Method for determining dissolution rate of semeglutide microspheres
By employing a flow cell method combined with a periodic pulsating constant current system using acetate buffer and 1,2-propanediol as a co-solvent, the problems of microsphere aggregation and degradation in the assay of smegglutide microspheres were solved, enabling accurate dissolution detection and in vivo release simulation, thus improving data accuracy and predictability.
Patent Information
- Application Number
- CN202511305934.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-12
- Publication Date
- 2025-12-12
AI Technical Summary
Existing traditional dissolution testing methods for semaglutide microspheres suffer from microsphere aggregation, floating, or adhesion phenomena, leading to uneven contact of the dissolution medium and affecting data accuracy. Furthermore, semaglutide is subject to chemical degradation during flow cell testing, which fails to accurately reflect the microsphere release characteristics.
The dissolution rate of smegglutide microspheres was determined using the flow cell method. A dissolution medium and a co-solvent were added to the flow cell, and a closed-loop flow cell system with periodic pulsating constant flow was used. Samples were taken in stages, and the concentration was determined by high performance liquid chromatography. A cumulative dissolution curve was plotted. Suitable dissolution media, such as acetate buffer, and co-solvents, such as 1,2-propanediol, were selected to avoid drug degradation.
This method enables precise dissolution determination of smegglutide microsphere formulations, avoiding microsphere floating and adhesion issues, simulating the in vivo release process, and providing a simple and accurate dissolution detection method that improves data reliability and IVIVC predictability.
Smart Images
Figure CN121114267A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of testing methods, specifically to a method for determining the dissolution rate of smegglutinin microspheres. Background Technology
[0002] Dissolution refers to the rate and extent to which an active pharmaceutical ingredient dissolves from a solid dosage form, such as tablets, capsules, or granules, in a specified medium. It is a key indicator for evaluating the quality of pharmaceutical preparations. For special dosage forms such as sustained-release, controlled-release, enteric-coated, and transdermal patches, the dissolution behavior is usually referred to as release rate. Dissolution testing plays multiple core roles in drug development and quality control: it provides a direct assessment of drug performance through in vitro release behavior, guides formulation design and process optimization, predicts in vivo efficacy and safety risks, ensures batch-to-batch consistency, and provides a basis for stability studies.
[0003] Microsphere formulations are widely used in long-acting drug delivery systems due to their unique sustained-release properties. However, traditional dissolution assays (such as the roller bottle method and the paddle method) have significant limitations when applied to microspheres: microspheres are prone to aggregation, floating, or adhesion to the wall, leading to uneven contact of the dissolution medium, interfering with the accuracy of the release curve, and affecting the reliability of the data.
[0004] Smegglutide, a novel peptide drug, is not yet available in its microsphere formulation in China. During the development phase, establishing a precise dissolution / release evaluation method is crucial. This method must be able to support process parameter optimization, the establishment of quality control standards, and in vitro-in vivo correlation (IVIVC) studies.
[0005] The 2020 edition of the Chinese Pharmacopoeia has added the flow cell method as one of the methods for dissolution determination, which is particularly suitable for long-acting injectable formulations. Compared with the traditional paddle basket method, the flow cell method has the following breakthrough advantages:
[0006] 1. Avoid physical interference: Eliminate the problems of microspheres floating, accumulating, and adhering;
[0007] 2. Flexible control of the release environment: By adjusting the flow rate and fluid mode (laminar / turbulent flow), physiological conditions are simulated, improving the method's discriminative power;
[0008] 3. Overcoming the limitations of leakage conditions: adaptable to drugs with low solubility;
[0009] 4. Improve the predictability of IVIVC: reduce burst release and more accurately reflect the release behavior in the body.
[0010] Although flow cell dissolution assays are theoretically applicable to microsphere formulations, in actual testing of semaglutide microspheres, significant chemical degradation of the drug was observed in the flow cell system. This degradation did not originate from the formulation itself but was induced by the dynamic environment of the flow cell, leading to distorted dissolution data that failed to accurately reflect the microsphere release characteristics. Therefore, developing a dissolution detection method that avoids drug degradation while retaining the advantages of the flow cell assay has become an urgent need for the development and quality control of semaglutide microspheres. Summary of the Invention
[0011] Therefore, it is necessary to provide a
[0012] To achieve the above objectives, the present invention provides a technical solution:
[0013] A method for determining the dissolution rate of smegglutinin microspheres, comprising the following steps:
[0014] Add a dissolution medium and a co-solvent of volume V1 to the flow cell;
[0015] The smegglutinin microsphere sample was placed in the flow cell and continuously dissolved for ≥480h. During the dissolution process, the volume of dissolution medium was taken out from the solvent bottle in stages at selected time points as the test solution. After sampling, the same volume of dissolution medium was immediately added. During the dissolution process, the closed-loop flow cell system was operated with periodic pulsating constant flow.
[0016] Prepare a reference solution of semaglutide at a known concentration. Based on the concentration of the semaglutide reference solution, determine the concentration C of the test solution at different time points using high-performance liquid chromatography (HPLC). n Then, the cumulative dissolution rate of each sampling point is calculated using the cumulative dissolution rate calculation method.
[0017] Plot a dissolution curve against the cumulative dissolution rate (%) at the sampling points over time;
[0018] Where L represents the labeled amount of the formulation.
[0019] Preferably, the dissolution medium is an acetate buffer solution.
[0020] Preferably, the acetate buffer includes sodium acetate buffer, potassium acetate buffer, and ammonium acetate buffer, with ammonium acetate buffer being the most preferred.
[0021] Preferably, the dissolution medium comprises a buffer solution with a pH of 4.5 to 10.0.
[0022] Preferably, the dissolution medium comprises a buffer solution with a pH of 8.0 to 9.4.
[0023] Preferably, the co-solvent comprises 0.01 wt% to 0.5 wt% 1,2-propanediol.
[0024] Preferably, the co-solvent comprises 0.2 wt% to 0.3 wt% 1,2-propanediol.
[0025] Preferably, the flow rate of the closed-loop pulsation is 2–16 mL / min, more preferably 6–10 mL / min.
[0026] Preferably, the periodic pulsating flow is a sinusoidal waveform pulse.
[0027] Preferably, the phased sampling includes:
[0028] Initial phase (0-48 hours): Sampling ≥ 4 times;
[0029] Continuous release phase (48-336 hours): ≥10 samplings;
[0030] End of release (336-480 hours): Sampling ≥3 times and must include the 480-hour endpoint.
[0031] The beneficial effects of this invention are:
[0032] 1. This invention is the first to realize the determination of the dissolution rate of smegglutide microsphere formulation using the flow cell method;
[0033] 2. By screening the dissolution medium and other parameters, this invention can, to a certain extent, avoid the degradation and adsorption of smegglutide microsphere formulations in the flow cell system;
[0034] 3. The dissolution determination method described in this invention can well simulate the dissolution process of microsphere formulations in vivo. It is simple, accurate, effective and convenient to operate, and can quantitatively reflect the release of smegglutide microspheres at different time points.
[0035] 4. This invention avoids problems such as floating, accumulation, and adhesion that occur in conventional dissolution determination methods such as the paddle basket method. Attached Figure Description
[0036] Figure 1 The curves show the dissolution rate of microsphere samples in different media as a function of time.
[0037] Figure 2 The curve shows the stability of the API solution over time under the experimental conditions. Detailed Implementation
[0038] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.
[0039] In the embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.
[0040] A method for determining the dissolution rate of smegglutinin microspheres, comprising the following steps:
[0041] Add a dissolution medium and a co-solvent of volume V1 to the flow cell;
[0042] The smegglutinin microsphere sample was placed in the flow cell and continuously dissolved for ≥480h. During the dissolution process, the volume of dissolution medium was taken out from the solvent bottle in stages at selected time points as the test solution. After sampling, the same volume of dissolution medium was immediately added. During the dissolution process, the closed-loop flow cell system was operated with periodic pulsating constant flow.
[0043] Prepare a reference solution of semaglutide at a known concentration. Based on the concentration of the semaglutide reference solution, determine the concentration C of the test solution at different time points using high-performance liquid chromatography (HPLC). n Then, the cumulative dissolution rate of each sampling point is calculated using the cumulative dissolution rate calculation method.
[0044] Plot a dissolution curve against the cumulative dissolution rate (%) at the sampling points over time;
[0045] Where L represents the labeled amount of the formulation;
[0046] V2 ranges from 2 mL to 10 mL.
[0047] This invention is the first to realize the determination of the dissolution rate of semaglutide microsphere formulation using the flow cell method;
[0048] By screening the dissolution medium and other parameters, this invention can, to a certain extent, avoid the degradation and adsorption of smegglutide microsphere formulations in the flow cell system;
[0049] The dissolution determination method described in this invention can effectively simulate the dissolution process of microsphere formulations in vivo. It is simple, accurate, effective, and convenient to operate, and can quantitatively reflect the release of smegglutide microspheres at different time points.
[0050] This invention avoids problems such as floating, accumulation, and adhesion that occur in conventional dissolution determination methods such as the paddle basket method.
[0051] In some embodiments, the dissolution medium is an acetate buffer solution.
[0052] In some embodiments, the acetate buffer includes sodium acetate buffer, potassium acetate buffer, and ammonium acetate buffer, preferably ammonium acetate buffer.
[0053] In some embodiments, the dissolution medium comprises a buffer solution with a pH of 4.5 to 10.0.
[0054] In some embodiments, the dissolution medium comprises a buffer solution with a pH of 8.0 to 9.4.
[0055] In some embodiments, the co-solvent comprises 0.01 wt% to 0.5 wt% 1,2-propanediol.
[0056] In some embodiments, the co-solvent comprises 0.2 wt% to 0.3 wt% 1,2-propanediol.
[0057] In some embodiments, the flow rate of the closed-loop pulsation is 2 to 16 mL / min, preferably 6 to 10 mL / min.
[0058] In some embodiments, the periodic pulsating flow is a sinusoidal pulse.
[0059] In some embodiments, the phased sampling includes:
[0060] Initial phase: sampling ≥ 4 times; more specifically, the initial phase is a phase lasting 0-48 hours.
[0061] Continuous release phase: sampling ≥10 times; more specifically, the continuous release phase is a phase lasting 48-336 hours.
[0062] End of release: Sampling ≥3 times and must include a 480-hour endpoint. More specifically, the end of release is a phase lasting 336-480 hours.
[0063] Example 1
[0064] A flow cell method for determining the dissolution rate of semaglutide long-acting sustained-release microspheres.
[0065] 1. Dissolution method: Flow cell method;
[0066] 2. Dissolution parameters:
[0067] Dissolution medium: pH 9.0 acetate buffer;
[0068] Flow rate: 8 mL / min, sinusoidal pulse, closed-loop mode; temperature: 37℃; tank: standard large tank, φ22.6 mm; replenish with an equal volume of medium after sampling.
[0069] 3. Dissolution system:
[0070] The preferred choice is the DS-7CP piston pump flow cell leaching system from Huarong Analytical Instruments Co., Ltd.
[0071] The method specifically includes the following steps:
[0072] (1) Test solution: Take a microsphere sample and accurately weigh a certain amount and add it to the inner cell of the flow cell; after starting the instrument, it will automatically take samples at 1, 2, 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, 168, 192, 216, 240, 264, 288, 312, 336, 360, 384, 408, 432, 456, and 480h, filter the sample, and inject 1mL of the filtrate into the liquid phase bottle as the test solution;
[0073] (2) Reference solution: Take an appropriate amount of smegglutinin reference standard and dilute it with a dissolution medium to a solution of about 0.38 mg / mL as the reference solution;
[0074] (3) Detection method: The concentration of smegglutinin in the test solution and the reference solution was determined by high performance liquid chromatography and the concentration of smegglutinin in the test solution was calculated. The dissolution rate of each sampling point was calculated by the cumulative dissolution rate calculation method.
[0075] (4) Plot dissolution curves against cumulative dissolution rate (%) at sampling points (h). Two samples were measured in parallel for each of the two media. The four curves represent the dissolution of two parallel samples for each of the two media. The results are shown in […]. Figure 1 .
[0076] Depend on Figure 1 It can be seen that the dissolution rate of the microsphere sample is low in pH 7.4 phosphate buffer.
[0077] In pH 9.0 ammonium acetate buffer, the dissolution rate of the microsphere sample reached its peak at 168 h, and then decreased, which is related to the stability of the microsphere sample. The decrease in dissolution rate after 168 h was due to insufficient long-term stability of the sample in the dynamic environment of the flow cell.
[0078] Example 2
[0079] Cosolvent screening test.
[0080] Smegglutide microsphere formulations are susceptible to degradation in flow cell systems, making it essential to screen for a stable dissolution medium. To accelerate dissolution, an appropriate amount of co-solvent needs to be added to the medium.
[0081] Media with pH 6.8-9.4 and various co-solvents, including Brij-35, Tween 80, poloxamer 188, and propylene glycol, were screened. Smegglutide reference solution was prepared by mixing these media with the above-mentioned media and circulated through a flow cell pipeline to investigate stability. After long-term stability testing, ammonium acetate buffer (containing propylene glycol) at pH 9.0 was finally selected as the dissolution medium. The initial screening results of the 24-hour stability media are shown in Table 1.
[0082] Table 1. Initial screening of 24h stable media
[0083] Dissolution medium Cosolvent Changes in the concentration of the reference standard over 24 hours pH 6.8 phosphate buffer Brij35 -67.17％ pH 7.4 phosphate buffer Propylene glycol -3.02％ pH 7.4 phosphate buffer Twain 80 -98.38％ pH 9.0 ammonium acetate buffer Propylene glycol -2.02％ pH 9.0 ammonium acetate buffer Polosham 188 -33.59％ pH 9.4 Tris buffer Polosham 188 -19.95％
[0084] As shown in Table 1, the stability of smegglutide solution is better when pH 7.4 phosphate buffer + propylene glycol and pH 9.0 ammonium acetate buffer + propylene glycol are used as dissolution media.
[0085] Example 3
[0086] Stability testing of API solutions (Active Pharmaceutical Ingredients).
[0087] Using the aforementioned pH 7.4 phosphate buffer and pH 9.0 ammonium acetate buffer as media, solutions of smegglutinin API of the same concentration were prepared, and stability tests were conducted simultaneously under the experimental conditions described in Example 1. The results are as follows: Figure 2 As shown.
[0088] Depend on Figure 2 It can be seen that, under the above experimental conditions, the smegglutinin API solution prepared with the two buffer solutions was relatively stable within 168 hours, but its stability began to decrease as the experimental time was further extended.
[0089] In summary, this invention can be used for dissolution testing of smegglutide microsphere formulations.
[0090] Example 4
[0091] The dissolution test results of smegglutide microspheres in different media and co-solvents over 24 hours are shown in Table 2.
[0092] Table 2.24h dissolution results
[0093]
[0094] As shown in Table 2, under the selected conditions, except for pH 9.0 ammonium acetate buffer + propylene glycol, the smegglutinin microsphere samples were difficult to dissolve in other dissolution media, with low dissolution rate at 24h and a continuing decreasing trend.
[0095] It should be noted that the specific parameters or reagents in the above embodiments are specific or preferred embodiments under the concept of the present invention, and not limitations thereof; those skilled in the art can make adaptive adjustments within the concept and protection scope of the present invention.
Claims
1. A method for determining the dissolution rate of smegglutinin microspheres, characterized in that, Including the following steps: Add a dissolution medium and a co-solvent of volume V1 to the flow cell; The smegglutinin microsphere sample was placed in the flow cell and continuously dissolved for ≥480h. During the dissolution process, the volume of dissolution medium was taken out from the solvent bottle in stages at selected time points as the test solution. After sampling, the same volume of dissolution medium was immediately added. During the dissolution process, the closed-loop flow cell system was operated with periodic pulsating constant flow. Prepare a reference solution of semaglutide at a known concentration. Based on the concentration of the semaglutide reference solution, determine the concentration C of the test solution at different time points using high-performance liquid chromatography (HPLC). n Then, the cumulative dissolution rate of each sampling point is calculated using the cumulative dissolution rate calculation method. Plot a dissolution curve against the cumulative dissolution rate (%) at the sampling points over time; Where L represents the labeled amount of the formulation.
2. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The dissolution medium is acetate buffer.
3. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The acetate buffer includes sodium acetate buffer, potassium acetate buffer, and ammonium acetate buffer, preferably ammonium acetate buffer.
4. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The dissolution medium includes a buffer solution with a pH of 4.5 to 10.
0.
5. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The dissolution medium includes a buffer solution with a pH of 8.0 to 9.
4.
6. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The co-solvent includes 0.01 wt% to 0.5 wt% 1,2-propanediol.
7. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The co-solvent includes 0.2 wt% to 0.3 wt% 1,2-propanediol.
8. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The flow rate of the closed-loop pulsation is 2–16 mL / min.
9. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The periodic pulsating flow is a sinusoidal waveform pulse.
10. The method for determining the dissolution rate of smegglutinin microspheres according to claim 1, characterized in that, The phased sampling includes: Initial stage: Sampling ≥ 4 times; Continuous release phase: ≥10 samplings; Late release phase: Sampling ≥ 3 times.