Method for detecting hydroxypropylcellulose in a povidone-containing formulation

Abstract

The application provides a detection method of hydroxypropyl cellulose in a povidone-containing preparation, and specifically comprises the following steps: (1) preparing a sample solution by pretreating a sample to be detected; (2) detecting the sample solution by using HPLC, wherein an evaporative light scattering detector or an electrospray detector is used as a detector, a C18 chromatographic column is used as a chromatographic column, the column temperature is 20-40 DEG C, water is used as a mobile phase A, methanol is used as a mobile phase B, the flow rate is 0.5 ml / min-1.5 ml / min, and gradient elution is adopted. The detection method has good specificity and peak type, can not only separate hydroxypropyl cellulose from povidone and other high-molecular auxiliary materials in a pharmaceutical preparation, accurately quantify the content of hydroxypropyl cellulose, but also effectively identify the model, and provides a good method for reverse analysis, component analysis, auxiliary material release detection of the pharmaceutical preparation.

Description

Technical Field

[0001] This invention belongs to the field of chemical analysis technology, specifically relating to a method for detecting hydroxypropyl cellulose in povidone-containing preparations. Background Technology

[0002] Hydroxypropyl cellulose is a nonionic cellulose ether obtained by reacting basic cellulose with propylene oxide. Depending on the content of hydroxypropoxy groups, it can be divided into low-substituted hydroxypropyl cellulose and high-substituted hydroxypropyl cellulose. It is commonly used in pharmaceutical preparations as a binder, thickener, and disintegrant. Povidone K30 is a 1-vinyl-2-pyrrolidone homopolymer obtained by polymerizing vinylpyrrolidone. It has high viscosity and can be used as a binder for tablets and granules, a solubilizer and stabilizer for injections, and a dispersant for liquid preparations.

[0003] Reverse analysis of pharmaceutical formulations is a key technology that uses analytical methods to reverse analyze factors such as the crystal form and particle size of active pharmaceutical ingredients (APIs), the type and amount of excipients, and the formulation process in order to produce a product with the same quality and efficacy as the target drug formulation. For the reverse analysis of hydroxypropyl cellulose in pharmaceutical formulations, liquid chromatography equipped with a differential refractive index detector is typically used, with detection performed on a size-exclusion column. Zhang Li et al., Determination of Hydroxypropyl Methylcellulose Content in Corneal Contact Lens Solution by High Performance Gel Chromatography [J], Physicochemical Testing (Chemical Analysis), 2014, 50(09): 1139-1141, disclosed a method for determining the content of hydroxypropyl methylcellulose in corneal contact lens solution by high performance gel chromatography. The method uses a hydrogel chromatography column (TSK-Gelα3000 and TSK-Gelα3000 in series) as the separation column, sodium chloride solution as the mobile phase, a flow rate of 0.7 mL / min, a column temperature of 30℃, and a differential refractive index detector for detection. This method can eliminate interference from trehalose, polyvinylpyrrolidone, poloxamer, carboxymethyl cellulose, etc., on hydroxypropyl methylcellulose. When using gel chromatography to detect cetylpyridinium chloride tablets, the peaks of hydroxypropyl methylcellulose and povidone K30 overlapped. Patent CN116165289A discloses a method for determining the content of hydroxypropyl cellulose using HPLC-CAD. The method employs an acetonitrile / methanol-water system as the mobile phase for gradient elution. The elution program is: 0 minutes 100% water; 20 minutes 10% water, 90% acetonitrile / methanol; 20.1 minutes 100% water; 30 minutes 100% water. A Presto FF-C18 column is used, with CAD as the detector. The column temperature is 40–80℃, and the flow rate is 0.3–0.8 mL / min. When this method was used to detect hydroxypropyl cellulose in cetylpyridinium chloride tablets, it was found that hydroxypropyl cellulose could not be separated from excipients such as povidone K30 in the formulation.

[0004] In summary, although existing technologies disclose various methods for detecting hydroxypropyl cellulose, for pharmaceutical preparations such as cetirizine chloride tablets that contain both povidone K30 and hydroxypropyl cellulose excipients, existing methods cannot separate povidone from hydroxypropyl cellulose and cannot perform reverse analysis on hydroxypropyl cellulose in such pharmaceutical preparations. Summary of the Invention

[0005] To address the problem of reverse analysis of hydroxypropyl cellulose in pharmaceutical formulations containing povidone K30 in existing technologies, this invention provides a method for detecting hydroxypropyl cellulose in povidone-containing formulations, specifically including the following steps:

[0006] (1) Pretreatment of the sample to be tested to prepare a sample solution;

[0007] (2) The sample solution was detected by HPLC. The detector was an evaporative light scattering detector or an electrospray detector. The chromatographic column was a C18 column. The column temperature was 20-40℃. The mobile phase A was water and the mobile phase B was methanol. The flow rate was 0.5-1.5 mL / min. Gradient elution was performed. The gradient elution program was as follows: 0-8 minutes, 80% mobile phase B; 8-18 minutes, 80% mobile phase B changed to 100% mobile phase B; 18-25 minutes, 100% mobile phase B was maintained; 25-35 minutes, 80% mobile phase B.

[0008] A method for detecting hydroxypropyl cellulose in povidone-containing preparations, specifically including the following steps:

[0009] (1) Pretreatment of the sample to be tested to prepare a sample solution;

[0010] (2) The sample solution was detected by HPLC. The detector was an evaporative light scattering detector or an electrospray detector. The chromatographic column was a C18 column. The column temperature was 20-40℃. The mobile phase A was water and the mobile phase B was methanol. The flow rate was 0.5-1.5 mL / min. Gradient elution was performed. The gradient elution program was as follows: 0-8 minutes, 10% mobile phase B; 8-18 minutes, 10% mobile phase B changed to 100% mobile phase B; 18-25 minutes, 100% mobile phase B was maintained; 25-35 minutes, 10% mobile phase B.

[0011] Preferably, the column temperature is 30°C.

[0012] Preferably, the flow rate of the mobile phase is 1.0 mL / min.

[0013] Preferably, the chromatographic conditions are as follows: evaporative light scattering detector, air flow rate of 3.0 L / min, drift tube temperature of 80 °C, column of Inert Sustain C18, 250 mm × 4.6 mm, 5 μm, injection volume of 10 μl, column temperature of 30 °C, mobile phase A is water, mobile phase B is methanol, gradient elution: 0–8 min, 80% mobile phase B; 8–18 min, 80% mobile phase B changes to 100% mobile phase B; 18–25 min, maintain 100% mobile phase B; 25–35 min, 80% mobile phase B; mobile phase flow rate of 1.0 mL / min.

[0014] This invention is applicable to common types of C18 chromatographic columns, such as Inert Sustain C18 and Agilent Zorbax SB-C18.

[0015] The detection method of this invention is applicable to the detection of hydroxypropyl cellulose in various pharmaceutical preparations containing povidone K30, such as cetirizine tablets, glipizide tablets, and loratadine capsules.

[0016] It is understood that the detection method of the present invention can also be used to detect hydroxypropyl cellulose in medical devices or cosmetics containing povidone K30. It is also understood that the detection method of the present invention is equally applicable to the detection of hydroxypropyl cellulose in different types of povidone formulations.

[0017] The detection method of this invention has good specificity and excellent peak shape, and can avoid interference from various excipients in pharmaceutical preparations, especially other soluble polymeric excipients such as povidone K30, as well as solvent peaks, on the detection of hydroxypropyl cellulose. It can not only accurately quantify the content of hydroxypropyl cellulose in pharmaceutical preparations, but also effectively identify its type, providing a good method for reverse analysis, component analysis, and excipient release testing of pharmaceutical preparations. Attached Figure Description

[0018] Figure 1 This is a chromatogram of the system suitability solution from Example 1;

[0019] Figure 2 The linear relationship graph of hydroxypropyl cellulose in Example 1 is shown.

[0020] Figure 3 The chromatogram of the sample solution in Example 1 is shown below.

[0021] Figure 4 This is the chromatogram for the specificity test in Example 2;

[0022] Figure 5 Chromatograms of different types of hydroxypropyl cellulose solutions in Example 3;

[0023] Figure 6 Chromatograms of the reference solution and negative solution from Example 4;

[0024] Figure 7 This is a comparison chromatogram of the reference solution and the sample solution in Example 5;

[0025] Figure 8 The chromatogram for the mobile phase of 90% methanol in Example 9 is shown below.

[0026] Figure 9 The chromatogram for the mobile phase of 95% methanol in Example 9 is shown below.

[0027] Figure 10 The chromatogram for the mobile phase of 100% methanol in Example 9 is shown. Detailed Implementation

[0028] To better understand the technical solution and advantages of the present invention, the present invention will be further described below through specific embodiments.

[0029] Example 1: Detection of hydroxypropyl cellulose content in cetirizine lozenges

[0030] (1) Take appropriate amounts of hydroxypropyl cellulose and povidone K30, dissolve and dilute them in water to prepare a solution containing approximately 0.3 mg of each of hydroxypropyl cellulose and povidone K30 per 1 mL, as the system suitability solution. Take an appropriate amount of hydroxypropyl cellulose, accurately weigh it, dissolve and dilute it in water to prepare solutions containing approximately 0.1, 0.2, 0.3, 0.4, and 0.5 mg of hydroxypropyl cellulose per 1 mL, as the linear solutions. Cetylpyridinium chloride tablets were used as the test sample, with a specification of 2 mg and the trade name IWAKI. The product instructions indicate that it contains excipients magnesium stearate, povidone, menthol, carbomer, and hydroxypropyl cellulose. Take 20 cetylpyridinium chloride tablets as the sample to be tested, weigh them accurately, grind them into powder, weigh about 750 mg of cetylpyridinium chloride tablet powder, place it in a 25 mL volumetric flask, add an appropriate amount of water, sonicate to dissolve hydroxypropyl cellulose, dilute with water to the mark, shake well, filter through a 0.45 μm polytetrafluoroethylene filter, and take the filtrate as the sample solution.

[0031] (2) The system suitability solution, linear solution and sample solution obtained in step (1) were determined by HPLC-ELSD, and the content of hydroxypropyl cellulose in the sample was analyzed. The chromatographic conditions were as follows: the detector was an evaporative light scattering detector, the air flow rate was 3.0 L / min, the drift tube temperature was 80℃, the column was a C18 column, model InertSustain C18, 250 mm × 4.6 mm, 5 μm, the injection volume was 10 μL, the column temperature was 30℃, the mobile phase A was water, the mobile phase B was methanol, gradient elution (0-8 min, 80% mobile phase B; 8-18 min, 80% mobile phase B changed to 100% mobile phase B; 18-25 min, 100% mobile phase B was maintained, 25-35 min, 80% mobile phase B), and the mobile phase flow rate was 1.0 ml / min.

[0032] See the chromatogram of the system suitability solution. Figure 1 The hydroxypropyl cellulose peak shape was good and completely separated from the povidone K30 peak; the linear relationship between the logarithm of the hydroxypropyl cellulose concentration and the logarithm of the peak area was obtained as shown in the figure. Figure 2 As shown, the square of the correlation coefficient R 2 The value was 0.997, indicating that hydroxypropyl cellulose showed good linearity in the range of 0.1–0.5 mg / mL. The chromatogram of the sample solution is shown below. Figure 3 According to the linear equation, the hydroxypropyl cellulose content in cetirizine tablets is 0.67%, which is approximately equivalent to 5 mg / tablet.

[0033] Example 2: Study on the specificity, accuracy, repeatability and precision of analytical methods

[0034] Prepare the test solution as needed, and detect it using HPLC-ELSD under the chromatographic conditions of Example 1.

[0035] (a) Exclusivity

[0036] According to the formulation of cetylpyridinium chloride lozenges in Example 1, a hydroxypropyl cellulose-free mixed powder B was prepared, consisting of cetylpyridinium chloride, magnesium stearate, povidone, menthol, and carbomer. Approximately 750 mg of mixed powder B was placed in a 25 mL volumetric flask, an appropriate amount of water was added, and the mixture was sonicated. The solution was diluted to the mark with water, shaken well, and filtered through a 0.45 μm polytetrafluoroethylene filter. The filtrate was used as the negative solution. Approximately 750 mg of cetylpyridinium chloride lozenge powder was accurately weighed and placed in a 25 mL volumetric flask, an appropriate amount of water was added, and the mixture was sonicated to dissolve the hydroxypropyl cellulose. The solution was diluted to the mark with water, shaken well, and filtered through a 0.45 μm polytetrafluoroethylene filter. The filtrate was used as the sample solution. The negative solution and sample solution were injected for testing. The experimental results are as follows: Figure 4As shown in the spectrum, the other excipients and active pharmaceutical ingredient in cetylpyridinium chloride tablets do not interfere with the detection of hydroxypropyl cellulose. This method can achieve the separation of hydroxypropyl cellulose from other components, especially other polymeric excipients.

[0037] (ii) Accuracy

[0038] Take approximately 750 mg of mixed powder B (without hydroxypropyl cellulose) and place it in a 25 mL volumetric flask. Add an appropriate amount of water and different amounts of hydroxypropyl cellulose. Sonicate the mixture, dilute with water to the mark, shake well, and filter through a 0.45 μm polytetrafluoroethylene filter. Use the filtrate as the accuracy solution. Inject the accuracy solution into samples, and the recovery results are shown in Table 1.

[0039] Table 1

[0040]

[0041] (III) Repeatability

[0042] Take approximately 750 mg of cetylpyridinium chloride tablet powder and place it in a 25 mL volumetric flask. Add an appropriate amount of water and sonicate to dissolve the hydroxypropyl cellulose. Dilute with water to the mark, shake well, and filter through a 0.45 μm polytetrafluoroethylene filter. Take the filtrate and prepare 6 parallel aliquots as repeat solutions. Inject the repeat solutions separately, and the content results are shown in Table 2.

[0043] Table 2

[0044]

[0045] (iv) Precision

[0046] Take 15 mg of hydroxypropyl cellulose, place it in a 50 mL volumetric flask, dissolve and dilute to the mark with water, and shake well to prepare the reference solution. Inject the reference solution six times consecutively, and the peak area and retention time results are shown in Table 3.

[0047] Table 3

[0048]

[0049] Example 3: Detection of different types of hydroxypropyl cellulose

[0050] Take 15 mg each of type I, II, III, and IV hydroxypropyl cellulose and place them in different 50 mL volumetric flasks. Dissolve and dilute with water to the mark, and shake well to obtain reference solutions containing different types of hydroxypropyl cellulose. Detect the reference solutions according to the chromatographic conditions of Example 1 and analyze the type of hydroxypropyl cellulose excipient in the samples.

[0051] Test results as follows Figure 5As shown, there are slight differences in the retention time of different types of hydroxypropyl cellulose. A comparison of the chromatograms of these hydroxypropyl cellulose types with those of the cetylpyridinium chloride lozenge sample solution shows that the retention time and peak shape of type I hydroxypropyl cellulose are consistent with those of the hydroxypropyl cellulose in the cetylpyridinium chloride lozenge, indicating that the hydroxypropyl cellulose in the cetylpyridinium chloride lozenge is type I.

[0052] Example 4: Detection of hydroxypropyl cellulose using different types of chromatographic columns

[0053] (1) Take 15 mg of hydroxypropyl cellulose, place it in a 50 mL volumetric flask, dissolve and dilute with water to the mark, shake well to obtain the reference solution. Take about 750 mg of hydroxypropyl cellulose-free powder B, place it in a 25 mL volumetric flask, add an appropriate amount of water, sonicate, dilute with water to the mark, shake well, filter through a 0.45 μm polytetrafluoroethylene filter, and take the filtrate as the negative solution.

[0054] (2) The reference solution and negative solution obtained in step (1) were analyzed by HPLC-ELSD. The chromatographic conditions were as follows: the detector was an evaporative light scattering detector, the air flow rate was 3.0 L / min, the drift tube temperature was 80℃, the column was a gel chromatography column, model TSK-Gel G3000PW XL, 300 mm × 7.8 mm, 7 μm, the injection volume was 10 μL, the column temperature was 30℃, the mobile phase was water, and the mobile phase flow rate was 1.0 mL / min.

[0055] Chromatograms of the reference solution and negative solution are shown below. Figure 6 As shown, the retention time of the hydroxypropyl cellulose peak is about 7.6 minutes, the theoretical plate number of the peak is low, and it overlaps with the povidone K30 peak in the cetirizine tablets, making separation impossible and the specificity does not meet the requirements.

[0056] Example 5: Detection of hydroxypropyl cellulose using different organic solvents

[0057] Take 15 mg of hydroxypropyl cellulose, place it in a 50 mL volumetric flask, dissolve and dilute to the mark with water, and shake well to obtain the reference solution. Take approximately 750 mg of cetylpyridinium chloride tablet powder, place it in a 25 mL volumetric flask, add an appropriate amount of water, sonicate to dissolve the hydroxypropyl cellulose, dilute to the mark with water, shake well, filter through a 0.45 μm polytetrafluoroethylene filter, and use the filtrate as the sample solution. Analyze the reference solution and sample solution using HPLC-ELSD to determine the retention time of the hydroxypropyl cellulose peak. The chromatographic conditions were as follows: evaporative light scattering detector (ELSD), air flow rate of 3.0 L / min, drift tube temperature of 80 °C, Inert Sustain C18 column (250 mm × 4.6 mm, 5 μm), injection volume of 10 μL, column temperature of 30 °C, mobile phase A of water, mobile phase B of acetonitrile, gradient elution (0–8 min, 80% mobile phase B; 8–18 min, 80% mobile phase B changing to 100% mobile phase B; 18–25 min, maintaining 100% mobile phase B; 25–35 min, 80% mobile phase B), mobile phase flow rate of 1.0 mL / min. A comparison of the chromatograms of the reference solution and the sample solution is shown below. Figure 7 As shown, the retention time of the hydroxypropyl cellulose peak in the reference solution was approximately 1.9 minutes, and it could not be separated from the baselines of other excipient peaks, thus failing to meet the specificity requirements.

[0058] Example 6: Detection of hydroxypropyl cellulose using an electrospray detector

[0059] Linear solutions and sample solutions were prepared according to the method in Example 1. The linear solutions and sample solutions were analyzed using HPLC-CAD, and the content of the excipient hydroxypropyl cellulose in the samples was determined. The chromatographic conditions were as follows: electrospray ionization detector (ESI), Inert Sustain C18 column (250 mm × 4.6 mm, 5 μm), injection volume 10 μl, column temperature 30 °C, mobile phase A was water, mobile phase B was methanol, gradient elution (0–8 min, 80% mobile phase B; 8–18 min, 80% mobile phase B changing to 100% mobile phase B; 18–25 min, maintaining 100% mobile phase B; 25–35 min, 80% mobile phase B), mobile phase flow rate 1.0 mL / min. The results showed that when using the ESI detector, the hydroxypropyl cellulose peak was completely separated from other chromatographic peaks, and the linear relationship between hydroxypropyl cellulose concentration and peak area was good, enabling quantitative detection of hydroxypropyl cellulose content.

[0060] Example 7: Detection of hydroxypropyl cellulose using different column temperatures

[0061] The column temperatures were set to 20℃ and 40℃, respectively. Solutions were prepared and tested according to Example 1. The results showed that at column temperatures of 20℃ and 40℃, the retention time of the hydroxypropyl cellulose peak remained essentially unchanged, and it was completely separated from the chromatographic peaks of other components in the sample, thus enabling quantitative detection of the hydroxypropyl cellulose content.

[0062] Example 8: Detection of hydroxypropyl cellulose using different flow rates

[0063] The mobile phase flow rates were set to 0.5 mL / min and 1.5 mL / min, respectively. Solutions were prepared and tested according to Example 1. The results showed that when the mobile phase flow rates were 0.5 mL / min and 1.5 mL / min, the hydroxypropyl cellulose peak was completely separated from other chromatographic peaks, enabling quantitative detection of hydroxypropyl cellulose content.

[0064] Example 9: Isocratic elution detection of hydroxypropyl cellulose

[0065] Take 15 mg of hydroxypropyl cellulose, place it in a 50 mL volumetric flask, dissolve and dilute to the mark with water, and shake well to obtain the reference solution; take approximately 750 mg of fine powder of cetylpyridinium chloride tablets, place it in a 25 mL volumetric flask, add an appropriate amount of water, sonicate to dissolve the hydroxypropyl cellulose, dilute to the mark with water, shake well, filter through a 0.45 μm polytetrafluoroethylene filter, and take the filtrate as the sample solution. The reference solution and sample solution were determined by HPLC-ELSD. The chromatographic conditions were as follows: detector: evaporative light scattering detector; air flow rate: 3.0 L / min; drift tube temperature: 80 °C; column: InertSustain C18, 250 mm × 4.6 mm, 5 μm; injection volume: 10 μL; column temperature: 30 °C; mobile phase: 90% methanol, 95% methanol, 100% methanol; mobile phase flow rate: 1.0 mL / min; isocratic elution; acquisition time: 35 minutes. The chromatograms of the reference solution and sample solution obtained using 90% methanol as the mobile phase are shown below. Figure 8 As shown, the hydroxypropyl cellulose peak was not eluted from the chromatographic system within 35 minutes, which is unfavorable for the detection of hydroxypropyl cellulose. The chromatogram of the reference solution obtained using 95% methanol as the mobile phase is shown below. Figure 9 As shown, the peak shape of hydroxypropyl cellulose was poor, making it difficult to quantitatively calculate its content. The chromatograms of the reference solution and sample solution obtained using 100% methanol as the mobile phase are shown below. Figure 10 As shown, hydroxypropyl cellulose in the control solution eluted at 2.2 minutes and could not be separated from the chromatographic peaks of other excipients, indicating that its specificity did not meet the requirements.

[0066] Example 10: Detection of hydroxypropyl cellulose with different initial organic phase ratios

[0067] The solution was prepared according to the method in Example 1. The linear solution and sample solution were analyzed using HPLC-ELSD, and the content of the excipient hydroxypropyl cellulose in the sample was determined. The chromatographic conditions were as follows: evaporative light scattering detector, air flow rate of 3.0 L / min, drift tube temperature of 80 °C, Inert Sustain C18 column (250 mm × 4.6 mm, 5 μm), injection volume of 10 μL, column temperature of 30 °C, mobile phase A of water, mobile phase B of methanol, gradient elution (0–8 min, 10% mobile phase B; 8–18 min, 10% mobile phase B changing to 100% mobile phase B; 18–25 min, maintaining 100% mobile phase B; 25–35 min, 10% mobile phase B), mobile phase flow rate of 1.0 mL / min, and acquisition time of 35 minutes. The results showed that when the initial mobile phase was 10% methanol, the retention time of hydroxypropyl cellulose remained essentially unchanged, and the separation from other excipient peaks was good, with specificity meeting the requirements.

[0068] Example 11: Detection of hydroxypropyl cellulose content in glipizide tablets

[0069] Glipizide tablets (commercially available) were used as the test sample. The product's formulation contains glipizide, lactose, microcrystalline cellulose, hydroxypropyl cellulose, povidone K30, and magnesium stearate. Twenty tablets were accurately weighed, ground into a fine powder, and approximately 300 mg of the powder was accurately weighed and placed in a 25 mL volumetric flask. An appropriate amount of water was added, and the hydroxypropyl cellulose was dissolved by sonication. The solution was diluted to the mark with water, shaken well, and filtered through a 0.45 μm polytetrafluoroethylene filter. The filtrate was used as the sample solution. The test was performed according to the method described in Example 1. The results showed that other components in the glipizide tablets did not interfere with the detection of hydroxypropyl cellulose, indicating that this method is also applicable to the detection of hydroxypropyl cellulose in glipizide tablets.

[0070] Example 12: Detection of hydroxypropyl cellulose content in loratadine capsules

[0071] The contents of commercially available loratadine capsules were used as the test sample. The product's contents contain loratadine, lactose, povidone K30, hydroxypropyl cellulose, and magnesium stearate. Twenty capsules were accurately weighed, the contents were poured out, and the capsule shells were accurately weighed to determine the average fill weight. The contents were mixed thoroughly, and approximately 200 mg of the contents was placed in a 25 mL volumetric flask. An appropriate amount of water was added, and the hydroxypropyl cellulose was dissolved by sonication. The solution was diluted to the mark with water, shaken well, and filtered through a 0.45 μm polytetrafluoroethylene filter. The filtrate was used as the sample solution. The test was performed according to the method described in Example 1. The results showed that other components in the loratadine capsule contents did not interfere with the detection of hydroxypropyl cellulose, indicating that this method is also applicable to the detection of hydroxypropyl cellulose in loratadine capsule contents.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting hydroxypropyl cellulose in a povidone-containing preparation, characterized in that, Specifically, the following steps are included: (1) Using cetylpyridinium chloride tablets as the test sample, the excipients of the test sample are magnesium stearate, povidone, menthol, carbomer and hydroxypropyl cellulose. Accurately weigh about 750 mg of cetylpyridinium chloride tablet powder, place it in a 25 mL volumetric flask, add an appropriate amount of water, sonicate to dissolve hydroxypropyl cellulose, dilute with water to the mark, shake well, filter through a 0.45 μm polytetrafluoroethylene filter, and take the filtrate as the sample solution. (2) The sample solution was detected by HPLC. The detector was an evaporative light scattering detector. The air flow rate was 3.0 L / min, the drift tube temperature was 80℃, the column was an Inert Sustain C18, 250 mm × 4.6 mm, 5 µm, the injection volume was 10 µl, the column temperature was 30℃, the mobile phase A was water, the mobile phase B was methanol, and the gradient elution was as follows: 0-8 min, 80% mobile phase B; 8-18 min, 80% mobile phase B changed to 100% mobile phase B; 18-25 min, maintained 100% mobile phase B; 25-35 min, 80% mobile phase B; the mobile phase flow rate was 1.0 ml / min.

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