Preparation method and device of large-size microspheres with uniform particle size and regular shape

Abstract

The present invention discloses a method and device for preparing large-sized microspheres with uniform particle size and regular shape, which relates to the field of emulsion preparation technology, including: preparing a double emulsion microsphere material containing an inner phase, an intermediate phase and an outer phase, wherein the inner phase includes an aqueous solution containing an active ingredient and a hydrophilic polymer surfactant, and the intermediate phase includes a melting point of 50°C. <T 熔 The oil phase and lipophilic nonionic surfactant at a temperature of <85°C, the external phase is an aqueous solution, or a single emulsion microsphere material is prepared; the material is then passed into the microfluidic chip for molding, and the microsphere molding temperature is T 熔 + (10~15) ℃; the formed microspheres are cured by gradient cooling in the liquid outlet tube or the formed microspheres are directly dropped into the receiving liquid for curing. The receiving liquid temperature is (T 熔 ‑30)~(T 熔 ‑5) ℃; the preparation method of the present invention ensures stable microsphere molding, low probability of microsphere demulsification and irregular shape, and the prepared large-sized microspheres have uniform particle size and regular morphology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of emulsion preparation, and in particular to a preparation method and device of large-size microspheres with uniform particle size and regular shape. BACKGROUND

[0002] Large-size microspheres have a wide range of applications. In the field of biological medicine, they can be used as tissue repair scaffolds and large-vessel embolization microspheres. In the field of environmental monitoring, they can be used as pollutant adsorption carriers. In the field of daily chemicals, they can be used for encapsulating active ingredients. However, the process stability of the emulsion method for preparing large-size microspheres is poor, and the particle size of the obtained microspheres is not uniform, and the batch difference is large. Microfluidic technology can precisely control the flow and dispersion of multiphase fluids in microchannels, and thus has unique advantages in controllable emulsion preparation.

[0003] However, compared with small-size microspheres, there are significant technical challenges in preparing large-size microspheres using microfluidic technology. The main difficulties include the following aspects: 1. interfacial tension limitation: small-size droplets are easily stabilized by interfacial tension, while large droplets are more easily affected by material properties and inertial force or gravity in flow, and breaking or coalescence caused by breaking through interfacial tension; 2. multiphase flow regulation difficulty / fluid instability: the flow rate ratio (such as capillary number and Weber number) of the continuous phase and the dispersed phase needs to be accurately controlled for large droplet generation, and a slightly high flow rate easily leads to turbulent flow, which destroys the laminar flow condition; 3. collection collision: large microspheres are easily broken by collision or gravity settlement during the collection process; 4. uneven solidification: when the inside of a large-size microsphere is solidified, the outside may be quickly cross-linked and solidified while the inside is not completely reacted, resulting in uneven structure (such as hollow or collapse).

[0004] Due to the above technical difficulties, the large-size microspheres prepared by microfluidic technology have poor forming stability, resulting in uneven particle size, easy coalescence, emulsion breaking, or the generation of irregular spheres. SUMMARY

[0005] The present application is to solve the technical problems of poor forming stability of large-size microspheres prepared by microfluidic technology using the prior art, resulting in uneven particle size, easy coalescence, emulsion breaking, or the generation of irregular spheres. The purpose is to provide a preparation method and device of large-size microspheres with uniform particle size and regular shape. The microspheres are stably formed during the preparation process, and the probability of emulsion breaking and irregularity is small. The prepared large-size microspheres have uniform particle size and regular shape.

[0006] The present application is realized by the following technical solutions.

[0007] The first purpose of the present application is to provide a preparation method of large-size microspheres with uniform particle size and regular shape, comprising:

[0008] Material preparation: the double emulsion microsphere material includes: inner phase, intermediate phase and outer phase, the inner phase includes active ingredient-containing aqueous solution and hydrophilic polymer surfactant, the intermediate phase includes oil phase with melting point 50℃<T 熔 <85℃ and oleophilic nonionic surfactant, and the outer phase is aqueous solution; the single emulsion microsphere material includes: inner phase and outer phase, the inner phase includes oil phase with melting point 50℃<T 熔 <85℃, active ingredient and oleophilic nonionic surfactant, and the outer phase is aqueous solution;

[0009] Microsphere forming: each material is introduced into the corresponding liquid inlet of the microfluidic chip to form microspheres, and the microsphere forming temperature is T 熔 + (10-15) ℃;

[0010] Microsphere receiving and solidification: the formed microspheres are solidified in the outlet pipe by gradient cooling, and then are dropped into the receiving liquid or the formed microspheres are directly dropped into the receiving liquid for receiving and solidification, and the receiving liquid temperature is (T 熔 -30)~(T 熔 -5) ℃.

[0011] The present application adopts microfluidic technology to prepare millimeter-level large-size microspheres, and by adding surfactants in the inner phase and the intermediate phase, the interface wettability of the intermediate phase and the inner phase is effectively enhanced, and the stability of microsphere forming is improved; by using oil phase with melting point T 熔 greater than 50℃, the emulsion can be solidified at 30℃-50℃, and the solidification speed is delayed; when receiving solidification, two methods can be used, the first method is to solidify in the outlet pipe by setting gradient cooling, which can reduce the stress accumulation generated in the microsphere solidification process, and is beneficial to maintaining the good shape of the microspheres, so that the microspheres with regular shape and uniform particle size are obtained; the second method is to set the receiving liquid temperature to (T 熔 -30)~(T 熔 -5) ℃, since the microspheres are formed at T 熔 + (10-15) ℃, and are received and solidified at (T 熔 -30) ℃~(T 熔 -5) ℃, the temperature gradient formed among the solidification temperature of the oil phase, the forming temperature of the microspheres and the solidification temperature can ensure solidification and forming, and appropriately slow down the solidification speed, so that the oil phase of the microspheres can retain appropriate fluidity at the moment when the microspheres enter the receiving liquid surface, thereby repairing the abnormal shape generated in the instant of drop collision, and then slowly solidifying, which can greatly improve the stability of microsphere forming, and the obtained microspheres have more uniform particle size and more regular shape.

[0012] The active ingredient can be any bioactive substance, such as penicillin, adrenaline, dopamine, kojic acid, ferulic acid, coenzyme Q10s, green tea extract (EGCG), panthenol or citric acid, and the like, and the solubility concentration thereof can be set as required, for example, the active ingredient concentration can be adjusted from 0 to the maximum solubility of the active ingredient in the corresponding inner phase / intermediate phase, and the present application does not limit this.

[0013] Further, 50℃<T 熔 The oil phase at 85℃ is composed of small molecule oil with a melting point lower than 45℃ and solid wax with a melting point higher than 60℃. The small molecule oil with a melting point lower than 45℃ can enhance the wettability of the intermediate phase, improve the moisturizing effect, and improve the uniformity and stability of the phase state, and the surface smoothness and smoothness of the oil phase. The solid wax with a melting point higher than 60℃ can enhance the hardness of the intermediate phase, and the mixture of the two can improve the uniformity, stability and surface smoothness of the microspheres after being used as the oil phase.

[0014] Further, the small molecule oil is any one or more of coconut oil, cocoa butter, sasobit, shea butter, olive oil, palm oil, liquid paraffin, lanolin; and the solid wax is any one or more of beeswax, rice bran wax, carnauba wax, candelilla wax, microcrystalline wax, solid paraffin. The melting point 50℃<T 熔 The oil phase at 85℃ can have various combinations as long as the melting point of the mixed system meets the requirements, and as a preferred embodiment, the small molecule oil is liquid paraffin and the solid wax is beeswax, and more preferably, the mass ratio of liquid paraffin to beeswax is 6:4, and the melting point of the mixed system is 60℃.

[0015] Further, the microsphere forming temperature is 55℃~95℃. The microsphere forming temperature is adjusted according to the melting point T 熔 of the oil phase, for example, when the mass ratio of liquid paraffin to beeswax is 6:4 and the melting point of the mixed system is 60℃, the microsphere forming temperature is 75℃.

[0016] Further, in the double emulsion microspheres, the mass concentration of the hydrophilic polymer surfactant in the inner phase is 0.2% to 10%, for example, the mass concentration is 0.2%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, preferably the mass concentration is 5%, the mass concentration of the lipophilic nonionic surfactant in the middle phase is 1% to 4%, for example, the mass concentration is 1%, 2%, 3% or 4%, preferably the content of the lipophilic nonionic surfactant is 3%; in the single emulsion microspheres, the mass concentration of the lipophilic nonionic surfactant in the inner phase is 1% to 4%, for example, the mass concentration is 1%, 2%, 3% or 4%, preferably the content of the lipophilic nonionic surfactant is 3%.

[0017] Further, the hydrophilic polymer surfactant in the inner phase of the double emulsion microspheres is any one or more of polyvinyl alcohol, sodium alginate, chitosan, polyethylene glycol, preferably polyvinyl alcohol; the lipophilic nonionic surfactant in the middle phase of the double emulsion microspheres and the inner phase of the single emulsion microspheres is any one or more of Span 80, Span 60, Span 83, EM90, polyglycerol ricinoleate, preferably EM90.

[0018] Further, the outer phase is an aqueous solution of any one or more of polyvinyl alcohol, sodium alginate, chitosan, polyethylene glycol, and the mass concentration is 1% to 5%. For example, the mass concentration is 1%, 2%, 3%, 4% or 5%, preferably 3% polyvinyl alcohol.

[0019] In a specific embodiment, since the inner phase component contains a high molecular compound (such as PVA), the middle phase contains a high molecular substance such as beeswax, and the outer phase also contains a high molecular compound (such as PVA), the presence of these high molecular compounds greatly increases the interfacial tension of the solution, improves the stability of the microspheres, and at the same time greatly improves the viscosity of the solution, reduces the Reynolds number, and reduces the risk of fluid turbulence producing turbulent flow.

[0020] Further, in the preparation of double emulsion microspheres, the flow ratio of the inner phase, the middle phase and the outer phase is 1: (1 to 10): (1 to 100), for example, the flow ratio of the inner phase, the middle phase and the outer phase is 1:3:50, 1:5:50, 1:8:80, 1:2:20, and as a preferred, the flow ratio of the inner phase, the middle phase and the outer phase is 1:3:30, for example, the flow of the inner phase, the middle phase and the outer phase is 10 ml / h, 30 ml / h and 300 ml / h respectively; in the preparation of single emulsion microspheres, the flow ratio of the inner phase and the outer phase is (1 to 10): (1 to 100).

[0021] As preferred, in the process of forming the double emulsion microspheres, the inner phase solution is first introduced, and when it flows smoothly, the intermediate phase solution is introduced to shear with the inner phase solution to form stable single emulsion droplets; finally, the outer phase solution is introduced to form W / O / W double emulsion droplets by wrapping the intermediate phase single emulsion droplets.

[0022] Further, the microspheres have a receiving height of 5-50 cm, preferably 5-20 cm. When solidification is performed in a receiving liquid, due to the influence of volume and gravity, large-sized microspheres are prone to be deformed or broken at the moment of collision. By optimizing the receiving height to 5-20 cm and matching the temperature gradient formed among the solidification temperature of the oil phase, the microsphere forming temperature and the solidification temperature, the probability of deformed microspheres and broken microspheres can be greatly reduced.

[0023] Further, the gradient cooling refers to cooling the temperature from the microsphere forming temperature to the receiving liquid temperature or room temperature at intervals of 10 DEG C. The principle of microsphere solidification is to change the oil phase from liquid to solid with the decrease of temperature. The temperature gradient is set to 5 DEG C, 10 DEG C or 20 DEG C, preferably 10 DEG C. The temperature is cooled from T 成型 The gradient is decreased to the receiving liquid temperature or room temperature. The solidification and gradient cooling in the outlet pipe can reduce the stress accumulation generated in the process of microsphere solidification, which is beneficial to maintaining the good shape of the microspheres.

[0024] The second object of the present application is to provide a device for preparing large-sized microspheres with uniform particle size and regular shape, which comprises an upper clamp plate, a glass capillary, a lower clamp plate and a support plate connected in sequence from top to bottom, and an elastic gasket is further arranged between the upper clamp plate and the lower clamp plate, and the glass capillary is embedded in the elastic gasket, and the glass capillary comprises an outer phase glass tube, an intermediate phase glass tube and an inner phase glass tube connected in sequence, and the end of the outer phase glass tube away from the inner phase glass tube is connected with an outlet pipe.

[0025] The upper clamp plate is provided with a plurality of liquid inlet ports, including an inner phase liquid inlet port, an intermediate phase liquid inlet port and an outer phase liquid inlet port, which are connected with liquid inlet pipes, and the inner phase liquid inlet port, the intermediate phase liquid inlet port and the outer phase liquid inlet port are respectively communicated with the inlet of the outer phase glass tube, the intermediate phase glass tube and the inner phase glass tube below, and the upper clamp plate, the lower clamp plate and the support plate are provided with screw fixing thread holes in penetration, and the support plate + screw fixing mode is used to limit the deformation of the chip clamp plate under high temperature and avoid the risk of liquid leakage.

[0026] The upper clamping plate lower surface and the lower clamping plate upper surface are provided with the same PMMA recesses matching the glass capillary profile, the gasket is transparent silica gel, the gasket thickness is 0.1 mm, the gasket shape is a special-shaped annular strip, and the strip-shaped inner cavity matches the recess structure corresponding to the glass capillary.

[0027] The inner diameter and the outer diameter of the inner phase glass tube, the intermediate phase glass tube and the outer phase glass tube are 0.7 mm and 1 mm, 1.25 mm and 1.9 mm, and 2.0 mm and 2.5 mm, respectively.

[0028] The chip support plate is provided with an internal cavity for observing the internal structure of the chip, and the material is aluminum alloy.

[0029] Compared with the prior art, the present application has the following advantages and beneficial effects.

[0030] 1. The present application uses microfluidic technology to prepare millimeter-sized large-size microspheres, and the microspheres are stable in forming, have small probability of breaking and being shaped abnormally, and the prepared large-size microspheres are uniform in particle size and regular in shape.

[0031] 2. The present application effectively enhances the interface wettability of the intermediate phase and the inner phase by adding surfactants in the inner phase and the intermediate phase, and improves the stability of microsphere forming.

[0032] 3. The present application uses an oil phase with a melting point of 50℃ 熔 <85℃, which can ensure the emulsion to be solidified at 30℃~50℃, and can delay the solidification speed; at the same time, the receiving liquid temperature is set to (T 熔 -30)~(T 熔 -5)℃, since the microspheres are formed at T 熔 +(10~15)℃, and are solidified at (T 熔 -30)℃~(T 熔 -5)℃, the temperature gradient formed among the oil phase solidification temperature, the microsphere forming temperature and the solidification temperature can not only ensure the solidification and forming, but also appropriately slow down the solidification speed, so that the oil phase can retain appropriate fluidity when the microspheres enter the receiving liquid surface, thereby repairing the abnormal shape caused by droplet dropping and collision, and then slowly solidifying, which can greatly improve the stability of microsphere forming, and the obtained microspheres are more uniform in particle size and more regular in shape.

[0033] 4. The present application can also be solidified in the liquid outlet pipe, and a gradient cooling is arranged to solidify, so that the stress accumulation generated in the solidification process of the microspheres can be reduced, and the good shape of the microspheres can be maintained, so that the microspheres with regular shape and uniform particle size are obtained. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without any creative effort. In the drawings:

[0035] Figure 1 It is a structural schematic diagram of the microsphere preparation device of the present application;

[0036] Figure 2 It is a schematic diagram of the connection of the gasket and the glass capillary tube

[0037] Figure 3 It is a morphology diagram of the microspheres prepared in Example 2;

[0038] Figure 4 It is a morphology diagram of the microspheres prepared in Comparative Example 1;

[0039] Figure 5 It is a morphology diagram of the microspheres prepared in Comparative Example 2;

[0040] Figure 6 It is a morphology diagram of the microspheres prepared in Comparative Example 3;

[0041] Figure 7 It is a morphology diagram of the microspheres prepared in Comparative Example 4;

[0042] Figure 8 It is a morphology diagram of the microspheres prepared in Example 3;

[0043] Figure 9 It is a morphology diagram of the microspheres prepared in Example 4.

[0044] The marks in the drawings and the corresponding names of the parts are as follows:

[0045] 1 - upper clamping plate, 2 - outer phase glass tube, 3 - intermediate phase glass tube, 4 - inner phase glass tube, 5 - elastic gasket, 6 - lower clamping plate, 7 - support plate, 8 - threaded hole, 9 - inner phase liquid inlet, 10 - intermediate phase liquid inlet, 11 - outer phase liquid inlet, 12 - internal cavity, 13 - liquid outlet pipe. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the embodiments and drawings. Obviously, the illustrative embodiments of the present application and their descriptions are only used to explain the present application and not to limit the present application.

[0047] Throughout this specification, the recitation "one embodiment," "an embodiment," "one example," or "example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment," "an embodiment," "in one example," or "an example" in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0048] In the description of the present application, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and is only for the purpose of facilitating the description of the present application and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0049] Meanwhile, the terms "arranged", "assembled", "connected", "linked" should be interpreted broadly, for example, can be fixedly connected, or detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, or can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0050] The "range" disclosed in the present application is defined in the form of lower limit and upper limit, and the given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of the specific range. The range defined in this way can include or not include the end value, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range.

[0051] If not specifically stated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0052] If there is no special description, all the technical features of the present application and optional technical features can be combined with each other to form new technical solutions.

[0053] If there is no special description, the "including" and "containing" mentioned in the present application means open type, which can also be closed type. For example, the "including" and "containing" can mean that other substances not listed can also be included or contained, or only the listed substances can be included or contained.

[0054] If there is no special description, all the steps of the present application can be carried out in sequence or randomly, preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method can also comprise step (c), which means that step (c) can be added to the method in any order. For example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0055] The technical solutions of the present application are further described in detail in combination with the examples.

[0056] It should be noted that the experimental methods used in the examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, which can be obtained by commercial channels by those skilled in the art.

[0057] Example 1

[0058] A device for preparing large-size microspheres with uniform particle size and regular shape, that is, a microfluidic chip, as shown in Figure 1 and 2 from top to bottom, the upper clamp plate 1, the glass capillary, the lower clamp plate 6 and the support plate 7, the elastic gasket 5 is further arranged between the upper clamp plate 1 and the lower clamp plate 6, the glass capillary is embedded in the elastic gasket 5, the glass capillary comprises an outer phase glass tube 2, an intermediate phase glass tube 3 and an inner phase glass tube 4 which are connected in sequence, and the end of the outer phase glass tube 2 away from the inner phase glass tube 4 is connected with a liquid outlet pipe 13.

[0059] The upper clamping plate 1 is provided with a plurality of liquid inlets, including inner phase liquid inlet 9, intermediate phase liquid inlet 10, and outer phase liquid inlet 11, which are connected with the liquid inlet pipe, and the inner phase liquid inlet 9, intermediate phase liquid inlet 10, and outer phase liquid inlet 11 are respectively communicated with the inlet of the outer phase glass tube 2, intermediate phase glass tube 3, and inner phase glass tube 4 below. The upper clamping plate 1, lower clamping plate 6, and support plate 7 are provided with threaded holes 8 for screw fixation. The use of the support plate 7 and screw fixation mode limits the deformation of the chip clamping plate at high temperature and avoids liquid leakage.

[0060] The upper surface of the upper clamping plate 1 and the lower surface of the lower clamping plate 6 are provided with the same recess matching the shape of the glass capillary tube, and the material is PMMA. The elastic gasket 5 is transparent silica gel, and the thickness of the elastic gasket 5 is 0.1 mm. The shape of the elastic gasket 5 is a special-shaped annular strip, and the internal cavity 12 of the strip matches the recess structure corresponding to the glass capillary tube. The maximum forming temperature of the microspheres can reach 95℃. The gasket can avoid liquid leakage caused by chip deformation at high temperature of 95℃. The use of the gasket for sealing can avoid liquid leakage caused by glue bonding or other high-temperature compression methods. The gasket itself can accommodate the unevenness of the sealing surface and the micro deformation of the sealing surface caused by high temperature.

[0061] The inner diameter and outer diameter of the inner phase glass tube 4, intermediate phase glass tube 3, and outer phase glass tube 2 are 0.7 mm and 1 mm, 1.25 mm and 1.9 mm, and 2.0 mm and 2.5 mm, respectively.

[0062] The chip support plate 7 is provided with an internal cavity 12 for observing the internal structure of the chip, and the material is aluminum alloy.

[0063] Example 2

[0064] The preparation of double-milk microspheres is carried out according to the following steps:

[0065] 1. Material preparation: ultrasonic the inner phase material (10% D-panthenol solution containing 5% PVA) for 20 minutes to remove air bubbles, and ultrasonic the intermediate phase material (liquid paraffin: beeswax = 6:4, intermediate phase melting point T 熔 = 60℃, add 3% EM90 surfactant) and outer phase material (3% PVA solution) in a 75℃ water bath for 1 hour;

[0066] 2. Chip connection: connect the inner phase, intermediate phase, and outer phase solutions to the corresponding liquid inlets of the chip through the liquid inlet pipe;

[0067] 3. Microsphere forming: the constant temperature environment for microsphere forming is T 成型 = 60℃, and the constant temperature environment for microsphere forming is T 熔+15℃=75℃, set the inner phase, intermediate phase, the outer phase flow is 10 ml / h, 30 ml / h, 300 ml / h. First, the inner phase solution, when the smooth flow, the intermediate phase solution is introduced, so that it is cut with the inner phase solution to form a stable single emulsion droplets; Finally, the outer phase solution, so that the outer phase to wrap the intermediate phase single emulsion droplets form W / O / W double emulsion droplets;

[0068] 4. Microspheres receiving and curing: the receiving liquid is ultrapure water, the receiving liquid temperature is 30℃ (T 熔 -30℃), the microsphere receiving height is 20cm.

[0069] It is detected that the double emulsion microsphere preparation process has good stability, the microsphere encapsulation rate is 99.65%, the average particle size is 2.01mm (the CV value is 4.37%); the stable forming time percentage in the microsphere forming stage is 99.33%, the stable forming number percentage is 100%; the abnormal ball percentage in the microsphere receiving and curing stage is 1.27%, the broken ball percentage is 2.24%, and the product morphology is as shown in Figure 3 It can be seen that the microspheres prepared by the method of the application can effectively reduce the abnormal ball and broken ball probability, have high forming stability, and the obtained microspheres have uniform particle size and regular shape.

[0070] Comparative Example 1

[0071] The difference between the present comparative example and Example 2 is that the oil phase formula does not contain a surfactant. The double emulsion microspheres are prepared according to the following steps:

[0072] 1. Material preparation: ultrasonic the inner phase material (10% D-panthenol solution containing 5% PVA) for 20 minutes to remove air bubbles, and preheat and ultrasonic the intermediate phase material (liquid paraffin: beeswax = 6:4, melting point T 熔 =60℃) and the outer phase material (3% PVA solution) in a 75℃ water bath for 1 hour;

[0073] 2. Chip connection: connect the inner phase, intermediate phase and outer phase solutions to the corresponding liquid inlets of the chip through the liquid inlet pipes;

[0074] 3. Microsphere forming: the microsphere preparation constant temperature environment is 75℃, and the inner phase, intermediate phase and outer phase flow rates are set to 10ml / h, 30ml / h and 300ml / h, respectively;

[0075] 4. Microspheres receiving and curing: the receiving liquid is ultrapure water, the receiving liquid temperature is 30℃, and the microsphere receiving height is 20cm.

[0076] It is detected that the stable microsphere preparation cannot be realized without adding surfactant in the oil phase (middle phase), the stable forming time percentage is 13.55%, the stable forming number percentage is 9.10%, and the product morphology is as shown in Figure 4 .

[0077] Comparative Example 2

[0078] The difference between this comparative example and Example 2 is that the oil phase formula is different, and the double emulsion microspheres are prepared according to the following steps:

[0079] 1. Material preparation: the inner phase material (10% D-panthenol solution containing 5% PVA) is ultrasonicated for 20 minutes to remove bubbles, the middle phase material (liquid paraffin: beeswax = 8.5: 1.5, melting point T 熔 = 32℃, adding 3% EM90 surfactant) and the outer phase material (3% PVA solution) are preheated and ultrasonicated in a 75℃ water bath for 1 hour;

[0080] 2. Chip connection: the inner phase, middle phase and outer phase solutions are connected to the corresponding liquid inlets of the chip through the liquid inlet pipes;

[0081] 3. Microsphere forming: the microsphere preparation constant temperature environment is 75℃, and the inner phase, middle phase and outer phase flow rates are set to 10ml / h, 30ml / h and 300ml / h respectively;

[0082] 4. Microsphere receiving and solidification: the receiving liquid is ultrapure water, the receiving liquid temperature is 30℃, and the microsphere receiving height is 20cm.

[0083] It is detected that microspheres can be formed at 75℃, the high encapsulation efficiency is 97.98%, the stable forming time percentage is 99.34%, and the stable forming number percentage is 100%, but it cannot be effectively solidified at 30℃, as shown in Figure 5 , the un-solidified microspheres are transparent green; it can be seen that because the melting point of the oil phase is 32℃ and the receiving temperature is 30℃, the receiving temperature is too close to the melting point of the middle phase, and the temperature difference is too small, which leads to the microspheres cannot be effectively solidified.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 2 is that the receiving temperature is different, and the double emulsion microspheres are prepared according to the following steps:

[0086] 1. Material preparation: the inner phase material (10% D-panthenol solution containing 5% PVA) is ultrasonicated for 20 minutes to remove bubbles, the middle phase material (liquid paraffin: beeswax = 8.5: 1.5, melting point T 熔1. Material preparation: The inner phase material (10% D-panthenol solution containing 5% PVA) was ultrasonicated for 20 minutes to remove air bubbles, the middle phase material (liquid paraffin: beeswax = 6:4, melting point T 熔 = 60°C) and the outer phase material (3% PVA solution) were preheated and ultrasonicated in a 75°C water bath for 1 hour;

[0087] 2. Chip connection: The inner phase, middle phase and outer phase solutions were respectively connected to the corresponding liquid inlet ports of the chip through the liquid inlet pipes;

[0088] 3. Microsphere formation: The microsphere preparation constant temperature environment was 75°C, and the inner phase, middle phase and outer phase flow rates were set to 10 ml / h, 30 ml / h and 300 ml / h respectively;

[0089] 4. Microsphere receiving and solidification: The receiving liquid was ultrapure water, the receiving liquid temperature was 15°C, and the microsphere receiving height was 20 cm.

[0090] It was detected that microsphere formation could be achieved at 75°C, the stable formation time percentage was 99.53%, the stable formation times percentage was 100%, but a large number of fusiform tail-shaped abnormal spheres (as shown in Figure 6 ) appeared in the solidification process, and the abnormal sphere probability was 72.83%; it can be seen that, due to the receiving liquid temperature and T 熔 The temperature gradient of 60°C reached 45°C, and the abnormal sphere probability increased significantly compared with Example 2.

[0091] Comparative Example 4

[0092] The difference between this comparative example and Example 2 is that the receiving temperature and height are different, and the double emulsion microspheres are prepared according to the following steps:

[0093] 1. Material preparation: The inner phase material (10% D-panthenol solution containing 5% PVA) was ultrasonicated for 20 minutes to remove air bubbles, the middle phase material (liquid paraffin: beeswax = 6:4, melting point T 熔 = 60°C) and the outer phase material (3% PVA solution) were preheated and ultrasonicated in a 75°C water bath for 1 hour;

[0094] 2. Chip connection: The inner phase, middle phase and outer phase solutions were respectively connected to the corresponding liquid inlet ports of the chip through the liquid inlet pipes;

[0095] 3. Microsphere formation: The microsphere preparation constant temperature environment was 75°C, and the inner phase, middle phase and outer phase flow rates were set to 10 ml / h, 30 ml / h and 300 ml / h respectively;

[0096] 4. Microsphere receiving and solidification: The receiving liquid was ultrapure water, the receiving liquid temperature was 15°C, and the microsphere receiving height was 20 cm.

[0097] It is detected that microspheres can be formed at 75℃, the stable forming time percentage is 99.37%, and the stable forming number percentage is 100%, but a large amount of emulsion breaking and floating occurs in the receiving solidification process (as shown in Figure 7 It can be seen that, due to the temperature of the receiving liquid and T 熔 The temperature gradient at 60℃ reaches 45℃, and the receiving height of the microspheres is high, so that large-size microspheres are easily deformed or broken at the moment of collision, and the probability of emulsion breaking is large.

[0098] Example 3

[0099] The difference between this embodiment and Example 2 is that the outflow pipe is solidified, and the double-emulsion microspheres are prepared according to the following steps:

[0100] 1. Material preparation: ultrasonic the inner phase material (10% D-panthenol solution containing 5% PVA) for 20 minutes to remove bubbles, ultrasonic the middle phase material (liquid paraffin: beeswax = 6:4, the melting point of the middle phase is T 熔 = 60℃) and the outer phase material (3% PVA solution) in a 75℃ water bath for 1 hour;

[0101] 2. Chip connection: connect the inner phase, middle phase and outer phase solutions to the corresponding liquid inlets of the chip through the liquid inlet pipes, respectively;

[0102] 3. Microsphere forming: the constant temperature environment for microsphere forming is T 成型 = T 熔 + 15℃ = 75℃, and the flow rates of the inner phase, middle phase and outer phase are set to 10ml / h, 30ml / h and 300ml / h, respectively. First, the inner phase solution is introduced, and then the middle phase solution is introduced to shear the inner phase solution to form stable single-emulsion droplets; finally, the outer phase solution is introduced to wrap the middle phase single-emulsion droplets to form W / O / W double-emulsion droplets;

[0103] 4. Microsphere solidification: set a temperature gradient in the outflow pipe for solidification, and the gradient temperature is 75℃, 65℃, 55℃, 45℃ and 35℃ in turn, and the temperature is realized through the condenser pipe surrounding the outflow pipe;

[0104] 5. Microsphere receiving: after the microspheres are solidified in the outflow pipe, they flow out and are received by the receiving liquid. The receiving liquid is ultrapure water, the receiving temperature is 30℃, and the microsphere receiving height is 20cm.

[0105] The double emulsion microsphere preparation process has good stability, the microsphere encapsulation rate is 98.82%, the average particle size is 1.97mm (the CV value is 4.22%), the stable forming time percentage in the microsphere forming stage is 99.13%, the stable forming number percentage is 100%, the abnormal shape ball percentage in the microsphere receiving and solidification stage is 1.52%, and the broken ball percentage is 2.02%, and the product appearance is as shown in Figure 8 The particle size is uniform, and the morphology is regular.

[0106] Example 4

[0107] The single emulsion microsphere preparation is carried out according to the following steps:

[0108] 1. Material preparation: the inner phase material (liquid paraffin: beeswax = 6:4, melting point is 60℃), 3% EM90 surfactant, 5% β-carotene, and the outer phase material (3% PVA solution) are preheated and ultrasonicated in a 75℃ water bath for 1 hour;

[0109] 2. Chip connection: the inner phase and the outer phase solution are connected to the corresponding liquid inlet of the chip through the liquid inlet pipe;

[0110] 3. Microsphere forming: the microsphere forming constant temperature environment is T 成型 =75℃, the inner phase and the outer phase flow rates are set to 30ml / h and 300ml / h respectively. First, the inner phase solution is introduced, and then the outer phase solution is introduced when it flows smoothly, so that the outer phase wraps the inner phase to form a single emulsion droplet;

[0111] 4. Microsphere receiving and solidification: the receiving liquid is ultrapure water, the receiving temperature is 30℃, and the microsphere receiving height is 20cm.

[0112] The double emulsion microsphere preparation process has good stability, the microsphere encapsulation rate is 99.76%, the average particle size is 1.99mm (the CV value is 3.58%), the stable forming time percentage in the microsphere forming stage is 99.53%, the stable forming number percentage is 100%, the abnormal shape ball percentage in the microsphere receiving and solidification stage is 1.43%, and the broken ball percentage is 1.71%, and the product appearance is as shown in Figure 9 The particle size is uniform, and the morphology is regular.

[0113] Finally, it should be noted that the above specific examples are only used to explain the purposes, technical solutions and beneficial effects of the present application in detail, and it should be understood that the above description is only a specific embodiment of the present application and does not limit the protection scope of the present application; although the present application has been described in detail with reference to the foregoing specific embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement, improvement, etc. to part or all of the technical features; and these modifications, equivalent replacement, improvement do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and description of the present application.

Claims

1. A method for preparing large-sized microspheres of millimeter scale with uniform particle size and regular shape, characterized in that: The small molecule oil is any one or more of coconut oil, cocoa butter, babassu oil, shea butter, olive oil, palm oil, liquid paraffin, lanolin; the solid wax is any one or more of beeswax, rice bran wax, carnauba wax, candelilla wax, microcrystalline wax, solid paraffin. Preparation of materials: the double emulsion microspheres material includes: inner phase, intermediate phase and outer phase, the inner phase includes active ingredient containing aqueous solution and hydrophilic polymer surfactant, the intermediate phase includes oil phase with melting point 50℃ 熔 <85℃ and lipophilic nonionic surfactant, the outer phase is aqueous solution; the single emulsion microspheres material includes: inner phase and outer phase, the inner phase includes oil phase with melting point 50℃ 熔 <85℃, active ingredient and lipophilic nonionic surfactant, the outer phase is aqueous solution; Microsphere forming: each material is introduced into the corresponding inlet of the microfluidic chip to form microspheres, and the microsphere forming temperature is T 熔 + (10~15) ℃; Microsphere receiving and solidification: the formed microspheres are cooled and solidified in the outlet pipe, and then dropped into the receiving liquid or the formed microspheres are directly dropped into the receiving liquid for receiving and solidification, the microsphere receiving height is 5-20 cm, and the temperature of the receiving liquid is (T 熔 -30)~(T 熔 -5)℃.

2. The method according to claim 1, wherein the method is characterized by, said melting point 50°C < T 熔 < The oil phase at 85°C consists of small molecule oils with a melting point below 45°C and solid waxes with a melting point above 60°C.

3. The method according to claim 2, wherein the method is characterized by, In the double emulsion microsphere material, the mass concentration of the hydrophilic polymer surfactant in the inner phase is 0.2%-10%, and the mass concentration of the oleophilic nonionic surfactant in the intermediate phase is 1%-4%; in the single emulsion microsphere material, the mass concentration of the oleophilic nonionic surfactant in the inner phase is 1%-4%.

4. The method according to claim 1, wherein the method is characterized by, The hydrophilic polymer surfactant in the inner phase of the double emulsion microsphere material is any one or more of polyvinyl alcohol, sodium alginate, chitosan, and polyethylene glycol, and the oleophilic nonionic surfactant in the intermediate phase of the double emulsion microsphere material and the inner phase of the single emulsion microsphere material is any one or more of Span 80, Span 60, Span 83, EM90, and polyglycerol ricinoleate.

5. The method according to claim 1, wherein the method is characterized by: The outer phase is an aqueous solution of any one or more of polyvinyl alcohol, sodium alginate, chitosan, and polyethylene glycol, and the mass concentration is 1-5%.

6. The method according to claim 1, wherein the method is characterized by, In the preparation of the double emulsion microsphere, the flow rate ratio of the inner phase, the intermediate phase, and the outer phase is 1:(1-10):(1-100); in the preparation of the single emulsion microsphere, the flow rate ratio of the inner phase and the outer phase is (1-10):(1-100).

7. The method according to claim 1, wherein the method is characterized by, The gradient cooling refers to that the temperature is gradiently cooled from the microsphere forming temperature to the receiving liquid temperature or room temperature at intervals of 10 DEG C.

8. The method according to claim 1, wherein the method is characterized by, ​

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