Method for improving bioavailability of isepamicin

Abstract

The invention discloses a pharmaceutical composition for improving oral bioavailability of isepamicin sulfate and a preparation method of the pharmaceutical composition, and belongs to the technical field of pharmaceutical preparations. The pharmaceutical composition oil for improving the oral bioavailability of the isepamicin is prepared from the following raw materials: betulinic acid, polyethylene glycol, the isepamicin and an emulsifier. According to the invention, a synergistic solubilizing system is constructed by combining betulinic acid and polyethylene glycol (PEG) for use, so that the dissolution rate of the medicine and the intestinal absorption efficiency are remarkably improved by adopting the strategy of the synergistic solubilizing system disclosed by the invention. Experiments show that the composition can improve the oral bioavailability of isepamicin to 25%, and the method has the advantages that the bioavailability of the medicine can be greatly improved, the process flow is simple and convenient, the product is excellent in stability, and a solid foundation is laid for further clinical application of the composition.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical preparations, and particularly relates to a method for improving the oral bioavailability of isepamicin by combining a specific oil phase. Background Art

[0002] Isopamicin is an aminoglycoside antibiotic with potent bactericidal activity, low drug resistance, and minimal adverse reactions, making it widely used for a variety of infections. However, clinical applications suffer from poor oral absorption (bioavailability <5%) and low intestinal permeability, which limit its full therapeutic efficacy. Therefore, developing a method to effectively enhance the bioavailability of isopamicin is of great significance.

[0003] Betulinic acid is a natural pentacyclic triterpenoid compound found in a variety of plants, particularly the bark of birch trees. Betulinic acid is a highly valuable natural product with a wide range of biological and pharmacological activities, making it a promising natural product.

[0004] Polyethylene glycol (PEG) is a highly biocompatible, sterically unhindered, amphiphilic polymer. PEG-modified drugs can reduce their clearance or alter their distribution in the body, offering advantages such as improved stability, prolonged duration of action, reduced dosing frequency, and reduced antigenicity. Properties vary depending on molecular weight, with common commercially available PEGs being 400, 600, 800, 1000, 2000, 4000, and 6000.

[0005] Polysorbate (Tween) is a hydrophilic nonionic surfactant with a long carbon chain structure, which effectively solubilizes lipophilic drugs. It can be used as an emulsifier, dispersant, solubilizer, or stabilizer in the preparation of poorly soluble chemical drugs, traditional Chinese medicines, biological agents, and vaccine formulations. Tween is an ester formed by sorbitol and different higher fatty acids. It can be divided into Tween 20, Tween 40, Tween 60, and Tween 80 according to the different fatty acids.

[0006] Solid dispersion refers to a solid dispersion system formed by dispersing drugs in a suitable carrier material in a molecular, colloidal, microcrystalline or amorphous state, which significantly improves the solubility and bioavailability of drugs.

[0007] The present invention combines betulinic acid with polyethylene glycol to form a solid dispersion with isopamicin, thereby improving the oral bioavailability of isopamicin. Summary of the Invention

[0008] To solve the problem of low oral availability of isopamicin in the prior art, the present invention provides a simple method for improving bioavailability, wherein betulinic acid and polyethylene glycol (preferably PEG4000) are combined in a specific ratio, mixed with isopamicin and an emulsifier to form a solid dispersion.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A method for improving the oral bioavailability of isopamicin, characterized by comprising betulinic acid, polyethylene glycol, isopamicin and an emulsifier, wherein the amount of polyethylene glycol added is 20%-80% of the total weight of the composition, the amount of betulinic acid added is 20%-80%, the amount of isopamicin added is 10% of the total weight, and the amount of the emulsifier added is 10%;

[0011] The preparation method is as follows:

[0012] S1: Betulinic acid and PEG were weighed as needed, and the betulinic acid and polyethylene glycol were mixed. The mixture was heated in a water bath and magnetically stirred for 30 minutes to obtain a uniform and stable hot melt.

[0013] S2: Weigh the emulsifier as needed, heat in a water bath, add isopamicin, mix, and stir for 30 minutes to form a drug suspension. Add the drug suspension to the hot melt from step 1, heat in a water bath, and mix under magnetic stirring for 30 minutes.

[0014] S3: After natural cooling, a drug solid dispersion is obtained, which is crushed into powder and passed through a 100-mesh sieve to obtain a drug solid dispersion.

[0015] In the method for improving the oral bioavailability of isopamicin, the emulsifier in step 2 is one or more of Tween 20, Tween 40, Tween 60, Tween 80, gelatin, and gum arabic.

[0016] In the method for improving the oral bioavailability of isopamicin, the molecular weight of the polyethylene glycol in step 1 is 2000-6000, preferably 4000.

[0017] In the method for improving the oral bioavailability of isopamicin, the mass ratio of betulinic acid to polyethylene glycol in step 1 is 0.3 to 3:1, preferably 0.6:1.

[0018] In the method for improving the oral bioavailability of isopamicin, the water bath temperature is 70-100°C, preferably 80°C.

[0019] The method for improving the oral bioavailability of isopamicin has a dosage form of one or more of solid dispersion, tablet, powder and granule.

[0020] Technical effect: The present invention can increase the bioavailability to 10%-25%, and the preparation has good stability. DETAILED DESCRIPTION

[0021] The present invention is further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto:

[0022] Example 1:

[0023] The present invention provides a method for improving the oral bioavailability of isepamicin, comprising the following raw materials: betulinic acid (CAS: 472-15-1), a product of Hubei Jianchu Biopharmaceutical Co., Ltd.; PEG 4000; isepamicin; and Tween 80. When the mass ratio of betulinic acid to polyethylene glycol is 3:1, a PEG 4000 polymer is selected. 2 g of polyethylene glycol and 6 g of betulinic acid are mixed by a hot melt method in an 80°C water bath and magnetically stirred for 30 minutes to obtain a uniform and stable hot melt. 1 g of isepamicin and 1 g of Tween 80 are then added to the mixture in an 80°C water bath and stirred for 30 minutes to form a drug suspension. After natural cooling, a drug solid dispersion is obtained, which is pulverized and passed through a 100-mesh sieve. An HPLC method for the detection of isepamicin sulfate in rat plasma samples is established, and the plasma concentration of isepamicin in rats after oral gavage is measured. By comparing the bioavailability parameters of isepamicin API and isepamicin solid dispersion, the preliminary pharmacokinetic behavior of the two in rats was studied and their absolute bioavailability was determined.

[0024] Example 2:

[0025] The present invention provides a method for improving the oral bioavailability of isopamicin. When the mass ratio of betulinic acid to polyethylene glycol is 5:3, the method comprises the following ingredients: 5g betulinic acid; 3g PEG 4000; 1g isopamicin; and 1g Tween 80. The preparation method is as described above. The absolute bioavailability is determined.

[0026] Example 3:

[0027] The present invention provides a method for improving the oral bioavailability of isopamicin. When the mass ratio of betulinic acid to polyethylene glycol is 1:1, the method comprises the following ingredients: 4g betulinic acid; 4g PEG 4000; 1g isopamicin; and 1g Tween 80. The preparation method is as described above. The absolute bioavailability is determined.

[0028] Example 4:

[0029] The present invention provides a method for improving the oral bioavailability of isopamicin. When the mass ratio of betulinic acid to polyethylene glycol is 3:5, the method comprises the following ingredients: 3g betulinic acid; 5g PEG 4000; 1g isopamicin; and 1g Tween 80. The preparation method is as described above. The absolute bioavailability is determined.

[0030] Example 5:

[0031] The present invention provides a method for improving the oral bioavailability of isopamicin. When the mass ratio of betulinic acid to polyethylene glycol is 1:3, the method comprises the following ingredients: 2g betulinic acid; 6g PEG 4000; 1g isopamicin; and 1g Tween 80. The preparation method is as described above. The absolute bioavailability is determined.

[0032] Comparative Example 1:

[0033] Without betulinic acid solubilization, and with only 8g of PEG 4000, 1g of isopamicin was added to 1g of Tween 80 and 8g of polyethylene glycol in a 60°C water bath. The mixture was magnetically stirred for 30 minutes to obtain a homogeneous system. After natural cooling, a solid drug dispersion was obtained, which was pulverized and passed through a 100-mesh sieve. The absolute bioavailability was determined.

[0034] Comparative Example 2:

[0035] When PEG 4000 is omitted and only 8g of betulinic acid is present, 1g of isopamicin is added to 1g of Tween 80 and 8g of betulinic acid in a 60°C water bath. The mixture is magnetically stirred for 30 minutes to obtain a homogeneous system. After natural cooling, a solid dispersion of the drug is obtained, which is then pulverized and passed through a 100-mesh sieve. The absolute bioavailability is determined.

[0036] Bioavailability testing

[0037] An HPLC method for the detection of isepamicin in rat plasma samples was established to determine the plasma concentration of isepamicin in rats after oral gavage at a dose of 10 mg / kg. The bioavailability parameters of the comparative example and the example were compared to study the preliminary pharmacokinetic behavior of the two in rats and determine their bioavailability.

[0038] 35 Sprague-Dawley rats (SD rats) weighing (250±20) g were selected for bioavailability study. After purchase, the SD rats were adaptively fed in the animal room for 1 week, with free access to food and water. They were fasted for 12 hours before the experiment, but were not allowed to drink water. The SD rats used for the study were randomly divided into seven groups (example group and comparative example group), and were gavaged with the example suspension and the comparative example suspension respectively. At 0.25, 0.5, 0.75, 1, 2, 4, 6, 8, 10, and 12 hours after gavage, blood samples were collected by orbital venous sinus puncture in anticoagulant centrifuge tubes, and the upper plasma was obtained by centrifugation at 4°C and 3500r / min for 10 minutes, and stored in a -40°C refrigerator for later use.

[0039] Prior to analysis, frozen samples were thawed in a 37°C water bath. Plasma samples were pretreated by accurately aspirating 20 μL of serum sample and extracting it with 100 μL of anhydrous ethanol. The extraction system was shaken on a vortex mixer for 1 minute and then centrifuged (10,000 × g, 10 minutes). Finally, 10 μL of the supernatant was injected into the HPLC system for calculation of absolute bioavailability.

[0040] The experimental components are shown in Table 1.

[0041] Table 1 Experimental components

[0042]

[0043] Table 2 Efficacy data

[0044] AUC (μg·h / mL) Absolute bioavailability Example 1 21.2±3.8 19.0％ Example 2 22.7±3.9 20.2％ Example 3 18.3±4.1 18.5％ Example 4 26.5±5.2 25.1％ Example 5 16.1±3.5 15.6％ Comparative Example 1 5.4±2.1 5.2％ Comparative Example 2 4.5±3.2 3.9％

[0045] The results showed that the absolute bioavailability of Example 4 (betulic acid 30% and PEG 4000 50%) was as high as 25%, which was significantly better than the comparative example.

[0046] The absolute bioavailability of the regimens using polyethylene glycol alone or betulinic acid alone was less than 6%, which proved that the synergistic use of the two had the best effect.

[0047] The above only lists the preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any changes made by those skilled in the art within the scope of the claims of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for improving the oral bioavailability of isopamicin, characterized in that: The composition comprises betulinic acid, polyethylene glycol, isopamicin and an emulsifier, wherein the amount of polyethylene glycol added is 20%-80% of the total weight of the composition, the amount of betulinic acid added is 20%-80%, the amount of isopamicin added is 10% of the total weight, and the amount of the emulsifier added is 10%; Its preparation method is: S1: Betulinic acid and PEG were weighed as needed, mixed, heated in a water bath, and magnetically stirred for 30 min to obtain a uniform and stable hot melt; S2: Weigh the emulsifier as needed, heat in a water bath, add isopamicin, mix, and stir for 30 minutes to form a drug suspension. Add the drug suspension to the hot melt from step 1, heat in a water bath, and mix under magnetic stirring for 30 minutes. S3: After natural cooling, a drug solid dispersion is obtained, which is crushed into powder and passed through a 100-mesh sieve to obtain a drug solid dispersion.

2. The method according to claim 1, characterized in that The emulsifier is one or more of Tween 20, Tween 40, Tween 60, Tween 80, gelatin and gum arabic.

3. The method according to claim 1, wherein: The molecular weight of the polyethylene glycol is 2000-6000, preferably 4000.

4. The method according to claim 1, wherein: The mass ratio of betulinic acid to polyethylene glycol is 0.3 to 3:1, preferably 0.6:

1.

5. The method according to claim 1, wherein the water bath temperature is 70-100°C, preferably 80°C.

6. The method according to claim 1, wherein the dosage form is one or more of solid dispersion, tablet, powder, and granule.

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