Highly absorbent hydrogels grafted with digestive enzyme inhibitors, methods of making and uses thereof

Abstract

The application relates to the field of medical hydrogels, and discloses a high-absorbability hydrogel grafted with a digestive enzyme inhibitor and a preparation method and application thereof, wherein the high-absorbability hydrogel grafted with the digestive enzyme inhibitor comprises a hydrogel, a connecting linker and a digestive enzyme inhibitor, the digestive enzyme inhibitor is grafted on the hydrogel through the connecting linker, and the grafting rate of the digestive enzyme inhibitor on the hydrogel is below 10 wt.%. In the application, the digestive enzyme inhibitor is grafted and connected with the hydrogel, when orally entering the body, the hydrogel expansion reduces the food intake of an individual, and the digestive enzyme inhibitor can reduce food digestion into small molecules to be absorbed, so that energy intake is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical hydrogels, and in particular to a highly absorbent hydrogel grafted with a digestive enzyme inhibitor, its preparation method and application, compositions comprising the highly absorbent hydrogel, and drugs for treating obesity, prediabetes, diabetes, non-alcoholic fatty liver disease or chronic idiopathic constipation, or for reducing calorie intake or improving glycemic control. Background Technology

[0002] Obesity is a condition in which excessive body fat accumulates to the point that it can negatively impact health. Obesity is linked to a variety of diseases, particularly non-alcoholic steatohepatitis (NASH), type 2 diabetes, cardiovascular disease, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Globally, both obesity and NASH are on the rise, and while conservative treatments such as lifestyle modifications and dietary guidance are commonly used, their effectiveness is often limited.

[0003] Bariatric surgery is a method to promote long-term weight loss and treat obesity and NASH. Bariatric surgery primarily achieves this by reducing an individual's energy intake. The process by which energy is absorbed by the body is as follows: (1) it is ingested as food; (2) the food is broken down and digested into absorbable small molecules by corresponding digestive enzymes within the body; and (3) these absorbable small molecules are absorbed by the digestive system (mainly the gastrointestinal wall cells) and enter the bloodstream. Restricting any stage of this process can effectively reduce the body's energy intake, thereby achieving weight loss, treating obesity, and controlling blood sugar.

[0004] Hydrogels are networks of cross-linked polymer chains that are hydrophilic and capable of absorbing aqueous solutions through hydrogen bonds with water molecules. Water molecules are retained within the hydrogel, causing it to swell to many times its initial volume. Therefore, hydrogels can be formulated into corresponding pharmaceutical preparations. When these hydrogel pharmaceutical preparations are taken orally into the stomach, their volume expands many times, thus occupying a significant portion of the stomach and reducing food intake. Patent CN115335412A discloses a superabsorbent hydrogel, which can be used to treat obesity, prediabetes, diabetes, non-alcoholic fatty liver disease (NAFLD), or chronic idiopathic constipation, or to reduce calorie intake or improve glycemic control. In the second stage of energy intake, food needs to be digested by digestive enzymes in the gastrointestinal tract before it can be absorbed by the epithelial cells. Another method for treating obesity is to reduce the digestion and breakdown of food in the gastrointestinal tract by taking digestive enzyme inhibitors such as amylase inhibitors, lipase inhibitors, or glucosidase inhibitors, thereby reducing food efficiency and nutrient absorption.

[0005] There are some differences in the timing of administration between conventional digestive enzyme inhibitors and hydrogels. First, hydrogels should be taken before meals so that the gel expands in the stomach in advance, thereby reducing the amount of food consumed afterward. Second, digestive enzyme inhibitors should be taken with meals. The reason is that if digestive enzyme inhibitors are taken in advance, although they bind to the corresponding digestive enzymes in the stomach and inhibit their activity, the conjugate will be quickly excreted from the body, and the body will quickly release new digestive enzymes, thus rendering the digestive enzyme inhibitors ineffective.

[0006] In addition, some digestive enzyme inhibitors are small molecules that are easily absorbed into the bloodstream and may cause side effects, posing certain safety risks. Summary of the Invention

[0007] Therefore, there is a need to provide a highly absorbent hydrogel grafted with digestive enzyme inhibitors, its preparation method and application, which effectively solves the problem that digestive enzyme inhibitors are rapidly emptied from the body and easily enter the bloodstream.

[0008] To achieve the above objectives, the present invention provides a highly absorbent hydrogel grafted with a digestive enzyme inhibitor, comprising a hydrogel and a digestive enzyme inhibitor, wherein the digestive enzyme inhibitor is grafted onto the hydrogel via a connecting joint, and the grafting rate of the digestive enzyme inhibitor onto the hydrogel is less than 10% by weight.

[0009] The digestive enzyme inhibitors described in this article can inhibit the activity of relevant digestive enzymes in the digestive gastrointestinal environment of humans or animals or their simulated environment, thereby reducing the activity of digestive enzymes and making it difficult for large molecules such as fats or starches to be enzymatically broken down into small molecules that can be absorbed by the human body.

[0010] Another aspect of the present invention provides a method for preparing a highly absorbent hydrogel grafted with a digestive enzyme inhibitor, which is one of the following methods:

[0011] Method 1: The digestive enzyme inhibitor and hydrogel react to form the grafted target product, and the grafting joint is a linking group formed by the direct reaction of hydrogel and digestive enzyme inhibitor;

[0012] Method 2: The hydrogel reacts with the connector to form grafting intermediate I, and intermediate I reacts with digestive enzyme inhibitor to form the grafting target product.

[0013] Another aspect of the present invention provides a highly absorbent hydrogel composition comprising the above-described highly absorbent hydrogel and pharmaceutically acceptable excipients.

[0014] Another aspect of the present invention provides the use of a hyperabsorbent hydrogel or a hyperabsorbent hydrogel composition grafted with digestive enzyme inhibitors in the preparation of a medicament for treating obesity, prediabetes, diabetes, non-alcoholic fatty liver disease or chronic idiopathic constipation, or for reducing calorie intake or improving glycemic control.

[0015] Another aspect of the present invention provides a medicament for treating obesity, prediabetes, diabetes, non-alcoholic fatty liver disease or chronic idiopathic constipation, or for reducing calorie intake or improving glycemic control, comprising the above-mentioned hyperabsorbent hydrogel of grafted digestive enzyme inhibitor or the above-mentioned hyperabsorbent hydrogel composition.

[0016] The above technical solution has the following beneficial effects:

[0017] (1) Digestive enzyme inhibitors are firmly grafted onto hydrogels through chemical reactions. The two work together in vivo to restrict the body's energy absorption. The hydrogel can expand in the stomach and occupy a large volume in the stomach, so that individuals can feel full after eating a small amount of food, effectively reducing the amount of food consumed. When food enters the stomach, the digestive enzyme inhibitors can inhibit the activity of the corresponding digestive enzymes, so that the corresponding food types cannot be digested and broken down into small molecules, thus preventing the food from being absorbed. This reduces the body's calorie absorption. The hydrogel and digestive enzyme inhibitors work at different stages of inhibiting the body's calorie intake, thereby achieving the effects of treating obesity and controlling the body's blood glucose concentration. It can be used in the preparation of non-alcoholic fatty liver disease or chronic idiopathic constipation.

[0018] (3) Grafting of digestive enzyme inhibitors and hydrogels: When the drug enters the gastrointestinal tract, the hydrogel macromolecules are not easily absorbed, and the digestive enzyme inhibitors will also be difficult to be absorbed by the epithelial cells of the gastrointestinal tract. The digestive enzyme inhibitors do not enter the human blood circulation system, which can effectively avoid drug side effects and ensure the safety of drug use.

[0019] (4) In this invention, the digestive enzyme inhibitor is covalently linked to the hydrogel. When the product is taken orally into the stomach, the hydrogel expands and remains in the stomach. Since the digestive enzyme inhibitor is covalently linked to the hydrogel, the digestive enzyme inhibitor also remains in the stomach, thereby avoiding premature emptying of the digestive enzyme and enabling the digestive enzyme inhibitor to take effect in the gastrointestinal tract for a long time. Attached Figure Description

[0020] Figure 1 This is a possible grafting reaction formula between acarbose and hydrogel in Example 1.

[0021] Figure 2 This is a possible grafting reaction formula between acarbose and hydrogel in Example 12.

[0022] Figure 3This is the possible grafting reaction formula for acarbose and hydrogel in Example 13. Detailed Implementation

[0023] The present invention provides a highly absorbent hydrogel grafted with a digestive enzyme inhibitor, comprising a hydrogel and a digestive enzyme inhibitor, wherein the digestive enzyme inhibitor is grafted onto the hydrogel via a connector.

[0024] Preferably, the grafting rate of the digestive enzyme inhibitor on the hydrogel is less than 10% by weight, that is, the grafting amount is less than 100 μg / mg.

[0025] Advantageously, the grafting rate of digestive enzyme inhibitors on hydrogels determines the loading capacity of digestive enzyme inhibitors. The higher the grafting rate of digestive enzyme inhibitors, the stronger the inhibitory rate of the drug on digestive enzymes.

[0026] In some embodiments, the grafting rate of digestive enzyme inhibitors on the hydrogel can be in the range of 1%-8%, 1%-10%, 1%-5%, 3%-10%, 3%-8%, 3%-5%, 5%-10%, 5%-8%, or 8%-10%.

[0027] Preferably, the grafting rate of the digestive enzyme inhibitor is 1-5% by weight.

[0028] A favorable grafting ratio, within an appropriate range, can both prevent the grafted material from affecting the swelling rate of the hydrosol and ensure that the inhibitor maintains good inhibitory activity.

[0029] Preferably, the media uptake rate after grafting the hydrogel is at least 70%.

[0030] Advantageously, hydrogels with a media uptake rate of at least 70% can effectively expand and occupy gastric volume within the stomach, reducing food intake. The media is typically an 8:1 volume mixture of water and simulated gastric juice.

[0031] In some embodiments, the uptake rate of the grafted hydrogel can be at least 70%, at least 80%, at least 90%, or at least 100%.

[0032] Preferably, the hydrogel has a particle size of 0.1-3 mm.

[0033] In some embodiments, the hydrogel has a particle size of 0.1-2 mm, 0.1-1 mm, 1-2 mm, or 1-3 mm.

[0034] In some embodiments, the hydrogel is a hydrophilic polymer or a cross-linked polysaccharide.

[0035] In some embodiments, the polysaccharide is selected from the following compounds or derivatives thereof: starch, hydroxyethyl starch, hydroxypropyl starch, carboxymethyl starch, amylose, dextran, chitin, pullulan, gellan gum, xylan, carrageenan, agar, locust bean gum, guar gum, gum arabic, pectin, cellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethyl hydroxyethylcellulose, hydroxybutyl methylcellulose, hydroxyethyl methylcellulose, oxidized cellulose, carboxymethylcellulose, galactomannan, alginate, chitosan, cyclodextrin, xanthan gum, hyaluronic acid, heparin, chondroitin sulfate, keratin, dermatan, and polysaccharides having glucosamine residues in their natural or diacetylated form, and any mixtures thereof.

[0036] In some embodiments, the hydrophilic polymer is selected from polyacrylates, polyacrylamide, ethylene maleic anhydride polymers, polyvinyl alcohol, polyvinylpyrrolidone, cross-linked polyethylene oxide, starch-grafted polyacrylonitrile, and any copolymers thereof.

[0037] Preferably, the connector is a linker group formed by the direct covalent bonding of an organic linker and / or a hydrogel and a digestive enzyme inhibitor.

[0038] Advantageously, the direct reaction between hydrogels and digestive enzyme inhibitors to form covalently linked target products is suitable for reaction substrates with relatively low steric hindrance and high functional group reactivity. The reaction type can be a conventional addition or substitution reaction. Furthermore, the use of organic linkers can increase the grafting rate of digestive enzyme inhibitors onto hydrogels.

[0039] In some embodiments, the linking group formed directly by the hydrogel and the digestive enzyme inhibitor can be one of an ester bond, an amide bond, or an ether bond. Ester bonds, amide bonds, or ether bonds are linking groups formed by conventional addition or substitution reactions.

[0040] Preferably, the organic linker includes a first linking functional group and a second linking functional group, wherein the first linking functional group is covalently linked to the hydrogel, and the second linking functional group is covalently linked to a digestive enzyme inhibitor, and the first linking functional group and the second linking functional group may be the same or different.

[0041] Advantageously, because the polysaccharides or polymers cross-linked on general hydrogels have large steric hindrance or low functional group reactivity, their direct reaction with digestive enzyme inhibitors results in a low grafting rate of the reaction product. By introducing organic linkers, the grafting rate of digestive enzyme inhibitors on hydrogels can be more effectively improved, thereby increasing the loading capacity of digestive enzyme inhibitors on the hydrogel.

[0042] In some embodiments, the first and second connecting functional groups are individually selected from one of the following functional groups: -OH, -SH, -COOH, -CN, -NH2, -CHO, -CONH-,

[0043] Advantageously, the aforementioned functional groups are common substitution or addition reaction functional groups, and the organic linker has the aforementioned functional groups, enabling it to react with the functional groups on the hydrogel and digestive enzyme inhibitors for covalent linkage.

[0044] Preferably, the connector is polyethylene glycol, and the two ends of the polyethylene glycol respectively include the first connecting functional group and the second connecting functional group or their protected forms.

[0045] Advantageously, polyethylene glycol is a common linker. When the linker is linear polyethylene glycol, each polyethylene glycol is linked to one digestive enzyme inhibitor molecule. However, when the linker is multi-arm / branched polyethylene glycol, the multi-arm polyethylene glycol has multiple functional groups, which improves the grafting rate of digestive enzyme inhibitors.

[0046] The selected polyethylene glycol includes the first and second linking functional groups mentioned above, or their protected forms.

[0047] In some embodiments, linear polyethylene glycol may be selected with the following structure:

[0048]

[0049] The expression for PEG linker is as follows: For example, in Formula 2 above, PEG with amine groups at both ends can be represented as NH2-PEGn-NH2, where n represents the number of repeating units in the middle. In Formula 5 above, PEG with epoxy groups at both ends can be represented as EPO-PEGn-EPO.

[0050] In some embodiments, when polyethylene glycol is used as a binder, the value of n can be a positive integer from 3 to 12.

[0051] In some embodiments, the linker is an L-amino acid. For example, L-lysine and L-arginine may be selected as L-amino acids.

[0052] Preferably, the digestive enzyme inhibitor is a glucosidase inhibitor.

[0053] Optionally, in this invention, the digestive enzyme inhibitor may also be selected from amylase inhibitors and lipase inhibitors, which are molecules whose activity is not affected after grafting with the hydrogel.

[0054] The glucosidase inhibitor is one or more of the following: acarbose, voglibose, miglitol, ethylgliflozin, canagliflozin, pradimicin Q, salbostatin, and any mixture thereof. Pradimicin Q is a product described in The Journal of Antibiotics, September 29, 1992: PRADIMICIN Q, A NEW PRADIMICIN AGLYCONE, WITHα-GLUCOSIDASE IN HIBITORY ACTIVITY.

[0055] The preparation method of the above-mentioned highly absorbent hydrogel grafted with digestive enzyme inhibitors is one of the following:

[0056] Method 1: The digestive enzyme inhibitor and hydrogel react to form the grafted target product, and the linker is the linking group formed by the direct reaction of the hydrogel and the digestive enzyme inhibitor, as shown in the following formula;

[0057] M+N→MLN

[0058] Wherein, M is a hydrogel, N is a digestive enzyme inhibitor, and L is a linking group formed by the covalent linkage of M and N.

[0059] Method 2: The hydrogel reacts with the connector to form intermediate I for grafting, and intermediate I reacts with digestive enzyme inhibitor to form the target product for grafting, as shown in the following formula;

[0060]

[0061] Where M represents hydrogel, N represents digestive enzyme inhibitor, and L represents connector.

[0062] The preparation method can also be achieved through the following two methods:

[0063] Method 3: The digestive enzyme inhibitor reacts with the linker to form a covalently linked intermediate II, and intermediate II reacts with the hydrogel to form a covalently linked target product;

[0064] Method 4: The digestive enzyme inhibitor, the linker, and the hydrogel are mixed and reacted to form a covalently linked target product.

[0065] In the above preparation method, different digestive enzyme inhibitors can be selected for the grafting reaction. The digestive enzyme inhibitors are added together or sequentially. Taking the method in Method 2 as an example, the reaction formula can be as follows:

[0066]

[0067] In the above method, N1 and N2 represent different digestive enzyme inhibitor molecules.

[0068] A highly absorbent hydrogel composition comprising the above-described highly absorbent hydrogel and pharmaceutically acceptable excipients.

[0069] Furthermore, a lipase inhibitor can also be mixed into the highly absorbent hydrogel composition, wherein the lipase inhibitor is a product that is inconvenient to undergo reactive covalent grafting.

[0070] The lipase inhibitor is one or more of the following: liposatine, tetrahydrolipostigmine (orlistat), FL-386, WAY-121898, BAY-N-3176, valyl lactone, aprotinin, erbinolone A, erbinolone B, RHC 80267, and cetirizine.

[0071] FL-386 is: 1-(trans-4-isobutylcyclohexyl)-2-(benzenesulfonyloxy)ethenone;

[0072] WAY-121898 is: 4-methylpiperidine-1-carboxylic acid 4-phenoxyphenyl ester;

[0073] BAY-N-3176 is: N-[3-chloro-4-(trifluoromethyl)phenyl-]N'-[3-(trifluoromethyl)phenyl]urea;

[0074] RHC 80267 is: 1,6-bis(O-(carbamoyl)cyclohexanone oxime)hexane.

[0075] The pharmaceutically acceptable excipients are selected from fillers, diluents, disintegrants, colorants, lubricants, binders, film-forming agents, wetting agents, emulsifiers, and any mixtures thereof.

[0076] The use of hyperabsorbent hydrogels or hyperabsorbent hydrogel compositions grafted with digestive enzyme inhibitors in the preparation of medicaments for the treatment of obesity, prediabetes, diabetes, non-alcoholic fatty liver disease or chronic idiopathic constipation, or for reducing calorie intake or improving glycemic control.

[0077] A drug for treating obesity, prediabetes, diabetes, non-alcoholic fatty liver disease, or chronic idiopathic constipation, or for reducing calorie intake or improving glycemic control, comprising a hyperabsorbent hydrogel containing the above-mentioned grafted digestive enzyme inhibitor or a hyperabsorbent hydrogel composition thereof.

[0078] Preferably, the drug is in the form of capsules.

[0079] In this invention, in Method 1, the grafting rate of the digestive enzyme inhibitor is calculated as follows:

[0080] (1) Weigh out a hydrogel with a mass of m1, and stir the hydrogel in the reaction solution at room temperature for more than 30 minutes to allow the hydrogel to fully swell.

[0081] (2) Add digestive enzyme inhibitor (feed weight n2) and stir overnight at room temperature;

[0082] (3) Wash with distilled water to remove ungrafted organic binder, then heat and dry thoroughly to obtain a dry gel grafted with digestive enzyme inhibitor, weighing m3. Inhibitor grafting rate = (m3-m1) / m1×100%.

[0083] In this invention, in method two, the grafting rate of the digestive enzyme inhibitor is calculated as follows:

[0084] (1) Weigh out a hydrogel with a mass of m1, and stir the hydrogel in the reaction solution at room temperature for more than 30 minutes to allow the hydrogel to fully swell.

[0085] (2) Continue to add organic linker (feed weight n1), and react for more than 2 hours under heating and stirring to allow the organic linker to graft and modify the hydrogel.

[0086] (3) After the reaction is complete, the hydrogel is thoroughly washed with distilled water to remove the ungrafted organic linker. Then it is heated and dried to obtain the mass of the PEG-grafted dry gel and weigh it m2.

[0087] (4) Stir the dry gel obtained in step (3) and the digestive enzyme inhibitor (feed weight n2, molecular weight M2) at room temperature overnight;

[0088] 5) Wash with distilled water to remove ungrafted digestive enzyme inhibitors, then heat and dry thoroughly to obtain a dry gel grafted with digestive enzyme inhibitors, weighing m3. Therefore: Inhibitor grafting rate = (m3-m2) / m1 × 100%.

[0089] In summary, the "grafting rate" mentioned in this invention is the ratio of the grafted weight of the digestive enzyme inhibitor to the weight of the hydrogel.

[0090] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following detailed description is provided in conjunction with specific embodiments.

[0091] In the embodiments described below, unless otherwise specified, the materials used are:

[0092] The reference hydrogel is a hydrogel material (X-CMC) formed by crosslinking carboxymethyl cellulose with 0.25% by weight of citric acid. The crosslinked hydrogel is ground, pulverized and screened to a particle size of 0.1 mm-1 mm.

[0093] EPO-PEG10-EPO material is polyethylene glycol diglycidyl ether—Sigma Aldrich (average Mn500).

[0094] NH2-PEG10-NH2 has CAS number 928292-69-7 and is a commercially available product.

[0095] I. Preparation of Grafted Products

[0096] Example 1

[0097] The specific steps for preparing a highly absorbent hydrogel grafted with a digestive enzyme inhibitor are as follows:

[0098] 1) Mix X-CMC (200 mg) with 0.3 M AcOH (aq) (10 ml) and stir at room temperature for 30 minutes to allow the hydrogel to swell.

[0099] 2) Add EPO-PEG10-EPO (16mg) and heat to 60℃ and stir for 3 hours.

[0100] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 214.5g.

[0101] 4) Stir the dry gel obtained in step (3), acarbose (10 mg), and 0.3 M AcOH (aq) (10 ml) at room temperature overnight (15 h).

[0102] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 222.9g.

[0103] Therefore, the PEG grafting rate of the acarbose-grafted superabsorbent hydrogel prepared in this embodiment is 7.25% by weight, and the acarbose grafting rate is 4.2% by weight.

[0104] The epoxy groups at both ends of PEG are highly reactive and can react with the carboxyl or hydroxyl groups on the hydrogel under acid catalysis, as well as with the aldehyde or hydroxyl groups on acarbose for grafting. A possible grafting reaction between citric acid-crosslinked carboxymethyl cellulose and PEG / acarbose is as follows: Figure 1 .

[0105] Example 2

[0106] The preparation of the hyperabsorbent hydrogel grafted with digestive enzyme inhibitors differs from that in Example 1 in the following steps:

[0107] 1) Same as Example 1.

[0108] 2) Add EPO-PEG10-EPO (20mg) and heat to 60℃ and stir for 3 hours.

[0109] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 217.6g.

[0110] 4) Stir the dry gel obtained in step (3), acarbose (10 mg) and 0.3 M AcOH (aq) (10 ml) at room temperature overnight (15 h).

[0111] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 227.3g.

[0112] Therefore, the PEG grafting rate of the acarbose-grafted superabsorbent hydrogel prepared in this embodiment is 8.8% by weight, and the acarbose grafting rate is 4.85% by weight.

[0113] Example 3

[0114] The preparation of the hyperabsorbent hydrogel grafted with digestive enzyme inhibitors differs from that in Example 1 in the following steps:

[0115] 1) Same as Example 1.

[0116] 2) Add EPO-PEG10-EPO (30mg) and heat to 60℃ and stir for 3 hours.

[0117] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 224.7g.

[0118] 4) Stir the dry gel obtained in step (3), acarbose (20 mg) and 0.3 M AcOH (aq) (15 ml) at room temperature overnight (15 h).

[0119] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 242.8g.

[0120] Therefore, the PEG grafting rate of the acarbose-grafted superabsorbent hydrogel prepared in this embodiment is 12.35% by weight, and the acarbose grafting rate is 9.05% by weight.

[0121] Example 4

[0122] The preparation of the hyperabsorbent hydrogel grafted with digestive enzyme inhibitors differs from that in Example 1 in the following steps:

[0123] 1) Same as Example 1.

[0124] 2) Add EPO-PEG10-EPO (10mg) and heat to 60℃ and stir for 3 hours.

[0125] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 208.3g.

[0126] 4) Stir the dry gel obtained in step (3), acarbose (10 mg) and 0.3 M AcOH (aq) (10 ml) at room temperature overnight (15 h).

[0127] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 215.2g.

[0128] Therefore, the PEG grafting rate of the acarbose-grafted superabsorbent hydrogel prepared in this embodiment is 4.15% by weight, and the acarbose grafting rate is 3.45% by weight.

[0129] Example 5

[0130] The preparation of the hyperabsorbent hydrogel grafted with digestive enzyme inhibitors differs from that in Example 1 in the following steps:

[0131] 1) Same as Example 1.

[0132] 2) Add EPO-PEG10-EPO (40mg) and heat to 60℃ and stir for 4 hours.

[0133] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 236.1g.

[0134] 4) Stir the dry gel obtained in step (3), acarbose (30 mg), and 0.3 M AcOH (aq) (20 ml) at room temperature for 24 h.

[0135] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 258.4g.

[0136] Therefore, the PEG grafting rate of the acarbose-grafted superabsorbent hydrogel prepared in this embodiment is 18.05% by weight, and the acarbose grafting rate is 11.15% by weight.

[0137] Example 6

[0138] The hydrogel in this embodiment is cross-linked sodium carboxymethyl cellulose (X-CMC) prepared according to patent 202280002509.2. During preparation, sodium carboxymethyl cellulose is prepared by using citric acid-polyethylene glycol (4K)-citric acid as a cross-linking agent.

[0139] The grafted product is prepared as follows:

[0140] 1) Mix X-CMC (200 mg) with 0.3 M AcOH (a q) (10 ml) and stir at room temperature for 30 minutes to allow the hydrogel to swell.

[0141] 2) Add EPO-PEG10-EPO (20mg) and heat to 60℃ and stir for 3 hours.

[0142] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 212.3g.

[0143] 4) Stir the dry gel obtained in step (3), acarbose (10 mg) and 0.3 M AcOH (aq) (10 ml) at room temperature overnight (15 h).

[0144] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a carbose-grafted dry gel, weighing 216.6g.

[0145] Therefore, the PEG grafting rate of the acarbose-grafted high-absorption hydrogel prepared in this embodiment is 6.15% by weight, and the acarbose grafting rate is 2.15% by weight.

[0146] Example 7

[0147] Using the same hydrogel as in Example 1, the grafted product was prepared as follows:

[0148] 1) Stir the dry gel (200 mg), acarbose (10 mg) and 0.3 M AcOH (aq) (10 ml) at room temperature for 24 h.

[0149] 2) After filtering and removing acid, wash the gel multiple times with distilled water to remove ungrafted acarbose. Then dry it at 50°C for 4 hours to obtain a carbose-grafted dry gel, which weighs 203.4g.

[0150] Therefore, the acarbose-grafted high-absorption hydrogel prepared in this embodiment has an acarbose grafting rate of 1.7% by weight.

[0151] Example 8

[0152] The steps that differ from those in Example 1 are:

[0153] 1) Same as Example 1.

[0154] 2) Add EPO-PEG10-EPO (20mg) and heat to 60℃ and stir for 4 hours.

[0155] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 217.3g.

[0156] 4) Stir the dry gel obtained in step (3), voglibose (10 mg), and 0.3 M AcOH (aq) (20 ml) at room temperature for 24 h.

[0157] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 224.8g.

[0158] Therefore, the PEG grafting rate of the voglibose-grafted high-absorption hydrogel prepared in this embodiment is 8.65% by weight, and the voglibose grafting rate is 3.75% by weight.

[0159] Example 9

[0160] The steps that differ from those in Example 1 are:

[0161] 1) Same as Example 1.

[0162] 2) Add EPO-PEG10-EPO (20mg) and heat to 60℃ and stir for 4 hours.

[0163] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 216.8g.

[0164] 4) Stir the dry gel obtained in step (3), miglitol (10 mg), and 0.3 M AcOH (aq) (20 ml) at room temperature for 24 h.

[0165] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 222.6g.

[0166] Therefore, the PEG grafting rate of the miglitol-grafted high-absorption hydrogel prepared in this embodiment is 8.4% by weight, and the miglitol grafting rate is 2.9% by weight.

[0167] Example 10

[0168] The steps that differ from those in Example 1 are:

[0169] 1) Same as Example 1.

[0170] 2) Add EPO-PEG10-EPO (20mg) and heat to 60℃ and stir for 4 hours.

[0171] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, weighing 218.0g.

[0172] 4) Stir the dry gel obtained in step (3), ethylgliflozin (10 mg), and 0.3 M AcOH (aq) (20 ml) at room temperature for 24 h.

[0173] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a carbose-grafted dry gel, weighing 227.2g.

[0174] Therefore, the PEG grafting rate of the ethylglitazone-grafted high-absorption hydrogel prepared in this embodiment is 9% by weight, and the ethylglitazone grafting rate is 4.60% by weight.

[0175] Example 11

[0176] The steps that differ from those in Example 1 are:

[0177] 1) Same as Example 1.

[0178] 2) Add EPO-PEG10-EPO (20mg) and heat to 60℃ and stir for 4 hours.

[0179] 3) Filter to remove acid and wash the hydrogel thoroughly with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, which is 217.2g.

[0180] 4) Stir the dry gel obtained in step (3), acarbose (5 mg), voglibose (5 mg) and 0.3 M AcOH (aq) (20 ml) at room temperature for 24 h.

[0181] 5) Filter to remove acid, wash with distilled water to remove ungrafted acarbose, and then dry at 50°C for 4 hours to obtain a dry gel after acarbose grafting, weighing 226.5g.

[0182] Therefore, the PEG grafting rate of the grafted superabsorbent hydrogel prepared in this embodiment is 8.6% by weight, and the total grafting rate of acarbose and voglibose is 4.65% by weight.

[0183] In Examples 8-11, voglibose, miglibose, ethylgliflozin, etc., have a large number of hydroxyl groups in their structure. Under acidic conditions, the epoxy groups can undergo ring-opening reactions with the hydroxyl groups, thereby playing a covalent grafting role.

[0184] Example 12

[0185] The specific steps are as follows:

[0186] 1) Add 0.3M AcOH (aq) (10ml) to X-CMC (200mg) and stir at room temperature for 30 minutes to allow the hydrogel to swell. Add EDC·HCl and continue stirring for 0.5h. Then add NHS and continue stirring for 2h to activate the carboxyl groups on the hydrogel.

[0187] 2) After the carboxylic acid on the hydrogel in step (1) is activated, NH2-PEG10-NH2 (14mg) is added and heated to 60℃ and stirred for 3 hours.

[0188] 3) Filter to remove acid and wash with distilled water to remove ungrafted PEG. Then dry at 50°C for 4 hours to obtain the mass of PEG-grafted dry gel, weighing 212.6g.

[0189] 4) Stir 0.3M AcOH (aq) (10ml), the dry gel obtained in step (4), and acarbose (10mg) at room temperature overnight (15h). Filter to remove acid and wash with distilled water to remove excess unreacted acarbose. Then add distilled water (10ml) to adjust the pH to 5-6. Slowly add sodium cyanoborohydride and continue stirring for 24h to reduce the existing Schiff base-imine to amine, ensuring the stability of the product. 5) Filter and wash with distilled water several times to remove excess unreacted material. Then dry at 50℃ for 4 hours to obtain the acarbose-grafted dry gel, weighing 219.4g.

[0190] Therefore, the PEG grafting rate of the acarbose-grafted superabsorbent hydrogel prepared in this embodiment is 6.3% by weight, and the acarbose grafting rate is 3.4% by weight.

[0191] like Figure 2The possible reaction is that the amino group on polyethylene glycol first reacts with the carboxyl group on cross-linked carboxymethyl cellulose. The carboxyl group can be the carboxyl group of carboxymethyl cellulose or the carboxyl group of citric acid. Then, the amino group at the other end reacts with the aldehyde group on acarbose to form an imine. After reduction with sodium cyanoborohydride, a stable amino group structure is obtained.

[0192] Example 13

[0193] In this embodiment, L-lysine was selected as the organic linker, and the preparation method is as follows:

[0194] 1) Add 0.3M AcOH (aq) (10ml) to X-CMC (200mg) and stir at room temperature for 30 minutes to allow the hydrogel to swell. Add EDC·HCl and continue stirring for 0.5h. Then add NHS and continue stirring for 2h to activate the carboxyl groups on the hydrogel.

[0195] 2) After the carboxylic acid on the hydrogel in step (1) is activated, L-lysine (10 mg) is added and heated to 60 °C and stirred for 3 hours.

[0196] 3) Filter to remove acid and wash with distilled water to remove ungrafted amino acids. Then dry at 50°C for 4 hours to obtain the mass of amino acid-grafted dry gel, which weighs 208.4g.

[0197] 4) Stir 0.3M AcOH (aq) (10ml), the dry gel obtained in step (4) and acarbose (10mg) at room temperature overnight (15h), filter to remove acid and wash with distilled water to remove excess unreacted acarbose, then add distilled water (10ml) to adjust the pH to 5-6, slowly add sodium cyanoborohydride, and continue stirring for 24h to reduce the existing Schiff base-imine to amine to ensure the stability of the product.

[0198] 5) Filter and wash repeatedly with distilled water to remove excess unreacted material, then dry at 50°C for 4 hours to obtain a carbose-grafted dry gel, weighing 217.8g.

[0199] Therefore, the grafting rate of acarbose was 4.7% by weight.

[0200] like Figure 3 The possible reaction is that the amino group at one end of the lysine first reacts with the carboxyl group on the cross-linked carboxymethyl cellulose, and then the amino group at the other end reacts with the aldehyde group on the acarbose to form an imine, which is then reduced by sodium cyanoborohydride to obtain a stable amino group structure.

[0201] Example 14

[0202] In this embodiment, L-lysine was selected as the organic linker. The preparation process is as follows:

[0203] 1) Add 0.3M AcOH (aq) (10ml) to X-CMC (200mg) and stir at room temperature for 30 minutes to allow the hydrogel to swell. Add EDC·HCl and continue stirring for 0.5h. Then add NHS and continue stirring for 2h to activate the carboxyl groups on the hydrogel.

[0204] 2) After the carboxylic acid on the hydrogel in step (1) is activated, L-lysine (10 mg) is added and heated to 60 °C and stirred for 3 hours.

[0205] 3) Filter to remove acid and wash with distilled water to remove ungrafted amino acids. Then dry at 50°C for 4 hours to obtain the mass of amino acid-grafted dry gel, which weighs 208.7g.

[0206] 4) Stir 0.3M AcOH (aq) (10ml), the dry gel obtained in step (4) and acarbose (10mg) at room temperature overnight (15h), filter to remove acid and wash with distilled water to remove excess unreacted acarbose, then add distilled water (10ml) to adjust the pH to 5-6, slowly add sodium cyanoborohydride, and continue stirring for 24h to reduce any possible Schiff base-imine to amine, ensuring product stability.

[0207] 5) Filter and wash repeatedly with distilled water to remove unreacted material, then dry at 50°C for 4 hours to obtain a carbose-grafted dry gel, weighing 218.3g.

[0208] Therefore, the grafting rate of acarbose was 4.8% by weight.

[0209] In Examples 12-13, acarbose can be grafted onto X-CMC using nitrogen-containing bifunctional PEGs or L-amino acids. The nitrogen group of the bifunctional linker can be amino (NH2), aminooxy (ONH2), hydrazine (NHNH2), etc. Amino groups readily form amide bonds with carboxyl groups on the hydrogel; amide bond formation requires an EDC / NHS activator. However, when the amino group reacts with the aldehyde group on acarbose, a Schiff base-imine structure is easily formed under acid catalysis. Therefore, a reduction step is needed to avoid the presence of unstable imine-Schiff bases in the product and ensure product stability. Mild reducing agents, such as sodium cyanoborohydride, can be used.

[0210] Comparative Example 1

[0211] Carboxymethyl cellulose crosslinked with 0.25% by weight citric acid was used as a blank reference hydrogel.

[0212] Comparative Example 2

[0213] A composition is formed by mixing a reference hydrogel and acarbose in a 10:1 ratio.

[0214] II. Enzyme Inhibition Assay of Grafted Hydrogels

[0215] 2.1 Preparation for Amylase Digestion Test

[0216] 1) Set the water baths for both to 37 and 95°C.

[0217] 2) Dissolve 150 mg of soluble starch in 100 mL of hot distilled water at 95 °C for 10 minutes, then cool to room temperature to prepare a 0.15% soluble starch solution.

[0218] 3) Prepare PBS (pH 5.4) buffer using 0.1M HCl solution and pH 7.4 PBS buffer solution.

[0219] 4) Prepare a 50 μg / ml amylase solution (PBS pH 5.4). (Note: The amylase solution should be used within 3-4 days and stored in the refrigerator.)

[0220] 5) Dissolve 1.4g DNS in 2M NaOH (15mL) and distilled water (60mL) to prepare 75mL of 3,5-dinitrosalicylic acid (DNS) solution.

[0221] 6) Set the wavelength of the UV-Vis spectrometer to 540 nm (for amylase testing).

[0222] 2.2 Starch Digestion Test with Amylase

[0223] 1) The sample in the example (1 mg in 2 mL pH 5.4 PBS) was stirred at 37 °C for 30 minutes to allow the gel to swell, and then an equal volume of porcine α-amylase (50 μg / mL; 2 mL, pH 5.4 PBS) was added.

[0224] 2) Incubate the mixture at 37°C (500 rpm) for 30 minutes with stirring.

[0225] 3) Remove the stirring rod and centrifuge at 3000g for 3 minutes.

[0226] 4) The supernatant was filtered using a 0.45μm pore size filter.

[0227] 5) Incubate 3 ml (out of 4 ml) of the supernatant with soluble starch (1.5 mg / mL; 1.5 mL) at 37 °C with stirring (500 rpm) for 30 minutes.

[0228] 6) Add DNS solution (3 ml) to the mixture and heat at 95°C for 10 minutes.

[0229] 7) Then cool the tube in a water bath at room temperature for 20 minutes. (The extinction coefficient is temperature-dependent; it is important that the sample is at room temperature before any measurements are performed.)

[0230] 8) Place the sample in a quartz cuvette (optical path = 1 cm) and measure it using UV-vis analysis at 540 nm. Record the absorbance. (Note: The absorbance of the sample should be measured within 20 minutes, as the absorbance of the same sample will change over time.)

[0231] 9) Control experiments were conducted using amylase and starch (uninhibited enzyme activity) and buffer and starch (no enzyme activity).

[0232] 10) Data Processing: The UV-Vis absorption at 540 nm indicates that the amount of starch (reducing sugar) digested is related to the amount of amylase present in the supernatant. The percentage of α-amylase activity in the supernatant is expressed as [(sample absorbance - starch control absorbance) / (amylase control absorbance - starch control absorbance) × 100%].

[0233] III. Verification that the acarbose-grafted hydrogel still has a strong water absorption and swelling capacity

[0234] 3.1 Hydrogel water absorption and swelling test

[0235] 1) The water absorption and swelling of solid samples soaked in aqueous medium for 30 minutes were measured. First, a standard simulated gastric juice (SGF) was prepared by mixing 7 mL of 37% hydrochloric acid, 2 g of NaCl, and 3.2 g of pepsin in deionized (DI) water. After the solid dissolved, water was added to bring the volume to 1 L. A diluted SGF (Di-SGF) was prepared by mixing 8 parts DI water with 1 part SGF, and then used to simulate the gastric juice after ingestion of pills / capsules containing dry gel with water.

[0236] 2) The mediator uptake (MUR) of the hydrogel in Di-SGF was determined as follows: A dry glass funnel was placed on a stand, and 40 g of purified water was poured into the funnel. Once no droplets were detected at the neck of the funnel (approximately 5 minutes), the funnel was placed into a dry, empty glass beaker (beaker #1), and the beaker was placed on a balance to record the weight of the empty apparatus (W1). 40 g of Di-SGF solution was prepared as defined above and placed in beaker #2. 0.25 g of dry gel was accurately weighed using weighing paper. The dry gel was added to beaker #2 and gently stirred with a magnetic stirrer for 30 minutes without generating eddies. After a suspension was formed, the stir bar was removed, the funnel was placed on a stand, and the suspension was poured into the funnel and drained for 10 ± 1 minutes. The funnel containing the drained material was placed in beaker #1 and weighed (W2). Media uptake rate (MUR) is calculated using the following formula: MUR = (W2 - W1) / 0.25. The measurement is repeated three times.

[0237] IV. Experimental Results and Discussion. The experimental results are shown in Table 1.

[0238] Table 1. Results of enzyme inhibition test and water absorption swelling test

[0239]

[0240]

[0241] As shown in Table 1, based on the comparative examples of Examples 1-7, in this invention, grafting acarbose and other glucosidase inhibitors onto the hydrogel, within a grafting rate of 10% by weight, does not significantly affect the medium absorption ratio of the hydrogel. That is, the grafted hydrogel still maintains a high swelling ratio in the gastric environment, thus allowing it to expand and occupy a large space after oral administration. Simultaneously, the amylase inhibitor, after grafting onto the hydrogel, retains its inhibitory activity against amylase. Therefore, when acarbose and other inhibitors are grafted onto the hydrogel, both the hydrogel and the digestive enzyme inhibitor can exert their respective effects, thereby contributing to weight loss in the subjects. A comparison of Comparative Example 2 and Examples 1-4 shows that grafting acarbose onto the hydrogel particles can, to a certain extent, enhance its inhibitory activity against amylase.

[0242] In this invention, a hydrogel and a digestive enzyme inhibitor, particularly a glucosidase inhibitor, are grafted together. When the hydrogel is orally ingested into the stomach, it expands and occupies stomach volume, thereby reducing the amount of food ingested by the organism. The glucosidase inhibitor inhibits the action of α-glucosidase in the gastrointestinal tract, preventing starch from being broken down into glucose, thus reducing the digestion and absorption of carbohydrates in the intestine. The glucosidase inhibitor is firmly covalently grafted to the hydrogel through a linker, which effectively reduces the consumption of the glucosidase inhibitor and ensures its retention time in the gastrointestinal tract, thereby improving the utilization rate of the glucosidase inhibitor.

[0243] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element. Additionally, in this document, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number.

[0244] Although the above embodiments have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the above descriptions are merely embodiments of the present invention and do not limit the scope of patent protection of the present invention. Any equivalent structural or procedural transformations made using the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A hydrogel grafted with a digestive enzyme inhibitor, characterized in that, The invention comprises a hydrogel, a linker, and a digestive enzyme inhibitor. The digestive enzyme inhibitor is grafted onto the hydrogel via the linker, and the grafting rate of the digestive enzyme inhibitor onto the hydrogel is less than 10% by weight. The digestive enzyme inhibitor is a glucosidase inhibitor. The hydrogel is a polymer cross-linked by a cross-linking agent, the cross-linking agent including citric acid, the polymer including carboxymethyl cellulose, and the hydrogel being carboxymethyl cellulose cross-linked with citric acid. The linker is polyethylene glycol or an L-amino acid, and the two ends of the polyethylene glycol respectively include a first linker functional group and a second linker functional group or their protected forms.

2. The hydrogel grafted with a digestive enzyme inhibitor as described in claim 1, characterized in that, The amount of the digestive enzyme inhibitor grafted is 1-5 by weight.

3. The hydrogel grafted with a digestive enzyme inhibitor as described in claim 1, characterized in that, The uptake rate of the medium after grafting the hydrogel is at least 70%.

4. The hydrogel grafted with a digestive enzyme inhibitor as described in claim 1, characterized in that, The hydrogel has a particle size of 0.1-3 mm.

5. The hydrogel grafted with a digestive enzyme inhibitor as described in claim 1, characterized in that, The glucosidase inhibitor is one or more of the following: acarbose, voglibose, miglitol, ethylglitazone, canaglibose, pannamisin Q, and sabostatin.

6. The method for preparing a hydrogel grafted with a digestive enzyme inhibitor as described in any one of claims 1-5, characterized in that, One of the following methods: Method 1: The digestive enzyme inhibitor and hydrogel react to form the grafted target product, and the grafting joint is a linking group formed by the direct reaction of hydrogel and digestive enzyme inhibitor; Method 2: The hydrogel reacts with the connector to form grafting intermediate I, and intermediate I reacts with digestive enzyme inhibitor to form the grafting target product.

7. A hydrogel composition, characterized in that, Includes the hydrogel as described in any one of claims 1-5 and pharmaceutically acceptable excipients.

8. The hydrogel composition according to claim 7, characterized in that, It also includes lipase inhibitors.

9. The use of the hydrogel with grafted digestive enzyme inhibitor as described in any one of claims 1-5 or the hydrogel composition as described in any one of claims 7-8 in the preparation of a medicament for treating obesity, diabetes or lowering blood sugar.

10. A drug for treating obesity, diabetes, or lowering blood sugar, characterized in that, Hydrogels comprising the grafted digestive enzyme inhibitors of any one of claims 1-5 or the hydrogel compositions of any one of claims 7-8.

11. The medicament as claimed in claim 10, characterized in that, The drug is in capsule form.

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