Drug-loaded lacrimal suppository based on polyethylene glycol hydrogel

Abstract

The invention relates to the field of xerophthalmia treatment, and particularly provides a drug-loaded lacrimal passage suppository based on polyethylene glycol hydrogel. The drug-loaded lacrimal passage suppository comprises drug-loaded microspheres and polyethylene glycol hydrogel, and the drug-loaded microspheres are dispersed in the polyethylene glycol hydrogel; wherein the proportion of the drug-loaded microspheres in the drug-loaded lacrimal passage suppository is (40-50) wt%; the drug-loaded microspheres comprise hydrophilic drug active molecules and a carrier; wherein the carrier is selected from hydrophobic polyester, and the weight ratio of the hydrophobic polyester to the hydrophilic drug active molecules is 1: (1-3); the polyethylene glycol hydrogel is prepared from multi-arm polyethylene glycol and a cross-linking agent through a covalent bond cross-linking reaction. The drug-loaded lacrimal passage suppository has the advantages of accurate swelling size, drug sustained release and controllable degradation period, and the dry eye treatment effect can be effectively improved by combining the drug-loaded lacrimal passage suppository with a synergistic treatment mode of drugs (such as litamilast) for inhibiting ocular surface inflammation.

Description

Technical Field

[0001] This application relates to the field of dry eye treatment, specifically providing a drug-loaded lacrimal plug based on polyethylene glycol hydrogel. Background Technology

[0002] Dry eye syndrome, also known as keratoconjunctivitis sicca, refers to decreased tear film stability caused by abnormalities in the quality, quantity, or dynamics of tears, accompanied by ocular inflammation, eye discomfort, visual impairment, and ocular tissue lesions. Epidemiological surveys in recent years show that the prevalence of dry eye abroad is approximately 7.0%-34.0%, while in my country it is approximately 17%, making it a hot research topic internationally. Dry eye is also the most common disease seen in ophthalmology outpatient clinics, accounting for more than 30% of all outpatient visits. The main clinical treatments include surgical procedures and drug and device therapies. Among these, anti-inflammatory drugs (glucocorticoids or immunosuppressants), artificial tears, and lacrimal duct plugs, or the combination of anti-inflammatory drugs and lacrimal duct plug implantation, are the preferred treatments for moderate to severe dry eye. The "Chinese Dry Eye Diagnosis and Treatment Guidelines (2022)" states that "lacrimal duct plug implantation is relatively simple and safe, and is often the first choice for lacrimal duct plug treatment."

[0003] Dry eye is often accompanied by more severe local signs and inflammation; therefore, medication combined with lacrimal duct plug implantation is the preferred treatment for moderate to severe dry eye. Currently, lacrimal duct plugs under development contain dexamethasone, cyclosporine, and tacrolimus. In addition to these drugs, other medications used to treat dry eye include rebamipide, diquafosol sodium, lorteprednisolone, and ristatin, all of which are administered as eye drops.

[0004] In July 2016, the U.S. Food and Drug Administration (FDA) officially approved the application for listatin ophthalmic solution. This is the first new lymphocyte function-associated antigen 1 (LFA-1) antagonist drug approved by the FDA for the treatment of dry eye disease, and also the first prescription drug approved to treat the signs and symptoms of dry eye disease by inhibiting inflammation caused by dry eye. It has significant clinical advantages, with rapid onset of action, high safety, and good tolerability. However, eye drops need to be applied three times a day in clinical use, which is frequent and easy to forget. Therefore, there is an urgent need for a dry eye treatment product with sustained-release and embolizing functions. Summary of the Invention

[0005] In view of this, this application provides a drug-loaded lacrimal plug based on polyethylene glycol hydrogel.

[0006] This application provides a drug-loaded lacrimal plug based on polyethylene glycol hydrogel. The drug-loaded lacrimal plug includes drug-loaded microspheres and polyethylene glycol hydrogel, wherein the drug-loaded microspheres are dispersed in the polyethylene glycol hydrogel; wherein the proportion of the drug-loaded microspheres in the drug-loaded lacrimal plug is (40-50)wt% (e.g., 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, or any range of two values). The drug-loaded microspheres comprise a hydrophilic drug active molecule and a carrier; wherein the carrier is selected from a hydrophobic polyester, and the weight ratio of the hydrophobic polyester to the hydrophilic drug active molecule is 1:(1-3) (e.g., 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.0, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, 1:3.0 or any range of two values). The polyethylene glycol hydrogel is formed by a covalent crosslinking reaction of multi-arm polyethylene glycol and a crosslinking agent; wherein the multi-arm polyethylene glycol contains at least two functional end groups that can react with the crosslinking agent, and the functional end groups contain at least one of the following functional groups: aldehyde (-CHO) or The crosslinking agent contains at least two active groups that can react with the multi-arm polyethylene glycol, wherein the active groups are selected from primary amino groups (-NH2); the ratio of the total molar amount of functional end groups in the multi-arm polyethylene glycol to the total molar amount of active groups in the crosslinking agent is 1:(0.25-4) (e.g., 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, 1:0. 6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:1.5, 1:1.55, 1:1.6, 1:1.65, 1:1.7, 1:1.75 1:1.8, 1:1.85, 1:1.9, 1:1.95, 1:2, 1:2.05, 1:2.1, 1:2.15, 1:2.2, 1:2.25, 1:2.3, 1:2.35, 1:2.4, 1:2.45, 1:2.5, 1:2.55, 1:2.6, 1:2.65, 1:2.7, 1:2.75, 1:2.8, 1:2.85, 1:2.9, 1:2 .95, 1:3, 1:3.05, 1:3.1, 1:3.15, 1:3.2, 1:3.25, 1:3.3, 1:3.35, 1:3.4, 1:3.45, 1:3.5, 1:3.55, 1:3.6, 1:3.65, 1:3.7, 1:3.75, 1:3.8, 1:3.85, 1:3.9, 1:3.95, 1:4 or any range of two values).

[0007] In some alternative embodiments, the hydrophobic polyester comprises at least one selected from poly(lactic-co-glycolic acid) copolymer (CAS No. 34346-01-5), poly(lactic-co-glycolic acid), poly(L-lactic acid), polyhydroxyalkanoate, or racemic polylactic-co-caprolactone copolymer. In some specific embodiments, the hydrophobic polyester is selected from PLGA.

[0008] In some alternative embodiments, the weight average molecular weight (Mw) of the hydrophobic polyester is selected from 20,000 to 150,000 (e.g., 20,000, 25,000, 30,000, 34,407, 35,000, 40,000, 45,000, 50,000, 50,500, 55,000, 60,000, 65,000, 66,942, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000, 100,000, 105,000, 110,000, 115,000, 120,000, 125,000, 130,000, 135,000, 140,000, 145,000, 150,000 or any combination of two values).

[0009] In some alternative embodiments, the hydrophilic pharmaceutically active molecule includes at least one of ristatin, methylprednisolone, and diquafosol sodium. In some specific embodiments, the hydrophilic pharmaceutically active molecule is selected from ristatin.

[0010] In some alternative embodiments, the drug-loaded microspheres are prepared by sequentially emulsifying and curing the hydrophilic drug active molecule and the hydrophobic polyester in the presence of an emulsifier.

[0011] In some alternative embodiments, the weight ratio of the hydrophobic polyester to the hydrophilic pharmaceutical active molecule is 1:(1-3). The drug loading rate of the drug-loaded microspheres is calculated based on the mass ratio of the hydrophobic polyester to the hydrophilic pharmaceutical active molecule. Drug loading rate of the drug-loaded microspheres = (mass of hydrophilic pharmaceutical active molecule loaded in the microspheres / mass of the drug-loaded microspheres) * 100%.

[0012] In some alternative embodiments, the emulsifier includes at least one of polyvinyl alcohol (PVA), methylcellulose, Span-80, or Tween-80. In some specific embodiments, the emulsifier is selected from PVA.

[0013] In some specific implementations, the emulsification is selected from shear emulsification.

[0014] In some alternative embodiments, the conditions for shear emulsification include: a rotation speed of 4000-6000 rpm (e.g., 4000 rpm, 4100 rpm, 4200 rpm, 4300 rpm, 4400 rpm, 4500 rpm, 4600 rpm, 4700 rpm, 4800 rpm, 4900 rpm, 5000 rpm, 5100 rpm, 5200 rpm, 5300 rpm, 5400 rpm, 5500 rpm, 5600 rpm, 5700 rpm). The rotation speed can be 5000 rpm, 5800 rpm, 5900 rpm, 6000 rpm, or any two of these values; the time can be 90-300 s (e.g., 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, 210s, 220s, 230s, 240s, 250s, 260s, 270s, 280s, 290s, 300s, or any two of these values). In some specific embodiments, the shear emulsification conditions include: a rotation speed of 5000 rpm and a time of 120 s.

[0015] In some alternative embodiments, the curing conditions include: a rotational speed of 100-300 rpm (e.g., 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, 300 rpm, or any range of two values); and a curing time selected from 15-24 hours (15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, or any range of two values). In some specific embodiments, the curing conditions include: a rotational speed of 200 rpm; and a curing time of 17 hours.

[0016] In some alternative embodiments, the drug-loaded microspheres are prepared using the following method: Step S101: Dissolve the hydrophobic polyester in a first solvent to obtain a hydrophobic polyester solution; dissolve the hydrophilic drug active molecule in a second solvent to obtain a hydrophilic drug active molecule solution; mix the hydrophobic polyester solution and the hydrophilic drug active molecule solution evenly to obtain an oil phase; Step S102: Dissolve the emulsifier in a third solvent to obtain an aqueous phase; Step S103: Under shear conditions, the aqueous phase is added dropwise to the oil phase, and shearing is performed after the addition is complete; then solidification is carried out to obtain a suspension. Step S104: The suspension is subjected to solid-liquid separation, washing and drying in sequence to obtain drug-loaded microspheres.

[0017] In some optional embodiments, in step S101, the concentration of the hydrophobic polyester solution is 5-30% (w / v) (e.g., 5% (w / v), 10% (w / v), 15% (w / v), 20% (w / v), 25% (w / v), 30% (w / v), or any range of two such values). In some specific embodiments, in step S101, the concentration of the hydrophobic polyester solution is 15% (w / v).

[0018] In some optional embodiments, in step S101, the first solvent is selected from aprotic polar solvents. In other optional embodiments, the first solvent includes at least one of dichloromethane (DCM), tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile (ACN), or acetone. In some specific embodiments, the first solvent is selected from DCM.

[0019] In some optional embodiments, in step S101, the concentration of the hydrophilic drug active molecule solution is 75-120% (w / v) (e.g., 75% (w / v), 80% (w / v), 85% (w / v), 90% (w / v), 95% (w / v), 100% (w / v), 105% (w / v), 110% (w / v), 115% (w / v), 120% (w / v) or any range of two values).

[0020] In some optional embodiments, in step S101, the second solvent is selected from aprotic polar solvents. In other optional embodiments, the second solvent includes at least one of DCM, THF, DMF, DMSO, ACN, or acetone. In some specific embodiments, the second solvent is selected from THF. In other specific embodiments, the second solvent is selected from DMF.

[0021] In some optional embodiments, in step S102, the concentration of the emulsifier in the aqueous phase is 0.3-2% (w / v) (e.g., 0.3% (w / v), 0.4% (w / v), 0.5% (w / v), 0.6% (w / v), 0.7% (w / v), 0.8% (w / v), 0.9% (w / v), 1.0% (w / v), 1.1% (w / v), 1.2% (w / v), 1.3% (w / v), 1.4% (w / v), 1.5% (w / v), 1.6% (w / v), 1.7% (w / v), 1.8% (w / v), 1.9% (w / v), 2.0% (w / v), or any range of two values). In some specific embodiments, in step S102, the concentration of the emulsifier in the aqueous phase is 1.5% (w / v).

[0022] In some optional embodiments, in step S103, the weight ratio of the oil phase to the water phase is 1:(3-5) (e.g., 1:3, 1:3.1, 1:3.2, 1:3.3, 1:3.4, 1:3.5, 1:3.6, 1:3.7, 1:3.8, 1:3.9, 1:4, 1:4.1, 1:4.2, 1:4.3, 1:4.4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, 1:5, or any range of two values). In some specific embodiments, in step S103, the weight ratio of the oil phase to the water phase is 1:4.

[0023] In some optional embodiments, in step S103, the shearing speed is selected from 4000-6000 rpm (e.g., 4000 rpm, 4100 rpm, 4200 rpm, 4300 rpm, 4400 rpm, 4500 rpm, 4600 rpm, 4700 rpm, 4800 rpm, 4900 rpm, 5000 rpm, 5100 rpm, 5200 rpm, 5300 rpm, 5400 rpm, 5500 rpm, 5600 rpm, 5700 rpm, 5800 rpm, 5900 rpm, 6000 rpm, or any range of two values). In some specific embodiments, the shearing speed is selected from 5000 rpm.

[0024] In some alternative embodiments, in step S103, the cutting time is selected from 60-300s (e.g., 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, 210s, 220s, 230s, 240s, 250s, 260s, 270s, 280s, 290s, 300s, or any range of two values). In some specific embodiments, the cutting time is selected from 120s.

[0025] In some optional embodiments, in step S103, the curing rotation speed is selected from 100-300 rpm (e.g., 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, 300 rpm, or any range of two values). In some optional embodiments, in step S103, the curing time is selected from 15-24 hours (15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, or any range of two values).

[0026] In some optional embodiments, in step S104, the solid-liquid separation is selected from centrifugation. The centrifugation speed is selected from 5000-15000 rpm (e.g., 5000 rpm, 6000 rpm, 7000 rpm, 8000 rpm, 9000 rpm, 10000 rpm, 11000 rpm, 12000 rpm, 13000 rpm, 14000 rpm, 15000 rpm, or any combination of two values). The centrifugation time is selected from 5-30 minutes (5 min, 10 min, 15 min, 20 min, 25 min, 30 min, or any combination of two values).

[0027] In some alternative implementations, in step S104, the washing is a purified water wash.

[0028] In some alternative implementations, in step S104, the drying is vacuum drying.

[0029] In some alternative embodiments, the functional end group includes at least one of aldehyde, succinimide carbonate, succinimide acetate, succinimide propionate, succinimide succinate, succinimide glutarate, succinimide adipate, succinimide sebacic acid, or succinimide.

[0030] In some specific implementations, the functional end base includes the following functional groups: .

[0031] In some specific embodiments, the functional end group is selected from succinimide glutarate group.

[0032] In some alternative embodiments, the multi-arm polyethylene glycol includes at least one of four-arm polyethylene glycol succinimide glutarate (4-Arm PEG-SG), six-arm polyethylene glycol succinimide glutarate (6-Arm PEG-SG), or eight-arm polyethylene glycol succinimide glutarate (8-Arm PEG-SG).

[0033] In some embodiments, the multi-arm polyethylene glycol is selected from tetra-arm polyethylene glycol succinimide glutarate. In other embodiments, the multi-arm polyethylene glycol is selected from 6-Arm PEG-SG. In still other embodiments, the multi-arm polyethylene glycol is selected from 8-Arm PEG-SG.

[0034] In some alternative embodiments, the molecular weight of the multi-arm polyethylene glycol is 10,000-80,000 Da (e.g., 10,000 Da, 20,000 Da, 30,000 Da, 40,000 Da, 50,000 Da, 60,000 Da, 70,000 Da, 80,000 Da, or any range of two values).

[0035] In some alternative embodiments, the crosslinking agent comprises trilysine or its acid salt.

[0036] In some alternative embodiments, the acid salt of the trilysine includes at least one of trilysine monohydrochloride, trilysine dihydrochloride, trilysine monoacetate, or trilysine diacetate.

[0037] In some alternative embodiments, the crosslinking agent is selected from trilysine.

[0038] In some specific embodiments, the crosslinking agent is selected from the acid salt of trilysine. In some more specific embodiments, the crosslinking agent is selected from trilysine monoacetate.

[0039] In some alternative embodiments, the ratio of the total molar amount of functional end groups in the multi-arm polyethylene glycol to the total molar amount of active groups in the crosslinking agent is 1:(0.5-2). In some specific embodiments, the ratio of the total molar amount of functional end groups in the multi-arm polyethylene glycol to the total molar amount of active groups in the crosslinking agent is 1:1.

[0040] In some alternative embodiments, the drug-loaded lacrimal plug further includes a chromogenic agent, and the chromogenic agent is dispersed in the polyethylene glycol hydrogel; wherein the proportion of the chromogenic agent in the drug-loaded lacrimal plug is (0.01-0.13) wt% (e.g., 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.10 wt%, 0.11 wt%, 0.12 wt%, 0.13 wt%, or any range of two values).

[0041] In some alternative embodiments, the colorimetric agent includes at least one of sodium fluorescein, N-hydroxysuccinimide-fluorescein (CAS No. 117548-22-8, also known as 5(6)-carboxyfluorescein succinimide ester, abbreviated FITC-NHS), trypan blue, or brilliant blue G. In some specific embodiments, the colorimetric agent is selected from N-hydroxysuccinimide-fluorescein.

[0042] This application has the following beneficial effects: First, the drug-loaded lacrimal duct plug of this application has the advantages of precise swelling size, sustained drug release, and controllable degradation cycle. Combined with the synergistic treatment of anti-ocular surface inflammation drugs (such as ristatin), it can effectively improve the treatment effect of dry eye. Therefore, the drug-loaded lacrimal duct plug of this application solves the problem of excessively rapid release of water-soluble drugs and expands the range of drugs available for treating dry eye.

[0043] Second, this application integrates physical embolization and chemotherapy: the drug-loaded lacrimal plug based on polyethylene glycol hydrogel provides physical occlusion (reducing tear loss) while achieving local sustained-release therapy of drugs (anti-inflammatory, secretion-promoting, etc.), with the dual mechanisms working synergistically.

[0044] Third, the drug-loaded lacrimal plug of this application improves comfort and retention: by utilizing the softness, high water content and swelling properties of hydrogel, it is possible not only to design a plug shape that better fits the anatomical structure of the lacrimal canaliculus and has better compliance, but also to reduce the probability of foreign body sensation, friction and spontaneous dislodgement. Attached Figure Description

[0045] Figure 1 Microscopic photograph of drug-loaded microspheres in Example 9; Figure 2 Comparative Example 2: Microscopic image of drug-loaded microspheres. Detailed Implementation

[0046] This application discloses a drug-loaded lacrimal duct plug based on polyethylene glycol hydrogel. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this application. The methods and applications of this application have been described through preferred embodiments. Those skilled in the art can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this application to realize and apply the technology of this application.

[0047] In this article, the amino acid sequence of "trilylysine" is H2N-Lys-Lys-Lys-COOH.

[0048] In this article, "acidic salt of trilysine" refers to the treatment of trilysine with an acid (such as hydrochloric acid HCl, acetic acid CH3COOH, etc.) to protonate its basic amino group (-NH2+ H). + → -NH3 + Stable salts are formed after ( ).

[0049] Unless otherwise stated, all experimental methods involved in this application are conventional methods.

[0050] Unless otherwise stated, all reagents used in the experiments are pharmaceutical grade, and the water used in the experiments should meet the standards for purified water / water for injection in the Chinese Pharmacopoeia.

[0051] To make the objectives, technical solutions, and advantages of this application clearer, the implementation schemes of this application will be further described in detail below with reference to the embodiments.

[0052] Examples 1-9 and Comparative Examples 1-3 of drug-loaded lacrimal duct plugs: In Examples 1-9 and Comparative Examples 2-3, the preparation method of the drug-loaded lacrimal plug includes the following steps: Step S100: Preparation of drug-loaded microspheres: Step S101, Preparation of the oil phase: Preparation of polymer solution: Weigh PLGA (1500mg / 1.500g) and place it in a glass bottle. Add solvent (10ml, such as DMF) and mix until PLGA is completely dissolved to obtain a hydrophobic polyester solution with a concentration of 15% (w / v).

[0053] Preparation of drug solution: Weigh a certain amount of listatin and add it to a solvent (e.g., DMF or THF). Mix until the listatin is completely dissolved to obtain a drug solution of a certain concentration (e.g., 75% (w / v), 100% (w / v), 110% (w / v)).

[0054] Preparation of the oil phase: The polymer solution and the drug solution are mixed evenly in a certain volume ratio (such as 5:1, 4:1, 3:1, etc.) to obtain the oil phase.

[0055] Step S102, Preparation of the aqueous phase: Weigh 6g of PVA and place it in a beaker. Add purified water (400ml), heat to 70℃ and stir at 70℃ until the PVA is completely dissolved. After cooling to room temperature, filter through a 0.2μm filter membrane to obtain an aqueous phase (i.e., a PVA solution with a concentration of 1.5% (w / v)).

[0056] S103, Shear Emulsification and Curing: Turn on the shear emulsifier and adjust the speed to 5000 rpm. Add the oil phase solution dropwise while the aqueous phase is under shearing. After the addition is complete, shear for 2 minutes. Stir the sheared suspension at 200 rpm and solidify for 17 hours.

[0057] S104. Collection, rinsing, and drying of microspheres: The solidified suspension was centrifuged at 10,000 rpm for 10 min and the microspheres were collected. The microspheres were rinsed three times with purified water and then vacuum dried on a petri dish for 24 h to obtain drug-loaded microspheres.

[0058] Step S200: Preparation of drug-loaded lacrimal duct plugs: S201. Preparation of Solution I: Add a certain weight of drug-loaded microspheres and phosphate buffer A (2.314g) to a 10ml EP tube, vortex and sonicate until a homogeneous suspension is formed, add four-arm polyethylene glycol succinimide glutarate (325mg), vortex upright for 60s, vortex inverted for 30s, for a total of 90s, to obtain Solution I.

[0059] S202. Preparation of Solution II: Add N-hydroxysuccinimide-fluorescein (1.25 mg), trilysine salt (8.75 mg), and phosphate buffer B (0.575 g) to a 10 ml EP tube, vortex for 90 min, and obtain Solution II.

[0060] S203. Preparation of gel solution: Add solution II along the wall to solution I, and vortex for 10 seconds in the upright position, 10 seconds in the inverted position, and 10 seconds in the upright position in sequence, for a total of 30 seconds, to obtain the gel solution.

[0061] S204. Preparation of drug-loaded lacrimal plugs: Inject the gel solution into a silicone tube with an inner diameter of 2 mm and let it stand for 2.5 h; then, cut the silicone tube into sections, blow out the gel with compressed air, and stretch it 3 times; then, dry it at (18-26) ℃ in the dark to constant weight, and cut it into drug-loaded lacrimal plugs with a length of 3 mm.

[0062] The preparation of phosphate buffer A is as follows: add sodium dihydrogen phosphate monohydrate (0.524g) and disodium hydrogen phosphate dodecahydrate (5.802g) to a 200ml beaker, add purified water (96.5g), and mix well.

[0063] Preparation of phosphate buffer B: Weigh sodium dihydrogen phosphate monohydrate (0.524g) and disodium hydrogen phosphate dodecahydrate (5.802g), add them to a 200ml beaker, add purified water (96.5g) and mix well.

[0064] In Comparative Example 1, the preparation method of the drug-loaded lacrimal duct plug includes the following steps: S301, Preparation of Solution I: Add ristatin (414 mg) and buffer A (2.314 g) to a 10 ml EP tube, vortex and sonicate until a homogeneous suspension is formed, add multi-arm polyethylene glycol (325 mg), vortex upright for 60 s, vortex inverted for 30 s, for a total of 90 s, to obtain Solution I.

[0065] S302. Preparation of Solution II: Add N-hydroxysuccinimide-fluorescein (1.25 mg), trilysine salt (8.75 mg), and buffer B (0.575 g) to a 10 ml EP tube and vortex for 90 min to obtain Solution II.

[0066] S303, Gel preparation: Add solution II along the wall to solution I, and vortex for 10 seconds in the upright position, 10 seconds in the inverted position, and 10 seconds in the upright position in sequence, for a total of 30 seconds, to obtain the gel.

[0067] S304. Preparation of drug-loaded lacrimal plugs: Inject the gel into a silicone tube with an inner diameter of 2 mm and let it stand for 2.5 h; then, cut the silicone tube into sections, blow out the gel with compressed air, and stretch it (if it cannot be stretched, proceed directly to the next step); then, dry it at (18-26) ℃ in the dark until it reaches constant weight, and cut it into drug-loaded lacrimal plugs with a length of 3 mm.

[0068] The preparation of buffer A is as follows: Weigh 1.9734 g of disodium hydrogen phosphate dodecahydrate and 0.2245 g of potassium dihydrogen phosphate, add water to dissolve them into 1000 ml; measure 100 ml, add 1.21 g of sodium hydroxide and mix well.

[0069] Preparation of buffer B: Weigh sodium dihydrogen phosphate monohydrate (0.524 g) and disodium hydrogen phosphate dodecahydrate (5.802 g), add them to a 200 ml beaker, add purified water (96.5 g) and mix well.

[0070] Table 1. Preparation process parameters of drug-loaded microspheres in Examples 1-9 and Comparative Examples 2-3:

[0071] Performance testing of drug-loaded microspheres: (1) Drug loading of drug-loaded microspheres: Dissolve drug-loaded microspheres in DCM to obtain the sample to be tested; determine the drug content in the sample to be tested by high performance liquid chromatography; calculate the drug loading.

[0072] The formula for calculating drug loading is: Drug loading = W 11 / W 12 *100%; Among them, W 11 W represents the weight of the drug encapsulated in the drug-loaded microspheres. 12 This represents the total weight of the drug-loaded microspheres.

[0073] (2) Sphericity and particle size: The sphericity and particle size of the drug-loaded microspheres were observed under a microscope.

[0074] Table 2. Performance test results of drug-loaded microspheres:

[0075] Among them, the microscopic image of the drug-loaded microspheres in Example 9 is as follows: Figure 1 As shown, the microscopic image of the drug-loaded microspheres in Comparative Example 2 is as follows: Figure 2 As shown. In comparison, the drug-loaded microspheres of Example 9 exhibited good sphericity and a narrow particle size distribution range, while the drug-loaded microspheres of Comparative Example 2 had poor sphericity and a wide particle size distribution range.

[0076] Table 3. Preparation process parameters of drug-loaded lacrimal plugs in Examples 1-9 and Comparative Examples 1-3:

[0077] Performance testing of drug-loaded lacrimal duct plugs: (1) The formula for calculating the proportion of microspheres in the drug-loaded lacrimal plug is: Microsphere proportion = W 21 / (W 21 +W 22 +W 23 +W 24 +W 25 +W 26 )*100%; Among them, W 21 Represents the weight of the drug or drug-loaded microspheres; W 22 This represents the weight of the four-armed polyethylene glycol succinimide glutarate; W 23 Represents the weight of trilysine acetate; W 24 Represents the weight of N-carboxysuccinimide-fluorescein; W 25 Represents the weight of sodium dihydrogen phosphate monohydrate; W 26 This represents the weight of disodium hydrogen phosphate dodecahydrate.

[0078] Taking Example 1 as an example, the amount of drug-loaded microspheres was 506 mg, the amount of four-arm polyethylene glycol succinimide glutarate was 325 mg, the amount of trilysine acetate was 8.75 mg, the amount of N-carboxysuccinimide-fluorescein was 1.25 mg, the amount of sodium dihydrogen phosphate monohydrate was 14.722 mg, and the amount of disodium hydrogen phosphate dodecahydrate was 163.013 mg. The formula for calculating the proportion of microspheres in Example 1 is as follows: Microsphere percentage = 506mg / (506mg + 325mg + 8.75mg + 1.25mg + 14.722mg + 163.013mg) * 100% = 50%.

[0079] (2) Drug release detection: Protect from light. Take one sample and place it in a 125mL polypropylene bottle. Use 100mL of phosphate buffer as the medium, gently shake to fully wet the sample, tighten the cap, and place in a 37.0℃±0.3℃ water bath, avoiding vibration or shaking. Take the sample at 6 hours. Before taking the sample, gently shake the bottle to mix the solution evenly. Then, use a pipette (specification: 1mL) to take 1mL of the solution as the test solution. Immediately add 1.0mL of fresh medium at the same temperature to the container, tighten the cap, gently shake to suspend the sample, and place in a 37.0℃±0.3℃ water bath, avoiding vibration or shaking. Separately, accurately weigh approximately 10mg of ristatin reference standard, place it in a 20mL brown volumetric flask, dissolve and dilute to the mark with methanol, shake well, accurately measure 2.3mL, place it in a 100mL brown volumetric flask, dilute to the mark with the medium, shake well, and use this as the reference solution. Accurately measure the test solution and reference solution, and inject them separately into the high-performance liquid chromatograph. Detect and record the chromatograms at a detection wavelength of 220 nm. Calculate the 6-hour drug release ratio of each sample based on peak area using the external standard method.

[0080] (3) Diameter after swelling: Place the sample in phosphate buffer solution (10 ml), take it out after 10 min, wipe the surface moisture of the sample with filter paper, place it under a 4x objective lens to measure the diameter at both ends and the middle of the sample, and calculate the average diameter, which is the diameter after swelling.

[0081] (4) Degradation cycle: Place the sample in phosphate buffer solution (1 ml) and seal it; after sealing, place it in a water bath environment of 37℃±1℃, observe the degradation of the sample every week, and record the time of complete degradation of the sample.

[0082] Table 4. Performance test results of drug-loaded lacrimal plugs in Examples 1-9 and Comparative Examples 1-3:

[0083] As can be seen from Table 4, the drug-loaded lacrimal plugs prepared by pretreating water-soluble drugs with drug-loaded microspheres have a sustained-release effect and can delay the release of drugs.

[0084] In this application, the diameter of the drug-loaded lacrimal duct plug after swelling in Example 9 is close to that of the drug-loaded lacrimal duct plug in Comparative Example 1. Therefore, the preparation process of Example 9 was repeated twice to prepare the drug-loaded lacrimal duct plugs and their performance was tested.

[0085] Table 5. Performance test results of drug-loaded microspheres and drug-loaded lacrimal plugs in Example 9:

[0086] As can be seen from Tables 4 and 5, the drug-loaded lacrimal plug of this application has the advantages of precise swelling size, sustained drug release and controllable degradation cycle. Combined with the synergistic treatment of drugs that inhibit ocular surface inflammation (such as ristatin), it can effectively improve the treatment effect of dry eye.

[0087] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present application. It should be noted that those skilled in the art can make various improvements and modifications to the present application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A polyethylene glycol hydrogel-based drug-loaded lacrimal plug, characterized in that, The drug-loaded tear duct plug comprises drug-loaded microspheres and polyethylene glycol hydrogel, and the drug-loaded microspheres are dispersed in the polyethylene glycol hydrogel; wherein the proportion of the drug-loaded microspheres in the drug-loaded tear duct plug is (40-50) wt%; The drug-loaded microspheres comprise a hydrophilic pharmaceutically active molecule and a carrier; wherein the carrier is selected from a hydrophobic polyester, and the weight ratio of the hydrophobic polyester to the hydrophilic pharmaceutically active molecule is 1:(1-3); The polyethylene glycol hydrogel is formed by a covalent bond cross-linking reaction between a multi-arm polyethylene glycol and a cross-linking agent; wherein the multi-arm polyethylene glycol contains at least two functional end groups that can react with the cross-linking agent, and the functional end groups comprise at least one of the following functional groups: aldehyde group (-CHO) or ; the cross-linking agent contains at least two active groups that can react with the multi-arm polyethylene glycol, and the active groups are selected from primary amino groups; and the ratio of the total molar amount of the functional end groups in the multi-arm polyethylene glycol to the total molar amount of the active groups in the cross-linking agent is 1:(0.25-4).

2. The drug-loaded punctal plug of claim 1, wherein The hydrophobic polyester comprises at least one of poly(lactic-co-glycolic acid), poly-L-lactic acid, polyhydroxyalkanoate or racemic polylactic-co-polycaprolactone copolymer; Optionally, the hydrophobic polyester is selected from poly(lactic-co-glycolic acid).

3. The drug-loaded punctal plug of claim 1, wherein The weight average molecular weight of the hydrophobic polyester is selected from 20,000-150,000.

4. The medicated punctal plug of claim 1, wherein The hydrophilic pharmaceutically active molecule comprises at least one of lifitegrast, methylprednisolone and deflazacort sodium; Optionally, the hydrophilic pharmaceutically active molecule is selected from lifitegrast.

5. The drug-loaded lacrimal duct plug according to any one of claims 1 to 4, characterized in that, The drug-loaded microspheres are prepared by sequentially emulsifying and solidifying the hydrophilic pharmaceutically active molecule and the hydrophobic polyester in the presence of an emulsifier; Optionally, the emulsifier comprises at least one of polyvinyl alcohol (PVA), methyl cellulose, span-80 or tween-80.

6. The medicated punctal plug of claim 1, wherein The functional end group comprises at least one of aldehyde group, succinimidyl carbonate group, succinimidyl acetate group, succinimidyl propionate group, succinimidyl succinate group, succinimidyl glutarate group, succinimidyl adipate group, succinimidyl pimelate group or succinimidyl. Optionally, the functional end groups comprise the following functional groups: ; Optionally, the functional end group is selected from succinimidyl glutarate group.

7. The medicated punctal plug of claim 1, wherein The multi-arm polyethylene glycol comprises at least one of four-arm polyethylene glycol succinimidyl glutarate, six-arm polyethylene glycol succinimidyl glutarate or eight-arm polyethylene glycol succinimidyl glutarate; Optionally, the multi-arm polyethylene glycol is selected from four-arm polyethylene glycol succinimidyl glutarate. Optionally, the molecular weight of the multi-arm polyethylene glycol is 10,000-80,000 Da.

8. The medicated punctal plug of claim 1, wherein, The crosslinking agent comprises trilysine or an acid salt thereof; Optionally, the acid salt of trilysine comprises at least one of trilysine monohydrochloride, trilysine dihydrochloride, trilysine monoacetate or trilysine diacetate; Optionally, the crosslinking agent is selected from trilysine. Optionally, the crosslinking agent is selected from trilysine monoacetate.

9. The medicated punctal plug of claim 1 or 6 or 7 or 8, wherein, The ratio of the total molar amount of the functional end groups in the multi-arm polyethylene glycol to the total molar amount of the active groups in the crosslinking agent is 1:(0.5-2); Optionally, the ratio of the total molar amount of the functional end groups in the multi-arm polyethylene glycol to the total molar amount of the active groups in the crosslinking agent is 1:

1.

10. The medicated punctal plug of claim 1, wherein, The drug-loaded tear duct plug further comprises a color developing agent, and the color developing agent is dispersed in the polyethylene glycol hydrogel; wherein the proportion of the color developing agent in the drug-loaded tear duct plug is (0.01-0.15) wt%; Optionally, the color developing agent comprises at least one of fluorescein sodium, N-hydroxysuccinimidyl-fluorescein, trypan blue or brilliant blue G; Optionally, the color developing agent is selected from N-hydroxysuccinimidyl-fluorescein.

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