Rivastigmine-COF compound as well as preparation method and application thereof

Abstract

The invention discloses a rivastigmine-COF compound as well as a preparation method and application thereof, and relates to the technical field of pharmaceutical preparations, the rivastigmine-COF compound comprises COF and rivastigmine loaded on the COF; according to the invention, rivastigmine as a therapeutic drug for Alzheimer's disease is wrapped by the cubic COF, compared with spherical CD-NS, on one hand, the release of rivastigmine can be delayed, on the other hand, rivastigmine can be prevented from being quickly cleared by nasal mucus, the residence time of rivastigmine in the nasal cavity can be prolonged, the permeability of rivastigmine can be increased, and the curative effect of rivastigmine on the nasal cavity can be improved. The absorption of rivastigmine is promoted, so that the bioavailability and curative effect of rivastigmine are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical preparations, and in particular to a rivastigmine-COF complex and a preparation method and application thereof. Background Art

[0002] Alzheimer's disease (AD), a chronic disease characterized by reduced cholinergic transmission, is one of the most prominent neurodegenerative diseases in the world. AD is considered the most common cause of dementia, accounting for approximately 60-70% of dementia worldwide. The main risk factor for the onset of AD is age, and the number of patients is increasing as life expectancy increases. It is estimated that 135 million people worldwide will suffer from AD in 2050. AD symptoms are often accompanied by the occurrence of multiple cognitive impairments, such as executive function, language, visual-spatial ability, and decision-making. As the disease progresses, the neurons in the hippocampus responsible for memory no longer communicate effectively, and neurocognitive impairments become apparent. Brain damage leads to worsening symptoms, eventually requiring hospitalization, and patients lose the ability to perform daily tasks.

[0003] Rivastigmine (RIV) is a mainstream drug for the treatment of AD. It has dual inhibitory effects on acetylcholinesterase and butyrylcholinesterase. It is clinically administered orally in the form of tablets or capsules or via transdermal patches. However, oral rivastigmine is affected by first-pass metabolism, and its bioavailability is only 35.5%. Therefore, it must be administered frequently, which not only reduces the compliance of AD patients, but also increases the side effects of the drug, such as nausea, vomiting, and diarrhea. Rivastigmine transdermal patches successfully reduce the side effects of oral drugs, but transdermal patches waste about 50% of the drugs, causing a considerable economic burden. In addition, transdermal patches are slow to take effect, and administration can cause cholinergic overactivation, nausea, vomiting and other symptoms, which means that side effects still exist. In view of the above reasons, it is crucial to explore other routes of administration and technologies to develop more effective AD treatment options.

[0004] Intranasal administration is a non-invasive drug delivery strategy for delivering drugs to the brain. In addition to reducing drug accumulation in major organs and reducing systemic side effects, it can also avoid the influence of the blood-brain barrier (BBB). After intranasal administration, drugs reach the central nervous system through three main pathways: (1) the olfactory nerve pathway, in which the drug contacts the nasal mucosal epithelial cells, enters the olfactory nerve cells through pinocytosis and endocytosis, and then directly enters the brain through intracellular transport of the olfactory nerve cells, or enters the cerebrospinal fluid through paracellular transport of the olfactory nerve cells; (2) the trigeminal nerve pathway, in which the drug reaches the brainstem through the respiratory epithelium and enters the cerebrospinal fluid or brain; (3) the vascular pathway, which is an indirect drug delivery mechanism, that is, the drug is absorbed into the capillaries of the respiratory area to participate in the systemic circulation, and then enters the central nervous system (CNS) through the BBB. At the same time, it can take effect quickly and avoid the first-pass effect in the liver.

[0005] At present, the delivery systems for nasal administration of rivastigmine reported in the literature include microemulsions, microspheres, nanoparticles, solid lipid nanoparticles and liposomes. The rivastigmine microemulsion nasal administration system contains multiple components and uses surfactants, which increases safety issues. Liposomes are the most studied delivery system for nasal administration of rivastigmine. They can be used alone to load drugs, or they can be functionally modified to load drugs to enhance the stability and targeting of liposomes. However, the drug loading capacity of liposomes is limited, which limits their application in nasal administration. In drug delivery systems such as rivastigmine nanoparticles, lipid nanoparticles and microspheres, the preparation process is complicated and the reproducibility is poor, and researchers also pay more attention to the encapsulation rate of the carrier, and pay less attention to the drug loading. Patent CN115919767B provides a rivastigmine nasal spray for nasal administration, which can enhance the penetration of drugs in the nasal mucosa, aiming to improve the delivery efficiency of drugs in the brain. The patent mentions a specific concentration range of rivastigmine, and precise dosage control may be required in practical applications to avoid overdosage or underdosage; in addition, the preparation method involves multiple steps and multiple ingredients, which increases production costs and complexity.

[0006] Borneol, also known as borneol, has the function of guiding drugs upward, opening the mind and refreshing the brain. It has been proven to effectively promote the entry of drugs into the brain and increase the distribution of drugs in the brain. Co-encapsulation of borneol and drugs in nanocarriers can enhance the efficacy and bioavailability of drugs. Covalent coupling of borneol to nanoparticles can still retain the efficacy of borneol. When borneol is used for nasal administration, it has the ability to promote mucosal fluidization, open tight junctions between epithelial cells and inhibit efflux pumps, thereby increasing the permeability of drugs in the nasal mucosa. When borneol-modified dopamine nanoparticles are administered nasally, the dopamine concentration in the rat brain is significantly increased compared with ordinary dopamine nanoparticles. Solid lipid nanoparticles prepared by covalently binding borneol to lipid materials also show lower cytotoxicity, higher cell uptake rate and better BBB permeability when administered nasally. Docetaxel nanoparticles modified with borneol can effectively improve the brain tumor targeting of nanoparticles after nasal administration, increase their aggregation at the tumor site, and improve the therapeutic effect of drugs against brain gliomas.

[0007] Cyclodextrin metal organic framework (CD-MOF) is porous and has been widely used to improve the solubility, stability and bioavailability of drugs. More importantly, the cross-linked cyclodextrin metal organic framework (COF) formed by cross-linking CD-MOF with diphenyl carbonate can improve its stability in water environment without affecting its performance. The surfaces of CD-MOF and COF are rich in hydroxyl groups, which can be functionalized as active functional groups to expand their application range. In addition, the rich porosity of CD-MOF and COF gives them a high loading capacity for drugs to solve the problem of limited nasal administration. Summary of the invention

[0008] In order to overcome the problem of poor brain targeting of oral and transdermal administration of rivastigmine, the present invention provides a rivastigmine-COF complex and a preparation method thereof, and uses the complex in preparing a nasal preparation for treating Alzheimer's disease.

[0009] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0010] The first object of the present invention is to provide a rivastigmine-COF complex, wherein the rivastigmine-COF complex comprises COF and rivastigmine loaded on the COF.

[0011] A second object of the present invention is to provide a method for preparing a rivastigmine-COF complex, comprising the following steps:

[0012] (1) dissolving rivastigmine in a drug-carrying solvent to obtain a rivastigmine solution;

[0013] (2) Stirring and incubating the rivastigmine solution and COF, filtering, and drying to obtain a rivastigmine-COF complex.

[0014] The third object of the present invention is to provide a pharmaceutical composition comprising the rivastigmine-COF complex.

[0015] The fourth object of the present invention is to provide the use of the rivastigmine-COF complex or the pharmaceutical composition in the preparation of a nasal preparation for treating Alzheimer's disease.

[0016] The beneficial effect of the present invention is that the present invention uses cubic COF to encapsulate the Alzheimer's disease therapeutic drug rivastigmine. Compared with the spherical cyclodextrin nanosponge (CD-NS), on the one hand, it can delay the release of rivastigmine, and on the other hand, it can prevent rivastigmine from being quickly cleared by nasal mucus, prolong the retention time of rivastigmine in the nasal cavity, and can increase the permeability of rivastigmine, promote the absorption of rivastigmine, and thus improve the bioavailability and efficacy of rivastigmine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The scanning electron microscope image (A) of COF and the scanning electron microscope image (B) of BO-COF in Example 1;

[0018] Figure 2 The effects of reaction temperature (A), feed molar ratio (B), and reaction time (C) on the BO content in BO-COF;

[0019] Figure 3 The effect of the feed mass ratio of rivastigmine to COF on the drug loading of the composite;

[0020] Figure 4 The effect of drug loading time on the drug loading capacity of the complex;

[0021] Figure 5 is a scanning electron microscopy image of rivastigmine-COF complex;

[0022] Figure 6 is the particle size distribution diagram of rivastigmine-COF complex;

[0023] Figure 7 is the Fourier infrared spectrum of rivastigmine-COF complex;

[0024] Figure 8 is the DSC graph of rivastigmine-COF complex;

[0025] Fig. 9 is the in vitro release profile of rivastigmine-COF complex and rivastigmine;

[0026] Fig.10 Fluorescence micrographs (A) and normalized fluorescence intensity graphs (B) of the nasal mucosal adhesion of cubic COF and spherical CD-NS;

[0027] Fig.11 is the permeability coefficient of rivastigmine-COF complex and rivastigmine;

[0028] Fig.12 is the drug-dose curve of rivastigmine-COF complex in Wister rat plasma;

[0029] Fig.13 This is the concentration-time curve of rivastigmine-COF complex in the brain of Wister rats. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments and diagrams.

[0031] The present invention provides a rivastigmine-COF complex, wherein the rivastigmine-COF complex comprises COF and rivastigmine loaded on the COF.

[0032] Furthermore, the mass content of rivastigmine in the rivastigmine-COF composite is 5 to 30%.

[0033] Furthermore, the rivastigmine-COF complex has a cubic structure and a particle size range of 100 to 1000 nm.

[0034] The present invention also provides a method for preparing a COF, comprising the following steps:

[0035] S1, preparing CD-MOF by reacting γ-cyclodextrin (γ-CD), potassium hydroxide (KOH) and methanol;

[0036] S2. Prepare COF by reacting CD-MOF with a crosslinking agent.

[0037] Furthermore, the cross-linking agent is diphenyl carbonate (DPC).

[0038] Furthermore, the COF is a COF functionally modified by a penetration enhancer. Preferably, the penetration enhancer is borneol (BO). The functional modification includes physical modification and chemical modification.

[0039] Furthermore, the physical modification of the COF is to mix the COF with a penetration enhancer, wherein the mass proportion of the penetration enhancer is 0.5-10%, preferably 0.5-5%, of the total mass of the COF and the penetration enhancer.

[0040] As a specific embodiment, the physical modification of the COF is to mix COF with BO, seal and heat, and the heating temperature is 60-90°C, preferably 70-80°C.

[0041] Furthermore, the chemical modification of the COF is to prepare a carboxyl-containing penetration enhancer derivative to react with the COF.

[0042] As a specific embodiment, the chemical modification of COF includes: reacting succinic anhydride (SA) with BO to obtain a BO derivative containing a carboxyl group; reacting COF with a BO derivative containing a carboxyl group to obtain a BO-modified COF.

[0043] The present invention provides a method for preparing a rivastigmine-COF complex, comprising the following steps:

[0044] (1) dissolving rivastigmine in a drug-carrying solvent to obtain a rivastigmine solution;

[0045] (2) Stirring and incubating the rivastigmine solution and COF, filtering, and drying to obtain a rivastigmine-COF complex.

[0046] Furthermore, the drug-carrying solvent is selected from one or more of ethanol, methanol, dimethyl sulfoxide, acetonitrile, and n-hexanol, preferably ethanol.

[0047] Furthermore, the concentration of the rivastigmine solution is 40 to 160 mg / mL, preferably 80 to 120 mg / mL.

[0048] Furthermore, the mass ratio of rivastigmine to COF is 1:(1-5), preferably 1:(2-3).

[0049] The present invention provides a pharmaceutical composition, comprising the rivastigmine-COF complex.

[0050] The present invention provides use of the rivastigmine-COF complex or the pharmaceutical composition in preparing a nasal preparation for treating Alzheimer's disease.

[0051] Furthermore, the nasal preparation includes nasal spray and nasal powder aerosol.

[0052] Furthermore, in addition to the rivastigmine-COF complex, the nasal spray also contains the following weight percentages of pharmaceutically acceptable excipients: 0.005-2.0% thickener, 0.5-6.0% osmotic pressure regulator, 0.005-1.0% antibacterial agent, and the pH of the nasal spray is adjusted to 5.5-6.5 with a pH regulator. The thickener is selected from one or more of carbomer, xanthan gum, hydroxypropyl methylcellulose, poloxamer, and polyvinyl alcohol. The osmotic pressure regulator is selected from one or more of mannitol and sodium chloride, and sodium chloride is preferred. The antibacterial agent is selected from one or more of benzalkonium chloride, benzalkonium bromide, thimerosal, sorbic acid, boric acid, chlorobutanol, and methyl paraben. The pH regulator is selected from one or more of hydrochloric acid and sodium hydroxide.

[0053] Furthermore, the nasal powder spray contains, in addition to the rivastigmine-COF complex, the following pharmaceutically acceptable excipients in weight percentage: filler 0-50%, lubricant 0.001-0.5%. The filler is selected from one or more of lactose, microcrystalline cellulose, and hydroxypropyl methylcellulose. The lubricant is selected from one or more of magnesium stearate, sodium fumarate, and silicon dioxide.

[0054] The technical solution of the present invention is described in detail below through specific embodiments.

[0055] Example 1

[0056] (1) 12.96 g of γ-CD and 4.48 g of KOH were dissolved in 400 mL of water, filtered with a 0.45 μm water filter membrane, 240 mL of anhydrous methanol was added to the filtrate, stirred at 60°C until clear, and then 320 mL of methanol solution (containing 8 mg / mL of polyethylene glycol 20000) was added and stirred to obtain a milky white suspension. The suspension was kept at 60°C for 20 min, then transferred to an ice water bath and allowed to stand for 2 h. The resulting sediment was washed with anhydrous methanol and anhydrous ethanol in turn, and dried at 70°C for 3 h to obtain CD-MOF.

[0057] (2) Preparation of COF: 10 g of CD-MOF was suspended in 60 mL of N,N-dimethylformamide (DMF), and then 10.38 g of DPC was added and reacted at 80°C for 12 h. After the reaction, the mixture was cooled to room temperature, 95% ethanol was added to terminate the reaction, and the precipitate was washed with water and 95% ethanol in turn, and dried at 60°C for 3 h to obtain COF.

[0058] Figure 1 A is a scanning electron microscope image of the COF prepared in Example 1. Figure 1 As can be seen from A, the COF prepared in Example 1 has a cubic structure and a particle size range of 100 to 1000 nm.

[0059] (3) 1.95 g SA, 1.58 g 4-dimethylaminopyridine (DMAP) and 1 g BO were dissolved in 50 mL dichloromethane and stirred at room temperature for 48 h. The mixture was then extracted three times with an equal volume of 1N HCl in a separatory funnel. The oil phase was washed three times with an equal volume of purified water and once with an equal volume of saturated sodium chloride. Anhydrous sodium sulfate was added to remove water and the mixture was filtered. The filtrate was separated and purified by a silica gel column using petroleum ether-ethyl acetate as the eluent. The product was gradient eluted. The eluates were combined and the organic solvent was removed by rotary evaporation to obtain a carboxyl-containing borneol derivative (BO-SA).

[0060] (4) 40 mL of DMF was added to 1 g of COF, and 200 mg of BO-SA, 102 mg of DMAP and 148 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) were added in sequence according to the molar ratio of COF, BO-SA and DMAP of 7:8:8. The mixture was stirred at 25°C for 24 h. The reaction solution was centrifuged, and the precipitate was washed three times with 45 mL of anhydrous methanol and dried in vacuo at 40°C to obtain borneol-modified COF (BO-COF).

[0061] Figure 1 B is a scanning electron microscope image of BO-COF prepared in Example 1. Figure 1 B It can be seen that the BO-COF prepared in Example 1 has a cubic structure and a particle size range of 100 to 1000 nm.

[0062] (5) Rivastigmine was dissolved in 0.6 mL of anhydrous ethanol, and 140 mg of BO-COF was added according to a mass ratio of rivastigmine to BO-COF of 1:2. The mixture was stirred and incubated at 400 rpm for 1 h at room temperature, filtered, and dried at 60 °C for 1 h to obtain a rivastigmine-borneol modified COF complex.

[0063] (6) Rivastigmine was dissolved in 0.6 mL of anhydrous ethanol, and 140 mg of COF was added according to a mass ratio of rivastigmine to COF of 1:2. The mixture was stirred and incubated at 400 rpm for 1 h at room temperature, filtered, and dried at 60 °C for 1 h to obtain a rivastigmine-COF complex.

[0064] Example 2-3

[0065] The method of Example 1 was followed, except that the reaction temperatures in preparing BO-COF in step (4) were adjusted to 37° C. and 45° C., respectively.

[0066] Figure 2 A is the effect of reaction temperature on the BO content in BO-COF. Figure 2 A It can be seen that when the reaction temperature is 25 °C, the BO content in BO-COF is the highest.

[0067] Embodiment 4-5

[0068] The method of Example 1 is followed, except that the molar ratios of COF, BO-SA and DMAP in preparing BO-COF in step (4) are adjusted to 7:3:3 and 7:6:4, respectively.

[0069] Figure 2 B is the effect of the molar ratio of feed on the BO content in BO-COF. Figure 2 B It can be seen that when the molar ratio of COF, BO-SA, and DMAP is 7:8:8, the BO content in BO-COF is the highest.

[0070] Example 6

[0071] The method of Example 1 was followed, except that the reaction time for preparing BO-COF in step (4) was adjusted to 48 h.

[0072] Figure 2 C is the effect of reaction time on the BO content in BO-COF. Figure 2 C It can be seen that when the reaction time is 24h, the BO content in BO-COF is the highest.

[0073] Embodiment 7-8

[0074] The method of Example 1 is followed, except that the mass ratios of rivastigmine and BO-COF in preparing the rivastigmine-COF complex in step (5) are adjusted to 1:5 and 1:1, respectively.

[0075] Examples 9-10

[0076] The method of Example 1 was followed, except that the incubation time for preparing the rivastigmine-COF complex in step (5) was adjusted to 2 h and 3 h, respectively.

[0077] Determination of drug loading of rivastigmine-COF complex

[0078] Accurately weigh 15 mg of rivastigmine-COF complex into a 10 mL volumetric flask, dissolve it with 0.5 mL of NaOH solution (0.5 mol / L), then add 0.5 mL of HCl solution (0.5 mol / L) to neutralize it, make up to volume with mobile phase, and centrifuge (12000 rpm, 5 min) to obtain the test solution.

[0079] The content of rivastigmine was tested by high performance liquid chromatography, and the specific chromatographic conditions were as follows: the chromatographic column was a C18 column (150×4.6 mm, 5 μm); the mobile phase was methanol and phosphate buffer (25 mM Na2HPO4, pH 7.0) with a volume ratio of 58:42; the flow rate was 1.0 mL / min; the detection wavelength was 214 nm; the column temperature was 40°C; and the injection volume was 20 μL. The drug loading was calculated according to the following formula.

[0080]

[0081] Among them, W T represents the dosage of rivastigmine, W R Indicates the quality of COF.

[0082] It was determined that the drug loading of the rivastigmine-COF complex prepared in Example 1, Example 7, and Example 8 were 16.1%, 8.4%, and 23.4%, respectively. Figure 3 ); The drug loading of the rivastigmine-COF complex prepared in Example 9 and Example 10 was 16.5% and 17.1% respectively ( Figure 4 ).

[0083] Characterization of rivastigmine-COF complex

[0084] Scanning electron microscopy observation of rivastigmine-COF complex (Example 1) is a cubic shape ( Figure 5 ), particle size about 250nm( Figure 6 ), indicating that the drug loading process had no effect on the morphology and particle size of COF.

[0085] Fourier transform infrared spectroscopy shows ( Figure 7 ), Rivastigmine at 1717cm -1 The peak at 1396 cm is the carbonyl (C=O) vibration peak in the carbamate group, while the peak at 1396 cm -1 is the vibration of CN. When rivastigmine was loaded by COF and BO-COF, the two characteristic peaks of rivastigmine shifted to 1722-1723 cm -1 and 1403~1404cm -1 At the same time, COF at 1749cm -1 and BO-COF at 1745 cm -1 The peaks at 1756 cm -1 and 1752cm -1 The shift changes of the above characteristic peaks reveal that there is a strong interaction between the carrier and the drug molecules.

[0086] Differential scanning calorimetry (DSC) showed ( Figure 8), rivastigmine has an endothermic peak at 328°C. However, no endothermic peak was observed in the composite at this temperature, suggesting that there was an interaction between rivastigmine and COF.

[0087] In vitro release characteristics of rivastigmine-COF complex

[0088] Using artificial nasal fluid as the release medium, the drug release behavior of rivastigmine raw material and rivastigmine-COF complex (Example 1) was investigated. The preparation method of ANF is to dissolve NaCl (8.77g), CaCl2 (0.58g) and KCl (2.98g) in 1L of pure water. Weigh the rivastigmine-COF complex (equivalent to 2.5mg of rivastigmine), add 5mL of ANF at 37°C, and shake at 100rpm at 37°C. Take out 1mL of medium at 0.5, 1, 2, 4, 6, 8, and 12h, respectively, and then add isothermal and equal volume of fresh release medium. The sample is centrifuged at 12000rpm for 5min, and the supernatant is taken to determine the RIV amount and calculate the cumulative release rate Q.

[0089]

[0090] Among them, C t represents the drug concentration in the release medium at time t, V0 represents the total volume of the release medium, V1 represents the volume of the release medium taken out each time, and M represents the total amount of drug.

[0091] The results show that Fig. 9 ), the rivastigmine API released about 85% of rivastigmine within 30 minutes. In contrast, the rivastigmine-COF complex showed sustained release behavior at 37°C, with a cumulative release of 20% to 30% of rivastigmine within 30 minutes and a release plateau after 6 hours.

[0092] Mucoadhesion of COF

[0093] Using spherical CD-NS as a control, CD-NS, COF and BO-COF were labeled with rhodamine B (RhoB) (Example 1). 10 μL of RhoB-labeled nanoparticle suspension was placed on the surface of the sheep nasal mucosa, incubated at 37°C for 3 minutes, and then the fluorescence micrographs were recorded again. The nasal mucosa was then rinsed with 1 mL or 5 mL of artificial nasal fluid for a total of 13 cycles. Fluorescence micrographs were recorded in sequence after each flushing cycle. The fluorescence intensity of the fluorescence image was extracted using ImageJ software, and the fluorescence intensity was analyzed using the normalization method.

[0094] The results showed that after 13 washes with artificial nasal fluid, the fluorescence image on the sheep nasal mucosa was gradually weakening ( Fig.10A). Approximately 57% of the fluorescence of BO-COF remained on the mucosa after 5 mL of artificial nasal fluid was used, and 40% of the fluorescence remained on the mucosa after 10 mL of artificial nasal fluid was used. The retention of COF on the sheep nasal mucosa was comparable to that of BO-COF. At the end of each washing cycle, there was no significant difference in retention between COF and BO-COF (P>0.05). The fluorescence intensity of CD-NS decreased more rapidly compared to COF, showing 24% retention of fluorescence intensity after washing CD-NS with 5 mL of artificial nasal fluid and approximately 6% retention after 10 mL of artificial nasal fluid. The fluorescence retention of CD-NS was significantly different from that of COF ( Fig.10 B).

[0095] Permeation of rivastigmine-COF complex in nasal mucosal cell model

[0096] Calu-3 cells were used as a nasal mucosal cell model. Calu-3 cell suspension was inoculated into the Transwell supply pool, and 1.5 mL of fresh complete medium was added to each well of the receiving pool for culture. On the 8th day of liquid-liquid culture, it was changed to air-liquid culture until a dense cell monolayer membrane was formed for cell transport research. At this time, the cell resistance was about 380 Ω·cm 2 . 0.5 mL of each HBSS suspension of rivastigmine solution (60 μg / mL), rivastigmine-COF complex and rivastigmine-borneol modified COF complex (Example 1) (equivalent to rivastigmine 60 μg / mL) was added to the supply pool (3 wells for each sample), and 1.5 mL of Hank's balanced salt solution (HBSS) was added to the receiving pool. 200 μL of sample was taken out from the receiving pool at 0.5, 1, 1.5, 2, 3, and 4 h, respectively, and 200 μL of HBSS solution was added at the same time. The concentration of the samples taken out at different time points was calculated, and the apparent permeability coefficient (P app ).

[0097]

[0098] where δQ / δt is the membrane permeability through the Calu-3 monolayer and A is the membrane surface area (cm 2 ), C0 is the initial concentration of the drug supplied to the pool.

[0099] The results show that Fig.11 ) The apparent permeability coefficient of rivastigmine in Calu-3 cell monolayer membrane is about 4.4×10 - 6 cm / s. The apparent permeability coefficient of rivastigmine-COF composite is 8.7×10 -6cm / s, indicating that the COF complex itself can enhance the penetration ability of rivastigmine. When the borneol content is 0.5%, the apparent permeability coefficient of the rivastigmine-borneol modified COF complex is 9.14×10 -6 cm / s, which was not significantly different from that of the rivastigmine-COF complex (p>0.05). app At 1.5% borneol content, drug P app The results showed that the COF complex could promote drug absorption more effectively after borneol modification.

[0100] Pharmacokinetics of rivastigmine-COF complex in rat plasma

[0101] Male Wistar rats were randomly divided into four groups, 5 in each group. The first group was gavaged with rivastigmine solution. The second to fourth groups were given rivastigmine solution, rivastigmine-COF complex and rivastigmine-borneol functionalized COF complex (Example 1) by nasal administration, respectively. According to the dose conversion between humans and animals, the dosage was 1.08 mg / kg. Before the start of the experiment, the animals fasted for 12 hours and had free access to water. During nasal administration, rats were anesthetized with isoflurane and kept in a supine position. A micropipette was inserted into the rat nostril for 10 mm and the sample was slowly pushed in. 0.5 mL of blood samples were collected from the orbital vein at 0.083, 0.25, 0.5, 1, 2, 4 and 6 hours after administration, respectively, and placed in heparin-coated test tubes and centrifuged at 12000 rpm for 10 minutes. The supernatant was stored at -80°C until analysis. DAS2.0 software was used to analyze the concentration-time data of rivastigmine in different experimental groups (Table 1) and calculate the pharmacokinetic parameters (Table 2).

[0102] Table 1. Concentration of rivastigmine in plasma of Wister rats after administration of rivastigmine and rivastigmine-COF complex by different routes (mean ± SD, n = 5)

[0103]

[0104] The pharmacokinetic results showed that ( Fig.12 , Table 2), compared with free rivastigmine taken orally, the plasma rivastigmine levels of the three nasal formulations were higher. max The plasma concentration of free rivastigmine after intranasal administration of COF complex modified with rivastigmine-borneol was higher than that of free rivastigmine after oral or intranasal administration. maxThe values ​​were 3.5 times, 2.2 times and 1.6 times those of oral rivastigmine solution, nasal rivastigmine solution and intranasal rivastigmine-cross-COF complex, respectively. In addition, the plasma AUC of intranasal rivastigmine-borneol modified COF complex was 0-t The highest was 420.76 ng / mL·h, which was 1.7 times, 1.5 times and 1.2 times that of oral rivastigmine solution, nasal rivastigmine solution and nasal rivastigmine-COF complex, respectively. Compared with nasal rivastigmine solution, nasal rivastigmine-COF complex and rivastigmine-borneol modified COF complex had a higher plasma AUC than that of oral rivastigmine solution. 0-t The results showed that the high C max and AUC can be attributed to the mucosal adhesive properties of the carrier, which can effectively prolong the retention of nanoparticles in the nasal cavity and enhance the ability of the drug to enter the systemic circulation.

[0105] Table 2 Pharmacokinetic parameters of rivastigmine and rivastigmine-COF complex in Wister rat plasma after administration by different routes (mean ± SD, n = 5)

[0106]

[0107] Pharmacokinetics of rivastigmine-COF complex in rat brain

[0108] In the brain pharmacokinetic study, Wister rats were randomly divided into four groups, 30 in each group, and then divided into 6 subgroups (5 in each subgroup), each subgroup representing a sampling point (5, 15, 30, 60, 120 and 240min after administration). According to the dose conversion between humans and animals, the dosage was 1.08mg / kg. The first group was gavaged with rivastigmine solution. The second to fourth groups were given rivastigmine solution, rivastigmine-COF complex and rivastigmine-borneol functionalized COF complex (Example 1) by nasal cavity, respectively. Before the experiment began, the animals fasted for 12h and had free access to water. During nasal administration, rats were anesthetized with isoflurane and kept in a supine position. A micropipette was inserted into the rat nostril for 10mm and the sample was slowly pushed in. At a predetermined time point, each group of rats was anesthetized with isoflurane, and the abdominal aorta was bled and then killed to collect the whole brain. The residual blood in the brain was washed away with normal saline and weighed after drying. Physiological saline was added at a ratio of 1:1.5 (w / v), homogenized in an ice bath, and then the homogenate was centrifuged at 12000 rpm for 10 min. The supernatant was stored at -80°C until analysis. DAS2.0 software was used to analyze the concentration-time data of rivastigmine in different experimental groups (Table 3) and calculate the pharmacokinetic parameters (Table 4).

[0109] Table 3 Rivastigmine concentration in the brain of Wister rats after administration of rivastigmine and rivastigmine-COF complex by different routes (mean ± SD, n = 5)

[0110]

[0111] The concentration-time curve of rivastigmine in the brain showed a pattern similar to that of the drug in plasma ( Fig.13 , Table 3). T in the brain after nasal administration max Appeared at 0.083h, while oral administration of T max The C in the brain of the rivastigmine-borneol modified COF complex was observed after intranasal administration. max The highest value was 975.27 ng / g, which was 8.0 times, 2.6 times and 1.3 times that of oral rivastigmine solution, nasal rivastigmine solution and nasal rivastigmine-COF complex, respectively. Compared with oral rivastigmine, the brain AUC of the nasal administration group was 0-t Higher. AUC in the brain of rivastigmine-COF complex and rivastigmine-borneol modified COF complex after intranasal administration 0-t The values ​​were 1.8 and 2.3 times that of oral rivastigmine, respectively, and the AUC of rivastigmine administered intranasally was 0-t The C of rivastigmine-borneol modified COF complex was 1.3 and 1.6 times higher than that of rivastigmine-borneol modified COF complex. max and AUC 0-t This further confirms that the adhesion of the carrier can prolong the residence time of the drug on the nasal mucosa, while the use of borneol can enhance the permeability of the drug. The combined effect of the two helps promote the absorption of the drug in the brain.

[0112] Table 4 Pharmacokinetic parameters of rivastigmine and rivastigmine-COF complex in Wister rat brain after administration by different routes (mean ± SD, n = 5)

[0113]

[0114]

[0115] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A rivastigmine-COF complex, characterized in that: The rivastigmine-COF complex comprises COF and rivastigmine loaded on COF.

2. The rivastigmine-COF complex according to claim 1, characterized in that: The mass content of rivastigmine in the rivastigmine-COF composite is 5 to 30%; Preferably, the rivastigmine-COF complex has a cubic structure and a particle size range of 100 to 1000 nm.

3. The rivastigmine-COF complex according to claim 1 or 2, characterized in that: The preparation method of the COF comprises the following steps: S1, preparing CD-MOF by reacting γ-CD, KOH and methanol; S2, preparing COF by reacting CD-MOF with a crosslinking agent; Preferably, the cross-linking agent is DPC.

4. The rivastigmine-COF complex according to any one of claims 1 to 3, characterized in that: The COF is a COF functionally modified by a penetration enhancer; Preferably, the functional modification includes physical modification and chemical modification.

5. The rivastigmine-COF complex according to claim 4, characterized in that: The physical modification of the COF is mixing the COF with a penetration enhancer; Preferably, the amount of the penetration enhancer is 0.5-10%, preferably 0.5-5%, of the total mass of COF and the penetration enhancer; Preferably, the penetration enhancer is BO.

6. The rivastigmine-COF complex according to claim 5, characterized in that: The physical modification of the COF is to mix COF with BO, seal and heat, the heating temperature is 60-90°C, preferably 70-80°C.

7. The rivastigmine-COF complex according to claim 4, characterized in that: The chemical modification of the COF is to prepare a carboxyl-containing penetration enhancer derivative to react with the COF; Preferably, the penetration enhancer is BO; Preferably, the chemical modification of the COF comprises: reacting SA with BO to obtain a BO derivative containing a carboxyl group; reacting COF with a BO derivative containing a carboxyl group to obtain a BO-modified COF.

8. The method for preparing the rivastigmine-COF complex according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) dissolving rivastigmine in a drug-carrying solvent to obtain a rivastigmine solution; (2) stirring and incubating the rivastigmine solution and COF, filtering, and drying to obtain a rivastigmine-COF complex; Preferably, the drug-carrying solvent is selected from one or more of ethanol, methanol, dimethyl sulfoxide, acetonitrile, and n-hexanol; ethanol is further preferred; Preferably, the concentration of the rivastigmine solution is 40 to 160 mg / mL; more preferably 80 to 120 mg / mL; Preferably, the mass ratio of rivastigmine to COF is 1:(1-5); more preferably 1:3-1:

2.

9. A pharmaceutical composition comprising the rivastigmine-COF complex according to any one of claims 1 to 7 or the rivastigmine-COF complex prepared by the preparation method according to claim 8.

10. Use of the rivastigmine-COF complex of any one of claims 1 to 7, or the rivastigmine-COF complex prepared by the preparation method of claim 8, or the pharmaceutical composition of claim 9 in the preparation of a nasal preparation for treating Alzheimer's disease.

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