ml 60.00 0.396 LR-7ml 70.00 0.445 LR-8ml 80.00 0.483

[0181] Determination of aluminum ion content in samples

[0182] The absorbance of the sample solution was measured by ultraviolet spectrophotometry at a wavelength of 528 nm using a 1 cm cuvette. The absorbance was substituted into the regression equation obtained from the above standard curve: y = 0.0054x + 0.0624 to obtain the aluminum ion content of the sample.

[0183] Repeatability:

[0184] Repeatability standard: RSD of dissolution shall not exceed 2.0%.

[0185] The experimental results are shown in Table 13 below. The RSD of dissolution is 81.2%, which is greater than 2.0% and does not meet the expected standard.

[0186] Table 13

[0187]

[0188] in conclusion:

[0189] 1. The preparation process is cumbersome and the operation timeliness is poor;

[0190] 2. There are many interfering factors in the preparation and measurement processes, and the repeatability of the measurement results is poor.

Claims

1. A method for detecting the dissolution of a sucralfate suspension, the method comprising the following steps: Step a. It comprises: preparing a color developing solution; Step b comprises: using a color developing solution to prepare an aluminum standard curve solution; Step c comprises: using a color developing solution to prepare a blank preparation dissolution solution and a test solution; Step d comprises: measuring the solution obtained in step b by ultraviolet spectrophotometry to obtain a response value and drawing a standard curve; Step e. comprising: measuring the solution obtained in step c by ultraviolet spectrophotometry to obtain a response value, and Step f. It includes: substituting the response value obtained in step e into the standard curve obtained in step d to calculate the aluminum dissolution content.

2. The method according to claim 1, wherein: The color developing solution described in step a comprises a color developer, a pH adjuster and a solvent, wherein the color developer is selected from 8-hydroxyquinoline, the pH adjuster is selected from ammonium acetate, and the solvent is selected from one or more of acetonitrile and water.

3. The method according to claim 2, wherein the color developing solution comprises 3 g / L 8-hydroxyquinoline acetonitrile solution and 0.2 mol / L ammonium acetate aqueous solution.

4. The method according to any one of claims 1 to 3, wherein: The step b comprises: respectively taking different volumes of aluminum standard solutions, and quantitatively diluting them with a color developing solution to a solution with a concentration range of 2.0 to 6 μg / ml to obtain a standard curve solution.

5. The method according to claim 4, wherein: The concentration range after quantitative dilution with the color developing solution in step b is 2 μg / ml, 3.2 μg / ml, 4 μg / ml, 5 μg / ml, and 6 μg / ml.

6. The method according to any one of claims 1 to 5, wherein: The preparation of the blank preparation dissolution solution in step c comprises the steps of mixing the blank preparation centrifuged supernatant with the dissolution medium and diluting with a color developing solution.

7. The method according to any one of claims 1 to 6, wherein: The preparation of the test solution in step c includes the step of diluting the sample dissolution solution with a color developing solution.

8. The method according to any one of claims 1 to 7, wherein: The step d comprises: measuring the solution obtained in step b at 385-420 nm by ultraviolet spectrophotometry, and drawing a standard curve; preferably, measuring the solution obtained in step b at 390-415 nm by ultraviolet spectrophotometry, and drawing a standard curve.

9. The method according to any one of claims 1 to 8, wherein: The step f comprises: using ultraviolet spectrophotometry to measure the response value of the solution obtained in step c at 385-420 nm, and substituting it into the standard curve obtained in step d to calculate the aluminum dissolution content; preferably, using ultraviolet spectrophotometry to measure the response value of the solution obtained in step c at 390-415 nm, and substituting it into the standard curve obtained in step d to calculate the aluminum dissolution content.

10. The method according to any one of claims 1 to 9, wherein the ultraviolet spectrophotometry is performed at a wavelength of 393 nm.

11. A method for detecting the dissolution of a sucralfate suspension, the method comprising the following steps: Step a. It comprises: mixing 3 g / L 8-hydroxyquinoline acetonitrile solution with 0.2 mol / L ammonium acetate aqueous solution in a volume ratio of 1:1 to obtain a color developing solution; Step b. It comprises: taking different volumes of aluminum standard solution, quantitatively diluting the solution with the color developing solution in step a to a concentration range of 2 to 6 μg / ml, and leaving it at room temperature for 20 minutes to obtain a standard curve solution; Step c comprises: taking 1 ml of the centrifuged supernatant of the blank preparation and mixing it with 90 ml of the dissolution medium, filtering it through a filter membrane, taking 1 ml of the mixed solution, and diluting it to 50 ml with a color developing solution; Step c. further comprises: taking 1 ml of the sample solution and diluting the volume to 50 ml with a color developing solution; Step d comprises: measuring the solution obtained in step b at 393 nm by ultraviolet spectrophotometry, and drawing a standard curve; Step e. It includes: using ultraviolet spectrophotometry to measure the solution obtained in step c at 393nm, and substituting the response value into the standard curve obtained in step d to calculate the aluminum dissolution content.

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