CN116407509A - Riagliptin long-acting sustained-release microsphere and preparation method thereof - Google Patents

Abstract

The invention discloses a linagliptin long-acting sustained-release microsphere and a preparation process thereof. The invention adopts the emulsification-solvent evaporation method (O/W) to prepare the linagliptin long-acting sustained-release microspheres, and the method has a simple preparation process and is easy to scale up. The prepared microspheres have good safety, high drug loading and encapsulation efficiency, uniform particle size distribution, smooth surface, sustainable long-term stable release, and no obvious burst release.

Description

Linagliptin long-acting sustained-release microspheres and preparation method thereof

technical field

The invention belongs to the technical field of pharmaceutical preparations, and relates to a linagliptin long-acting sustained-release microsphere and a preparation process thereof.

Background technique

Currently, 1 out of every 11 adults in the world suffers from diabetes, and about 90% of them belong to type Ⅱ diabetes mellitus (T2DM). Type Ⅱ diabetes is also known as non-insulin-dependent diabetes. Its prevalence is high, its onset is hidden, and its early symptoms are not obvious, resulting in a large increase in undiagnosed diabetes cases. Patients are generally aging and treatment costs are high. The occurrence and development of T2DM involves many a pathophysiological mechanism. And with changes in diet structure, environmental pollution, and life pressure, the incidence of T2DM and its complications continues to increase, which has become the main reason for the disability and death of T2DM patients.

According to the data of the International Diabetes Federation (IDF), the number of adult diabetic patients in the world will reach 537 million in 2021. As the country with the largest number of diabetic patients in the world, the number of diabetic patients in my country has increased from 90 million to 1.41 in the past 10 years (2011-2021). billion, an increase of 56%. However, the current global diabetes diagnosis rate is less than 45%, and the treatment rate is less than 50%. With the gradual increase in the diagnosis rate and treatment rate of diabetes, the patient pool will usher in more volume.

At present, the domestic diabetes market is still dominated by insulin and its analogs, followed by traditional oral drugs such as biguanides and α-glucosidase inhibitors. However, new drugs such as DPP-4 inhibitors have not been fully promoted in the Chinese market due to their late entry into the market, accounting for only about 10% of the market share of diabetes drugs, and there is a lot of room for improvement. The linagliptin compound is the main component of the drug named linagliptin tablets; it was first developed by Boehringer Ingelheim in Germany, and it was launched in the United States in June 2011. Approved by the State Food and Drug Administration, it was approved for marketing in China.

Clinically, the medicine synthesized by the compound belongs to a new and effective selective dipeptidyl peptidase-4 (DPP-4) inhibitor, and can be used for treating type 2 diabetes. Linagliptin is a dipeptidyl peptidase inhibitor, which can reduce the inactivation of GLP-1 in vivo by inhibiting DPP-4, increase the level of endogenous GLP-1, promote the rapid release of intestinal insulin in the blood, and finally The purpose is to reduce glucagon in the body to meet the hypoglycemic needs of diabetic patients. Linagliptin has the advantages of no need to adjust the dose according to the patient's liver and kidney function status, stable hypoglycemia and less likely to induce hypoglycemia, less gastrointestinal adverse reactions, and more suitable for the elderly and patients with liver and kidney damage.

At present, most of the dosage forms of linagliptin on the market are tablets, and the marketed drugs need to be used in combination with metformin and sulfonylureas. Linagliptin Tablets (O'Donnell) needs to be taken every day for more than 36 months. The cycle is long, and the phenomenon of missed doses and multiple doses often occurs, which brings great inconvenience to the patients. Therefore, it is of great significance to develop sustained-release microspheres.

Linagliptin, the chemical name is 8-[(3R)-3-amino-1-piperidinyl]-7-(2-butynyl-1)-3,7-dihydro-3-methyl- 1-[(4-Methyl-2-quinazolinyl)methyl]-1H-purine-2,6-dione. Its chemical structural formula is as follows:

Patent CN 110151719 A discloses a preparation process of linagliptin tablets. In the preparation process, the linagliptin, mannitol, starch and pregelatinized starch are uniformly mixed in a wet granulator, and then copovidone solution is added for wet granulation. Then the prepared granules are moved to a fluidized bed for drying, and the moisture in the granules is measured with a halogen fast moisture analyzer, and then the dried granules are moved to a three-dimensional motion mixer and added magnesium stearate for Total blending; Finally, the linagliptin tablet is obtained by a tablet press. However, in clinical use, for some patients, especially children, the elderly or other patients with dysphagia, ordinary tablets greatly reduce the patient's medication compliance. And the dissolution rate of common oral tablet is not high, and bioavailability is low, only about 30%.

Patent CN 105853382 A discloses a preparation of linagliptin orally disintegrating tablets, the method is to prepare linagliptin with erythritol, disintegrant, lubricant and flavoring agent to prepare linagliptin Mouth disintegration. Although the orally disintegrating tablet prepared by the method has good taste, is convenient to take, does not need water, and can be taken anytime and anywhere. However, there are certain difficulties in making linagliptin into orally disintegrating tablets: linagliptin tastes bitter, and ordinary fillers cannot effectively improve its mouthfeel; sugars such as lactose and sucrose taste good, but diabetic patients are not suitable for use, so There are no reports of orally disintegrating tablets of linagliptin.

Patent CN 105878219 B discloses a linagliptin oral film and its preparation process. The oral fast-dissolving film is made of linagliptin, erythritol, hydroxypropylmethylcellulose, hydroxypropylcellulose, plasticizer and flavoring agent. However, it is also because linagliptin has a bitter taste, and ordinary fillers cannot effectively improve its taste; sugars such as lactose and sucrose taste good, but diabetic patients are not suitable for use, so there is no oral instant film of linagliptin at present reports.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention discloses a linagliptin long-acting sustained-release microsphere and a preparation method thereof. The linagliptin long-acting sustained-release microspheres use biodegradable polymer material lactide-glycolide copolymer as the sustained-release carrier to slowly release the drug through the degradation of the carrier material, reduce the frequency of administration, and improve the patient's compliance and medication adherence.

The present inventor has carried out in-depth research on the existing technical situation, and found through a large number of experimental results that the above-mentioned purpose can be achieved by adopting the following technical solutions, thereby completing the present invention. The technical scheme of the present invention is as follows: a linagliptin long-acting sustained-release microsphere, comprising 10%-30% of the weight of the linagliptin sustained-release microsphere, lactide-glycolide The copolymer accounts for 70%-90% of the weight of the linagliptin sustained-release microspheres.

The linagliptin long-acting sustained-release microspheres have high encapsulation efficiency and drug loading capacity, uniform particle size, smooth surface and stable release, and the release period can be as long as about one month.

In the long-acting sustained-release microspheres of linagliptin, the end group of the selected lactide-glycolide copolymer is a -COOH group, and the molar ratio of lactide to glycolide is 90:10-10 :90, preferably, the mol ratio of lactide and glycolide is 75:25～50:50; More preferably, the mol ratio of lactide and glycolide is 75:25, 65:35 or 50 :50. The molecular weight of the lactide-glycolide copolymer is 5000-80000 Daltons, preferably, the molecular weight of the lactide-glycolide copolymer is 10000-50000 Daltons.

The particle size range of the linagliptin long-acting sustained-release microspheres is 20-200 μm, preferably, the particle size range of the linagliptin sustained-release microspheres is 40-150 μm.

The invention provides a preparation method of linagliptin long-acting sustained-release microspheres, the specific steps of the preparation process are as follows:

(1) Dissolving the linagliptin drug and the lactide-glycolide copolymer in an organic solvent to form a clear and transparent solution as an oil phase;

(2) prepare a certain concentration of polyvinyl alcohol (PVA) aqueous solution as the water phase;

(3) The solution obtained in step (1) is mixed with the PVA solution obtained in step (2), and high-speed shear emulsification is made into an O/W emulsion;

(4) Add dipotassium hydrogen phosphate solution to the emulsion prepared in step (3), stir at a low speed, volatilize and remove the organic solvent; collect after solidification, wash, freeze-dry, and obtain.

The organic solvent described in step (1) is selected from dichloromethane (DCM), benzyl alcohol, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), dimethyl One of sulfoxide (DMSO), methanol, or two or more mixed solvents, preferably, dichloromethane (DCM) and dimethyl sulfoxide (DMSO);

The polyvinyl alcohol concentration in step (2) is 0.1% to 2% (w/v), preferably 0.5 to 1% (w/v);

The temperature of the polyvinyl alcohol described in step (2) is 0-30°C, preferably 5-25°C;

The volume ratio of the organic solvent to the polyvinyl alcohol solution in step (3) is 1:50 to 1:300, preferably 1:50 to 1:200;

The concentration of the dipotassium hydrogen phosphate solution in step (4) is 0.02mol/L-0.2mol/L, preferably 0.05mol/L-0.2mol/L.

Compared with prior art, core creation point of the present invention is as follows:

1. The present invention has strong dissolving power, good volatility and less residual amount for dichloromethane, can dissolve linagliptin drug and lactide-glycolide copolymer, and the prepared microspheres have encapsulation efficiency and drug loading capacity Therefore, it is preferable to use dichloromethane as an organic solvent for preparing linagliptin long-acting sustained-release microspheres.

2. The present invention adopts an O/W single emulsification-solvent evaporation method to prepare linagliptin long-acting sustained-release microspheres. The microspheres prepared by the O/W single emulsification-solvent evaporation method have high drug loading and encapsulation efficiency, high yield, reduced drug particle size, avoid drug particle phase aggregation, stable release, can greatly prolong drug action time, reduce The frequency of administration can improve the patient's compliance and medication compliance; the process of the O/W method has the characteristics of common equipment, simple process, short time consumption, low solvent residue, easy to scale up production, etc., and has good industrial application.

3. The microspheres prepared by the emulsification (O/W)-solvent evaporation method of the present invention have a unique core-shell structure, the drug is evenly distributed in the microsphere, and the sudden release of the drug is small, realizing the stable release of the drug.

4. The invention microspherizes the drug, which can not only cover up the bad smell of the drug, but also improve the stability of the drug, prevent the inactivation of the drug in the stomach or reduce the irritation of the drug to the stomach, reduce the number of times of taking the drug and improve the patient's compliance, etc. Advantage.

Description of drawings

Figure 1: Optical microscope image of the linagliptin long-acting sustained-release microspheres prepared in Example 1 before curing;

Figure 2: Optical microscope image of the linagliptin long-acting sustained-release microspheres prepared in Example 1 after solidification;

Figure 3: The finished product figure of the linagliptin long-acting sustained-release microspheres prepared in Example 1 after lyophilization and collection;

Figure 4: Scanning electron micrograph of linagliptin long-acting sustained-release microspheres prepared in Example 1;

Figure 5: High performance liquid chromatogram of linagliptin long-acting sustained-release microspheres prepared in Example 1;

Fig. 6: The release high performance liquid chromatogram of linagliptin long-acting sustained-release microspheres prepared in Example 1;

Figure 7: The in vitro release curve of linagliptin long-acting sustained-release microspheres prepared in Example 3;

Figure 8: The in vitro release curve of linagliptin long-acting sustained-release microspheres prepared in Example 6;

Fig. 9: In vitro release curve of linagliptin long-acting sustained-release microspheres prepared in Example 9.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

The microspheres in the present invention are microspheres in a broad sense, which refer to tiny particles formed by dissolving/dispersing drugs in polymer materials. .

The lactide-glycolide copolymer used is from Evonik Specialty Chemicals Co., Ltd.

The dimethyl sulfoxide, dichloromethane and methanol used come from Tianjin Fuyu Fine Chemical Co., Ltd.;

The PVA used comes from Shanghai Yingjia Industrial Development Co., Ltd.

Embodiment one:

Preparation of long-acting sustained-release microspheres of linagliptin

S1 Weigh 50.9 mg of linagliptin and 150.8 mg of lactide-glycolide copolymer (50:50, molecular weight 18,000), add 0.6 ml of dichloromethane, and dissolve to obtain a clear solution as the oil phase;

S2 Prepare 250ml of 0.5% PVA solution, control the temperature at 20-25°C, and use it as the water phase;

S3 disperses the oil phase into the water phase under the action of high-speed shearing at a speed of 1200rpm and shearing for 10s to form an O/W emulsion;

S4 Slowly add 50ml of 0.2mol/L dipotassium hydrogen phosphate solution to the emulsion, stir and solidify at a low speed for 4 hours, volatilize and remove the organic solvent methylene chloride; after solidification, wash, freeze-dry, and sieve to collect.

Microsphere morphology observation:

10 mg of linagliptin long-acting slow-release microspheres prepared in Example 1 were uniformly dispersed on the conductive adhesive, and after spraying gold at a voltage of 10Kv, the appearance of the microspheres was observed with a scanning electron microscope (SEM, Coxem, Korea). The obtained microspheres are round in shape and smooth in surface, and the observation results are shown in Figure 4.

The preparation method of embodiment 2-embodiment 14 is the same as that of embodiment 1, except that the drug loading, lactide-glycolide copolymer specification and concentration, water phase concentration, curing temperature and the concentration of adding dipotassium hydrogen phosphate, Embodiment 1-Embodiment 8 are specifically shown in Table 1.

Table 1 Embodiment 1-10 Specifications of PLGA

Remarks: In the PLGA model, 5050, 6535, and 7525 indicate that the lactic acid/glycolic acid (LA/GA) in the polymer material is 50:50, 65:35, and 75:25, respectively.

Taking the PLGA specification in Example 3 as an example, Example 11-Example 14 used the method of changing a single factor to explore the influence of other factors on linagliptin long-acting sustained-release microspheres. See Table 2 for details.

The influencing factors of table 2 embodiment 3,11-14

Experimental Example 1 Determination of Linagliptin Long-acting Sustained Release Microspheres Drug Loading Capacity and Encapsulation Efficiency

Need testing solution: take by weighing about 20mg of linagliptin microspheres, put in a 50ml volumetric flask, add 2mlDMSO to dissolve, and ultrasonic for about 5min, after the dissolution is complete, constant volume with 0.01mol/L HCL, shake up, dilute ten times, Shake well, filter (PTFE, 0.22μm, 25mm), discard 3ml, and take the continued filtrate.

Reference substance solution: Weigh about 20 mg of linagliptin, put in a 100ml volumetric flask, add 2ml of methanol to dissolve, dilute to volume with water, shake well, dilute ten times, filter (PTFE, 0.22μm, 25mm), discard 3ml, take Continue filtrate.

Drug loading (%)=(mass of drug contained in microspheres)/(total mass of microspheres)*100%

Encapsulation efficiency (%)=(actual drug loading of microspheres)/(theoretical drug loading of microspheres)*100%

Encapsulation rate formula:

W _free —the amount of free drug, mg;

W _total —the total amount of the drug, mg;

The linagliptin long-acting sustained-release microspheres obtained in Examples 1 to 14 were measured for encapsulation efficiency by high performance liquid chromatography (HPLC).

Columns packed with octadecylsilane bonded silica gel

Liquid phase conditions: mobile phase 50mmol/L potassium dihydrogen phosphate: acetonitrile = 72:28.

The detection wavelength is 294nm, the column temperature is 35°C, and the flow rate is 1ml/min.

Table 3 Example 1-14 drug loading and encapsulation efficiency results:

It can be seen from Table 3 that with the increase of drug loading, the encapsulation efficiency decreased gradually, and with the increase of PLGA molecular weight, the encapsulation efficiency gradually increased. The concentration of PLGA and K ₂ HPO ₄ had great influence on the long-acting sustained-release microspheres of linagliptin.

Experimental example 2 In vitro release experiment of linagliptin long-acting sustained-release microspheres

Experimental samples: linagliptin long-acting sustained-release microspheres prepared in Example 3, Example 6, and Example 9.

Experimental method: Precisely weigh a certain amount of linagliptin long-acting sustained-release microspheres into a 50ml capped centrifuge tube, add 30ml of PBS buffer, put it in a constant temperature shaker at 37°C, and reciprocate at a frequency of 100rpm. Take it out at the specified time point, let it rest or centrifuge, take 5ml of the supernatant and filter it (PTFE, 0.22μm, 25mm), discard 3ml, and take the subsequent filtrate. And add an equal volume of fresh PBS buffer. The reference substance solution is the same as in Experimental Example 1, and the release filtrate concentration is calculated by the external standard method.

Cumulative release, the calculation formula is as follows:

formula:

V ₀ —the volume of release medium used, ml;

C _t — the concentration of the drug contained in the release medium measured at the sampling time point, mg/ml;

V—the volume of each sample, ml;

W—the total weight of the input microspheres, mg;

X—drug loading of microspheres (%).

As can be seen from the release curves of linagliptin long-acting sustained-release microspheres as shown in Fig. 7, Fig. 8 and Fig. 9, the burst release of linagliptin long-acting sustained-release microspheres is not large and tends to accelerate gradually. The release rate of PLGA will be affected by factors such as the specification model, molecular weight, and solvent ratio of PLGA. As we all know, the large molecular weight of the PLGA used leads to slow drug release from the drug-loaded microspheres. Under the same viscosity and the same molecular weight, the specification is 50:50 The PLGA with the specifications of 65:35 and 75:25 will release faster than the PLGA with specifications of 65:35 and 75:25. Combined with multiple factors such as drug loading, encapsulation rate and release, after repeated experimental verifications, the present invention finally determines the optimal prescription as PLGA specification 50:50 31,000, linagliptin long-acting sustained-release microspheres with a drug loading of 25%, the release cycle reaches about 35 days, and the release is safe and stable.

Claims (8)

1. A linagliptin long-acting sustained release microsphere, characterized in that the microsphere comprises linagliptin and a lactide-glycolide copolymer; wherein the content of linagliptin is 10% -30% and the content of the lactide-glycolide copolymer is 70% -90% relative to the total weight of the microsphere composition.

2. The linagliptin sustained-release microsphere according to claim 1, characterized in that the molar ratio of lactide to glycolide in the selected lactide-glycolide copolymer is 90:10-10:90, preferably the molar ratio of lactide to glycolide is 75:25-50:50.

3. The linagliptin sustained release microsphere according to claim 2, wherein the lactide-glycolide copolymer has a molecular weight of 5000-80000 dalton, preferably 10000-50000 dalton.

4. The linagliptin sustained release microsphere according to claim 2, wherein the terminal group of the lactide-glycolide copolymer is-COOH group.

5. The method for preparing the linagliptin sustained-release microspheres according to any one of claims 1 to 4, comprising the following steps:

(1) Dissolving linagliptin drug and lactide-glycolide copolymer in organic solvent to form clear and transparent solution as oil phase;

(2) Preparing a polyvinyl alcohol aqueous solution with a certain concentration as a water phase;

(3) Mixing the solution obtained in the step (1) with the PVA solution obtained in the step (2), and performing high-speed shearing emulsification to prepare O/W emulsion;

(4) Slowly adding a dipotassium hydrogen phosphate solution into the emulsion prepared in the step (3), stirring at a low speed, and volatilizing to remove the organic solvent; and (5) after solidification, collecting, washing and freeze-drying to obtain the product.

6. The method for preparing the linagliptin sustained-release microspheres according to claim 5, wherein the organic solvent in the step (1) is one, two or more mixed solvents selected from dichloromethane, benzyl alcohol, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide and methanol;

the concentration of the polyvinyl alcohol solution in the step (2) is 0.1% -2% (w/v); the temperature of the polyvinyl alcohol is 0-30 ℃; the volume ratio of the organic solvent to the polyvinyl alcohol solution in the step (3) is 1:50-1:300; the concentration of the dipotassium hydrogen phosphate solution in the step (4) is 0.02 mol/L-0.2 mol/L.

7. The method for preparing linagliptin sustained-release microspheres according to claim 5, wherein the particle size of the prepared microspheres is 20-200 μm.

8. Use of the microsphere composition according to any one of claims 1-7 for the preparation of a medicament for the treatment of diabetes.

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