Determination method of dissolubility of duiyiwai soft capsule

Abstract

This invention provides a method for determining the dissolution rate of *Duyiwei* soft capsules, belonging to the field of dissolution testing technology. The method employs a flow cell method, using a solution containing pH 4.5 acetate buffer, 4% Tween 80, and 1% pepsin as the dissolution medium, and luteolin as the dissolution index. Compared to existing technologies, this invention overcomes the limitations of complex components and low content of individual components in traditional Chinese medicine solid dosage forms. By integrating the flow cell method and model-dependent methods, it overcomes the limitations of the similarity factor method in complex traditional Chinese medicine systems, providing a new pathway for the quality consistency evaluation of traditional Chinese medicine solid dosage forms.

Description

Technical Field

[0001] This invention relates to a method for determining the dissolution rate of Duyiwei soft capsules, belonging to the field of dissolution testing technology. Background Technology

[0002] Dissolution rate, a key indicator for the quality evaluation of oral solid dosage forms, reflects the rate and extent of release of active ingredients in vivo and is an important in vitro parameter for predicting the bioavailability of formulations. However, the complex composition and generally low content of each component in traditional Chinese medicine (TCM) solid dosage forms, coupled with fluctuations in the quality of raw materials and differences in production processes, make it difficult to standardize their dissolution behavior. Currently, except for a few TCM preparations with relatively simple components (such as andrographolide pills and Yixintong powder), dissolution testing is still rarely used in the quality standards of TCM preparations, which restricts the improvement of the consistency evaluation system for the quality of TCM preparations.

[0003] Traditional basket and paddle methods have significant shortcomings in the determination of dissolution of solid Chinese medicine preparations: basket methods are prone to clogging, and paddle methods have "dead zones," both of which affect the uniformity of the fluid; the stationary medium cannot simulate the pH changes in the gastrointestinal tract and maintain the conditions of the leak tank; excessive stirring often masks subtle differences between preparations, resulting in weak distinguishing power; at the same time, it is difficult to handle viscous and floating samples (such as for oil-based soft capsules, traditional methods (basket and paddle methods) may cause oil to float or suspend, resulting in uneven mixing of the sample solution), and lacks dynamic monitoring capabilities.

[0004] To advance the modernization of quality evaluation of traditional Chinese medicine preparations, the National Medical Products Administration (NMPA) clearly stated in the "Technical Guidelines for Dissolution Testing of Common Oral Solid Dosage Forms" that, in addition to the traditional basket method and slurry method, the flow cell method is particularly suitable for the accurate characterization of dissolution behavior of complex dosage forms and special preparations. By simulating the in vivo fluid dynamics environment, the flow cell method can effectively evaluate various dosage forms, including soft capsules, patches, and microspheres, thus making up for the limitations of traditional methods in the application of complex systems of traditional Chinese medicine.

[0005] Lamiophlomis rotata (Benth.) Kudo is a traditional Tibetan medicine. Its main active ingredient, luteolin, possesses multiple pharmacological activities, including anti-inflammatory, antioxidant, and cardiovascular protective effects. Lamiophlomis soft capsules are widely used clinically for symptoms such as postoperative pain, traumatic bleeding, and dysmenorrhea; however, systematic studies on its in vitro dissolution behavior are still lacking in quality consistency evaluation.

[0006] This invention uses Duyiwei soft capsules as a model drug and, based on the Quality by Design (QbD) principle, establishes a dissolution determination method combining the slurry method and flow cell method, using luteolin as the indicator component. This method systematically evaluates the differences in dissolution behavior among products from different manufacturers. To address the limitations of the f2 method due to highly variable data, a model-dependent method (Mahalanobis Distance, MSD) is introduced for similarity analysis. The aim is to provide a new analytical method for evaluating the quality consistency of complex traditional Chinese medicine systems and to offer methodological basis and practical pathways for quality control and standard improvement of solid dosage forms of traditional Chinese medicine. Summary of the Invention

[0007] To address the above problems, the purpose of this invention is to provide a method for determining the dissolution rate of Duyiwei soft capsules, thereby overcoming the limitation of the lack of standardized evaluation methods for in vitro dissolution behavior in the quality consistency evaluation of traditional Chinese medicine solid dosage forms in the prior art.

[0008] To achieve the above objectives, the present invention provides a method for determining the dissolution rate of Duyiwei soft capsules, wherein the dissolution rate is determined by flow cell method; the flow cell method is performed using a flow cell dissolution apparatus, and one or more of acetate buffer, Tween 80 and pepsin are used as dissolution media.

[0009] Furthermore, the acetate buffer has a pH of 4.5, the Tween concentration is 4%, and the pepsin concentration is 1%.

[0010] Furthermore, the dissolution rate for the dissolution test is 8-16 ml / min.

[0011] Furthermore, the dissolution test method uses luteolin as the key quality dissolution indicator.

[0012] Furthermore, the luteolin detection method is as follows: using an Agilent SB-C18 column, with a mobile phase of methanol-0.3% phosphoric acid + 0.4% Tween 80 solution at a ratio of 65:35, a detection wavelength of 350 nm, and a flow rate of 0.3-1 ml / min, the detection is performed.

[0013] Furthermore, the dissolution determination method is as follows: Take 6 capsules of Duyiwei soft capsules, and dissolve and release them according to the sixth method of General Chapter 0931 of Part IV of the Chinese Pharmacopoeia 2020, at a temperature of 37℃ and a flow rate of 16ml / min. The dissolution medium is 100ml of a solution containing pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin. Samples are taken at 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 7h, and 8h, respectively, to determine the luteolin content and plot the dissolution curve.

[0014] In another aspect, the present invention provides a method for evaluating the quality consistency of Duyiwei soft capsules. The method involves using a flow cell method to determine the dissolution curves of Duyiwei soft capsules from different manufacturers and a reference preparation to evaluate their similarity.

[0015] Furthermore, the similarity evaluation method is the f2 non-model-dependent similarity factor method. For batch-to-batch differences with an RSD greater than 10%, the MSD model-dependent method is introduced for similarity evaluation.

[0016] Furthermore, the MSD model dependency evaluation method includes the following steps:

[0017] (1) Determine the batch-to-batch differences in the dissolution of the reference sample, and then use this as a basis to determine the similarity limit of the multivariate statistical moments (MSD);

[0018] (2) Determine the multivariate statistical moments of the mean dissolution of the test and reference samples;

[0019] (3) Determine the 90% confidence intervals of the multivariate statistical moments of the measured dissolution amounts of the test and reference samples;

[0020] (4) If the upper limit of the confidence interval in step (3) is less than or equal to the similarity limit of the reference sample, the two batches of samples can be considered to be similar.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] (1) A method for determining the dissolution rate of Duyiwei soft capsules is provided. The detection method has good accuracy and can more effectively evaluate the dissolution of Duyiwei soft capsules.

[0023] (2) The flow cell method can establish a good in vivo-in vitro correlation by simulating the physiological environment. In vitro dissolution data has the potential to predict the bioavailability of drugs in vivo, which helps to more accurately assess and predict the performance of Duyiwei soft capsules in the human body.

[0024] (3) The flow cell method effectively reduces the variation caused by differences in personnel operation or equipment through precise temperature control, accurate liquid delivery and standardized operation, so that the test results have good reproducibility and consistency.

[0025] (4) The flow cell method has high discrimination power and can sensitively capture the differences in dissolution behavior caused by small changes in the formulation or process (such as the disintegration performance of the capsule shell and the amount of excipients), providing guidance for formulation screening and process optimization, and helping to determine whether different batches of samples have consistent in vivo release behavior.

[0026] (5) Model-dependent methods, by fitting dissolution data to specific mathematical models (such as the Weibull model, first-order models, etc.), can quantify the dissolution process of soft capsules into parameters with clear drug release significance (such as release rate constant, delay time, etc.), thereby deeply analyzing different release mechanisms such as capsule disintegration, drug diffusion, or erosion. Compared with non-model-dependent methods (such as the f2 similarity factor method), model-dependent methods have the following advantages: ① High flexibility: It does not require the same sampling time point or low-variance data, and is suitable for the complex or atypical dissolution curves commonly found in soft capsules; ② Rich information: It summarizes the key features of the entire curve through a small number of model parameters, which is convenient for quantitative comparison and statistical inference; ③ Support for in vivo-in vitro correlation (IVIVC): It provides a mathematical basis for establishing A-level in vivo-in vitro correlation and can be used to predict the absorption behavior of soft capsules in vivo; ④ Overcome the limitations of traditional methods (f2 method caused by high-variance data): When the f2 method is not applicable, it can be used as a reliable alternative evaluation method to support generic drug consistency evaluation and prescription optimization. Attached Figure Description

[0027] Figure 1 Dissolution curves of Duyiwei soft capsules in different dissolution media

[0028] Figure 2 Dissolution curves of Duyiwei soft capsules at different flow rates

[0029] Figure 3 Dissolution curves of the reference and test formulations of Duyiwei soft capsules (Jiangsu Wango)

[0030] Figure 4 Dissolution profiles of the reference and test formulations of Duyiwei soft capsules (Guizhou Shunjian)

[0031] Figure 5 Dissolution curves of the reference and test formulations of Duyiwei soft capsules (Hainan Haishen)

[0032] Figure 6 Dissolution curve of Duyiwei soft capsules (using syrup method)

[0033] Figure 7 Dissolution curve of Duyiwei soft capsules by flow cell method Detailed Implementation

[0034] To better illustrate the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0035] In the embodiments, all original reagent materials are commercially available, and experimental methods without specific conditions are conventional methods and conditions well known in the art, or according to the conditions recommended by the instrument manufacturer.

[0036] The instruments and reagents used in the following examples and comparative examples

[0037] Instruments: CE7s flow cell dissolution apparatus (SOTAX), ZRD-6 dissolution tester (Beijing Beiyan Scientific Instrument Co., Ltd.), ACQuity UPLC H CLASS PLUS ultra-high performance liquid chromatograph (Waters), XPE26 part per million balance.

[0038] Reagents: Hydrochloric acid (Chongqing Chuandong Chemical Group Co., Ltd.), sodium dodecyl sulfate (Sinopharm Chemical Reagent Co., Ltd.), pepsin (Macklin), Tween 80 (Merck), glacial acetic acid (Sinopharm Chemical Reagent Co., Ltd.), sodium acetate (Sinopharm Chemical Reagent Co., Ltd.), potassium dihydrogen phosphate (Sinopharm Chemical Reagent Co., Ltd.), sodium hydroxide (Sinopharm Chemical Reagent Co., Ltd.), methanol was used as the chromatographic alcohol, water was Wahaha purified water, and all other reagents were analytical alcohols; luteolin reference standard (China National Institutes for Food and Drug Control, 111520-202107, 96.3%).

[0039] Example 1: Preliminary confirmation of the detection method for index components of dissolution in Duyiwei soft capsules

[0040] 1.1 Reference method: The content of luteolin was determined according to the [Content Determination] item in the quality standard of Duyiwei soft capsules (YBZ0212005-2014Z-9).

[0041] Luteolin was determined by high performance liquid chromatography:

[0042] Chromatographic conditions and system suitability tests were conducted using octadecylsilane-bonded silica gel as the packing material; methanol-0.3% phosphoric acid solution (75:25) as the mobile phase; detection wavelength of 350 nm; and theoretical plate number calculated based on the luteolin peak, which should be no less than 1500.

[0043] Preparation of the reference solution: Take an appropriate amount of luteolin reference standard, accurately weigh it, and add methanol to prepare a solution containing approximately 14 μg per ml.

[0044] Preparation of the test solution: Take the contents of this product under the "Variation in Content" section, mix well, take about 0.2 g, accurately weigh it, place it in a 25 ml volumetric flask, accurately add 20 ml of methanol, sonicate (power 250 W, frequency 33 kHz) for 30 minutes, remove, cool, add methanol to the mark, shake well, filter, and take the filtrate to obtain the test solution.

[0045] The assay involves precisely pipetting 10 μl each of the reference solution and the test solution into a liquid chromatograph and measuring the results.

[0046] 1.2 Chromatographic conditions

[0047] An Agilent SB-C18 (2.1*100mm, 1.8um) column was used with methanol-0.3% phosphoric acid + 0.4% Tween 80 solution (65:35), a detection wavelength of 350nm, a flow rate of 0.3ml / min, an injection volume of 1ul of reference standard and 4ul of sample, and a column temperature of 30℃.

[0048] 1.3 Preparation of the test solution

[0049] Take the contents of this product (Duyiwei Soft Capsules: 20240501) under the "Variation in Content" section, mix well, take about 0.2g, accurately weigh it, place it in a 25ml volumetric flask, accurately add 20ml of methanol, sonicate (power 250W, frequency 33kHz) for 30 minutes, remove, cool, add methanol to the mark, shake well, filter, and take the filtrate to obtain the product.

[0050] 1.4 Limit of Quantitation and Precision

[0051] According to the luteolin content determination item of the Duyiwei soft capsule quality standard, the limit of quantitation was tested at 10 times the signal-to-noise ratio using the reference standard dilution method, and the precision of the limit of quantitation was tested. The range that meets the requirements was taken as the acceptable range for quantitative detection in this test.

[0052]

[0053] Precision testing was performed using luteolin (concentration: 0.0875 μg / ml), and the results are shown in the table below:

[0054]

[0055] According to the table above, the signal-to-noise ratio and precision of 0.087 μg / ml meet the requirements and are used as the limit of quantitation for this test.

[0056] 1.5 Accuracy

[0057] In this study, an ultra-high performance liquid chromatograph was selected for content determination, and the method was validated using samples with known content.

[0058] The sample, Duyiwei soft capsules 20240501, was analyzed using high performance liquid chromatography (HPLC) with octadecylsilane-bonded silica gel as the packing material, methanol-0.3% phosphoric acid solution (75:25), a flow rate of 1.0 ml / min, an injection volume of 10 μl, and a detection wavelength of 350 nm. The content was determined to be 0.80 mg / capsule.

[0059] The content of sample Duyiwei soft capsule 20240501 was determined by ultra-high performance liquid chromatography under the chromatographic conditions in section "1.2", and the result was 0.78 mg / capsule.

[0060] It has been confirmed that the relative deviation between the content determination (luteolin) using ultra-high performance liquid chromatography and the content determination of the same batch of products using high performance liquid chromatography is 1.3%, which is within the required range, thus eliminating the detection error between the two instruments.

[0061] Example 2: Establishment of the Paddle Dissolution Method

[0062] 2.1 Theoretical Basis

[0063] Based on the concept of Quality by Design (QbD), this study identified the dissolution behavior of luteolin as a critical quality attribute (CQAs) through risk assessment. Referring to the Biopharmaceutics Classification System (BCS) principles, Duyiwei soft capsules belong to the category of low-solubility, high-permeability drugs (Class II), and dissolution is the rate-limiting step. Therefore, a funnel-condition medium was designed (Tween 80 concentration > critical micelle concentration).

[0064] 2.2 Investigation of the dissolution medium

[0065] According to the "Technical Guidelines for Dissolution Testing of Common Oral Solid Dosage Forms" and Appendix II, Dissolution Medium, the selection of the dissolution medium should generally be an aqueous medium with a pH of 1.2 to 6.8. Studies have shown that during storage, capsule formulations may form a membrane due to the cross-linking effect of gelatin; therefore, it may be necessary to add pepsin or pancreatic enzymes to the medium to promote drug dissolution.

[0066] The disintegration of soft capsules was investigated using artificial gastric juice and hydrochloric acid solution. It was found that the sample without added pepsin did not disintegrate within 2 hours due to the cross-linking effect of gelatin. Therefore, pepsin was added to the dissolution medium in this experiment to solve the problem of delayed disintegration caused by gelatin cross-linking. The amount of pepsin added was 1%, which is consistent with the proportion of pepsin added in artificial gastric juice.

[0067] Analysis of this experiment revealed that many factors influence dissolution rate, such as pH, surfactant, temperature, rotation speed, and time. Finally, pH and surfactant were determined to be the most important factors.

[0068] pH: pH 2.0 0.01 mol / L hydrochloric acid solution, pH 4.5 acetate buffer, pH 6.8 phosphate buffer.

[0069] Surfactants: 4% sodium dodecyl sulfate, 4% Tween 80.

[0070] Table 1.1 Orthogonal investigation of buffer solutions and surfactants

[0071] Paddle method, temperature: 37±0.5℃, rotation speed: 75 rpm.

[0072] Sampling time points: 15min, 30min, 45min, 60min, 75min, 90min.

[0073] Sampling volume: 1 ml; Refill required: No; Results have been corrected during calculation.

[0074] Determination: Ultra-high performance liquid chromatography was used, and the determination was performed under the chromatographic conditions described in section "1.2".

[0075] The results showed that, under slurry conditions, Tween 80, as the surfactant, had a significantly higher dissolution rate than sodium dodecyl sulfate (SDS), and the three pH buffers had no significant effect on the dissolution behavior. Therefore, pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin was ultimately selected as the optimized medium. (See attached image) Figure 1

[0076] Table 1.2 Results of the orthogonal investigation of buffer solutions and surfactants

[0077]

[0078] Example 3: Validation of the method for detecting index components in the dissolution of Duyiwei soft capsules

[0079] 3.1 Solution Preparation

[0080] 3.1.1 Dissolution medium

[0081] 1. (pH 1.2 0.01mol / L hydrochloric acid solution + 4% Tween 80 + 1% pepsin)

[0082] 2. (pH 4.5 acetate solution + 4% Tween 80 + 1% pepsin)

[0083] 3. (pH 6.8 phosphate solution + 4% Tween 80 + 1% pepsin)

[0084] 3.1.2 Reference solution

[0085] Accurately weigh approximately 14 mg of luteolin reference standard and place it in a 100 ml volumetric flask. Dissolve it in methanol and dilute to the mark. Shake well and set aside. Accurately measure 10 ml of the above solution into a 100 ml volumetric flask, dilute to the mark with methanol, and shake well. This is the reference standard.

[0086] 3.1.3 Test solution

[0087] Take one capsule of Duyiwei soft capsule as the test sample, place it in a flow cell, add 100 ml of dissolution medium (2), flow rate 16 ml / min, and automatically sample 1 ml at 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 4 h, 5 h, 6 h, 7 h, and 8 h respectively, and place it at room temperature to obtain the sample.

[0088] 3.2 Chromatographic conditions

[0089] An Agilent SB-C18 (2.1*100mm, 1.8um) column was used with methanol-0.3% phosphoric acid + 0.4% Tween 80 solution (65:35), a detection wavelength of 350nm, a flow rate of 0.3ml / min, an injection volume of 1ul of reference standard and 4ul of sample, and a column temperature of 30℃.

[0090] 3.3 Methodological Validation

[0091] 3.3.1 Specificity

[0092] Excipient solution: Take the excipients polyethylene glycol 400 and glycerin, weigh them according to the formulation, and dissolve them separately in dissolution media (1, 2, 3) to obtain the solution.

[0093] Accurately measure 1 μL of blank solution, 1 μL of reference solution, 4 μL of test solution, and 4 μL of excipient solution, and inject them into the liquid chromatograph, recording the chromatograms. Under these chromatographic conditions, luteolin was not detected in the blank solvent and excipient solution, and did not interfere with the peak area of ​​the main peak.

[0094] 3.3.2 Linear Range

[0095] The linear relationship was determined within the specified range. The stock solution was precisely diluted stepwise to prepare at least 5 test sample concentrations within the concentration range not lower than the limit of quantitation. One sample of each concentration was prepared. 1 μl of each test sample solution was accurately measured and injected into the liquid chromatograph, and the chromatogram was recorded. (1) Stock solution (140 μg / ml): 14 mg of luteolin was accurately weighed, placed in a 100 ml volumetric flask, dissolved in methanol and diluted to the mark, and shaken well. (2) Linearity 1 (0.35 μg / ml): 0.5 ml of stock solution was accurately measured into a 200 ml volumetric flask, diluted to the mark with methanol, and shaken well. (3) Linearity 2 (0.7 μg / ml): 1 ml of stock solution was accurately measured into a 200 ml volumetric flask, diluted to the mark with methanol, and shaken well. (4) Linearity 3 (1.4 μg / ml): Accurately measure 1 ml of stock solution into a 100 ml volumetric flask, dilute to the mark with methanol, and shake well. (5) Linearity 4 (14 μg / ml): Accurately measure 10 ml of stock solution into a 100 ml volumetric flask, dilute to the mark with methanol, and shake well. (6) Linearity 5 (140 μg / ml): Inject the stock solution.

[0096] Perform the determination according to the chromatographic conditions under section "3.2". Plot a standard curve with concentration on the x-axis and peak area on the y-axis, calculate the regression equation, and examine the linear relationship.

[0097] y = 15218x + 148.3 R = 0.9999 Intercept: 148.3

[0098] The results showed that luteolin exhibited good linearity in the range of 0.35–140 μg / ml, with a correlation coefficient r of not less than 0.999.

[0099] 3.3.3 Precision

[0100] The reference solution under section “3.1.2” was continuously injected and measured 6 times. The peak area RSD of luteolin was 0.5%, indicating that the instrument injection precision was good.

[0101] 3.3.4 Accuracy

[0102] The results of the recovery analysis of samples of the same concentration spiked with four different concentrations of reference standards were evaluated. Recovery was determined using 1 ml of reference standards of known concentrations (Linear 1, Linear 2, Linear 3, and Linear 4). This involved precisely adding a certain amount of reference standard of known purity to 1 ml of the sample solution containing the known analyte, and then determining the recovery according to the prescribed method. The recovery rate was calculated by dividing the difference between the measured value and the content in the sample by the amount of reference standard added. The determination was performed under the chromatographic conditions described in section "3.2". The average recovery rate of luteolin (n=12) was 105%, with an RSD of 5.4%, indicating good accuracy of the method.

[0103] 3.3.5 Limit of Quantitation and Limit of Detection

[0104] Detection limit: Accurately measure 1 ml of the reference stock solution under section "3.1.2" and place it in a 200 ml volumetric flask. Dilute to the mark with methanol. Shake well to obtain the solution.

[0105] Limit of quantitation: Accurately measure 0.5 ml of the reference stock solution under section "3.1.2" and place it in a 200 ml volumetric flask. Dilute to the mark with methanol. Shake well to obtain the solution.

[0106] The determination was performed under the chromatographic conditions described in section "3.2". The signal-to-noise ratio (S / N) of the luteolin peak in the solution at the limit of quantitation was 14, and the signal-to-noise ratio (S / N) of the luteolin peak in the solution at the limit of detection was 3.5, indicating that the method has good sensitivity.

[0107] 3.3.6 Stability

[0108] Take the test solution from the first sampling point (0.5h) of leaching from sample 20240501-1, place it at room temperature, and inject it at 0h, 1h, 2h, 3h, 6h, 12h, 24h, and 36h, recording the chromatograms. Determine the peak area RSD of luteolin under the chromatographic conditions in section "3.2". The peak area change at 36h compared to 0h was less than 20%.

[0109] Example 4: Establishment of the flow cell dissolution method

[0110] 4.1 Investigation of the dissolution medium

[0111] Select the dissolution medium determined by the paddle method: pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin, 100 ml.

[0112] 4.2 Examination of Flow Velocity

[0113] According to Method VI, Dissolution and Release Determination, Part IV, General Chapter 0931, 2020 Edition of the Chinese Pharmacopoeia. Temperature: 37±0.5℃; Dissolution medium: pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin, volume 100ml. Flow rate requirements were as specified in the pharmacopoeia: "Standard flow rates are 4ml / min, 8ml / min, and 16ml / min." Dissolution behavior was investigated at flow rates of 8ml / min and 16ml / min.

[0114] The results showed that the RSD of dissolution at all time points was less than 10% at a flow rate of 16 ml / min, while the RSD at early time points was greater than 15% at a flow rate of 8 ml / min, which did not meet the requirements for dissolution data variability in the "Technical Guidelines for Bioequivalence Studies of Chemical Drug Preparations in Humans". Therefore, 16 ml / min was selected as the standard flow rate to ensure that the hydrodynamic conditions met the sink condition. See Table 4.1 and... Figure 2

[0115] Table 4.1 Selection of dissolution media at different flow rates

[0116] 4.3 Determination of dissolution rate by flow tank method

[0117] The parameters were selected according to the "Technical Guidelines for Dissolution Testing of Common Oral Solid Dosage Forms," ​​and the operation followed Method VI of the General Chapter 0931 Dissolution and Release Determination in Part IV of the 2020 edition of the Chinese Pharmacopoeia. The temperature was 37±0.5℃, the flow rate was 16ml / min, the dissolution medium was 100ml of a solution containing pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin, and the filtration method was a 0.22um PTFE microporous membrane.

[0118] Twelve samples from different manufacturers were taken and sampled at 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 7h, and 8h respectively. The samples were injected and analyzed according to the chromatographic conditions in section “3.2”. The results are shown in Tables 4.2, 4.3, 4.4, and 4.5.

[0119] Table 4.2 Cumulative dissolution rate of Duyiwei soft capsules (our company, batch: 20240501)

[0120]

[0121] Table 4.3 Cumulative dissolution rate of Duyiwei soft capsules (Jiangsu Wango)

[0122]

[0123] Table 4.4 Cumulative dissolution rate of Duyiwei soft capsules (Guizhou Shunjian)

[0124]

[0125] Table 4.5 Cumulative dissolution rate of Duyiwei soft capsules (Hainan Haishen)

[0126]

[0127] Example 5: Similarity Analysis

[0128] In recent years, the consistency evaluation of generic drugs has received increasing attention both domestically and internationally. For research on generic oral solid dosage forms, in vitro dissolution testing is crucial. The non-model-dependent similarity factor (f2) method is typically used to determine the similarity between the dissolution curves of the generic and reference formulations. However, the non-model-dependent similarity factor (f2) method has the following requirements:

[0129] ① No more than one sampling point shall be used where the drug dissolution rate exceeds 85%;

[0130] ② The relative standard deviation of dissolution at the first sampling time point (e.g., 15 minutes) shall not exceed 20%, and the relative standard deviation of dissolution at other sampling time points shall not exceed 10%.

[0131] In our study on the similarity of dissolution behavior of Duyiwei soft capsules, we found that the relative standard deviation (RSD) of dissolution at each sampling time point was relatively large, making the f² method unsuitable for comparing similarity. To address this, we introduced the model-dependent method (Mahalanobis Distance, MSD) for similarity evaluation.

[0132] The specific comparison method is as follows:

[0133] (1) Determine the batch-to-batch differences in dissolution of the reference sample, and then use this as a basis to determine the similarity limit of the multivariate statistical distance (MSD).

[0134] (2) Determine the multivariate statistical moments of the average dissolution of the test and reference samples.

[0135] (3) Determine the 90% confidence interval of the multivariate statistical moments of the measured dissolution of the test and reference samples.

[0136] (4) If the upper limit of the confidence interval in step (3) above is less than or equal to the similarity limit of the reference sample, the two batches of samples can be considered to be similar.

[0137] Based on the dissolution properties of Duyiwei soft capsules, a model-dependent method was used to investigate the dissolution behavior of our company's Duyiwei soft capsules (batch number: 20240501) and Duyiwei soft capsules produced by several other manufacturers (Jiangsu Wango, Guizhou Shunjian, and Hainan Haishen). Our company's Duyiwei soft capsules were used as the reference formulation. DDSolver software was used for the calculation.

[0138] The MSDs of the fitted model parameters for the reference and test formulations were calculated to be 2.4180, 3.4677, and 2.1125, respectively, as shown in Tables 4.6, 4.7, and 4.8. The results indicate that the dissolution behavior of our company's Duyiwei soft capsules is similar to that of Duyiwei soft capsules from other manufacturers; the dissolution curves are shown in Tables 4.6, 4.7, and 4.8. Figure 3 , 4 5.

[0139] Table 4.6 MSD of the reference and test formulations of Duyiwei soft capsules (Jiangsu Wango)

[0140]

[0141] 4.7 MSD of the reference and test formulations of Duyiwei soft capsules (Guizhou Shunjian)

[0142]

[0143] 4.8 MSD of the reference and test formulations of Duyiwei soft capsules (Hainan Haishen)

[0144]

[0145] Comparative Example 1: The same batch of Duyiwei soft capsules was tested using the paddle method and flow cell method.

[0146] (1) Paddle method determination: Take 3 batches of Duyiwei soft capsules and operate according to the "Technical Guidelines for Dissolution Test of Ordinary Oral Solid Dosage Forms" and the second method (paddle method) of the Dissolution and Release Determination Method in Section 0931 of the 2020 edition of the Chinese Pharmacopoeia.

[0147] Temperature: 37±0.5℃, Rotation speed: 50~75 rpm as required by the guidelines, but 75 rpm was selected considering the difficulty of sample dispersion, pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin, Volume: 200ml.

[0148] Sampling times: 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 7h, 8h

[0149] Sampling volume: 1 ml; Refill required: No; Results have been corrected during calculation.

[0150] The experimental results are shown in Table 4.9:

[0151] 4.9 Results of the determination of Duyiwei soft capsules by the slurry method

[0152] (2) Flow cell method: Take the above 3 batches of Duyiwei soft capsules and determine the dissolution and release rate according to the sixth method (flow cell method) of General Chapter 0931 of Part IV of the Chinese Pharmacopoeia 2020 edition.

[0153] The temperature was 37±0.5℃, the flow rate was 16ml / min, the dissolution medium was 100ml of pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin solution, and the filtration method was a 0.22um PTFE microporous membrane.

[0154] Samples were taken and tested at 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 7h, and 8h respectively.

[0155] The measurement results are shown in Table 4.10:

[0156] 4.10 Results of the determination of Duyiwei soft capsules by flow cell method

[0157] in conclusion:

[0158] ① The large number of outliers in the slurry method may be related to disintegration or dissolution that is too fast or too slow;

[0159] ② The smoothness of the slurry dissolution curve is low and the data variability (RSD) is high, indicating that the data is seriously affected by physical interference;

[0160] The flow pool method is controllable, and the data is stable with a low coefficient of variation.

Claims

1. A method for determining the dissolution of a Duhong soft capsule, characterized in that, The dissolution rate is determined using the flow cell method; the flow cell method is determined using a flow cell dissolution apparatus, using one or more of acetate buffer, Tween 80, and pepsin as the dissolution medium.

2. The dissolution test method according to claim 1, characterized in that, The acetate buffer has a pH of 4.5, the Tween concentration is 4%, and the pepsin concentration is 1%.

3. The dissolution test method according to claim 1, characterized in that, The dissolution rate for the test is 8-16 ml / min.

4. The dissolution test method according to claim 1, characterized in that, The dissolution test method uses luteolin as the key quality dissolution index.

5. The dissolution test method according to claim 4, characterized in that, The method for detecting luteolin is as follows: using an Agilent SB-C18 column, with a mobile phase of methanol-0.3% phosphoric acid + 0.4% Tween 80 solution at a ratio of 65:35, a detection wavelength of 350 nm, and a flow rate of 0.3-1 ml / min.

6. The dissolution test method according to any one of claims 1 to 5, characterized in that, The dissolution determination method is as follows: Take Duyiwei soft capsules and determine the dissolution and release rate according to the flow cell method under the General Chapter of Chinese Pharmacopoeia, Part IV. The temperature is 37℃, the flow rate is 16ml / min, and the dissolution medium is 100ml of pH 4.5 acetate buffer + 4% Tween 80 + 1% pepsin solution. Samples are taken at 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 7h, and 8h, respectively, and the luteolin is determined and the dissolution curve is plotted.

7. A method for evaluating the quality consistency of Duiyi soft capsules, characterized in that, The quality consistency evaluation method uses the flow cell method to determine the dissolution curves of Duyiwei soft capsules and reference preparations from different manufacturers to evaluate their similarity.

8. The method of mass consistency evaluation according to claim 7, characterized in that, The similarity evaluation method is f 2 Non-model-dependent similarity factor method, for batch difference RSD greater than 10%, using MSD model-dependent method for similarity evaluation.

9. The quality consistency evaluation method according to claim 8, characterized in that the MSD model dependency method includes the following steps: ① Determine the batch-to-batch differences in dissolution of the reference sample, and then use this as a basis to determine the similarity limit of the multivariate statistical moments (MSD); ② Determine the multivariate statistical moments for the average dissolution of the test and reference samples; ③ Determine the 90% confidence intervals of the multivariate statistical moments of the measured dissolution amounts of the test and reference samples; ④ If the upper limit of the confidence interval in step ③ is less than or equal to the similarity limit of the reference sample, the two batches of samples can be considered to be similar.

10. The application of the evaluation method as described in claim 9 in the quality consistency evaluation method of traditional Chinese medicine solid dosage forms.

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