Gastrodin nasal cavity-brain targeting double-channel synergistic delivery preparation and preparation method thereof

Abstract

The application discloses a gastrodin nasal cavity-brain target double-channel synergistic delivery preparation and a preparation method thereof, and belongs to the field of pharmaceutical preparations. In view of the problems of the existing gastrodin nasal cavity administration, such as only relying on a single olfactory pathway, limited coverage in the brain, short retention time and the like, the preparation comprises chitosan modified PLGA nanoparticles (80-120 nm), TAT peptide modified lipid nanoparticles (200-300 nm) and poloxamer temperature-sensitive gel. The two kinds of nanoparticles target the nasal cavity olfactory area and respiratory area respectively, synergistically enter the brain through the olfactory pathway and the trigeminal nerve pathway, and the temperature-sensitive gel prolongs the nasal cavity retention. Experiments show that the brainstem gastrodin glycoside AUC of the double-channel preparation is 2.49 times that of the single-olfactory area preparation, the brainstem AUC is only 31.6% of that without TAT peptide modification, and the nasal cavity retention half-life is 8.3 times that of the ordinary solution. The application is used for preparing drugs for treating neurasthenia, headache, migraine, insomnia and the like.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical formulation technology, specifically to a gastrodin nasal-brain targeted dual-channel synergistic delivery formulation, its preparation method, and its application in the preparation of drugs for treating central nervous system diseases. Background Technology

[0002] The brain is a complex central organ in the human body, and drugs must cross the blood-brain barrier to enter brain tissue and exert their therapeutic effects. The blood-brain barrier is mainly formed by the tight junctions of brain capillary endothelial cells, with no gaps between the cells. Furthermore, the endothelial cells possess efflux pump systems such as P-glycoproteins, which, under the action of ATPases, pump substances back into the bloodstream, making it difficult for most drugs to enter the brain. Gastrodin (4-hydroxymethylphenyl-β-D-glucopyranoside) is the effective monomeric component of Gastrodia elata, possessing central inhibitory effects such as sedation, hypnosis, and analgesia, and is widely used clinically for neurasthenia, headache, migraine, and other conditions. However, after oral administration, gastrodin is affected by the first-pass effect and requires hydrolysis by intestinal flora into gastrodin before it can cross the blood-brain barrier to exert its central pharmacological effects. This results in low oral bioavailability, insufficient drug concentration in the brain, and the need for large clinical doses and frequent administration.

[0003] To address the aforementioned issues, existing technologies have explored various nasal administration routes to achieve brain-targeted delivery of gastrodin. A direct pathway exists between the nasal cavity and the brain that can bypass the blood-brain barrier, allowing drug molecules to reach the cerebrospinal fluid or brain via the olfactory mucosa along the connective tissue surrounding the olfactory nerve bundle or olfactory neuron axons. Generally, transport from the nose to the brain involves three pathways: the olfactory nerve pathway, the olfactory mucosal epithelial pathway, and the blood circulation pathway.

[0004] Existing patented technology solution 1: CN100542540C - Gastrodin nasal administration formulation: This patent discloses a nasal administration formulation containing gastrodin, which is prepared by dispensing and sterilizing gastrodin as the main drug and one or more excipients selected from the group consisting of a penetration enhancer, solubilizer, emulsifier, preservative, thickener, fragrance, and pH buffer. The dosage form is a nasal spray, nasal drops, ointment, gel, or powder. The patent proposes targeting gastrodin to the brain via nasal administration, with each dose being 1-80 mg of gastrodin, exhibiting brain-targeting characteristics. The patent also discloses that the drug in the formulation can be added in the form of micronized powder, solid dispersion, or inclusion compound, and that natural or synthetic polymers can be added to the formulation to prolong the drug's residence time in the nasal cavity. Experimental data shows that the absolute plasma bioavailability of this patented gastrodin nasal drops is only 9.1% of that of the intravenous injection, while the cerebrospinal fluid bioavailability is 103.8% of that of the intravenous injection.

[0005] Existing patented technology solution two: CN101053550A - Gastrodin nasal gel: This patent application discloses a gastrodin nasal gel, using an aqueous gel matrix including ordinary hydrophilic gel, ion-sensitive in-situ gel, temperature-sensitive in-situ gel, and pH-sensitive in-situ gel. The patent aims to prolong the retention time of gastrodin in the nasal cavity through the gel matrix.

[0006] Existing patent technology solution three: CN103877008A - A gastrodin in-situ gel for treating inner ear diseases: This patent discloses a gastrodin in-situ gel suitable for nasal administration, composed of 10-20 parts by weight of gastrodin, 0.3-0.8 parts by weight of ion-sensitive gel material, 0.5-2 parts by weight of transport promoter, 0.02-0.05 parts by weight of preservative, and 100 parts by weight of purified water. It can significantly improve the efficiency of gastrodin transport to the inner ear via the Eustachian tube. However, this patent targets the inner ear rather than the brain, and does not address the issue of brain-targeted delivery.

[0007] The aforementioned existing technologies have the following objective shortcomings: First, while CN100542540C achieves nasal delivery of gastrodin to the brain, its formulation design relies on a single delivery pathway, primarily the olfactory nerve pathway. Studies have shown that the olfactory pathway mainly delivers drugs to the forebrain (olfactory bulb and cerebral cortex), while the trigeminal nerve pathway can reach the brainstem and hindbrain; the two pathways have significantly different brain regions. Single-pathway delivery suffers from limitations in brain coverage and delivery capacity, constrained by the capacity of a single neural pathway.

[0008] Secondly, although existing gastrodin nasal preparations use thickeners or gel matrices to prolong nasal retention time, the retention time of gastrodin solution or ordinary gel in the nasal cavity is still relatively short, making it easy to be cleared by nasal cilia. The contact time between the drug and the nasal mucosa is insufficient, limiting the full absorption of the drug.

[0009] Third, existing technologies do not differentiate formulations based on the anatomical characteristics of different regions of the nasal mucosa. The olfactory region, located at the top of the nasal cavity, has an area of ​​only about 2-4 cm², while the respiratory region occupies most of the nasal cavity area. The drug concentrations encountered by these two regions after administration differ significantly. Existing technologies use a uniform formulation for drug delivery, failing to achieve differentiated drug distribution and simultaneous delivery between the olfactory and respiratory regions.

[0010] Fourth, the brain-targeting efficiency of existing nasal gastrodin formulations still needs improvement. Taking CN100542540C as an example, although its cerebrospinal fluid bioavailability reaches 103.8% of that of intravenous injection, this patent does not have a nanocarrier system. Gastrodin is mainly absorbed through the nasal mucosa in free molecule form, and its brain entry efficiency is limited by the nasal mucosal barrier and ciliary clearance.

[0011] Recent advances in naso-brain delivery have provided new insights into overcoming the aforementioned technical challenges. Studies have shown that naso-brain drug delivery can bypass the blood-brain barrier via the olfactory and trigeminal nerve pathways, enabling direct drug delivery to the central nervous system. TAT peptide (transcriptional transactivator)-modified lipid nanoparticles, when administered nasally, can increase their accumulation in the brain. Chitosan-modified PLGA nanoparticles can be taken up by the olfactory mucosa; 80nm and 175nm nanoparticles are internalized in the lamina propria of the olfactory mucosa within just 5 minutes after administration. The combination of poloxamer 407 and poloxamer 188 as a thermosensitive gel matrix allows the solution to transform into a gel at temperatures above 30°C, adhering to the nasal cavity and prolonging drug residence time. However, there are currently no reports of integrating these technologies for nasal-brain targeted delivery of gastrodin. Summary of the Invention

[0012] Based on this, it is necessary to address the technical problems of existing gastrodin nasal delivery formulations that rely solely on a single olfactory delivery pathway, resulting in limited brain coverage and insufficient delivery efficiency; the short retention time of ordinary solutions or gels in the nasal cavity, making them easily cleared by cilia; and the lack of differentiated formulation design based on the anatomical characteristics of different regions of the nasal mucosa (olfactory and respiratory regions), leading to uneven drug distribution in the olfactory and respiratory regions and failing to fully utilize the synergistic delivery potential of the two neural pathways. Therefore, it is necessary to provide a gastrodin nasal-brain targeted dual-channel synergistic delivery formulation and its preparation method.

[0013] A gastrodin nasal-brain targeted dual-channel synergistic delivery formulation comprising the following components: Olfactory delivery component: Chitosan-modified PLGA nanoparticles with a particle size of 80-120 nm, encapsulating gastrodin. Chitosan, as a functional material, has the ability to open tight junctions, promoting the transport of nanoparticles via paracellular pathways of the olfactory mucosa. After intranasal administration, PLGA nanoparticles of this size range can be rapidly taken up by the lamina propria of the olfactory mucosa within 5-15 minutes, delivering gastrodin to the olfactory bulb and forebrain region via olfactory nerve axonal transport and the olfactory mucosal epithelial pathway.

[0014] Trigeminal nerve pathway delivery component: TAT peptide-modified lipid nanoparticles with a particle size of 200-300 nm, encapsulating gastrodin. TAT peptide is a cell-penetrating peptide, and its modification can significantly improve the cellular uptake efficiency and intracranial accumulation of nanoparticles. After administration via the nasal respiratory zone, nanoparticles in this particle size range are transported via endocytosis at the trigeminal nerve endings, entering the brainstem along the ophthalmic and maxillary branches of the trigeminal nerve, achieving drug delivery to the posterior brain region.

[0015] Thermosensitive gel matrix: using poloxamer 407 and poloxamer 188 as the matrix. This matrix is ​​a free-flowing solution at room temperature. After administration via the nasal cavity, it undergoes in-situ gelation at the nasal cavity temperature, approximately 33°C, forming a semi-solid gel that adheres to the nasal mucosa surface, extending the drug's retention time in the nasal cavity to 4-6 hours, while simultaneously achieving sustained release of nanoparticles.

[0016] Optional bioadhesion enhancer: carbomer or hydroxypropyl methylcellulose, for further enhancing the adhesion between the gel and the nasal mucosa (this component is optional; the formulation of the present invention can still achieve dual-channel synergistic delivery even without this component).

[0017] The mass ratio of gastrodin in the olfactory delivery component and the trigeminal pathway delivery component is 1:1; in a preferred embodiment, this ratio is beneficial for balancing drug exposure in both the olfactory bulb and the brainstem.

[0018] This invention also provides a method for preparing the above-mentioned gastrodin nasal-brain targeted dual-channel synergistic delivery formulation, comprising the following steps: Step 1: Chitosan-modified PLGA nanoparticles were prepared using an emulsification solvent evaporation method: PLGA was dissolved in dichloromethane as the oil phase, and gastrodin was dissolved in deionized water as the inner aqueous phase. The oil phase and the aqueous phase were mixed at a volume ratio of 10:1 and ultrasonically emulsified to form a primary emulsion. The primary emulsion was added to the outer aqueous phase containing chitosan and polyvinyl alcohol, and the organic solvent was evaporated by stirring. The nanoparticles were collected by centrifugation and then freeze-dried for storage.

[0019] Step 2: Prepare TAT peptide-modified lipid nanoparticles using thin film dispersion method: Dissolve lecithin, cholesterol and gastrodin in anhydrous ethanol, rotary evaporate to form a lipid film, add phosphate buffer containing TAT peptide for hydration, sonicate to form a nanoparticle suspension, extrude through a membrane for granulation, and freeze-dry for storage.

[0020] Step 3: Dissolve poloxamer 407 and poloxamer 188 in cold water (4°C) in proportion, stir until completely dissolved, add the nanoparticles obtained in Step 1 and Step 2, mix evenly, and store at 4°C to obtain the thermosensitive gel formulation.

[0021] Compared with the prior art, the present invention has the following significant advantages: First, this invention is the first to propose and realize a dual-pathway synergistic delivery strategy for gastrodin via nasal administration using the olfactory and trigeminal nerve pathways. By designing gastrodin-encapsulated nanoparticles into two components with different particle sizes and surface modifications, targeting the olfactory and respiratory regions of the nasal cavity respectively, and entering the brain through different neural pathways, simultaneous drug delivery to the forebrain and hindbrain regions is achieved, overcoming the limitation of brain coverage area in single-pathway delivery. Experiments have confirmed that the AUC of gastrodin in the brainstem of this invention is 2.49 times that of the control formulation containing only a single olfactory delivery component and 1.07 times that of the control formulation containing only a single trigeminal nerve pathway delivery component. The total AUC of the olfactory bulb and brainstem in the experimental group reached 77.3% of the sum of the total AUC of the two single-pathway formulations, and maintained a high drug concentration in both the olfactory bulb and brainstem regions. This overcomes the inherent defects of single-pathway formulations, which are either "strong in the forebrain and weak in the hindbrain" or "strong in the hindbrain and weak in the forebrain," achieving effective coverage of multiple brain regions and obtaining technical effects that single-pathway formulations cannot achieve simultaneously.

[0022] Secondly, the thermosensitive gel matrix of this invention forms an adhesive gel layer after in-situ gelation in the nasal cavity, extending the drug retention time in the nasal cavity to 4-6 hours, significantly improving the problem of short drug retention time caused by nasal ciliary clearance. Quantitative fluorescence labeling experiments show that the half-life of the fluorescence signal of the formulation of this invention in the nasal cavity is 8.3 times that of ordinary gastrodin solution.

[0023] Third, chitosan-modified PLGA nanoparticles can promote paracellular transport by opening tight junctions in epithelial cells, while TAT peptide-modified lipid nanoparticles can enhance transmembrane transport through cell-penetrating peptide-mediated endocytosis. A necessity-controlled experiment with TAT peptide modification confirmed that the AUC of gastrodin in unmodified lipid nanoparticles in the brainstem was only 31.6% of that in TAT peptide-modified lipid nanoparticles, demonstrating that TAT peptide modification makes a crucial contribution to delivery in the trigeminal neural pathway.

[0024] Fourth, in the formulation of this invention, gastrodin is encapsulated in nanoparticles, which reduces direct release of the drug into the nasal cavity and systemic absorption, thereby lowering the drug concentration in peripheral blood. Experiments show that the plasma AUC of the formulation of this invention is only 15.3% of that of intravenously administered drugs, effectively reducing systemic side effects. Attached Figure Description

[0025] Figure 1 This is a pharmacokinetic curve (mean ± standard deviation, n=6) of the gastrodin nasal-brain targeted dual-channel synergistic delivery formulation of the present invention after nasal administration to different brain regions with gastrodin concentrations. Figure 2A is a bar chart comparing the AUC of gastrodin in the rat olfactory bulb of the present invention and the comparative formulation (mean ± standard deviation, n=6). The horizontal axis represents the groups, from left to right: experimental group (dual-channel formulation), comparative example 1 (ordinary gel), comparative example 2 (intravenous administration), comparative example 3 (olfactory single-channel formulation only), comparative example 4 (trifurcation single-channel formulation only), and comparative example 5 (ordinary lipid nanoparticle gel formulation without TAT peptide modification); the vertical axis represents the AUC of gastrodin (μg·h / g). Figure 2 B is a bar chart comparing the AUC of gastrodin in the rat cerebral cortex of the formulation of this invention and the comparative formulation (mean ± standard deviation, n=6). The horizontal and vertical axes of the figure are set in the same way. Figure 2 A; Figure 2 C is a bar chart comparing the AUC of gastrodin in the rat brainstem of the formulation of this invention and the comparative formulation (mean ± standard deviation, n=6). The horizontal and vertical axes in the figure are set in the same way. Figure 2 A; Figure 3 A is the particle size distribution diagram of the chitosan-modified PLGA nanoparticles of this invention (determined by dynamic light scattering method); Figure 3 B is the particle size distribution diagram of the TAT peptide-modified lipid nanoparticles of this invention (determined by dynamic light scattering method). Figure 4 This is a graph showing the relationship between the gelation temperature of the thermosensitive gel of the present invention and the concentration of poloxamer. Figure 5 This is a schematic diagram of the formulation structure and dual-pathway delivery mechanism of the present invention. Detailed Implementation

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Specifically, this invention provides a method for preparing a gastrodin nasal-brain targeted dual-channel synergistic delivery formulation, as follows: (1) Preparation of chitosan-modified PLGA nanoparticles: 100 mg of PLGA (lactic acid:glycolic acid = 50:50, molecular weight 30 kDa) was dissolved in 2 mL of dichloromethane to form the oil phase. 50 mg of gastrodin was dissolved in 0.2 mL of deionized water to form the inner aqueous phase. The oil and aqueous phases were mixed and ultrasonically emulsified for 3 minutes (3 seconds on, 3 seconds off) under ice bath conditions using a 200 W probe to form the primary emulsion. The primary emulsion was slowly added dropwise to 10 mL of the outer aqueous phase containing 0.5% (w / v) chitosan (molecular weight 150-300 kDa, degree of deacetylation 80%) and 1% (w / v) polyvinyl alcohol. The mixture was magnetically stirred at room temperature for 4 hours to evaporate the organic solvent. The nanoparticles were collected by centrifugation at 12000 rpm for 30 minutes, washed three times with deionized water, and then freeze-dried for storage. The average particle size was 105±12 nm, the Zeta potential was +18.6±2.3 mV, the gastrodin encapsulation efficiency was 62.3±3.5%, and the drug loading was 8.7±1.2%.

[0028] (2) Preparation of TAT peptide-modified lipid nanoparticles: 200 mg of lecithin, 50 mg of cholesterol, and 100 mg of gastrodin were dissolved in 10 mL of anhydrous ethanol. The organic solvent was removed by vacuum evaporation in a rotary evaporator to form a uniform lipid film. 10 mL of phosphate buffer (pH 7.4, 0.01 M) containing 2 mg of TAT peptide (sequence: YGRKKRRQRRR) was added, and the mixture was hydrated at 40 °C for 30 minutes. The mixture was then sonicated with a probe (200 W, 5 minutes) to form a nanoparticle suspension. The nanoparticles were extruded sequentially through 400 nm and 200 nm polycarbonate membranes, granulated, and freeze-dried for storage. Dynamic light scattering analysis showed an average particle size of 235 ± 18 nm, a Zeta potential of +12.4 ± 1.8 mV, a gastrodin encapsulation efficiency of 55.8 ± 4.1%, and a drug loading of 10.2 ± 1.5%.

[0029] (3) Preparation of thermosensitive gel matrix: Weigh 18 g of poloxamer 407 and 2 g of poloxamer 188, add 100 mL of deionized water (4℃), and stir magnetically overnight at 4℃ until completely dissolved to obtain a 20% (w / v) poloxamer mixed solution. The gelation temperature was determined using the inverted test tube method, and the results showed that the gelation temperature of the matrix was 33.2 ± 0.5℃, which meets the nasal cavity temperature requirements. Add the above-mentioned chitosan-modified PLGA nanoparticles and TAT peptide-modified lipid nanoparticles (the total ratio of gastrodin in the two nanoparticles was 1:1) in the specified proportion, mix thoroughly, and store at 4℃ for later use.

[0030] Furthermore, the following provides an evaluation of the brain-targeting properties of the gastrodin nasal-brain targeted dual-channel synergistic delivery formulation (including single-channel controls and TAT peptide necessity controls): Experimental animals: Healthy male SD rats, weighing 220-250g, were randomly divided into six groups, with six rats in each group.

[0031] Group administration: Experimental group: The gastrodin nasal-brain targeted dual-channel synergistic delivery formulation prepared in Example 1 of this invention was administered via the nasal cavity, with a gastrodin dose of 20 mg / kg and 25 μL administered per nostril.

[0032] Comparative Example 1: Gastrodin ordinary gel (without nanoparticles, the rest of the formulation is the same as in Example 1), administered intranasally, with a gastrodin dose of 20 mg / kg.

[0033] Comparative Example 2: Gastrodin saline solution, administered intravenously, at a dose of 20 mg / kg.

[0034] Comparative Example 3: A single-channel gel formulation containing only chitosan-modified PLGA nanoparticles. The formulation contained only chitosan-modified PLGA nanoparticles (gastrodin dose 20 mg / kg), without TAT peptide-modified lipid nanoparticles. The other excipients were the same as those in the experimental group. The product was administered via nasal cavity.

[0035] Comparative Example 4: A single-channel gel formulation containing only TAT peptide-modified lipid nanoparticles. The formulation contains only TAT peptide-modified lipid nanoparticles (gastrodin dose 20 mg / kg), without chitosan-modified PLGA nanoparticles. The other excipients are the same as those in the experimental group. The product is administered via nasal cavity.

[0036] Comparative Example 5: A gel formulation containing unmodified TAT peptide-containing ordinary lipid nanoparticles, in which ordinary lipid nanoparticles without TAT peptide modification were used instead of TAT peptide-modified lipid nanoparticles, and the rest of the formulation and administration conditions were the same as those of the experimental group.

[0037] Sample collection and testing: Animals were sacrificed at 15 min, 30 min, 1 h, 2 h, 4 h, and 6 h after drug administration. Plasma and brain tissue (olfactory bulb, cerebral cortex, and brainstem) were collected. The concentrations of gastrodin in plasma and gastrogenin in brain tissue were determined by HPLC. Drug-time curves were plotted, and the AUC and mean residence time (MRT) were calculated using DAS 2.0 pharmacokinetic software. The brain targeting index (BTI = brain tissue AUC / plasma AUC) was calculated.

[0038] Experimental results: Table 1. Comparison of AUC of gastrodin / gastrodin in brain tissue and plasma of rats in each group (mean ± standard deviation, n=6)

[0039] Note: The brain tissue test index is gastrodin (the active metabolite of gastrodin), and the plasma test index is the original gastrodin drug.

[0040] Synergistic effect analysis: The brainstem AUC of the experimental group (8.7 μg·h / g) was 2.49 times that of Comparative Example 3 (single channel in the olfactory region only, 3.5 μg·h / g) and 1.07 times that of Comparative Example 4 (single channel in the trigeminal region only, 8.1 μg·h / g). The olfactory bulb AUC of the experimental group (18.6 μg·h / g) was 2.70 times that of Comparative Example 4 (single channel in the trigeminal region only, 6.9 μg·h / g) and 1.11 times that of Comparative Example 3 (single channel in the olfactory region only, 16.8 μg·h / g).

[0041] Key efficacy evidence: Using the total AUC in the olfactory bulb and brainstem as the evaluation index, the total AUC of the experimental group was 27.3 μg·h / g, the total AUC of Comparative Example 3 was 20.3 μg·h / g, and the total AUC of Comparative Example 4 was 15.0 μg·h / g. The sum of the total AUC of the two single-channel formulations was 35.3 μg·h / g, and the total AUC of the experimental group reached 77.3% of this sum. Although the total AUC of the experimental group did not exceed the sum of the AUCs of the two single-channel formulations administered separately, the experimental group maintained high drug concentrations in both the olfactory bulb and brainstem regions: the AUC in the olfactory bulb was 2.70 times that of Comparative Example 4 (trigeminal single-channel only), and the AUC in the brainstem was 2.49 times that of Comparative Example 3 (olfactory single-channel only). This indicates that the dual-channel formulation overcomes the inherent defects of single-channel formulations, which are "strong in the forebrain and weak in the hindbrain" or "strong in the hindbrain and weak in the forebrain," achieving effective coverage of multiple brain regions and obtaining technical effects that single-pathway formulations cannot achieve simultaneously.

[0042] Necessity analysis of TAT peptide modification: The AUC of gastrodin in the brainstem of Comparative Example 5 (unmodified TAT peptide ordinary lipid nanoparticles) was 2.75 μg·h / g, only 31.6% of that of the experimental group (8.7 μg·h / g) and only 34.0% of that of Comparative Example 4 (TAT peptide-modified lipid nanoparticle single-channel formulation, 8.1 μg·h / g). This indicates that TAT peptide modification is a key factor in trigeminal nerve pathway delivery, and unmodified TAT peptide nanoparticles cannot effectively deliver drugs to the brainstem region via the trigeminal nerve pathway. The AUC of the olfactory bulb of Comparative Example 5 (17.9 μg·h / g) was close to that of the experimental group (18.6 μg·h / g), indicating that TAT peptide modification mainly affects the delivery efficiency of the trigeminal nerve pathway, while having a smaller impact on the olfactory pathway, further validating the rationality of the dual-pathway design.

[0043] The above data collectively demonstrate that the AUC of gastrodin in the olfactory bulb, cerebral cortex, and brainstem of the experimental group of this invention was significantly higher than that of Comparative Example 1 (conventional gel) and Comparative Example 2 (intravenous administration). Furthermore, compared to the two single-channel formulations, the dual-channel formulation achieved effective coverage of the posterior brain region while maintaining high concentrations in the forebrain region, producing a multi-regional synchronous delivery effect in the brain that single-channel formulations could not achieve. The BTI of the olfactory bulb in the experimental group reached 2.86, and the BTI in the brainstem reached 1.34, significantly better than that of Comparative Example 1. Simultaneously, the plasma AUC of the experimental group (6.5 μg·h / mL) was only 15.3% of that of Comparative Example 2 (intravenous administration, 42.6 μg·h / mL), indicating that the formulation of this invention effectively reduced systemic exposure while increasing intracerebral drug concentration.

[0044] It should be noted that in the experimental group, the two types of nanoparticles were mixed at a 1:1 mass ratio with gastrodin, meaning that the olfactory delivery component and the trigeminal pathway delivery component each accounted for half of the dosage (10 mg / kg each). In Comparative Examples 3 and 4, the entire 20 mg / kg dose was delivered by a single nanoparticle. Under this dosage allocation, the olfactory bulb AUC (18.6 μg·h / g) in the experimental group was still slightly higher than that in Comparative Example 3 (16.8 μg·h / g), and the brainstem AUC (8.7 μg·h / g) was still slightly higher than that in Comparative Example 4 (8.1 μg·h / g). This indicates that the dual-channel formulation can simultaneously achieve effective drug exposure in both the forebrain and hindbrain with half the dose, further demonstrating the advantages of synergistic delivery via dual pathways.

[0045] Furthermore, the following section further reveals the methodology for quantitatively investigating the residence time of the formulation in the nasal cavity: The retention of the formulation in the nasal cavity was quantitatively investigated using a fluorescent labeling method. The FITC-labeled formulation was administered to the nasal cavity of rats (the experimental group received the thermosensitive gel formulation of this invention, and the control group received an equal concentration of gastrodin saline solution). Animals were sacrificed at 15 min, 30 min, 1 h, 2 h, 4 h, and 6 h after administration. Nasal mucosal tissue was collected and frozen sections were prepared. Fluorescence intensity was observed under a fluorescence microscope and quantitatively analyzed using ImageJ software. The fluorescence intensity immediately after administration (0 h) was normalized to 100%.

[0046] Experimental results: Table 2. Fluorescence intensity of the formulation in the nasal cavity over time (relative fluorescence intensity, %, mean ± standard deviation, n=4)

[0047] Log-linear regression was performed on the fluorescence intensity-time data to calculate the half-life of the fluorescence signal. Experimental group The duration was 3.8 ± 0.5 h, compared to the control group. The half-life of the nasal cavity retention time was 0.46 ± 0.08 h. The half-life of the nasal cavity retention time in the experimental group was 8.3 times that of the control group (p < 0.001, independent samples t test). The fluorescence signal of the thermosensitive gel formulation of this invention can be maintained in the nasal cavity for more than 4 hours after administration, while the fluorescence signal of ordinary gastrodin solution drops to 42.7% after 30 minutes after administration.

[0048] Furthermore, the following section further reveals the optimization scheme for the gelation temperature of the temperature-sensitive gel: The effect of different poloxamer 407 / 188 ratios on gelation temperature was investigated, and the results are as follows:

[0049] The results showed that when the concentration of poloxamer 407 was 18% (w / v) and the concentration of poloxamer 188 was 2% (w / v), the gelation temperature was 33.2℃, which was closest to the nasal cavity temperature and was the optimal formulation.

[0050] Furthermore, the following section further reveals the safety evaluation of nanoparticles on the nasal mucosa: The cytotoxicity of the nanoparticles to isolated rat nasal mucosal epithelial cells was evaluated using the MTT assay. Chitosan-modified PLGA nanoparticles and TAT peptide-modified lipid nanoparticles were co-incubated with nasal mucosal epithelial cells at different concentrations (10, 50, 100, 200, and 500 μg / mL) for 24 hours, and cell viability was determined by the MTT assay. The results showed that the cell viability of both nanoparticles was greater than 85% at concentrations below 500 μg / mL, indicating that the nanoparticles of this invention have good biosafety.

[0051] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A gastrodin nasal-brain targeted dual-channel synergistic delivery formulation, characterized in that, Include: Olfactory delivery component: Chitosan-modified PLGA nanoparticles with a particle size of 80-120 nm, loaded with gastrodin; Trigeminal nerve pathway delivery components: TAT peptide-modified lipid nanoparticles with a particle size of 200-300 nm, encapsulated with gastrodin; Thermosensitive gel matrix: Poloxamer 407 and Poloxamer 188; The olfactory delivery component, administered via the nasal olfactory region, delivers gastrodin to the olfactory bulb and forebrain region through the olfactory pathway. The trigeminal nerve pathway delivery component, administered via the nasal respiratory region, delivers gastrodin to the brainstem region through the trigeminal nerve pathway. The two delivery components are synergistically delivered in the same formulation.

2. The gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to claim 1, characterized in that, The chitosan in the chitosan-modified PLGA nanoparticles has a molecular weight of 150-300 kDa and a degree of deacetylation of 80%.

3. The gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to claim 1, characterized in that, The amino acid sequence of the TAT peptide is YGRKKRRQRRR.

4. The gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to claim 1, characterized in that, The concentration of poloxamer 407 in the thermosensitive gel matrix is ​​17%-19% (w / v), the concentration of poloxamer 188 is 1%-3% (w / v), and the gelation temperature is 31℃-35.5℃.

5. The gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to claim 1, characterized in that, The formulation also includes a bioadhesion enhancer, which is carbomer or hydroxypropyl methylcellulose.

6. The gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to claim 1, characterized in that, The mass ratio of gastrodin in the olfactory delivery component and the trigeminal nerve pathway delivery component is 1:

1.

7. The method for preparing the gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Chitosan-modified PLGA nanoparticles were prepared using an emulsification solvent evaporation method; Step 2: Prepare TAT peptide-modified lipid nanoparticles using a thin-film dispersion method; Step 3: Dissolve poloxamer 407 and poloxamer 188 in cold water at 4°C, add the nanoparticles obtained in Step 1 and Step 2, mix well, and obtain a temperature-sensitive gel formulation.

8. The preparation method according to claim 7, characterized in that, In step one, the oil phase of the emulsification solvent evaporation method is a dichloromethane solution of PLGA, the inner aqueous phase is an aqueous solution of gastrodin, and the outer aqueous phase contains chitosan and polyvinyl alcohol.

9. The use of the gastrodin nasal-brain targeted dual-channel synergistic delivery formulation according to any one of claims 1-6 in the preparation of a drug for treating neurasthenia, headache, migraine, and insomnia.

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