A method for preparing pH-responsive ethinyl estradiol composite hydrogel

Abstract

The present invention discloses a method for preparing a pH-responsive ethinyl estradiol composite hydrogel. The present invention also relates to a pharmaceutical composition of ethinyl estradiol, comprising the components of ethinyl estradiol, cyclodextrin, aldehyde cellulose, a water-soluble high molecular polymer, and diethylenetriamine. Compared with ethinyl estradiol alone, the pharmaceutical composition provided by the present invention has significantly enhanced solubility in water and has a sustained-release effect. The preparation method of the present invention is simple to operate, has strong controllability, and good reproducibility. The prepared pharmaceutical composition has stable quality and has broad market application prospects.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology and relates to a method for preparing a pH-responsive ethinyl estradiol composite hydrogel. Background Art

[0002] Ethinyloestradiol (EE), chemical name 3-hydroxy-19-nor-17α-pregnane-1,3,5(10)-triene-20-yn-17-ol, is an organic compound with the chemical formula C 20 H 24 O2, ethinyl estradiol has positive and negative feedback effects on the hypothalamus and pituitary gland. Small doses can stimulate the secretion of gonadotropin; large doses inhibit its secretion, thereby inhibiting ovarian ovulation and achieving an anti-fertility effect. This product can stimulate the pituitary gland to synthesize and release gonadotropins (FSH and LH), and gonadotropins stimulate the gonads to release sex hormones. The secretion of gonadotropin-releasing hormone by the hypothalamus is regulated by many factors, including circulating sex hormones. When used as a single dose, it can increase the circulating sex hormones; continuous use can cause the gonadotropin-releasing hormone receptors in the pituitary gland to downregulate, thereby reducing the secretion of sex hormones. Due to the low solubility of ethinyl estradiol in water, only 4.8 mg / L, its bioavailability in the human body is low. In addition, there are multiple obstacles in the oral delivery of ethinyl estradiol, such as the first-pass effect of the liver and enzymatic degradation in the digestive tract, which reduces its efficacy in the human body. Therefore, in order to improve the bioavailability of ethinyl estradiol, seeking a suitable delivery method has become one of the research hotspots. Summary of the invention

[0003] In order to make up for the deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing a pH-responsive ethinyl estradiol composite hydrogel.

[0004] The invention provides an ethinyl estradiol pharmaceutical composition, which comprises ethinyl estradiol, diethylenetriamine, cyclodextrin, aldehyde cellulose, a water-soluble high molecular polymer and a hydrogel.

[0005] Furthermore, the hydrogel comprises sodium alginate (SA).

[0006] Furthermore, the hydrogel is a wrapper.

[0007] Furthermore, the ethinyl estradiol, diethylenetriamine, cyclodextrin, aldehyde cellulose and water-soluble high molecular polymer are encapsulated materials.

[0008] Furthermore, the water-soluble high molecular polymer includes one or more of hydroxypropyl methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl cellulose, sodium carboxymethyl cellulose, povidone, gelatin, gum arabic, and polyethylene glycol.

[0009] As used herein, the term "pharmaceutical composition" refers to any composition comprising at least one biologically active agent. As used herein, the term "pharmaceutical composition" also refers to a composition comprising an active pharmaceutical ingredient to be delivered to a subject, e.g., to achieve a therapeutic, prophylactic, diagnostic, deterrent or prognostic effect.

[0010] In certain embodiments, the pharmaceutical composition comprises an active pharmaceutical ingredient and a pharmaceutically acceptable carrier. When used herein, the term "pharmaceutically acceptable carrier" includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, etc. that are physiologically compatible. Examples of pharmaceutically acceptable carriers include one or more of water, saline, phosphate buffered saline, dextrose, glycerol, ethanol, etc., and combinations thereof.

[0011] The present invention provides a method for preparing an ethinyl estradiol pharmaceutical composition, which comprises preparing the reagents or powders required for preparing the pharmaceutical composition described above.

[0012] Furthermore, the preparation method comprises the following steps:

[0013] A. dissolving the recrystallized cyclodextrin in an aqueous sodium hydroxide solution and stirring to obtain an alkaline β-cyclodextrin solution;

[0014] B. dissolving p-toluenesulfonyl chloride in acetonitrile and adding dropwise to the alkaline cyclodextrin solution in step A;

[0015] C. Stir, adjust the solution pH, freeze overnight, and completely precipitate;

[0016] D. Filter and collect the precipitate, wash, and dry the precipitate to obtain a pure white solid;

[0017] E. Dissolve the pure white solid obtained in step D, heat, add potassium iodide and diethylenetriamine, and stir under nitrogen protection;

[0018] F. The obtained solution is cooled to room temperature, washed, and the precipitate is separated and collected by suction filtration. The obtained solid is vacuum dried to obtain a white solid powder;

[0019] G. Dissolve the white solid powder obtained in step F in water until saturated, add ethinyl estradiol and a cosolvent, and heat with stirring;

[0020] H. Continue stirring at room temperature and freeze overnight;

[0021] I. Filter the solution in step H, and freeze-dry the filtrate to obtain a white solid powder;

[0022] J. Dissolve the white solid powder in step 1 in water;

[0023] K. Dissolve aldehyde cellulose in sodium hydroxide solution, add a certain amount of the solution in step J, stir, add water-soluble polymer powder and stir to form a uniformly dispersed paste;

[0024] L. Place the paste in step K into a capsule template, press it into a solid shape, and shape it;

[0025] M. Coating the surface of the capsule in step L with sodium alginate mucus, immersing in a CaCl2 solution, and cross-linking;

[0026] N. Rinse the capsules in step M N times to obtain a finished pharmaceutical composition.

[0027] In some specific embodiments, the sodium hydroxide aqueous solution in step A has a certain concentration, which is 8.4 mol / L. In some specific embodiments, the concentration of the sodium hydroxide solution of the aldehyde cellulose solvent in step K is 0.1 mol / L.

[0028] Furthermore, the stirring time of step A is 30 minutes.

[0029] Furthermore, the stirring time in step C includes 2 hours.

[0030] Furthermore, the stirring temperature in step C is room temperature.

[0031] Furthermore, in step C, the pH is adjusted to a range of 5-7.

[0032] Furthermore, the conditions for freezing overnight in step C include 4°C.

[0033] Furthermore, the solution used for washing in step D is an ethanol solution.

[0034] Furthermore, the drying condition in step D is drying at 50° C. for 12 hours.

[0035] Furthermore, the solvent used for dissolving in step E is N-methylpyrrolidone.

[0036] Furthermore, the heating temperature in step E is 70°C.

[0037] Furthermore, the stirring time under nitrogen protection in step E is 7 hours.

[0038] Furthermore, in step E, the stirring temperature under nitrogen protection is 70°C.

[0039] Furthermore, the solution used for washing in step F is ethanol.

[0040] Furthermore, the time for vacuum drying the solid in step F is 12 hours.

[0041] Furthermore, the temperature for vacuum drying the solid in step F is 50°C.

[0042] Furthermore, the co-solvent in step G includes ethanol.

[0043] Furthermore, the heating and stirring time in step G is 1 hour.

[0044] Furthermore, the temperature of heating and stirring in step G is 40°C.

[0045] Furthermore, the stirring time at room temperature in step H is 3 h.

[0046] Furthermore, the overnight freezing time in step H is 12 hours.

[0047] Furthermore, the temperature of freezing overnight in step H is 4°C.

[0048] Furthermore, the freeze-drying time in step I is 12 hours.

[0049] Furthermore, the value of the flushing number N in step N is 2-3.

[0050] Furthermore, the concentration of the sodium alginate is in the range of 1wt%-3wt%.

[0051] Furthermore, the concentration of the sodium alginate is 3wt%.

[0052] Furthermore, the concentration range of the CaCl2 is 2wt%-6wt%.

[0053] Furthermore, the concentration range of the CaCl2 concentration is 6wt%.

[0054] Furthermore, the diameter of the pharmaceutical composition ranges from 1 mm to 10 mm.

[0055] Furthermore, the diameter of the pharmaceutical composition is 4 mm.

[0056] The invention provides application of diethylenetriamine, cyclodextrin and aldehyde cellulose in sustained release of a pharmaceutical composition, wherein the pharmaceutical composition comprises ethinyl estradiol.

[0057] The present invention provides a device for preparing an ethinyl estradiol pharmaceutical composition, wherein the device automatically executes the steps described in the above-mentioned preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is a scanning electron microscope image of a hydrogel capsule, wherein A is a surface structure image of a hydrogel capsule (×200), and B is a cross-sectional structure image of a hydrogel capsule (×200);

[0059] Figure 2is a diagram of the swelling process of the hydrogel capsule, wherein A is a diagram of SA concentration, B is a diagram of CaCl2 concentration, and C is a diagram showing the effect of the diameter of the hydrogel capsule on the swelling performance of the hydrogel capsule;

[0060] Figure 3 is the effect of calcium chloride concentration or sodium alginate concentration on the mechanical properties of hydrogel capsules, wherein A is the effect of calcium chloride concentration on the mechanical properties of hydrogel capsules, and B is the effect of sodium alginate concentration on the mechanical properties of hydrogel capsules;

[0061] Figure 4 is the standard curve graph of ethinyl estradiol;

[0062] Figure 5 It is a diagram of the release process of the hydrogel capsule in simulated gastric fluid and simulated intestinal fluid, wherein a is simulated gastric fluid and b is simulated intestinal fluid;

[0063] Figure 6 is a diagram of the EE release process of the hydrogel capsule, in which a represents a core-shell structure hydrogel capsule composed of ethinyl estradiol, diethylenetriamine, β-cyclodextrin, hydroxyethyl cellulose, aldehyde cellulose, and sodium alginate hydrogel, b represents a core-shell structure sodium alginate hydrogel capsule composed of ethinyl estradiol, hydroxyethyl cellulose, and aldehyde cellulose, and c represents a non-core-shell structure hydrogel capsule of ethinyl estradiol, diethylenetriamine, β-cyclodextrin, hydroxyethyl cellulose, aldehyde cellulose, and sodium alginate;

[0064] Figure 7 It is a graph of cell viability at 24h and 48h after adding different concentrations of hydrogel capsule extract. DETAILED DESCRIPTION

[0065] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples and experimental examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. Where specific conditions are not specified in the examples and test examples, the conditions are carried out under conventional conditions or conditions recommended by the manufacturer, and where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be obtained commercially.

[0066] Example 1

[0067] 1. Experimental Materials

[0068] β-Cyclodextrin was purchased from Zibo Qianhui Biotechnology Co., Ltd. Diethylenetriamine and p-toluenesulfonyl chloride (99%) were purchased from Aladdin Company (Shanghai, China). N-Methylpyrrolidone and acetonitrile were provided by Tianjin Kermiou Chemical Reagent Co., Ltd., China. Potassium iodide was purchased from Tianjin Hengxing Chemical Reagent Manufacturing Co., Ltd. Sodium hydroxide was purchased from Tianjin Chemical Reagent Shanghai Co., Ltd. Hydrochloric acid (HCl) was purchased from Aladdin Reagent Shanghai Co., Ltd. Sodium alginate was purchased from Tianjin Kermiou Chemical Reagent Co., Ltd. Hydroxyethyl cellulose was purchased from Aladdin Reagent Shanghai Co., Ltd. Calcium chloride (CaCl2) was purchased from Tianjin Kermiou Chemical Reagent Co., Ltd. (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was purchased from Sigma Chemical Co., Ltd. Human skin fibroblasts (L929) were purchased from Pasteur Institute, Iran.

[0069] 2. Experimental methods

[0070] A. Dissolve 0.054 mol of recrystallized β-cyclodextrin in 8.4 mol / L sodium hydroxide aqueous solution and stir for about 30 minutes to obtain an alkaline β-cyclodextrin solution;

[0071] B. Dissolve 0.058 mol p-toluenesulfonyl chloride in 30 mL acetonitrile and add dropwise to the above β-cyclodextrin solution;

[0072] C. After stirring at room temperature for 2.0 h, the pH of the solution was adjusted to 5-7 with hydrochloric acid, and the resulting suspension was frozen at 4°C overnight to allow the precipitate to settle completely;

[0073] D. Collect the precipitate by filtration, wash with a large amount of ethanol solution, and dry all the precipitate at 50°C for 12 hours to obtain 9.2 g of pure white solid;

[0074] E. 1.59×10 -3 The pure white solid in step D of 1 mol was dissolved in 5 mL of N-methylpyrrolidone and heated to 70°C, then 0.025 g of potassium iodide and 0.73 g of diethylenetriamine were added, and the mixture was stirred at 70°C for 7 h under nitrogen protection;

[0075] F. After the obtained solution was cooled to room temperature, it was washed with 100 mL of ethanol, and the white precipitate was separated and collected by suction filtration. The obtained solid was vacuum dried at 50° C. for 12 h to obtain a white solid powder;

[0076] G. Dissolve the white solid powder in step F in 10 mL of 40° C. deionized water, add 0.085 g of ethinyl estradiol and 1 ml of ethanol as a cosolvent, and stir at 40° C. for 1 h;

[0077] H. Stop heating, continue stirring at room temperature for 3 hours, and then place in a 4°C refrigerator overnight;

[0078] I. After 12 hours, the solution in step H was filtered and the filtrate was freeze-dried for 12 hours to obtain a white solid powder;

[0079] J. Dissolve the white solid powder in step I in water;

[0080] K. Dissolve aldehyde cellulose in 0.1 mol / L sodium hydroxide solution, add a certain amount of the aqueous solution in step J, stir thoroughly, add hydroxyethyl cellulose powder and stir evenly until a uniformly dispersed paste is formed;

[0081] L. Put the paste into the capsule template and press it into a solid shape. After extrusion and shaping, remove excess cellulose and unqualified products to ensure the accuracy of the capsule;

[0082] M. Uniformly coating the surface of the capsule in step L with a layer of sodium alginate mucus, and then quickly immersing it in a CaCl2 solution of a certain concentration for cross-linking;

[0083] N. Rinse the capsules in step M with distilled water two to three times to remove excess CaCl2 on the surface of the hydrogel capsules to obtain finished capsules.

[0084] 3. Experimental results

[0085] 1) Morphology analysis of hydrogel capsules

[0086] The microstructure of the core-shell structure of the hydrogel capsule was observed using a scanning electron microscope. Figure 1 As shown, the microstructure of the hydrogel capsule shell is significantly different from that of the hydrogel core, and the capsule shell presents a relatively dense shell-like structure. The structure of the hydrogel capsule core presents a sparse and porous mesh structure, which is caused by the synthesis of the core-shell structure by different materials and different methods. It is precisely by utilizing the different structures and different properties of the hydrogel capsule core and the hydrogel capsule shell that a drug hydrogel capsule carrier with such a controlled release effect is produced, which is used to carry the drug molecule ethinyl estradiol, and transport ethinyl estradiol to the designated organs of the human body through the protective effect of the capsule shell and then release it, so as to achieve the purpose of sustained-release drug molecule ethinyl estradiol release.

[0087] 2) Analysis of swelling properties of hydrogel capsules

[0088] Swelling properties are the key criteria for determining the release of drug molecules from hydrogel capsules. The swelling behavior of hydrogel capsules in simulated gastric fluid (pH = 1.5) and simulated intestinal fluid (pH = 7.5) is shown in Figure 2. Figure 2 The experiment showed that the rupture process of the hydrogel capsule was related to the concentration of the sodium alginate solution, the concentration of CaCl2 and the size of the hydrogel capsule.

[0089] Figure 2A shows the effect of sodium alginate concentration on the rupture process of hydrogel capsules. When the sodium alginate concentration is 1wt%, the capsule shell prepared by cross-linking has weak mechanical strength and is easily deformed and ruptured. The hydrogel capsules were immersed in simulated gastric fluid and began to rupture within 4 hours. As the sodium alginate concentration increases, the hydrogel capsules are not easy to rupture because the high-concentration sodium alginate solution forms a shell with high mechanical strength. Figure 2 As shown in Figure B, when the CaCl2 concentration is 2wt%, the hydrogel capsule begins to rupture in the simulated gastric fluid, and as the CaCl2 concentration increases, the time for the hydrogel capsule to rupture gradually increases. However, the effect of the extension gradually weakens because the carboxyl groups in the sodium alginate gradually bind to the CaCl2 in the solution. 2+ The ligands reached saturation, and further increasing the concentration of CaCl2 did not improve the strength of the hydrogel cross-linked with sodium alginate. Therefore, the median concentrations of CaCl2 and sodium alginate solution (6wt% and 3wt%) were selected as the preparation parameters for subsequent studies of hydrogel capsules.

[0090] The size of the hydrogel capsule is another important factor affecting the capsule rupture time. Figure 2 As shown in Figure C, when the concentrations of CaCl2 and sodium alginate solution are 6wt% and 3wt% respectively, the larger the diameter of the hydrogel capsule, the faster the hydrogel capsule breaks. When the diameter of the hydrogel capsule is 10mm, the capsule begins to break within 4h under simulated gastric fluid conditions, and as the diameter of the hydrogel capsule decreases, the time it takes for the capsule to start breaking gradually increases. This is because the core of the hydrogel capsule with a larger diameter contains more swellable cellulose, which can absorb more water and swell faster, thereby quickly releasing the encapsulated drug. At the same time, hydrogel capsules with too large a diameter are not easy to swallow and take orally, so a diameter of 4mm is selected as the preparation parameter for subsequent studies of hydrogel capsules.

[0091] 3) Mechanical properties analysis of hydrogel capsules

[0092] The mechanical properties of the hydrogel capsules were tested by an Edelberg push-pull dynamometer, and the effects of different sodium alginate and calcium chloride concentrations on the mechanical properties of the hydrogel capsules were explored. Hydrogels used for drug delivery applications must have a certain mechanical strength to avoid rapid erosion and thus fail to achieve the effect of targeted release. Figure 3It can be seen that the hydrogel capsule shell prepared by low concentration of sodium alginate and calcium chloride can only withstand a pressure of 1.9Kpa. As the concentration increases, the mechanical properties of the hydrogel gradually improve. The reason is that sodium alginate and calcium chloride are more highly cross-linked, forming a tighter shell, which delays the rupture time of the hydrogel capsule and enhances the mechanical properties of the hydrogel capsule. However, since the hydrogel capsule needs to rupture under simulated intestinal fluid conditions to release the drug, it is not advisable to prepare a gel shell with too high mechanical strength to avoid it being difficult to rupture.

[0093] 4) Analysis of sustained release performance of hydrogel capsules

[0094] In order to quantitatively determine the release of ethinyl estradiol from the hydrogel capsules, a UV standard curve of ethinyl estradiol was drawn. Figure 4 shown.

[0095] The release performance of hydrogel capsules in a simulated human gastrointestinal environment was studied. Figure 5 As shown in curve a, the cumulative release rate of EE hydrogel capsules in simulated gastric fluid (pH = 1.5) reached 50% within 12 hours, and the release amount of EE was limited. Figure 5 As shown in curve b, the cumulative release rate of EE in simulated intestinal fluid reaches 60% in 4 hours and 90% in 9 hours, and the release rate of EE in simulated intestinal fluid is much higher than that in simulated intestinal fluid. This shows that the hydrogel capsule shell made by cross-linking sodium alginate and calcium ions has a certain protective effect under acidic conditions and can slow down the release of drug molecules EE.

[0096] In order to make the release process of hydrogel capsules closer to the real gastrointestinal environment of the human body, a simulation study of the continuous release process was conducted. Figure 6 As shown in the figure, the core-shell structure hydrogel capsule composed of ethinyl estradiol, diethylenetriamine, β-cyclodextrin, hydroxyethyl cellulose, cellulose formaldehyde, and sodium alginate hydrogel (a), the core-shell structure hydrogel capsule composed of ethinyl estradiol, hydroxyethyl cellulose, cellulose formaldehyde, and sodium alginate (b), and the non-core-shell structure hydrogel capsule of ethinyl estradiol, diethylenetriamine, β-cyclodextrin, hydroxyethyl cellulose, cellulose formaldehyde, and sodium alginate (c) were placed in simulated gastric fluid (pH = 1.5) for 4 hours, and then the pH value of the solution was adjusted to 7.5 (simulated intestinal fluid pH) to monitor the release of EE. Before the capsule a entered the simulated intestinal fluid, the release of EE in the hydrogel capsule was limited, and the EE release in the simulated gastric fluid was only 20%. After the hydrogel capsule entered the simulated intestinal fluid for 1 hour, the EE concentration in the solution increased rapidly, indicating that the shell formed by sodium alginate and calcium chloride has pH-sensitive properties.

[0097] The cumulative release rate of capsule c reached 90% within 5 hours, indicating that the capsule shell has a certain protective effect on slowing down the release of EE. Due to the low water solubility of EE, the cumulative release rate of hydrogel capsule b within 12 hours did not exceed 5%, while the cumulative release rate of capsule a within 9 hours reached 90%, indicating that diethylenetriamine and β-cyclodextrin did improve the water solubility of EE. The preparation of hydrogel capsule a can enable the continuous release of EE in simulated gastrointestinal fluid, which is conducive to the medical application of EE.

[0098] 5) Cytotoxicity analysis of hydrogel capsules

[0099] The MTT assay was used to detect the biocompatibility of the hydrogel capsules. The MTT assay is usually highly correlated with the number of living cells and cell proliferation. Figure 7 The effects of 5 different concentrations of hydrogel capsule extracts on the survival rate of L929 cells after 24h and 48h of culture were shown. As the concentration of the extract increased, the relative viability of L929 cells was affected but partially decreased but still remained at a high level. The cell survival rate exceeded 85%. According to the GB / T16886.5-2003 (ISO 10993-5:1999) standard, samples with cell viability greater than 75% are non-cytotoxic. It is proved that the prepared hydrogel capsules have no effect on human health.

[0100] The description of the above embodiments is only used to understand the method and core idea of ​​the present invention. It should be pointed out that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications will also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing an ethinyl estradiol pharmaceutical composition, characterized in that: The preparation method comprises the following steps: A. dissolving the recrystallized cyclodextrin in an aqueous sodium hydroxide solution and stirring to obtain an alkaline cyclodextrin solution; B. dissolving p-toluenesulfonyl chloride in acetonitrile and adding dropwise to the alkaline cyclodextrin solution in step A; C. Stir, adjust the solution pH, freeze overnight, and completely precipitate; D. Filter and collect the precipitate, wash, and dry the precipitate to obtain a pure white solid; E. Dissolve the pure white solid obtained in step D, heat, add potassium iodide and diethylenetriamine, and stir under nitrogen protection; F. The obtained solution is cooled to room temperature, washed, and the precipitate is separated and collected by suction filtration. The obtained solid is vacuum dried to obtain a white solid powder; G. Dissolve the white solid powder obtained in step F in water until saturated, add ethinyl estradiol and a cosolvent, and heat with stirring; H. Continue stirring at room temperature and freeze overnight; I. Filter the solution in step H, and freeze-dry the filtrate to obtain a white solid powder; J. Dissolve the white solid powder in step 1 in water; K. Dissolve aldehyde cellulose in sodium hydroxide solution, add a certain amount of the solution in step J, stir, add hydroxyethyl cellulose powder and stir to form a uniformly dispersed paste; L. Place the paste in step K into a capsule template, press it into a solid shape, and shape it; M. Coating the surface of the capsule in step L with sodium alginate mucus, immersing in a CaCl2 solution, and cross-linking; N. Rinse the capsules in step M 2-3 times to obtain a finished pharmaceutical composition.

2. The preparation method according to claim 1, characterized in that: The stirring time of step A is 30 min.

3. The preparation method according to claim 1, characterized in that: The stirring time in step C is 2h.

4. The preparation method according to claim 1, characterized in that: The stirring temperature in step C is room temperature.

5. The preparation method according to claim 1, characterized in that: The pH value in step C is adjusted to be in the range of 5-7.

6. The preparation method according to claim 1, characterized in that: The condition for freezing overnight in step C is 4°C.

7. The preparation method according to claim 1, characterized in that: The solution used for washing in step D is an ethanol solution.

8. The preparation method according to claim 1, characterized in that: The drying condition in step D is 50° C. for 12 h.

9. The preparation method according to claim 1, characterized in that: The solvent used for dissolving in step E is N-methylpyrrolidone.

10. The preparation method according to claim 1, characterized in that: The heating temperature in step E is 70°C.

11. The preparation method according to claim 1, characterized in that: The stirring time under nitrogen protection in step E is 7 hours.

12. The preparation method according to claim 1, characterized in that: The stirring temperature under nitrogen protection in step E is 70°C.

13. The preparation method according to claim 1, characterized in that: The solution used for washing in step F is ethanol.

14. The preparation method according to claim 1, characterized in that: The time for vacuum drying the solid in step F is 12 hours.

15. The preparation method according to claim 1, characterized in that: The temperature for vacuum drying of the solid in step F is 50°C.

16. The preparation method according to claim 1, characterized in that: In step G, the cosolvent is ethanol.

17. The preparation method according to claim 1, characterized in that: The heating and stirring time in step G is 1 hour.

18. The preparation method according to claim 1, characterized in that: The temperature for heating and stirring in step G is 40°C.

19. The preparation method according to claim 1, characterized in that: The stirring time at room temperature in step H is 3 h.

20. The preparation method according to claim 1, characterized in that: The overnight freezing time in step H is 12 hours.

21. The preparation method according to claim 1, characterized in that: The temperature of the overnight freezing in step H is 4°C.

22. The preparation method according to claim 1, characterized in that: The freeze-drying time in step I is 12 h.

23. The preparation method according to claim 1, characterized in that: The concentration of the sodium alginate is 3wt%.

24. The preparation method according to claim 1, characterized in that: The concentration range of the CaCl2 concentration is 6wt%.

25. The preparation method according to claim 1, characterized in that: The diameter of the pharmaceutical composition is 4 mm.

26. An ethinyl estradiol pharmaceutical composition, characterized in that The pharmaceutical composition includes a pharmaceutical composition prepared by the preparation method according to any one of claims 1 to 25.

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