Slow-release microspheres with high drug loading capacity, regular morphology and no adhesion as well as preparation method and application of sustained-release microspheres

Abstract

The invention relates to a sustained release microsphere with high drug loading capacity, regular morphology and no adhesion as well as a preparation method and application of the sustained release microsphere, and relates to the field of pharmaceutical preparations. A sustained release microsphere with high drug loading capacity, regular morphology and no adhesion is specifically prepared by the following steps: mixing a drug and a high-molecular polymer, adding an organic solvent, and dissolving to obtain an oil phase solution; injecting the obtained oil phase solution into a water phase solution containing PVA and a surfactant under high-speed shearing, and emulsifying to obtain a uniform emulsion; and curing the obtained emulsion, volatilizing the solvent for a period of time, curing to form balls, centrifuging, washing, collecting and freeze-drying to obtain the sustained-release microspheres with high drug loading capacity. According to the preparation method provided by the invention, the condition that microsphere particles are adhered to one another due to the fact that drugs are separated out on the surfaces of the microspheres due to too high drug loading capacity is avoided, the bottleneck that the drug loading capacity of the microspheres cannot be improved due to the morphology problem is broken through, and burst release is reduced.

Description

Technical Field

[0001] The invention relates to a sustained-release microsphere with high drug loading, regular morphology and no adhesion, a preparation method and application thereof, and relates to the field of pharmaceutical preparations. Background Art

[0002] Microspheres refer to a particle dispersion system formed by dispersing or adsorbing drugs in a polymer matrix, and are matrix-type skeleton particles. Microspheres play an important role in the field of pharmaceutical preparations, especially in the direction of long-acting sustained-release injections. Because long-acting injectable microspheres have the following advantages compared to other types of long-acting sustained-release injections (such as long-acting microcrystals and nanocrystal suspensions for injection, long-acting in situ formed implants for injection, long-acting oil solvents for injection, etc.): 1) The preparation is stored in the form of lyophilized powder injection, and the drug stability is good; 2) It uses aqueous media as a carrier and has low irritation; 3) The drug is dispersed or adsorbed in the polymer matrix and does not directly contact the tissue at the injection site, so it has good biocompatibility; 4) The drug release rate is highly adjustable, especially compared to the common slow dissolution of the initial drug in long-acting microcrystals and nanocrystal suspensions for injection, which require oral supplementation to quickly reach effective blood drug concentrations during administration, or the common problem of excessive burst release in long-acting in situ formed implants for injection; 5) There are a wide variety of applicable drugs, which can be small molecule drugs as well as large molecule drugs such as peptides and proteins.

[0003] Although long-acting injectable microspheres have the above advantages, their drug loading capacity needs to be paid special attention to in practical applications. Because long-acting injections are usually administered in large doses in order to maintain a sustained-release effect for a month or even longer, but the volume of intramuscular injection is limited, so the theoretical drug loading capacity needs to be increased as much as possible to reduce the volume of administration and improve patient compliance. However, when the theoretical drug loading capacity is high, due to the limited capacity of the carrier for the drug, the drug will precipitate on the surface of the microspheres, resulting in adhesion between particles, which will have an adverse effect on the needleability, stability, and burst release of the preparation. Summary of the invention

[0004] The object of the present invention is to provide a sustained-release microsphere with high drug loading, regular morphology and no adhesion, as well as a preparation method and application thereof. The microspheres described in the present invention use synthetic high molecular polymers as carriers, and the preparation method is an emulsification-solvent volatilization method. The oil phase solvent is a single organic solvent or an organic solvent mixed in a certain proportion. The aqueous phase solution contains PVA and a certain concentration of surfactant. The morphology of the microspheres is regulated by adding surfactants to avoid the adhesion of the microspheres caused by the precipitation of drugs on the surface of the microspheres, further increase the drug loading, and reduce the sudden release of drugs. The preparation method of the present invention can break through the bottleneck that the drug loading of the microspheres cannot be increased due to the problems of sudden release and morphology. The drug loading of the microspheres is not less than 20%, and the preparation process is simple.

[0005] A method for preparing sustained-release microspheres with high drug loading, regular morphology and no adhesion, comprising the following process steps:

[0006] 1) mixing the drug with the high molecular weight polymer, adding an organic solvent to dissolve the mixture, and obtaining an oil phase solution;

[0007] 2) injecting the oil phase solution obtained in step 1) into the aqueous phase solution containing PVA and a surfactant under high-speed shearing, and emulsifying to obtain a uniform emulsion;

[0008] 3) solidifying the emulsion obtained in step 2), and after a period of time, the solvent evaporates and solidifies into spheres, which are then centrifuged, washed, collected, and freeze-dried to obtain sustained-release microspheres with high drug loading.

[0009] In the above technical solution, the mass ratio of the PVA to the surfactant is 1:10-10:1. Preferably, the mass ratio of the PVA to the surfactant is 1:5-5:1.

[0010] In the above technical solution, the concentration of the surfactant in the aqueous solution is 0.1%-5% (w / v). Preferably, the concentration of the surfactant in the aqueous solution is 0.5%-3% (w / v).

[0011] In the above technical solution, the mass ratio of the drug to the high molecular polymer is 2.2:7.8 to 7:3. Preferably, the mass ratio of the drug to the high molecular polymer is 3:7 to 6:4.

[0012] In the above technical solution, the concentration of the drug in the oil phase solution is 1.5%-12% (w / v), preferably, the concentration of the drug in the oil phase solution is 2%-10% (w / v).

[0013] In the above technical solution, the volume ratio of the oil phase solution to the water phase solution is 1:50-1:200. Preferably, the volume ratio of the oil phase solution to the water phase solution is 1:100-1:150.

[0014] In the above technical solution, the high molecular polymer is at least one of polylactic acid-glycolic acid, polylactic acid, and polycaprolactone.

[0015] In the above technical solution, the organic solvent is dichloromethane, chloroform, a mixed solvent of dichloromethane and chloroform in a volume ratio of 1:5-5:1, or a mixed solvent of dichloromethane and ethyl acetate in a volume ratio of 1:1-5:1.

[0016] In the above technical solution, the surfactant is a non-ionic surfactant.

[0017] Preferably, the surfactant is selected from one or more of poloxamer series surfactants, vitamin E polyethylene glycol succinate (TPGS), polyethylene glycol-15-hydroxystearate (Kolliphor HS15), Tween series surfactants, Span series surfactants, and polyethylene caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus).

[0018] Furthermore, the poloxamer series surfactant is a commercially available poloxamer series surfactant, such as poloxamer 188 and poloxamer 407.

[0019] Furthermore, the Tween series surfactant is a commercially available Tween series surfactant, such as Tween 20, Tween 80, and Tween 85.

[0020] Furthermore, the Span series surfactant is a commercially available Span series surfactant, such as Span 20, Span 80, and Span 85.

[0021] The drug loading of the drug-loaded microspheres prepared by the method of the present invention is not less than 20%, preferably 50-70%.

[0022] The sustained-release microspheres obtained by the invention have regular morphology and no adhesion.

[0023] The method of the present invention regulates the morphology of microspheres by adding a surfactant, avoids the adhesion of microspheres caused by the precipitation of drugs on the surface of microspheres, further increases the drug loading, and reduces the sudden release of drugs.

[0024] On the other hand, the present invention provides a high drug loading sustained-release microsphere long-acting injection suspension, wherein the suspension comprises the high drug loading sustained-release microsphere of the present invention and a pharmaceutically acceptable carrier.

[0025] As an option, in the above-mentioned pharmaceutical preparation, the pharmaceutically acceptable carrier comprises a suspending agent, a surfactant, a pH regulator and / or an isotonicity regulator.

[0026] The suspending agent includes one or more of the following materials: hydroxypropyl cellulose, methyl cellulose, polyvinyl pyrrolidone, sodium carboxymethyl cellulose, sodium alginate or glycerol.

[0027] The pH adjuster includes one or more of the following materials: sodium hydroxide or phosphoric acid.

[0028] The isotonicity adjusting agent includes one or more of the following materials: sodium chloride, glucose or mannitol.

[0029] The surfactant includes one or more of the following materials: polysorbate 20, polysorbate 40, polysorbate 80, poloxamer or polyoxyethylene castor oil.

[0030] The beneficial effects of the present invention are as follows: the preparation method provided by the present invention avoids the situation where the microsphere particles adhere to each other due to the precipitation of the drug on the surface of the microsphere due to the excessive drug loading, breaks through the bottleneck that the drug loading of the microsphere cannot be increased due to the morphology problem, and reduces the burst release. The preparation method provided by the present invention has a simple preparation process, stable results, good reproducibility, and is expected to achieve large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Scanning electron microscopy image of the microsphere sample prepared in Example 1;

[0032] Figure 2 : Scanning electron microscope image of the microsphere sample prepared in Comparative Example 1;

[0033] Figure 3 : Scanning electron microscopy image of the microsphere sample prepared in Example 3;

[0034] Figure 4 : Scanning electron microscopy image of the microsphere sample prepared in Comparative Example 3;

[0035] Figure 5 : Scanning electron microscopy image of the microsphere sample prepared in Example 7;

[0036] Figure 6 : Scanning electron microscopy image of the microsphere sample prepared in Comparative Example 7;

[0037] Figure 7 : Scanning electron microscopy image of the microsphere sample prepared in Example 9;

[0038] Figure 8 : Scanning electron microscopy image of the microsphere sample prepared in Comparative Example 9;

[0039] Fig. 9 : In vitro release curves of Example 9 and Comparative Example 9;

[0040] Fig.10 : Scanning electron microscopy image of the microsphere sample prepared in Example 10;

[0041] Fig.11 : Scanning electron microscopy image of the microsphere sample prepared in Comparative Example 10;

[0042] Fig.12 : In vitro release curves of Example 10 and Comparative Example 10;

[0043] Fig.13 : Blood drug concentration-time curve of rats in Example 10 and Comparative Example 10. DETAILED DESCRIPTION

[0044] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0045] The test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0046] Determination of particle size:

[0047] The particle size and particle size distribution of the microspheres were measured using a BT-9300s laser particle size analyzer. The specific method is as follows: Take a certain amount of microsphere sample, add it to the sample pool, and ultrasonically disperse it (the medium refractive index is 1.333, and the shading rate range is 5-12). Each sample is measured three times in parallel. The volume average diameter D 50 As a measure of the particle's geometric diameter, the span is used as a measure of the particle size distribution range. The span value is calculated using the following formula:

[0048] Span=(D 90 -D 10 ) / D 50

[0049] Where D 10 , D 50 , D 90 They respectively represent the particle sizes corresponding to the frequencies of 10%, 50%, and 90% in a particle size cumulative distribution diagram (a curve plotted with cumulative frequency as the ordinate and particle size as the abscissa).

[0050] Determination of burst release and in vitro release:

[0051] Accurately weigh a certain amount of drug-loaded microspheres prepared according to the methods of the examples and comparative examples and place them in a 15mL centrifuge tube, add 10mL of release medium pH 7.4 PBS (containing 0.5% SDS), control the temperature at 37±1°C, rotate at 100r / min, take out all the release liquid at 1, 2, 3, 5, 7, 10, 13, 17, 21, 25, 29, 33 and 37d, and replenish an equal amount of fresh release medium in time, centrifuge and take the supernatant, calculate the cumulative release percentage of the drug release, and draw an in vitro release curve. Burst release refers to the percentage of drug release on the first day (24h).

[0052] Embodiment 1:

[0053] Prescription composition:

[0054]

[0055] Preparation method:

[0056] 225 mg of risperidone and 150 mg of polylactic acid were mixed, 2.25 mL of dichloromethane and 0.75 mL of ethyl acetate were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 450 mL of an aqueous phase solution containing 2% PVA and 1% Kolliphor HS15 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 10 krpm for dispersion. After shearing for 30 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 4 hours, and the microspheres were harvested by centrifugation washing and freeze-dried.

[0057] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 12.99 μm, and the span value was 2.11. The actual drug loading of the microspheres was 55.54%, and the burst release percentage of the drug after 24 hours in vitro release was 8.38%. The surface morphology of the obtained microspheres is shown in Figure 1 As shown, although there are tiny pores formed by solvent evaporation, the overall surface is smooth, the sphericity and dispersion are good, and there is no adhesion between particles.

[0058] Comparative Example 1:

[0059] The only difference from Example 1 is that the aqueous phase does not contain 1% Kolliphor HS15.

[0060] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 14.63 μm, and the span value was 2.24. The actual drug loading of the microspheres was 50.58%, and the burst release percentage of the drug after 24 h in vitro release was 13.57%, which was higher than the burst release in Example 1. The surface morphology of the obtained microspheres is as follows Figure 2 As shown, the surface of the microspheres is wrinkled and adhered, and there is a small amount of precipitates.

[0061] Embodiment 2:

[0062] Prescription composition:

[0063]

[0064] Preparation method:

[0065] 120 mg of risperidone and 280 mg of polylactic acid-glycolic acid were mixed, 4 mL of chloroform was added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 200 mL of an aqueous phase solution containing 4% PVA and 0.5% Soluplus was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution for dispersion under high-speed shearing at 12k rpm. After shearing for 25 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 3 hours, and the microspheres were harvested by centrifugation washing and freeze-dried.

[0066] Conclusion: The average particle size of microspheres D 50The diameter of the microspheres was 10.33 μm, and the span value was 2.07. The actual drug loading of the microspheres was 25.33%, and the drug burst release percentage was 7.95% at 24 h in vitro. The surface morphology of the microspheres was similar to that of Example 1, and the microspheres had a smooth surface, good sphericity and dispersion.

[0067] Comparative Example 2:

[0068] The only difference from Example 2 is that the aqueous phase does not contain 0.5% Soluplus.

[0069] Conclusion: The average particle size of microspheres D 50 The actual drug loading of the microspheres was 20.77%, and the burst release percentage of the drug at 24h in vitro was 13.99%, which was higher than the burst release in Example 2. The surface morphology of the microspheres was similar to that of Comparative Example 1, with adhesion and a small amount of material precipitation on the surface of the microspheres.

[0070] Embodiment 3:

[0071] Prescription composition:

[0072]

[0073] Preparation method:

[0074] 350 mg of paliperidone palmitate, 75 mg of polylactic acid-glycolic acid and 75 mg of polylactic acid were mixed, 2.5 mL of dichloromethane and 0.5 mL of ethyl acetate were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 600 mL of an aqueous phase solution containing 3% PVA and 1% Span 80 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 12k rpm for dispersion. After shearing for 25 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 3.5 hours, and the microspheres were harvested by centrifugation washing and freeze-dried.

[0075] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 10.92 μm, and the span value was 2.25. The actual drug loading of the microspheres was 64.57%, and the burst release percentage of the drug after 24 hours in vitro release was 11.33%. The surface morphology of the obtained microspheres is shown in Figure 3 As shown, the microspheres have a smooth surface, good sphericity and dispersion, and no adhesion between particles.

[0076] Comparative Example 3:

[0077] The only difference from Example 3 is that the aqueous phase does not contain 1% Span 80.

[0078] Conclusion: The average particle size of microspheres D 50The actual drug loading of the microspheres was 59.32%, and the burst release percentage of the drug after 24 hours in vitro release was 16.56%, which was higher than the burst release in Example 3. The surface morphology of the obtained microspheres is as follows Figure 4 As shown, the surface of the microspheres is rough and precipitates have attached to them.

[0079] Embodiment 4:

[0080] Prescription composition:

[0081]

[0082]

[0083] Preparation method:

[0084] 60 mg of paliperidone palmitate, 100 mg of polylactic acid-glycolic acid and 40 mg of polylactic acid were mixed, 1 mL of dichloromethane and 1 mL of ethyl acetate were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 300 mL of an aqueous phase solution containing 3% PVA, 0.3% Span 20 and 0.3% Span 85 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 10k rpm for dispersion. After shearing for 30 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 3.5 hours, and the microspheres were harvested by centrifugal washing and freeze-dried.

[0085] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 10.38 μm, and the span value was 1.99. The actual drug loading of the microspheres was 25.53%, and the drug burst release percentage was 10.23% at 24 h in vitro release. The surface morphology of the microspheres was similar to that of Example 3, and the microspheres had a smooth surface, good sphericity and dispersion.

[0086] Comparative Example 4:

[0087] The only difference from Example 4 is that the aqueous phase does not contain 0.3% Span 20 and 0.3% Span 85.

[0088] Conclusion: The average particle size of microspheres D 50 The actual drug loading of the microspheres was 20.32%, and the burst release percentage of the drug at 24h in vitro was 14.47%, which was higher than the burst release in Example 4. The surface morphology of the microspheres was similar to that of Comparative Example 3, and a small amount of material precipitated on the surface of the microspheres.

[0089] Embodiment 5:

[0090] Prescription composition:

[0091]

[0092] Preparation method:

[0093] 90 mg of budesonide, 50 mg of polylactic acid-glycolic acid and 160 mg of polylactic acid were mixed, 2.25 mL of dichloromethane and 0.75 mL of chloroform were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 240 mL of an aqueous phase solution containing 0.5% PVA, 2.5% poloxamer 188 and 2.5% poloxamer 407 was prepared, and all the obtained oil phase solution was injected into all the obtained aqueous phase solution under high-speed shearing at 8k rpm for dispersion. After shearing for 40 seconds, the mixture was magnetically stirred at room temperature for 2.5 hours to fully volatilize the organic solvent, and the microspheres were harvested by centrifugal washing and freeze-dried.

[0094] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 12.45 μm, and the span value was 2.07. The actual drug loading of the microspheres was 24.37%, and the burst release percentage of the drug was 13.33% at 24 hours in vitro. The microspheres had good sphericity and dispersibility, and there was no adhesion between the particles.

[0095] Comparative Example 5:

[0096] The difference from Example 5 is that the aqueous phase does not contain 2.5% poloxamer 188 and 2.5% poloxamer 407.

[0097] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 14.33 μm, and the span value was 2.12. The actual drug loading of the microspheres was 20.29%, and the burst release percentage of the drug at 24 h in vitro was 18.57%, which was higher than the burst release in Example 5. The surface of the obtained microspheres was slightly rough, and some particles were adhered to each other.

[0098] Embodiment 6:

[0099] Prescription composition:

[0100]

[0101] Preparation method:

[0102] 240 mg of budesonide, 30 mg of polylactic acid-glycolic acid and 73 mg of polycaprolactone were mixed, 0.5 mL of dichloromethane and 1.5 mL of chloroform were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 350 mL of an aqueous phase solution containing 1% PVA and 2% Tween 80 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 10k rpm for dispersion. After shearing for 30 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 4 hours, and the microspheres were harvested by centrifugation washing and freeze-dried.

[0103] Conclusion: The average particle size of microspheres D 50The diameter of the microspheres was 11.98 μm, and the span value was 2.20. The actual drug loading of the microspheres was 65.77%, and the drug burst release percentage was 11.33% at 24 hours in vitro. The microspheres had good sphericity and dispersibility, and there was no adhesion between the particles.

[0104] Comparative Example 6:

[0105] The difference from Example 6 is that the aqueous phase does not contain 2% Tween 80.

[0106] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 13.79 μm, and the span value was 2.23. The actual drug loading of the microspheres was 60.59%, and the burst release percentage of the drug at 24 h in vitro was 16.56%, which was higher than the burst release in Example 6. The surface of the obtained microspheres was slightly rough, and some particles were adhered to each other.

[0107] Embodiment 7:

[0108] Prescription composition:

[0109]

[0110] Preparation method:

[0111] Aripiprazole 180 mg, polycaprolactone 80 mg and polylactic acid 40 mg were mixed, 0.5 mL of dichloromethane and 2.5 mL of chloroform were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 300 mL of an aqueous phase solution containing 0.6% PVA, 1.5% Tween 20 and 1.5% Tween 85 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 8k rpm for dispersion. After shearing for 40 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 3.5 hours, and the microspheres were harvested by centrifugation washing and freeze-dried.

[0112] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 10.43 μm, and the span value was 1.99. The actual drug loading of the microspheres was 55.13%, and the burst release percentage of the drug after 24 hours in vitro release was 18.53%. The surface morphology of the obtained microspheres is shown in Figure 5 As shown, the surface of the microspheres presents uniform and regular depressions, no material precipitation, and no adhesion between particles.

[0113] Comparative Example 7:

[0114] The difference from Example 7 is that the aqueous phase does not contain 1.5% Tween 20 and 1.5% Tween 85.

[0115] Conclusion: The average particle size of microspheres D 50The diameter of the microspheres was 12.27 μm, and the span value was 2.11. The actual drug loading of the microspheres was 50.12%, and the burst release percentage of the drug after 24 h in vitro release was 24.33%, which was higher than the burst release in Example 7. The surface morphology of the obtained microspheres is as follows Figure 6 As shown, the surface of the microspheres presents irregular protrusions and a small amount of material is precipitated.

[0116] Embodiment 8:

[0117] Prescription composition:

[0118]

[0119]

[0120] Preparation method:

[0121] Aripiprazole 45 mg and polycaprolactone 105 mg were mixed, 1.5 mL of dichloromethane and 1.5 mL of chloroform were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 360 mL of an aqueous phase solution containing 1% PVA and 0.1% TPGS was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 11 krpm for dispersion. After shearing for 20 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 3 hours, and the microspheres were harvested by centrifugal washing and freeze-dried.

[0122] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 9.64 μm, and the span value was 2.08. The actual drug loading of the microspheres was 23.32%, and the drug burst release percentage was 11.23% at 24 h in vitro release. The surface morphology of the obtained microspheres was similar to that of Example 7, and the sphericity and dispersibility were good.

[0123] Comparative Example 8:

[0124] The difference from Example 8 is that the aqueous phase does not contain 0.1% TPGS.

[0125] Conclusion: The average particle size of microspheres D 50 The actual drug loading of the microspheres was 18.21%, and the burst release percentage of the drug at 24h in vitro was 17.37%, which was higher than the burst release in Example 8. The surface morphology of the obtained microspheres was similar to that of Comparative Example 7, and a small amount of material precipitated on the surface of the microspheres.

[0126] Embodiment 9:

[0127] Prescription composition:

[0128]

[0129] Preparation method:

[0130] 64.5 mg of lauroyl aripiprazole, 120 mg of polylactic acid-glycolic acid and 30 mg of polylactic acid were mixed, 2.5 mL of dichloromethane and 0.5 mL of chloroform were added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 450 mL of an aqueous phase solution containing 0.5% PVA and 0.5% Tween 80 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 9k rpm for dispersion. After shearing for 20 seconds, the mixture was magnetically stirred at room temperature for 3 hours to fully volatilize the organic solvent, and the microspheres were harvested by centrifugation washing and freeze-dried.

[0131] Conclusion: The average particle size of microspheres D 50 The actual drug loading of the microspheres was 26.76%, and the drug burst release percentage was 8.75% after 24 hours of in vitro release. The scanning electron microscopy image of the obtained microsphere sample is shown in Figure 7 As shown, the microsphere surface has uniform wrinkles, and the sphericity and dispersion are good.

[0132] Comparative Example 9:

[0133] The difference from Example 9 is that the aqueous phase does not contain 0.5% Tween 80.

[0134] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 10.95 μm, and the span value was 2.28. The actual drug loading of the microspheres was 21.49%, and the burst release percentage of the drug after 24 h in vitro release was 16.63%, which was higher than the burst release in Example 9. The scanning electron microscopy image of the obtained microsphere sample is shown in FIG. Figure 8 As shown, the surface of the microspheres is rough, and some particles aggregate and adhere to each other.

[0135] The in vitro release curves of Example 9 and Comparative Example 9 are as follows: Fig. 9 As shown, Example 9 not only has a smaller burst release than Comparative Example 9, but also has a more complete late release.

[0136] Embodiment 10:

[0137] Prescription composition:

[0138]

[0139] Preparation method:

[0140] 210 mg of lauroyl aripiprazole and 210 mg of polylactic acid-glycolic acid were mixed, 3 mL of dichloromethane was added, and the mixture was shaken to dissolve to obtain an oil phase solution. At the same time, 300 mL of an aqueous phase solution containing 1% PVA and 1.5% Kolliphor HS15 was prepared, and the entire obtained oil phase solution was injected into the entire obtained aqueous phase solution under high-speed shearing at 10 krpm for dispersion. After shearing for 30 seconds, the organic solvent was fully volatilized by magnetic stirring at room temperature for 4 hours, and the microspheres were harvested by centrifugal washing and freeze-dried.

[0141] Conclusion: The average particle size of microspheres D 50 The actual drug loading of the microspheres was 46.13%, and the drug burst release percentage was 5.17% after 24 hours of in vitro release. The scanning electron microscopy image of the obtained microsphere sample is shown in Fig.10 As shown, the surface of the microspheres presents uniform and regular depressions, no material precipitation, no adhesion between particles, and good sphericity and dispersion.

[0142] Comparative Example 10:

[0143] The difference from Example 10 is that the aqueous phase does not contain 1.5% Kolliphor HS15.

[0144] Conclusion: The average particle size of microspheres D 50 The diameter of the microspheres was 15.53 μm, and the span value was 2.31. The actual drug loading of the microspheres was 40.72%, and the burst release percentage of the drug after 24 h in vitro release was 11.74%, which was higher than the burst release in Example 10. The scanning electron microscopy image of the obtained microsphere sample is shown in FIG. Fig.11 As shown, the surface of the microspheres is not smooth, the material is severely precipitated, there is adhesion between the particles, and the sphericity and dispersion are poor.

[0145] The in vitro release curves of Example 10 and Comparative Example 10 are as follows: Fig.12 As shown, although the f2 similarity factor is calculated to be greater than 50, and there is no statistical difference between the two release curves, the comparative example 10 has a phenomenon of too fast drug release in the first 7 days, while the drug release of Example 10 is more uniform overall.

[0146] Example 11: Pharmacokinetic Experiment

[0147] Aripiprazole lauroxil is the first choice drug for treating schizophrenia in clinic. As a long-acting microcrystalline suspension for injection, there is a disadvantage that aripiprazole tablets need to be taken orally for 21 consecutive days after administration. Compared with Comparative Example 10, the lauroxil aripiprazole sustained-release microspheres prepared in Example 10 have the advantages of significantly improved microsphere morphology and reduced burst release. Therefore, the in vivo pharmacokinetic behavior thereof is investigated in order to achieve the purpose of achieving effective blood drug concentration quickly through a single injection without oral supplementation and continuous drug release for one month.

[0148] The sustained-release microspheres of aripiprazole lauroxil prepared in Example 10 and Comparative Example 10 were prepared into a preparation, specifically by weighing a certain amount of microspheres, adding a suspending agent (CMC-Na 2%) and a filler (mannitol 5%) in a certain proportion by mass percentage to prepare a stable suspension.

[0149] Twelve adult, healthy rats weighing about 250 g were selected. They were randomly divided into two groups, 6 rats in each group: 36.75 mg / kg (equivalent to 25 mg / kg of aripiprazole) of lauroyl aripiprazole sustained-release microspheres prepared by Example 10 and Comparative Example 10 were injected into the right thigh muscle. Dose selection basis: The recommended clinical dose of Abilify Maintena, a marketed aripiprazole preparation, is 300-400 mg / mL, and the equivalent dose range for rats is 25 mg / kg-50 mg / kg according to the body surface area conversion of 60 kg for humans. 1 mL of plasma samples were collected at 6h, 1d, 2d, 4d, 7d, 11d, 15d, 19d, 23d and 30d after administration, respectively, and placed in a polyethylene tube pre-anticoagulated with heparin and centrifuged at 12000 rpm for 10 min. The separated plasma was stored in a -20°C refrigerator for testing.

[0150] Plasma sample processing: Aripiprazole plasma sample processing adopts liquid-liquid extraction method, accurately measure 500μL of plasma, place it in an EP tube, add 40μL of pre-prepared internal standard solution (1μg / mL of perphenazine), 200μL of saturated sodium carbonate solution, and vortex mix for 3min. Then add 3mL of ethyl acetate for extraction and vortex mix for 5min. Then centrifuge at 5000rpm for 10min, remove all supernatant and purge with nitrogen in a 40℃ constant temperature water bath until the solvent evaporates. Redissolve with 100μL of mobile phase before injection analysis and then measure.

[0151] Chromatographic conditions: chromatographic column: Thermo C18 (5.0 μm, 150×4.0 mm); mobile phase: methanol: ammonium acetate solution (containing 0.1% triethylamine (w / v)) (80:20); column temperature: 30°C; flow rate: 1.0 mL / min; detection wavelength: 257 nm; injection volume: 20 μL.

[0152] The average blood drug concentration-time curve in rats is as follows Fig.13 shown.

[0153] The blood drug concentration of both groups of preparations has a double peak phenomenon, the first peak time is 6 hours after administration, and the second peak time is about 11 days after administration. The blood drug concentration can be maintained within the effective concentration range within a one-month drug release cycle, and the fluctuation is small. Since the effective blood drug concentration can be quickly reached within 6 hours after administration, which is close to the peak time of oral aripiprazole tablets, it means that the homemade microsphere preparation does not need to be supplemented with aripiprazole tablets or lauroyl aripiprazole nanocrystals after administration, which will greatly improve patient compliance and has significant advantages over marketed preparations. In addition, compared with the comparative group, the blood drug concentration of the embodiment group fluctuates less, indicating that the lauroyl aripiprazole microspheres prepared by the method of the present invention not only have a higher drug loading and improve the surface morphology of the microspheres, but also have a more uniform and controllable drug release rate.

Claims

1. A method for preparing sustained-release microspheres with high drug loading, regular morphology and no adhesion, characterized by: The process steps include: 1) mixing the drug with the high molecular weight polymer, adding an organic solvent to dissolve the mixture, and obtaining an oil phase solution; 2) injecting the oil phase solution obtained in step 1) into the aqueous phase solution containing PVA and a surfactant under high-speed shearing, and emulsifying to obtain a uniform emulsion; 3) solidifying the emulsion obtained in step 2), and after a period of time, the solvent evaporates and solidifies into spheres, which are then centrifuged, washed, collected, and freeze-dried to obtain sustained-release microspheres with high drug loading.

2. The method according to claim 1, characterized in that The mass ratio of the PVA to the surfactant is 1:10-10:1, and the concentration of the surfactant in the aqueous solution is 0.1%-5% (w / v); the mass ratio of the drug to the high molecular polymer is 2.2:7.8-7:3, and the concentration of the drug in the oil phase solution is 1.5%-12% (w / v).

3. The method according to claim 1, characterized in that The volume ratio of the oil phase solution to the water phase solution is 1:50-1:

200.

4. The method according to claim 1, characterized in that: The high molecular polymer is at least one of polylactic acid-glycolic acid, polylactic acid and polycaprolactone.

5. The method according to claim 1, characterized in that: The organic solvent is dichloromethane, chloroform, a mixed solvent of dichloromethane and chloroform in a volume ratio of 1:5-5:1, or a mixed solvent of dichloromethane and ethyl acetate in a volume ratio of 1:1-5:

1.

6. The method according to claim 1, characterized in that The surfactant is a nonionic surfactant.

7. The method according to claim 6, characterized in that The surfactant is selected from one or more of poloxamer series surfactants, vitamin E polyethylene glycol succinate (TPGS), polyethylene glycol-15-hydroxystearate (Kolliphor HS15), Tween series surfactants, Span series surfactants, and polyethylene caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus).

8. The method according to claim 1, characterized in that The drug loading of the high drug loading sustained-release microspheres is not less than 20%.

9. A high-drug-load sustained-release microsphere long-acting injection suspension, characterized in that: The suspension comprises sustained-release microspheres with high drug loading prepared by the method according to any one of claims 1 to 8, and a pharmaceutically acceptable carrier.

10. The pharmaceutical preparation according to claim 9, characterized in that: The pharmaceutically acceptable carrier comprises a suspending agent, a surfactant, a pH regulator and / or an isotonicity regulator, wherein: The suspending agent is one or more of hydroxypropyl cellulose, methyl cellulose, polyvinyl pyrrolidone, sodium carboxymethyl cellulose, sodium alginate or glycerol; The pH regulator is sodium hydroxide or phosphoric acid; The isotonicity regulator is one or more of sodium chloride, glucose or mannitol; The surfactant is one or more of Tween 20, Tween 40, Tween 80, poloxamer or polyoxyethylene castor oil.

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