Long-acting dry powder microsphere inhalant as well as preparation method and application thereof

Abstract

The invention belongs to the field of pharmaceutical preparations, and discloses a long-acting dry powder microsphere inhalant as well as a preparation method and application thereof. The inhalant is a long-acting dry powder microsphere inhalant prepared by taking a mixture of multi-cystic vesicles prepared from phospholipid and a dry powder auxiliary material as a drug carrier and entrapping active ingredients for treating lung diseases through a spray drying technology. Compared with a dry powder microsphere inhalant prepared from traditional monocystic lipidosome, the long-acting dry powder microsphere inhalant has a longer-time slow-release effect. According to the preparation, a unique process of firstly preparing multi-capsule vesicles and then performing spray drying is adopted, the obtained microspheres have an aerodynamic particle size of 1-5 microns, can be effectively deposited in the lung and show a remarkable long-acting slow-release characteristic, and the cumulative release rate reaches about 64% after 48-hour in-vitro release. Compared with a traditional monocystic liposome inhalant, the drug action time is effectively prolonged, the administration frequency is reduced, and the patient compliance is improved. The invention provides a new thought for the research of a pulmonary drug delivery system, and has a wide clinical application prospect.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical preparations, specifically to a long-acting dry powder microsphere inhaler, its preparation method, and its application. Background Technology

[0002] Respiratory diseases are becoming increasingly common, primarily affecting the trachea, bronchi, lungs, and pleural cavity. Mild cases often present with cough, chest pain, and impaired breathing, while severe cases can lead to difficulty breathing, hypoxia, and even respiratory failure and death. Major categories of respiratory diseases include asthma, tracheitis, bronchitis, chronic obstructive pulmonary disease (COPD), pulmonary heart disease, and tuberculosis. The main causes of respiratory diseases include weakened immune function, autonomic nervous system dysfunction, infection, and air pollution.

[0003] Most common respiratory diseases are chronic respiratory diseases. Chronic respiratory diseases are those with a long course, usually progressive, and that do not heal on their own. They mainly affect the airways and other lung structures, leading to difficulty breathing and a decline in quality of life. Common chronic respiratory diseases include pulmonary fibrosis, asthma, chronic obstructive pulmonary disease, and pulmonary hypertension.

[0004] Chronic respiratory diseases require long-term medication, with common treatment methods including oral administration, intravenous injection, and pulmonary administration. Oral administration suffers from the first-pass effect, significantly reducing drug bioavailability; intravenous injection requires hospital or specialized facilities, which patients cannot perform themselves, limiting treatment convenience and reducing long-term adherence. Therefore, chronic respiratory diseases require a long-acting, sustained-release formulation to prolong the effective blood concentration of the drug, reduce the frequency and dosage of medication, and greatly improve patient adherence and therapeutic efficacy.

[0005] Lung administration offers several advantages over other routes of administration, such as bypassing the first-pass effect of the liver, achieving high local concentrations, high bioavailability, rapid onset of action, and minimal systemic toxicity. Inhaled formulations offer significant therapeutic advantages for lung diseases. However, most current inhaled formulations are fast-acting and still face numerous limitations, including low drug deposition efficiency in the lungs, easy deposition in the upper respiratory tract after inhalation, and short drug retention time in the lungs. Frequent daily nebulization can cause throat irritation and pain, exacerbate lung inflammation, and require patients to carry nebulizers, severely impacting their quality of life and reducing patient adherence.

[0006] Therefore, long-acting inhaled formulations have emerged to address chronic respiratory diseases. These formulations can significantly improve treatment efficacy by optimizing the drug's residence time in the lungs, reducing the rate of local metabolic degradation, and achieving targeted delivery, while also reducing the frequency of administration, thereby improving patient compliance. Summary of the Invention

[0007] To address the aforementioned shortcomings, the present invention aims to provide a long-acting dry powder microsphere inhaler, its preparation method, and its application, thereby solving the technical problems of providing long-term release of active ingredients, improving drug bioavailability, and enhancing patient compliance.

[0008] The technical solution of the present invention is as follows: A long-acting dry powder microsphere inhaler, the inhaler comprising a drug carrier and an active pharmaceutical ingredient, and prepared by spray drying technology; wherein the drug carrier comprises multi-vesicles and dry powder excipients in a weight ratio of 1-5:5-9. The multivesicles have a multivesicle structure and are used to encapsulate active pharmaceutical ingredients.

[0009] Further optimization involves the inclusion of phospholipids and cholesterol in the multi-vesicle.

[0010] Further optimization involves selecting at least one of lecithin, hydrogenated soybean lecithin, DPPC, DPPG, DOPC, and DSPC.

[0011] Further optimization involves selecting at least one of mannitol, lactose, leucine, chitosan, and trehalose.

[0012] Further optimization involves selecting the active pharmaceutical ingredient from drugs used to treat lung diseases.

[0013] Further optimization results in the dry powder microsphere inhaler having an aerodynamic particle size of 1-5 μm, a fine particle fraction of 35-45%, and an air release rate of ≥95%.

[0014] A method for preparing a long-acting dry powder microsphere inhaler includes the following steps: (1) Phospholipids and cholesterol are dissolved in an organic solvent and formed into a lipid film by rotary evaporation. Then, an hydration solution is added for hydration, and after centrifugation and filtration, multi-vesicle vesicles are obtained. (2) Dissolve the active pharmaceutical ingredient and dry powder excipients in water or buffer solution, and mix them with the polycystic vesicles obtained in step (1) to form a spray-drying feed solution; (3) Spray dry the feed liquid from step (2), with the inlet temperature controlled at 100-150 ℃ and the outlet temperature controlled at 45-55 ℃, and collect the dried powder to obtain the multi-capsule liposome dry powder inhaler.

[0015] Further optimization is made by using a chloroform and methanol mixture in step (1) with a volume ratio of 1:1, and a deionized water solution containing 1 mmol CaCl2 in step (1).

[0016] Further optimization is achieved by using a fan with a frequency of 34-38 Hz and an atomization pressure of 0.24-0.28 MPa for spray drying in step (3).

[0017] Application of a long-acting dry powder microsphere inhaler in the preparation of a drug for treating chronic respiratory diseases.

[0018] The beneficial effects of this technical solution are: The long-acting dry powder microsphere inhaler prepared by this invention has an aerodynamic particle size of 1-5 μm, a fine particle fraction (FPF) of about 40%, and an emptying rate of over 95%, effectively achieving good distribution in the deep lung region; The unique multi-vesicle structure of this formulation significantly prolongs drug release time. In vitro release experiments show that the cumulative release rate after 48 hours is approximately 64%, with no significant burst release phenomenon, resulting in a longer duration of action compared to traditional single-vesicle liposome-based dry powder inhalers. The long-acting sustained-release properties can significantly reduce the frequency of administration, avoiding the drawbacks of traditional inhaled preparations that require multiple daily administrations, and greatly facilitating the long-term treatment of patients with chronic respiratory diseases. The product has low moisture content, weak hygroscopicity, good physicochemical stability, and is easy to store and transport; Therefore, long-acting dry powder microspheres have suitable physicochemical properties such as emptying rate and fine particle fraction, which meet the requirements of pulmonary inhalation administration and are easy to operate, and can be effectively deposited in the lungs. Attached Figure Description

[0019] Figure 1 Transmission electron microscopy image of a multicystic vesicle; Figure 2 Scanning electron microscope image of a long-acting dry powder microsphere inhaler; Figure 3 This is a particle size distribution diagram of a long-acting dry powder microsphere inhaler. Figure 4 TGA chromatogram and hygroscopicity investigation of long-acting dry powder microsphere inhalation agent; Figure 5 This is an in vitro deposition distribution map of long-acting dry powder microsphere inhalers (ILO-MPs); Figure 6 A diagram illustrating the aerosol formation of a long-lasting dry powder microsphere inhaler atomized by a powder mist injection. Figure 7 The in vitro drug release profiles are for free solution ILO, ILO-Lipo, and ILO-MPs. Figure 8 The lung tissue drug concentration-time curves after ILO and ILO-Mps inhalation administration are shown. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0024] Example 1

[0025] A method for preparing a long-acting dry powder microsphere inhaler includes the following steps: (1) Dissolve 1 mg iloprost (ILO), 26 mg DPPC, 16 mg DPPG, 12 mg DOPC and 6 mg CHO (cholesterol) in a mixed solvent of chloroform and methanol (1:1, v / v). After complete sonication, place the mixture in a 50 mL round-bottom flask and rotary evaporate at 45 °C and 0.05-0.06 Kpa until a uniform white lipid film forms in the round-bottom flask with no organic solvent residue. Add 5 mL of deionized water (1 mmol CaCl2) to the rotary evaporator and hydrate and stir at 50 °C for 1 h. Centrifuge at 1000 rpm for 5 min, repeat 3 times. Filter the resulting supernatant through a 0.45 μm aqueous microporous membrane to obtain iloprost polyvesicles for later use.

[0026] (2) Dry powder microspheres were prepared by spray drying. First, 135 mg of mannitol was added to 27 mL of deionized water and stirred until fully dissolved to prepare a 0.5% (w / v) mannitol solution. The multi-vesicles formed above were added to the mannitol solution, and then the liquid was dried using a micro spray dryer. The operating parameters were as follows: drying gas 100%, inlet temperature 100 ℃, outlet temperature 50±5 ℃, spray gas 40%, and injection pump flow rate 3 mL / min. Finally, the dry powder microspheres in the high-efficiency cyclone separator were collected into a container, sealed with sealing film, and placed in a vacuum dryer at 4 ℃ for storage and later use. This was designated as ILO-MPs (long-acting dry powder microsphere inhalation agent).

[0027] The prepared ILO-MPs were stained with 2% phosphotungstic acid and then observed as multi-vesicles under a transmission electron microscope at 120 kV. Morphological observation of iloprost multi-vesicles was performed using transmission electron microscopy, such as... Figure 1 As shown, iloprost polycystic vesicles exhibit a multicystic structure and a relatively uniform morphology.

[0028] Example 2 The ILO-MPs prepared in Example 1 were used as the target for investigation. They were characterized by SEM (scanning electron microscopy), laser particle size analyzer, DSC (differential scanning calorimetry), and TGA (thermogravimetric analysis). The powder properties of the dry powder inhaler were evaluated to explore whether it meets the requirements of dry powder inhaler and to investigate the in vitro deposition of the dry powder inhaler.

[0029] SEM Iloprost dry powder microspheres were uniformly adhered to conductive tape, sputtered with gold, and then placed under a SEM at a vacuum of 5×10⁻⁶. -4The sample was observed under the following conditions: Pa, electron beam working voltage of 10 kV, working distance of about 10 mm, and magnification of 1000-10000.

[0030] Morphological observation of ILO-MPs was performed using scanning electron microscopy, such as... Figure 2 As shown, the iloprost dry powder microsphere inhaler is spherical in shape and uniform in size.

[0031] (2) Particle size distribution Depend on Figure 3 The geometric particle size distribution diagram shows that the distribution of iloprost dry powder microspheres inhalers is significantly increased in the 1-5 μm particle size range, and the particle size at X50 is less than 5 μm, which is within the suitable inhalation particle size range and is conducive to the effective deposition of dry powder inhalers in the lungs.

[0032] (3) Liquidity assessment The angle of repose was measured using the fixed cone method. A funnel was fixed at a certain height above a petri dish of known diameter. Powder particles were slowly poured into the funnel from above until they flowed down the edge of the petri dish. The height of the cone formed by the powder accumulation was measured, and the angle of repose (θ = arctan(height / radius)) was calculated based on the ratio of the height to the radius of the petri dish. The measurement was repeated three times.

[0033] Take a clean, dry 5 mL graduated cylinder and accurately weigh its mass (m0). Slowly pour the dry powder particles into the cylinder to a certain volume (V1), and weigh the mass at this point (m1). Next, gently shake / tap the graduated cylinder until the volume of the particles in the cylinder no longer changes significantly, and record the volume of the powder at this point (V2). Repeat the measurement 3 times. Calculate the bulk density ρb and tap density ρt according to the formula. The results of the flowability test are shown in Table 1 below. The ILO-MPs angle of repose is 38.24%, ρb is 0.48 g / ml, ρt is 0.65 g / ml, and Carr... , The s Index (Carl Index) is 26.57%, and the fluidity of ILO-MPs meets the standards for inhalation use.

[0034] Table 1. Flowability Analysis of Long-Acting Dry Powder Microsphere Inhalation Products

[0035] (4) TGA Moisture content was determined using a thermogravimetric analyzer with a temperature range of 20-150 °C and a heating rate of 10 °C under nitrogen atmosphere. Figure 4 According to TGA testing, its moisture content is 0.3185%, which is low and meets the requirements for dry powder production.

[0036] (5) Hygroscopicity test According to the "Guiding Principles for Hygroscopicity Test of Drugs 9103" in Part IV of the 2020 edition of the Chinese Pharmacopoeia, take a dry, stoppered glass weighing bottle (outer diameter 50 mm, height 15 mm) and place it in a suitable constant temperature desiccator (with a saturated ammonium chloride solution at the bottom) at 25±1 ℃ one day before the test, and accurately weigh it (m1). Take an appropriate amount of the test sample and spread it evenly in the weighing bottle, with the sample thickness generally about 1 mm, and accurately weigh it (m2). Leave the weighing bottle open and place it under the above constant temperature and humidity conditions for 24 hours, along with the cap. Close the cap of the weighing bottle and accurately weigh it (m3). Figure 4 As shown, the moisture absorption weight gain ratio is about 1.59%, which falls within the slightly moisture-absorbing type. This meets the requirements for the production, transportation, and storage of dry powder inhalers and is suitable for pulmonary drug delivery systems. When encountering moisture in the respiratory system during delivery, it will not cause problems such as particle aggregation or deposition.

[0037] (6) Determination of deposition rate of effective sites in vitro The in vitro lung deposition of iloprost dry powder microsphere inhalation samples was investigated using a new-generation drug impactor (NGI). The instrument components, including the NGI device, adapter, artificial larynx, pre-separator, and collection tray, were connected sequentially. After assembly, the airtightness and uniformity of the device were checked, with a gas flow rate of 90 L / min. At this gas flow rate, the cutoff values ​​(Da) for each collection tray were: S1 = 6.4751 μm, S2 = 3.6122 μm, S3 = 2.3025 μm, S4 = 1.3720 μm, S5 = 0.7582 μm, S6 = 0.4312 μm, and S7 = 0.2591 μm.

[0038] The specific method is as follows: 5 mg of iloprost dry powder was filled into HMPC No. 3 plant capsules produced by CASUGEL Suzhou Capsules, and then loaded into a single-capsule inhalation device. After connecting to an NGI (Natural Genetic Inhaler), the measurement was performed. Five capsules were inhaled each time. The inhalation flow rate was 90 L / min, and the inhalation duration (A) was 2.7 s. The fine particle fraction (FPF), etc., were calculated, as shown in Table 2.

[0039] Table 2. Aerodynamic behavior analysis of long-acting dry powder microsphere inhalers

[0040] The deposition of iloprost dry powder microspheres in various NGI layers is as follows: Figure 5As shown in the figure. The results indicate that the emptying rate of iloprost dry powder microsphere inhaler is 96.12%, the fine particle fraction is 39.97%, and the aerodynamic particle size is approximately 4.52 μm, which is within the 1-5 μm range specified for inhaled formulations. This allows for better deposition in the lungs and meets the requirements for dry powder inhalation.

[0041] (7) Investigation on the dispersibility of dry powder aerosol Weigh approximately 5 mg of ILO-MPs, load them into a lung dry powder metered nebulizer, and quickly push the generator, as shown. Figure 6 As shown, the dry powder metered nebulizer emits a well-dispersed aerosol cloud, indirectly indicating that the dry powder inhaler can achieve a good uniform distribution in the lungs.

[0042] Example 3 The difference from Example 1 is that the preparation method of multi-vesicle vesicles is replaced with ordinary liposomes prepared by the traditional thin film dispersion method. The remaining steps are the same as in Example 1. The resulting inhalant is denoted as ILO-Lipo.

[0043] Example 4 The ILO-MPS and ILO-Lipo from Example 1 were subjected to an in vitro release assay using dynamic membrane dialysis, with a 200 μg / ml ILO solubilizing solution (ILO) as a control. Appropriate amounts of ILO-Lipo and ILO-MPS were accurately weighed and suspended in 1 ml of release medium (pH 7.4 PBS containing 1% Tween-80). The microspheres were placed in a dialysis bag, secured with dialysis clamps, and then immersed in the release medium. The isothermal shaker was set to 150 rpm and 37 °C. 1 ml samples were taken at each set time point, with the same volume of blank medium added simultaneously. The peak area of ​​the samples was determined by high-performance liquid chromatography (HPLC), and the cumulative release percentage was calculated. Figure 7 The in vitro release curves for ILO, ILO-Lipo, and ILO-MPs are shown.

[0044] ILO solution achieved a cumulative release of over 90% within 6 hours, exhibiting rapid release and a significant burst release phenomenon. ILO-Lipo, on the other hand, reached approximately 50% release within 6 hours, also showing a burst release phenomenon. ILO-MPs released more slowly, with a cumulative release of approximately 30% within 6 hours, showing no significant burst release phenomenon, and a cumulative release percentage of approximately 64% within 48 hours, indicating that ILO-MPs had a better sustained-release effect in vitro. Comparatively, our prepared multi-vesicle dry powder microsphere inhaler (ILO-MPs) showed better sustained-release effects than the dry powder inhaler (ILO-Lipo) prepared from ordinary liposomes and free ILO, with a significantly reduced burst release phenomenon. This indirectly reflects that the drug also reduced the side effects caused by burst release after in vivo application, demonstrating a good slow-release effect.

[0045] Example 5 To verify the sustained-release effect of iloprost dry powder microsphere inhalation, the sustained-release behavior of the formulation in vivo was investigated. The sustained-release effect of the iloprost dry powder microsphere inhalation prepared in Example 1 was applied to mice. Sixty-six mice were randomly divided into two groups of 33 each. Mice were administered ILO and ILO-MPs at 1.5 mg / kg via aerosol injection at 0 h. Lung tissues were dissected at 0 h, 0.08 h, 0.17 h, 0.25 h, 0.5 h, 1 h, 6 h, 12 h, 24 h, 48 h, and 72 h post-administration. Lung tissues were rinsed with PBS, blotted dry with filter paper, and lysed with RIPA lysis buffer on ice for 10 min. The tissues were then homogenized using a tissue homogenizer at 4 °C, centrifuged at 12000 rpm at 4 °C for 15 min, and the supernatant was collected. Acetonitrile solution was added at twice the volume, vortexed, and allowed to stand. The mixture was then centrifuged at 12000 rpm at 4 °C for 15 min. The supernatant was evaporated completely under nitrogen. 100 μl of mobile phase was added to each tube and vortexed until completely dissolved. The mixture was then filtered through a 0.22 μm organic filter membrane for concentration analysis. The drug concentration-time curves in lung tissue after ILO and ILO-MPs inhalation administration are shown below. Figure 8 As shown.

[0046] The results showed that ILO had a short duration of existence in lung tissue, with a half-life of 1.165 h (as shown in Table 3). The drug was almost non-existent 6 h after administration (e.g., ...). Figure 8 In contrast, ILO-MPs can persist in lung tissue for more than 48 hours (e.g., Figure 8 The half-life of ILO-MPs in lung tissue is 13.536 h, indicating that ILO-MPs have a sustained-release effect and can release the drug in lung tissue for a longer period of time.

[0047] Table 3 Half-life of ILO and ILO-MPs in lung tissue

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A long-acting dry powder microsphere inhaler, characterized in that, The inhalant comprises a drug carrier and an active pharmaceutical ingredient, and is prepared by spray drying technology; wherein the drug carrier comprises multi-vesicles and dry powder excipients in a weight ratio of 1-5:5-9. The multivesicles have a multivesicle structure and are used to encapsulate active pharmaceutical ingredients.

2. The long-acting dry powder microsphere inhaler according to claim 1, characterized in that, The multivesicles include phospholipids and cholesterol.

3. The long-acting dry powder microsphere inhaler according to claim 1, characterized in that, The phospholipid is selected from at least one of lecithin, hydrogenated soybean lecithin, DPPC, DPPG, DOPC, and DSPC.

4. The long-acting dry powder microsphere inhaler according to claim 1, characterized in that, The dry powder excipient is selected from at least one of mannitol, lactose, leucine, chitosan, and trehalose.

5. The long-acting dry powder microsphere inhaler according to claim 1, characterized in that, The active pharmaceutical ingredient is selected from drugs used to treat lung diseases.

6. The long-acting dry powder microsphere inhaler according to claim 1, characterized in that, The aerodynamic particle size of the dry powder microsphere inhaler is 1-5 μm, the fine particle fraction is 35-45%, and the air release rate is ≥95%.

7. A method for preparing a long-acting dry powder microsphere inhaler, characterized in that, Includes the following steps: (1) Phospholipids and cholesterol are dissolved in an organic solvent and formed into a lipid film by rotary evaporation. Then, an hydration solution is added for hydration, and after centrifugation and filtration, multi-vesicle vesicles are obtained. (2) Dissolve the active pharmaceutical ingredient and dry powder excipients in water or buffer solution, and mix them with the polycystic vesicles obtained in step (1) to form a spray-drying feed solution; (3) Spray dry the feed liquid from step (2), with the inlet temperature controlled at 100-150 ℃ and the outlet temperature controlled at 45-55 ℃, and collect the dried powder to obtain the multi-capsule liposome dry powder inhaler.

8. A method for preparing a long-acting dry powder microsphere inhaler according to claim 7, characterized in that, The mixed solvent in step (1) is a chloroform and methanol mixed solution with a volume ratio of 1:1, and the hydration solution in step (1) is deionized water containing 1 mmol CaCl2.

9. A method for preparing a long-acting dry powder microsphere inhaler according to claim 7, characterized in that, The frequency of the fan used for spray drying in step (3) is 34-38 Hz, and the atomization pressure is 0.24-0.28 MPa.

10. The use of any one of the long-acting dry powder microsphere inhalers as described in any one of claims 1-6 in the preparation of a medicament for treating chronic respiratory diseases.

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