Method for detecting particle size of empendectin

Abstract

The invention discloses a particle size detection method of empastine, and relates to the technical field of particle size detection, and the method comprises the following steps: dispersing an empastine sample in a dispersant to form a sample to be detected; dispersing and mixing the to-be-detected sample to obtain a pretreated sample; adding the pretreated sample into a sample pool of a laser particle size analyzer, stirring for 10 minutes, starting the laser particle size analyzer, and carrying out particle size detection on the ensafetine; according to the method for detecting the particle size of the empastine, a detection sample is treated through an ultrasonic instrument, so that the empastine is completely infiltrated into a medium before detection, and the problems of large detection result error and poor reproducibility caused by slow infiltration speed of the empastine in a sample pool are avoided; by adjusting the dispersing agent to be 0.05% poloxamer 188, the sample detection reproducibility is good, and the method is safer for users; and the detection method is suitable for the raw material medicine and preparation of the ensefentin, and has the advantages of strong universality, accurate detection result and good repeatability.

Description

Technical Field

[0001] This invention relates to particle size detection technology, and more specifically to a particle size detection method for Encerfentin. Background Technology

[0002] Ensifentrine is a novel phosphodiesterase 3 / 4 (PDE3 / PDE4) inhibitor with dual pharmacological activities of anti-inflammation and bronchodilator. Clinically, it is mainly used to treat asthma and chronic obstructive pulmonary disease (COPD). As a drug administered via inhalation, the particle size distribution of its active pharmaceutical ingredient (API) and formulations (such as inhalation suspensions) is a key quality attribute that directly affects pulmonary deposition efficiency, bioavailability, efficacy stability, and safety. Excessively large particle sizes may prevent the drug from effectively reaching the site of action, while excessively small particle sizes or uneven distribution can easily lead to aggregation, affecting the accuracy and uniformity of dosage. Therefore, establishing accurate and reliable particle size determination methods is crucial for the quality control of API and formulation production.

[0003] Currently, most particle size determination methods in this field employ wet dispersion techniques, which utilize surfactant solutions as the dispersion medium to prevent particle agglomeration and ensure representativeness of the results. Existing technologies often use traditional nonionic surfactants such as Tween 20 to prepare the dispersion. However, in practical applications, this method has several significant drawbacks: First, Tween 20 has limited wetting properties for encefentin particles, resulting in slow sample wetting in the dispersant and the formation of incompletely dispersed clumps, affecting the immediacy and accuracy of the detection. Second, this dispersion system is difficult to achieve a uniform and stable dispersion state in actual operation, leading to significant fluctuations in detection results and poor reproducibility. Furthermore, Tween 20 itself has a certain degree of cytotoxicity and irritation; long-term exposure may pose a potential health risk to laboratory personnel and does not meet the increasingly stringent safety and environmental protection requirements of modern pharmaceutical quality control.

[0004] Therefore, developing a particle size detection method with high dispersion efficiency, safe operation, and good reproducibility, tailored to the physicochemical properties of the specific compound encefentin, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a particle size detection method for encefentin, so as to solve the problems of large error and poor repeatability of particle size detection results caused by low dispersion efficiency of encefentin in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for particle size detection of encefenidine, comprising the following steps:

[0007] S1. Disperse the encefentin sample in a dispersant to form the test sample;

[0008] S2. The sample to be tested is dispersed and mixed to obtain a pretreated sample;

[0009] S3. Add the pretreated sample to the sample cell of the laser particle size analyzer, stir for 10 minutes, start the laser particle size analyzer, and perform encefentin particle size detection.

[0010] Furthermore, the stirring speed of the sample cell described in S3 is 500-1200 rpm, and the optical concentration is 8%-20%.

[0011] Further, the dispersant in S1 is an aqueous solution containing at least one of sorbitan fatty acid esters, alcohols, and polyoxyethylene-polyoxypropylene ether block copolymers.

[0012] Furthermore, the sorbitan fatty acid esters are Tween or Span; the alcohols are ethanol, isopropanol, propylene glycol or glycerol; and the polyoxyethylene polyoxypropylene ether block copolymers are poloxamer.

[0013] Furthermore, the dispersant in S1 is a mixed solution of poloxamer 188 and water.

[0014] Furthermore, the mass concentration of poloxamer 188 in the mixed solution is 0.05% to 1%.

[0015] Furthermore, the dispersion and mixing process described in S2 is at least one of ultrasonic dispersion, magnetic stirring, and shear dispersion.

[0016] Furthermore, the mass concentration of encefentin in the sample to be tested, as described in S1, is 0.03% to 10%.

[0017] Furthermore, the encefentin sample mentioned in S1 is encefentin raw material or encefentin inhalation suspension.

[0018] Compared with the prior art, the present invention provides a particle size detection method for encefentin, which uses an ultrasonic instrument to process the test sample so that the encefentin is completely impregnated in the medium before detection, thus avoiding the problems of large error in the test results and poor reproducibility caused by the slow impregnation speed of encefentin in the sample cell.

[0019] By adjusting the dispersant to 0.05% poloxamer 188, the sample detection reproducibility is good, and the low concentration of dispersant is safer for users. By adjusting the stirring speed of the sample cell, the test sample is completely dispersed, which improves the accuracy of the test results. This detection method is applicable to the active pharmaceutical ingredient and formulation of enstatin. The method is highly versatile, and the test results are accurate and reproducible. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0021] Figure 1 This is a comparative schematic diagram of particle size detection results provided in Embodiments 1 to 4 of the present invention;

[0022] Figure 2 This is a comparative schematic diagram of particle size detection results provided in Examples 5 to 9 of the present invention;

[0023] Figure 3 This is a comparative schematic diagram of particle size detection results provided in Examples 10 to 13 of the present invention;

[0024] Figure 4 This is a comparative schematic diagram of particle size detection results provided in Examples 14 to 16 of the present invention;

[0025] Figure 5 This is a comparative diagram of particle size detection results provided in Examples 17 to 19 of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] Example 1:

[0028] Please see Figure 1 A method for particle size determination of encefenidine, comprising the following steps:

[0029] S1. Accurately weigh poloxamer 188 and add it to deionized water, stirring and mixing to achieve a poloxamer 188 mass concentration of 0.2%, thus obtaining a dispersant. Accurately weigh encefentin active pharmaceutical ingredient (API) and add it to the dispersant to form the test sample, with an API concentration of 0.5%.

[0030] Poloxamer 188 is a nonionic polymeric surfactant that can adsorb onto the surface of particles and prevent particle aggregation in the medium through steric hindrance, ensuring that encefentin particles exist in a monodisperse state in the liquid medium. This is a prerequisite for obtaining true and reliable particle size distribution data.

[0031] The 0.2% mass concentration was optimized to strike a balance between effective dispersion and avoiding the introduction of additional interference. A 0.5% active pharmaceutical ingredient concentration ensures that, during laser particle size analysis, the particle concentration in the sample cell generates a sufficiently strong scattering signal without causing "multiple scattering" (i.e., the laser being repeatedly scattered by multiple particles) due to excessive concentration, thus affecting measurement accuracy.

[0032] S2. The sample to be tested was dispersed using an ultrasonic instrument. The Biosafer 900 ultrasonic instrument has a power of 540W. A No. 6 amplitude rod was used, and the dispersion time was 10 minutes to obtain the pretreated sample.

[0033] Using a specific power (540W) and a probe (amplifier bar #6), ultrasound was applied for 10 minutes. The immense shear force generated by the cavitation effect (formation and rupture of tiny bubbles) in the liquid mechanically disrupted any soft aggregates that might be present in the active pharmaceutical ingredient. This process restored the particles in the sample to their original primary particle state as much as possible, ensuring representative sampling and reflecting the size of individual particles rather than aggregates. Standardization of parameters (power, time, probe type) ensured consistency in pretreatment conditions across different batches of samples, which is crucial for method reproducibility.

[0034] S3. Take the pretreated sample and add it to the sample cell of the HELOSYBR laser particle size analyzer. Set the stirring speed of the sample cell to 800 rpm, adjust the optical concentration of the sample in the sample cell to 10%, stir for 10 minutes, start the laser particle size analyzer, and perform encefentin particle size detection.

[0035] The stirring speed of the sample cell is set to 800 rpm to maintain the uniform suspension of particles in the sample cell during the measurement process, prevent uneven concentration caused by particle settling due to gravity, and ensure that the area swept by the laser beam always represents the whole sample, thus guaranteeing the real-time performance and accuracy of the measurement.

[0036] Adjusting the sample optical concentration to 10% is a crucial measurement parameter for laser particle size analyzers, indicating the sample's occlusion rate of the laser. The optical concentration should be controlled within the instrument's recommended optimal measurement range. Too low a concentration results in a weak signal and poor signal-to-noise ratio; too high a concentration increases the risk of multiple scattering. 10% is an ideal compromise, ensuring high-quality light scattering data.

[0037] Stir for 10 minutes before starting the measurement. Perform secondary balancing and homogenization within the instrument to ensure that the sample taken from the sample cell reaches a uniform and stable suspension state after ultrasonic dispersion, and to eliminate local non-uniformity caused by transfer or temperature changes, thus standardizing the initial measurement conditions.

[0038] The analysis was performed using the NeoPatek HELOSYBR laser particle size analyzer, which is based on the principle of static laser diffraction. The scattering angle of the laser light by a particle is related to its particle size. By detecting the intensity distribution of scattered light at different angles and performing inversion calculations using Mie theory or Fraunhofer models, the volumetric particle size distribution of the sample from submicron to millimeter scale can be obtained. This method has the advantages of fast measurement, wide range, good repeatability, and strong statistical representativeness of results (millions of particles can be analyzed in a single measurement).

[0039] Example 2:

[0040] Please see Figure 1 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0041] The difference between this embodiment and Embodiment 1 is that the dispersant is an aqueous solution of Tween 20 with a mass concentration of 0.2%, while the other steps are the same.

[0042] Example 3:

[0043] Please see Figure 1 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0044] The difference between this embodiment and Embodiment 1 is that the dispersant is an aqueous solution of Span 20 with a mass concentration of 0.2%, while the other steps are the same.

[0045] Example 4:

[0046] Please see Figure 1 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0047] The difference between this embodiment and Embodiment 1 is that the dispersant is an aqueous solution of propylene glycol with a mass concentration of 0.2%, while the other steps are the same.

[0048] Please refer to Table 1 for the detection methods of Examples 1 to 4.

[0049] Table 1 Comparison of detection methods in Examples 1 to 4

[0050]

[0051] Please refer to Table 2 for the detection results of Examples 1 to 4.

[0052] Table 2. Particle size detection results of Examples 1 to 4

[0053]

[0054] As shown in Tables 1 and 2, poloxamer 188 aqueous solution, Tween 20 aqueous solution, Span 20 aqueous solution, and propylene glycol aqueous solution all exhibited good dispersion effects on encefentin API as dispersants, with accurate and repeatable particle size analysis results. Considering the toxicity of each dispersant, the low-toxicity poloxamer 188 aqueous solution was selected as the preferred dispersant.

[0055] Example 5:

[0056] Please see Figure 2 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0057] The difference between this embodiment and Embodiment 1 is that the dispersant is an aqueous solution of poloxamer 188, wherein the mass concentration of poloxamer 188 is 0.05%, and the other steps are the same.

[0058] Example 6:

[0059] Please see Figure 2 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0060] The difference between this embodiment and Embodiment 1 is that the dispersant is an aqueous solution of poloxamer 188, wherein the mass concentration of poloxamer 188 is 0.1%, and the other steps are the same.

[0061] Example 7:

[0062] Please see Figure 2 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0063] The difference between this embodiment and Embodiment 1 is that the dispersant poloxamer 188 is an aqueous solution, wherein the mass concentration of poloxamer 188 is 0.5%, and the other steps are the same.

[0064] Example 8:

[0065] Please see Figure 2 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0066] The difference between this embodiment and Embodiment 1 is that the dispersant poloxamer 188 is an aqueous solution, wherein the mass concentration of poloxamer 188 is 1%, and the other steps are the same.

[0067] Example 9:

[0068] Please see Figure 2 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0069] The difference between this embodiment and Embodiment 1 is that the dispersant poloxamer 188 aqueous solution is used, wherein the mass concentration of poloxamer 188 is 5%, while the other steps are the same.

[0070] Please refer to Table 3 for the detection methods of Examples 5 to 9.

[0071] Table 3 Comparison of detection methods in Examples 5 to 9

[0072]

[0073] Please refer to Table 4 for the test results of Examples 5 to 9.

[0074] Table 4. Particle size detection results of Examples 5 to 9

[0075]

[0076] As shown in Tables 3 and 4, when the concentration of the poloxamer 188 aqueous solution is 0.05%–1%, the particle size distribution is accurate, and the reproducibility is good when the concentration is 0.05%–0.5%. When the concentration of the poloxamer 188 aqueous solution is 5%, a large number of bubbles are generated during sample testing, making it impossible to accurately detect the particle size of the active pharmaceutical ingredient. Therefore, the preferred concentration of the poloxamer 188 aqueous solution is 0.05%–1%, more preferably 0.05%–0.5%.

[0077] Example 10:

[0078] Please see Figure 3 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0079] The difference between this embodiment and Embodiment 1 is that the mass concentration of encefentin raw material in the sample to be tested is 0.03%, while the other steps are the same.

[0080] Example 11:

[0081] Please see Figure 3 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0082] The difference between this embodiment and Embodiment 1 is that the mass concentration of encefentin raw material in the sample to be tested is 0.1%, while the other steps are the same.

[0083] Example 12:

[0084] Please see Figure 3This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0085] The difference between this embodiment and Embodiment 1 is that the mass concentration of encefentin raw material in the sample to be tested is 1%, while the other steps are the same.

[0086] Example 13:

[0087] Please see Figure 3 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0088] The difference between this embodiment and Embodiment 1 is that the mass concentration of encefentin raw material in the sample to be tested is 10%, while the other steps are the same.

[0089] Please refer to Table 5 for the detection methods of Examples 10 to 13.

[0090] Table 5 Comparison of detection methods in Examples 10 to 13

[0091]

[0092] Please refer to Table 6 for the test results of Examples 10 to 13.

[0093] Table 6. Particle size detection results of Examples 10 to 13

[0094]

[0095] As shown in Tables 5 and 6, the particle size distribution of encefentin API is accurate and reproducible when the concentration of the dispersant is between 0.03% and 10%. The preferred concentration is 0.03% to 1%, which provides an appropriate amount of encefentin API and avoids material waste caused by excessive API usage.

[0096] Example 14:

[0097] Please see Figure 4 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0098] The difference between this embodiment and Embodiment 1 is that the particle size detection sample cell is set to rotate at 500 rpm and the optical concentration is set to 8%, while the other steps are the same.

[0099] Example 15:

[0100] Please see Figure 4 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0101] The difference between this embodiment and Embodiment 1 is that the particle size detection sample cell is set to rotate at 800 rpm and the optical concentration is set to 15%, while the other steps are the same.

[0102] Example 16:

[0103] Please see Figure 4 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0104] The difference between this embodiment and Embodiment 1 is that the particle size detection sample cell is set to rotate at 1200 rpm and the optical concentration is set to 20%, while the other steps are the same.

[0105] Please refer to Table 7 for the detection methods of Examples 14 to 16.

[0106] Table 7 Comparison of Detection Methods in Examples 14 to 16

[0107]

[0108] Please refer to Table 8 for the test results of Examples 14 to 16.

[0109] Table 8. Particle size detection results of Examples 14 to 16

[0110]

[0111] As shown in Tables 7 and 8, when the optical concentration of the sample cell for particle size detection is set to 8%–20% and the stirring speed is set to 500–1200 rpm, the particle size detection results are accurate and the reproducibility of the results is good.

[0112] Example 17:

[0113] Please see Figure 5 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0114] The difference between this embodiment and Embodiment 1 is that the dispersant is a 1% aqueous solution of poloxamer 188. The sample was dispersed using magnetic stirring for 15 minutes before testing. All other steps are the same.

[0115] Example 18:

[0116] Please see Figure 5 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0117] The difference between this embodiment and Embodiment 1 is that the dispersant is a 1% aqueous solution of poloxamer 188. The sample was dispersed using a shearing machine before testing for 15 minutes. All other steps are the same.

[0118] Example 19:

[0119] Please see Figure 5 This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0120] The difference between this embodiment and Embodiment 1 is that the dispersant is a 1% aqueous solution of poloxamer 188. The sample is dispersed using an ultrasonic instrument before testing for 15 minutes. All other steps are the same.

[0121] Please refer to Table 9 for the detection methods of Examples 17 to 19.

[0122] Table 9 Comparison of Detection Methods in Examples 17 to 19

[0123]

[0124] Please refer to Table 10 for the test results of Examples 17 to 19.

[0125] Table 10. Particle size detection results of Examples 17 to 19

[0126]

[0127] As shown in Tables 9 and 10, the particle size analysis results were unsatisfactory when magnetic stirring or shear dispersion was used before sample testing. This is because mechanical dispersion of the active pharmaceutical ingredient generates a large number of air bubbles. Therefore, ultrasonic dispersion is preferred as the dispersion and mixing process before sample particle size analysis.

[0128] Example 20:

[0129] This embodiment provides a technical solution based on Embodiment 1: a particle size detection method for encefenidine.

[0130] S1. Accurately weigh poloxamer 188 and add it to deionized water. Stir and mix to obtain a poloxamer 188 mass concentration of 0.2%, thus obtaining a dispersant. Take 12 ml of encefentanyl inhalation suspension (2.5 mg: 3 ml) and add it to the dispersant to form the test sample. The concentration of the active pharmaceutical ingredient is 0.03%.

[0131] S2. The sample to be tested was dispersed using an ultrasonic instrument. The Biosafer 900 ultrasonic instrument has a power of 540W. A No. 6 amplitude rod was used, and the dispersion time was 10 minutes to obtain the pretreated sample.

[0132] S3. Take the pretreated sample and add it to the sample cell of the HELOSYBR laser particle size analyzer. Set the stirring speed of the sample cell to 800 rpm, adjust the optical concentration of the sample in the sample cell to 10%, stir for 10 minutes, start the laser particle size analyzer, and perform encefentin particle size detection.

[0133] Please refer to Table 11 for the test results.

[0134] Table 11 Particle size detection results

[0135]

[0136] As shown in Table 11, the RSD of D10 (μm) is 0.68%, <30%; the RSD of D50 (μm) is 1.09%, <20%; and the RSD of D90 (μm) is 2.39%, <30%.

[0137] The above results indicate that the particle size detection method is suitable for detecting the particle size of the active pharmaceutical ingredient in enstatin inhalation suspension, and the detection results have good repeatability.

[0138] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for particle size determination of encefenidine, characterized in that, Includes the following steps: S1. Disperse the encefentin sample in a dispersant to form the test sample; S2. Disperse and mix the sample to be tested to obtain the pretreated sample; S3. Add the pretreated sample to the sample cell of the laser particle size analyzer, stir for 10 minutes, start the laser particle size analyzer, and perform encefentin particle size detection.

2. The particle size detection method for encefenidine according to claim 1, characterized in that, The stirring speed of the sample cell described in S3 is 500-1200 rpm, and the optical concentration is 8%-20%.

3. The particle size detection method for encefenidine according to claim 1, characterized in that, The dispersant in S1 is an aqueous solution containing at least one of sorbitan fatty acid esters, alcohols, and polyoxyethylene-polyoxypropylene ether block copolymers.

4. The particle size detection method for encefenidine according to claim 3, characterized in that, The sorbitan fatty acid esters are Tween or Span; the alcohols are ethanol, isopropanol, propylene glycol or glycerol; and the polyoxyethylene polyoxypropylene ether block copolymers are poloxamer.

5. The particle size detection method for encefenidine according to claim 1, characterized in that, The dispersant in S1 is a mixed solution of poloxamer 188 and water.

6. The particle size detection method for encefenidine according to claim 5, characterized in that, The mass concentration of poloxamer 188 in the mixed solution is 0.05% to 1%.

7. The particle size detection method for encefenidine according to claim 1, characterized in that, The dispersion and mixing process described in S2 is at least one of ultrasonic dispersion, magnetic stirring, and shear dispersion.

8. The particle size detection method for encefenidine according to claim 1, characterized in that, The mass concentration of encefentanyl in the sample to be tested, as described in S1, is 0.03% to 10%.

9. The particle size detection method for encefenidine according to claim 1, characterized in that, The encefentin sample mentioned in S1 is encefentin raw material or encefentin inhalation suspension.

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