Diclofenac prodrug and its use

Abstract

The present disclosure discloses a diclofenac prodrug represented by formula (I), and formula (I) TIFF2025518477000057.tif43170, and each substituent is given the definition described in the specification and claims. The present disclosure also discloses a method for alleviating arthritis. The method includes administering the aforementioned diclofenac prodrug to a subject in need thereof.

Description

Technical Field

[0001] The present disclosure relates to diclofenac prodrugs and their use for relieving arthritis.

Background Art

[0002] Diclofenac is one of the most commonly prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) used for the treatment of inflammation and pain induced by inflammation, and is available in various dosage forms suitable for parenteral administration, oral administration, topical administration, etc. The most common side effects of diclofenac affect the digestive system, including abdominal pain, constipation, nausea, ulcers, bleeding, etc.

[0003] When diclofenac is administered systemically at a high dose (e.g., 150 mg / day) for a long term, it may have an adverse effect on the cardiovascular system. Therefore, patients diagnosed with congestive heart failure (i.e., NYHA class II-IV), ischemic heart disease, peripheral arterial disease, or cerebrovascular disease should not use diclofenac to reduce the risk of thromboembolism, and patients with cardiovascular risk factors including hypertension, hyperlipidemia, diabetes, and smokers should use diclofenac only after careful medical evaluation. Since the risk of cardiovascular diseases may increase with an increase in the dosage and duration of use of diclofenac, it is recommended to administer the minimum effective dose for the minimum period.

[0004] In addition, when diclofenac is administered parenterally (i.e., by injection), its effect cannot be effectively exerted because its metabolism is fast. Therefore, diclofenac is mainly administered orally. However, oral administration of diclofenac affects the digestive system. In view of the above, since the therapeutic benefit of diclofenac still outweighs its risk, those skilled in the art need to develop a diclofenac prodrug that can be administered by injection and has a sustained-release effect. “Electrical Parameters of Precision, Coaxial, Air-Dielectric Transmission Line,”

Summary of the Invention

Problems to be Solved by the Invention

[0005] Thus, in one aspect, the present disclosure provides a diclofenac prodrug that can alleviate at least one of the drawbacks of the prior art.

Means for Solving the Problems

[0006] The diclofenac prodrug is represented by formula (I). Formula (I)

Chemical Formula

Chemical Formula

Chemical Formula

[0007] In a second aspect, the present disclosure provides a method for alleviating arthritis that can mitigate at least one of the drawbacks of the prior art.

[0008] The method includes administering the diclofenac prodrug to a subject in need thereof.

Brief Description of the Drawings

[0009] Other features and advantages of the present disclosure will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0010] Before explaining the present disclosure in more detail, if prior art documents are referred to herein, such reference does not admit that the document forms part of the common general knowledge in the art.

[0011] For the purposes of this specification, the term "comprising" means "including but not limited to", and it is clearly understood that the term "comprises" has the corresponding meaning.

[0012] Unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this disclosure belongs. One of ordinary skill in the art will recognize many methods and materials similar or equivalent to those described herein that can be used in the practice of this disclosure. Indeed, this disclosure is in no way limited to the methods and materials described.

[0013] This disclosure provides a diclofenac prodrug represented by formula (I). Formula (I)

Chemical formula

Chemical formula

Chemical formula

[0014] According to this disclosure, R 1 and R 2In this case, examples of the linear alkyl group include linear alkyl groups having 1 to 8 carbon atoms, examples of the branched alkyl group include branched alkyl groups having 1 to 8 carbon atoms, and examples of the heterocyclic group include nitrogen heterocycles. Examples of the nitrogen heterocycle include saturated 5-membered nitrogen heterocycles and saturated 6-membered nitrogen heterocycles.

[0015] According to the present disclosure, R 3 In this case, examples of the substituent of the substituted phenyl group include alkyl groups, examples of the substituent of the substituted cycloalkyl group include alkyl groups, and examples of the heterocyclic group include nitrogen heterocycles and oxygen heterocycles. Examples of the nitrogen heterocycle include saturated 5-membered nitrogen heterocycles and saturated 6-membered nitrogen heterocycles, but are not limited thereto. Examples of the oxygen heterocycle include saturated 6-membered nitrogen heterocycles.

[0016] According to the present disclosure, R 3 In this case, examples of the heterocyclic group in the alkyl group having a heterocyclic group include oxygen heterocycles. Examples of the alkyl group having a heterocyclic group include

Chemical formula

[0017] According to the present disclosure, R 31 In this case, examples of the alkylene group include, but are not limited to, methylene, ethylidine, and propylidine.

[0018] According to the present disclosure, R 32 In this case, examples of the alkyl group include methyl and ethyl.

[0019] According to the present disclosure, the diclofenac prodrug of the present disclosure is synthesized according to the following synthetic route (A).

Chemical formula

[0020] As shown in synthetic route (A), diclofenac (i.e., the parent drug) is reacted with an alkaline reagent such as N,N - diisopropylethylamine, and then a substitution reaction is carried out in the presence of a solvent such as dimethylformamide.

[0021] In certain embodiments, the diclofenac prodrug of the present disclosure is synthesized according to the following synthetic route (B). [Chemical formula]

[0022] As shown in synthetic route (B), diclofenac is reacted with an alkaline reagent such as N,N - diisopropylethylamine, and then reacted with RI2 in the presence of a solvent such as dimethylformamide, where R is CH2.

[0023] According to the present disclosure, the carbonate ester of the diclofenac prodrug of the present disclosure is synthesized according to the following synthetic route (C). [Chemical formula]

[0024] As shown in synthetic route (C), chloromethyl chloroformate is reacted with an alcohol represented by HO - R 3 in the presence of a solvent such as dichloromethane and / or pyridine to obtain an intermediate product, and then the intermediate product and diclofenac are subjected to a substitution reaction at 50 °C in the presence of an alkaline solution and sodium iodide. The alkaline solution contains an alkaline reagent (e.g., N,N - diisopropylethylamine) and a solvent (e.g., acetone).

[0025] In certain embodiments, the ester urethane of the diclofenac prodrug of the present disclosure is synthesized according to the following synthetic route (D). [Chemistry]

[0026] As shown in the synthetic route (D), chloromethyl chloroformate is reacted with a nitrogen-containing heterocyclic amine in the presence of a solvent such as dichloromethane and / or pyridine to obtain an intermediate product, and then the intermediate product and diclofenac are subjected to a substitution reaction at 50 °C in the presence of an alkaline solution and sodium iodide. The alkaline solution contains an alkaline reagent (e.g., N,N-diisopropylethylamine) and a solvent (e.g., acetone).

[0027] In certain embodiments, R 0 represents hydrogen, X represents R 1 and R 1 is selected from the group consisting of straight-chain C1-C8 alkyl groups and branched-chain C1-C8 alkyl groups.

[0028] In certain embodiments, R 0 represents hydrogen, X is [Chemistry] and represents R 2 is a straight-chain alkyl group, a substituted heterocyclic group, an unsubstituted heterocyclic group, and [Chemistry] is selected from the group consisting of.

[0029] In certain embodiments, R 0 represents hydrogen, X is [Chemistry] and represents R 2 is -CH2CH2CH3, [Chemistry] is selected from the group consisting of.

[0030] In certain embodiments, R 0 represents hydrogen, and X represents

Chemical formula

Chemical formula

[0031] In certain embodiments,

Chemical formula

Chemical formula

Chemical formula

[0032] In certain embodiments,

Chemical formula

Chemical formula

Chemical formula

[0033] The present disclosure also provides a method for alleviating arthritis, the method comprising administering the diclofenac prodrug to a subject in need thereof.

[0034] As used herein, the term "alleviating" or "alleviate" refers to at least partially reducing, improving, alleviating, controlling, treating or eliminating one or more clinical signs of a disease or disorder, as well as reducing, delaying, halting or reversing the progression of the severity of the condition or symptoms being treated, and preventing or reducing the likelihood or probability thereof.

[0035] As used herein, the term "administering" or "administer" means introducing, providing or delivering a predetermined active ingredient to a subject by any suitable route for the purpose of fulfilling its intended function.

[0036] As used herein, the term "subject" refers to any subject animal such as a human, monkey, cow, sheep, horse, pig, goat, dog, cat, mouse, rat, etc.

[0037] Examples of arthritis include, but are not limited to, osteoarthritis, rheumatoid arthritis, gouty arthritis, psoriatic arthritis, infectious arthritis.

[0038] According to the present disclosure, the diclofenac prodrug can be formulated into a dosage form suitable for parenteral administration using techniques well known to those skilled in the art.

[0039] According to the present disclosure, for parenteral administration, the diclofenac prodrug according to the present disclosure can be formulated into an injection such as a sterile aqueous solution, dispersion or emulsion.

[0040] The diclofenac prodrug according to the present disclosure can be administered via any of the following parenteral routes: intraperitoneal injection, intrapleural injection, intramuscular injection, intravenous injection, intraarterial injection, intraarticular injection, intrasynovial injection, intrathecal injection, intracranial injection, intradermal injection, subcutaneous injection, intracutaneous injection, and intralesional injection.

[0041] In an exemplary embodiment, the diclofenac prodrug is formulated into a dosage form for intraarticular administration.

[0042] According to the present invention, the diclofenac prodrug formed by a chemical bond exists in the form of solid crystals and is formed using a combination of different crystallization solvents. The therapeutic effect of the diclofenac prodrug of the present disclosure may be different from that of the parent drug, i.e., diclofenac, when administered by intraarticular injection. The diclofenac prodrug of the present disclosure cannot achieve the desirable effect of long-term quantitative release like the parent drug when it exists in an amorphous form.

[0043] According to the present disclosure, the diclofenac prodrug has an average particle diameter (d50) in the range of 3 μm to 30 μm in order to avoid irritation to synovial tissue and meniscus when administered by intraarticular injection. In a particular embodiment, the diclofenac prodrug has an average particle diameter (d50) in the range of 8 μm to 13 μm.

[0044] According to the present disclosure, when the diclofenac prodrug exists in a transparent, viscous liquid form, it can be mixed with an excipient to form a diclofenac prodrug solution. Examples of excipients include, but are not limited to, Tween 20, Tween 80, polyethylene glycol, hyaluronic acid, etc. The diclofenac solution can be applied to the inside of the contact lens. When it comes into contact with the eye fluid of a subject with a pH of 7.4, the diclofenac prodrug is released in a dissolved and hydrolyzed form, exhibits an anti-inflammatory effect, and can prevent eye discomfort after wearing the contact lens for a long time. Note that poorly soluble diclofenac (i.e., the parent drug) can only be applied to the inside of the contact lens at a relatively low concentration, and a sustained-release or controlled-release effect cannot be obtained.

[0045] The dosage and frequency of administration of the diclofenac prodrug can vary depending on the following factors: the severity of the disease or disorder to be treated, the route of administration, and the age, physical condition, and response of the subject to be treated. Generally, the diclofenac prodrug may be administered as a single dose or divided into multiple doses.

[0046] The present disclosure will be described by the following examples. However, it should be understood that the following examples are for illustrative purposes only and should not be construed as actually limiting the present disclosure. Examples Preparation of Diclofenac Prodrug Example 1 (EX1)

[0047] The procedure for preparing the diclofenac prodrug of EX1 includes the following steps A to D.

[0048] In Step A, first, 0.586 g (1.98 mmol) of diclofenac was placed in a round-bottom flask, and then the diclofenac was dissolved in 4 mL of acetonitrile to obtain a solution. Then, 376 μL (2.2 mmol) of N,N-diisopropylethylamine was added to the solution at room temperature, followed by the dropwise addition of 0.268 g (0.995 mmol) of diiodomethane, and the mixture was stirred overnight for 16 hours to allow the reaction to proceed.

[0049] In Step B, 1.05 g of diiodomethane was added dropwise, and the reaction was continued at room temperature for 48 hours to obtain a mixture. During the reaction, high performance liquid chromatography (HPLC) was continuously performed to analyze the contents in the mixture.

[0050] In Step C, water was added to dilute the mixture, and then dichloromethane was added for extraction twice to form an organic layer. The collected organic layer was washed once with brine and then dried using anhydrous sodium sulfate to obtain a dehydrated organic layer.

[0051] In Step D, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. Then, the crude product was subjected to preparative reverse-phase HPLC to measure its purity. The reverse-phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS-3 (C18) column (size: 30 × 250 mm, 10 μm), stepwise gradient elution from 75% acetonitrile / water to 100% acetonitrile, UV detection at a wavelength of 275 nm. The collected peak-containing fractions were lyophilized to obtain a white solid diclofenac prodrug of EX1 with a weight of 94 mg, a purity of 98%, and a yield of 16%.

[0052] The chemical formula of the diclofenac prodrug of EX1

Chemical formula

[0053] The diclofenac prodrug of EX1 was determined to have the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 3.82 (s, 4H), 5.86 (s, 2H), 6.56 (d, J = 8.0 Hz, 2H), 6.65 (s, 2H), 6.93 - 7.01 (m, 4H), 7.10 - 7.15 (m, 2H), 7.18 - 7.22 (m, 2H), 7.33 (d, J = 7.5 Hz, 2H); 13 13C NMR (CDCl3, 125 MHz) δ 38.12, 80.07, 118.61, 122.68, 123.60, 124.08, 128.85, 129.41, 130.97, 137.76, 142.66, 170.93. Example 2 (EX2)

[0054] The procedure for preparing the diclofenac prodrug of EX2 includes the following steps A to E.

[0055] In step A, first, 258 mg (176 μL, 2 mmol) of diclofenac, 244 mg (2 mmol) of 2 - ethylphenol, and 4 mL of dichloromethane were mixed to form a mixture, and the mixture was cooled to 0 °C. Next, 210 μL (2.6 mmol) of pyridine was added dropwise to the cooled mixture, and after stirring at 0 °C for 2 hours, it was stirred overnight at room temperature. Then, water and dichloromethane were added for extraction, and the obtained organic layer was collected. The organic layer was washed with sodium hydrogen carbonate and brine, dried over anhydrous sodium sulfate, and then subjected to filtration and concentration to obtain 0.36 g of chloromethyl (2 - ethylphenyl) carbonate as a brown oil. When chloromethyl (2 - ethylphenyl) carbonate was subjected to NMR spectroscopic analysis, its 1 1H NMR (CDCl3, 500 MHz) spectrum has the following characteristics: 11H NMR (CDCl3, 500 MHz) δ 1.21 - 1.26 (m, 3H), 2.59 - 2.64 (m, 2H), 5.93 (s, 2H), 7.16 - 7.37 (m, 4H).

[0056] In Step B, 0.32 g (1.08 mmol) of diclofenac was placed in a round-bottom flask, and the round-bottom flask was placed in an ice bath having a temperature in the range of 0 °C to 3 °C. Next, 4 mL of N,N-dimethylacetamide was added to dissolve diclofenac, and then 369 mg (2.16 mmol) of N,N-diisopropylethylamine was added dropwise, followed by addition of 0.36 g (1.08 mmol) of chloromethyl (2-ethylphenyl) carbonate to obtain a mixture.

[0057] In Step C, the mixture was stirred and the reaction was continued at room temperature for 72 hours. During the reaction, HPLC was continuously performed to analyze the contents in the mixture.

[0058] In Step D, water was added to dilute the mixture, and then dichloromethane was added for extraction twice to form an organic layer. The collected organic layer was washed once with brine and then dried over anhydrous sodium sulfate to obtain a dehydrated organic layer.

[0059] In Step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. Thereafter, the crude product was subjected to preparative LC to measure its purity. Reverse-phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS-3 (C18) column (size: 30×250 mm, 10 μm), isocratic elution using 85% acetonitrile, UV detection at a wavelength of 220 nm. The collected peak-containing fractions were lyophilized to obtain a diclofenac prodrug of EX2 as a yellow powder with a weight of 134 mg, a purity of 98.2%, and a yield of 26%.

[0060] The chemical formula of the diclofenac prodrug of EX2

Chemical formula

[0061] The diclofenac prodrug of EX2 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 1.18 (t, J = 7.5 Hz, 3H), 2.57 (q, J = 7.5 Hz, 2H), 3.93 (s, 2H), 5.93 (s, 2H), 6.58 - 6.60 (m, 2H), 6.67 (s, 1H), 6.98 - 7.02 (m, 2H), 7.09 - 7.27 (m, 5H), 7.35 (d, J = 8.0 Hz, 2H); 13 C NMR (CDCl3, 125 MHz) δ 14.15, 22.89, 38.12, 82.73, 118.69, 121.44, 122.36, 123.53, 124.15, 126.77, 127.00, 128.36, 128.87, 129.45, 129.63, 130.98, 135.58, 137.75, 142.70, 148.82, 152.53, 170.73. Example 3 (EX3)

[0062] The procedure for preparing the diclofenac prodrug of EX3 includes the following steps A to E.

[0063] In Step A, first, 265 mg (3 mmol) of chloromethyl chloroformate, 477 mg (3.05 mmol) of menthol, and 4 mL of dichloromethane were mixed to form a first mixture, and the first mixture was cooled to 0 °C. Next, 291 μL (3.05 mmol) of pyridine was added dropwise to the cooled first mixture, and after stirring at 0 °C for 2 hours, it was stirred overnight at room temperature. Then, water and dichloromethane were added for extraction, and the obtained organic layer was collected. After washing the organic layer with sodium hydrogen carbonate and brine, it was dried over anhydrous magnesium sulfate, and then subjected to filtration and concentration to obtain 0.678 g of brown oil of chloromethyl ((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl, M-Cl) carbonate. When chloromethyl ((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl, M-Cl) carbonate was subjected to NMR spectroscopic analysis, its 1 1H NMR (CDCl3, 500 MHz) spectrum had the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 0.79 (d, J = 7.0 Hz, 3H), 0.86 - 0.93 (m, 8H), 1.03 - 1.12 (m, 2H), 1.58 - 1.60 (m, 1H), 1.68 - 1.71 (m, 2H), 1.88 - 1.96 (m, 1H), 2.10 - 2.14 (m, 1H), 4.57 - 4.61 (m, 1H), 5.71 - 5.75 (m, 2H).

[0064] In Step B, 0.681 g (2.3 mmol) of diclofenac was placed in a round-bottom flask, 8 mL of acetone was added at room temperature to dissolve diclofenac, then 418 μL (2.4 mmol) of N,N-diisopropylethylamine was added dropwise, and 3.5 mL of a solution containing 0.678 g (2.72 mmol) of chloromethyl ((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl) carbonate and acetone, as well as 100 mg of sodium iodide were added to obtain a second mixture.

[0065] In step C, the second mixture was stirred and the reaction was continued at room temperature for 16 hours, and the formed reaction product was heated and stirred at a temperature in the range of 50 °C to 53 °C for 8 hours. During the reaction, HPLC was continuously performed to analyze the content in the reaction product.

[0066] In step D, water was added to dilute the mixture, and then dichloromethane was added for extraction twice to form an organic layer. The collected organic layer was washed once with brine and then dried using anhydrous sodium sulfate to obtain a dehydrated organic layer.

[0067] In step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. The crude product was subjected to fast silica gel chromatography to measure its purity. The gel chromatography was performed under the following conditions: silica gel (manufactured by Merck) with a size of 40 to 63 μm and 60 Å, and elution using hexane and ethyl acetate with a volume ratio of 1:10. The collected elution fractions were lyophilized to obtain a diclofenac prodrug of EX3 with a weight of 1.06 g, a purity of 98.9%, and a yield of 90.7%.

[0068] The chemical formula of the diclofenac prodrug of EX3

Chemical formula

[0069] The diclofenac prodrug of EX3 was determined to have the following characteristics: 11H NMR (CDCl3, 500 MHz) δ 0.79 (d, J = 7.0 Hz, 3H), 0.82 - 0.94 (m, 7H), 1.01 - 1.11 (m, 2H), 1.38 - 1.57 (m, 2H), 1.67 - 1.69 (m, 2H), 1.90 - 1.97 (m, 1H), 2.08 - 2.11 (m, 1H), 3.88 (s, 2H), 4.53 - 4.57 (m, 1H), 5.79 - 5.83 (m, 2H), 6.56 (d, J = 7.5 Hz, 1H), 6.69 (s, 1H), 6.97 - 7.01 (m, 2H), 7.15 - 7.23 (m, 1H), 7.24 - 7.26 (m, 1H), 7.34 (d, J = 8.0 Hz, 2H). Example 4 (EX4)

[0070] The procedure for preparing the diclofenac prodrug of EX4 includes the following steps A to E.

[0071] In step A, a first solution containing 265 μL (3 mmol) of chloromethyl chloroformate and 4 mL of dichloromethane was cooled to 0 °C, and then 477 mg (3.05 mmol) of 1-methylpiperazine was added dropwise to form a first mixture. After stirring the first mixture at 0 °C for 2 hours, it was stirred overnight at room temperature and then concentrated to obtain 0.678 g by weight of powdered solid chloromethyl 4-methylpiperazine-1-carboxylate. When chloromethyl 4-methylpiperazine-1-carboxylate was subjected to NMR spectroscopic analysis, its 1 1H NMR (CDCl3, 500 MHz) spectrum has the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 2.94 (s, 2H), 3.11 - 3.64 (m, 6H), 4.21 - 4.38 (m, 2H), 5.86 (s, 2H).

[0072] In step B, 430 mg (1.45 mmol) of diclofenac was placed in a round-bottom flask, 5 mL of acetone was added at room temperature to dissolve the diclofenac, and then 333 mg (1.45 mmol) of chloromethyl 4-methylpiperazine-1-carboxylate dissolved in 2 mL of acetone and 50 mg (0.33 mmol) of sodium iodide were added to obtain a second mixture.

[0073] In step C, the second mixture was heated and stirred at 53 °C for 16 hours and then concentrated under reduced pressure to obtain a concentrated product.

[0074] In step D, 30 mL of water was added to dilute the concentrated product, and then dichloromethane was added and extracted twice (20 mL each time) to form an organic layer. The collected organic layer was washed with 20 mL of brine, dried over anhydrous magnesium sulfate, and then filtered to obtain a dehydrated organic layer.

[0075] In step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. The crude product was diluted with 4.0 mL of an acetonitrile / water solvent and then subjected to preparative reverse-phase HPLC to measure its purity. The reverse-phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS-3 (C18) column (size: 30 × 250 mm, 10 μm), flow rate 32.5 mL / min, stepwise gradient elution from 43% acetonitrile / water to 90% acetonitrile / water (water containing 0.1% trifluoroacetic acid), UV detection at a wavelength of 245 nm. The collected peak-containing fractions were lyophilized to obtain a white solid diclofenac prodrug of EX4 with a weight of 296 mg, a purity of 98%, and a yield of 45.2%.

[0076] The chemical formula of the diclofenac prodrug of EX4

Chemical formula

[0077] The diclofenac prodrug of EX4 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 2.61 - 2.74 (m, 2H), 2.75 (s, 3H), 3.25 - 3.61 (m, 4H), 3.06 (s, 2H), 3.90 - 4.31 (m, 2H), 5.82 (br, s, 2H), 6.52 - 6.59 (m, H), 6.65 (br, s, 1H), 6.95 - 7.04 (m, 2H), 7.13 - 7.16 (m, 1H), 7.22 - 7.29 (m, 1H), 7.35 (d, J = 8.5 Hz, 2H); 13 C NMR (CDCl3, 125 MHz) δ 38.23, 41.15, 53.03, 80.99, 118.29, 122.16, 123.44, 124.47, 128.38, 128.96, 129.55, 131.05, 142.73, 152.66, 171.16. Example 5 (EX5)

[0078] The procedure for preparing the diclofenac prodrug of EX5 includes the following steps A to E.

[0079] In step A, a first solution containing 176 μL (2 mmol) of chloromethyl chloroformate and 2 mL of dichloromethane was cooled to 0 °C, and then mixed with a second solution containing 174 mg (2 mmol) of morphine, 210 μL of pyridine, and 2 mL of dichloromethane to form a first mixture. After stirring the first mixture at 0 °C for 2 hours, it was stirred overnight at room temperature, and then concentrated to obtain chloromethylmorpholine-4-carboxylate as an intermediate oily product with a weight of 272 mg and a yield of 70%. Chloromethylmorpholine-4-carboxylate may be further lyophilized to obtain an amorphous product. When chloromethylmorpholine-4-carboxylate was subjected to NMR spectroscopic analysis, its 1 1H NMR (CDCl3, 500 MHz) spectrum has the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 3.52 (br s, 4H), 3.64 - 3.74 (m, 4H), 5.80 (s, 2H).

[0080] In Step B, 418 mg (1.41 mmol) of diclofenac dissolved in 4 mL of acetone was mixed with 260 μL (1.5 mmol) of N,N - diisopropylethylamine, and then 272 mg (1.45 mmol) of chloromethyl morpholine - 4 - carboxylate dissolved in 2 mL of acetone and 100 mg (0.67 mmol) of sodium iodide were added little by little to form a second mixture.

[0081] In Step C, the second mixture was heated and stirred at 53 °C for 16 hours, and then concentrated under reduced pressure to obtain a concentrated product.

[0082] In Step D, 30 mL of water was added to dilute the concentrated product, then dichloromethane was added and extracted twice (20 mL each time) to form an organic layer. The collected organic layer was washed with 20 mL of brine, dried over anhydrous magnesium sulfate, and then filtered to obtain a dehydrated organic layer.

[0083] In Step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. The crude product was diluted with 4.0 mL of acetonitrile / water solvent and then subjected to preparative reverse - phase HPLC to measure its purity. The preparative reverse - phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS - 3 column (size: 30×250 mm, 10 μm), flow rate 32.5 mL / min, step - gradient elution from 60% acetonitrile / water to 74% acetonitrile / water (water containing 0.1% trifluoroacetic acid), UV detection at a wavelength of 254 nm. The collected peak - containing fractions were lyophilized to obtain a crystalline solid of the diclofenac prodrug of EX5 with a weight of 124 mg, a purity of 95%, and a yield of 34.5%.

[0084] The chemical formula of the diclofenac prodrug of EX5

Chemical formula

[0085] The diclofenac prodrug of EX5 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 3.41 - 3.65 (m, 8H), 3.87 (br s, 2H), 5.83 (br s, 2H), 6.56 (d, J = 8.0 Hz, 1H), 6.71 (bs, 1H), 6.95 - 7.12 (m, 2H), 7.14 - 7.16 (m, 2H), 7.23 - 7.25 (m, 1H), 7.34 (d, J = 8.0 Hz, 2H); 13 C NMR (CDCl3, 125 MHz) δ 38.30, 43.96, 44.40, 66.29, 66.48, 80.76, (C, -OCH2O-), 118.47, 122.21, 123.69, 124.13, 128.23, 128.87, 129.47, 130.98, 137.74, 142.69, 153.36 (C, -OCOO-), 171.27 (C, -OCOCH2-). Example 6 (EX6)

[0086] The procedure for preparing the diclofenac prodrug of EX6 includes the following steps A to E.

[0087] In step A, a first solution containing 180 μL (2.05 mmol) of chloromethyl chloroformate and 2 mL of dichloromethane was cooled to 0 °C, and then mixed with a second solution containing 274 mg (2 mmol) of (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanol, 210 μL of pyridine, and 3 mL of dichloromethane to form a first mixture. After stirring the first mixture at 0 °C for 2 hours, it was stirred overnight at room temperature, then water and dichloromethane were added for extraction to form an organic layer. Subsequently, the formed organic layer was washed with brine, dried over anhydrous magnesium sulfate, and filtered to obtain a dehydrated organic layer. Then, the dehydrated organic layer was concentrated to obtain chloromethyl ((2,2-dimethyl-1,3-dioxolan-4-yl)methyl) carbonate as an intermediate oily product with a weight of 363 mg and a yield of 81%. When chloromethyl ((2,2-dimethyl-1,3-dioxolan-4-yl)methyl) carbonate was subjected to NMR spectroscopic analysis, its 1 1H NMR (CDCl3, 500 MHz) spectrum had the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 1.36 (s, 3H), 1.44 (s, 3H), 3.78 - 3.81 (m, 1H), 4.09 - 4.11 (m, 1H), 4.21 - 4.29 (m, 2H), 4.34 - 4.36 (m, 1H), 5.72 - 5.75 (m, 2H).

[0088] In step B, 280 μL (1.63 mmol) of N,N-diisopropylethylamine was added to a third solution containing 478 mg (1.61 mmol) of diclofenac dissolved in 4 mL of acetone, followed by adding 363 mg (1.45 mmol) of chloromethyl ((2,2-dimethyl-1,3-dioxolan-4-yl)methyl) carbonate dissolved in 2 mL of acetone, and 100 mg (0.67 mmol) of sodium iodide to obtain a second mixture.

[0089] In step C, after heating and stirring the second mixture at 53 °C for 24 hours, it was concentrated under reduced pressure to obtain a concentrated product.

[0090] In step D, after adding 30 mL of water to dilute the concentrated product, dichloromethane was added and extraction was performed twice (20 mL each time) to form an organic layer. The collected organic layer was washed with 20 mL of brine, dried over anhydrous magnesium sulfate, and then filtered to obtain a dehydrated organic layer.

[0091] In step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. After diluting the crude product with 4.0 mL of an acetonitrile / water solvent, it was subjected to preparative reverse-phase HPLC to measure its purity. The preparative reverse-phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS-3 column (size: 30×250 mm, 10 μm), flow rate 32.5 mL / min, stepwise gradient elution from 60% acetonitrile / water to 74% acetonitrile / water (water containing 0.1% trifluoroacetic acid), UV detection at a wavelength of 275 nm. The collected peak-containing fractions were lyophilized to obtain a colorless oil diclofenac prodrug of EX6 with a weight of 417 mg, a purity of 95%, and a yield of 53.5%. Additionally, the colorless oil may be further recrystallized using ethyl acetate and n-hexane in a volume ratio ranging from 1:6 to 1:10 to obtain a crystalline product.

[0092] The chemical formula of the diclofenac prodrug of EX6

Chemical formula

[0093] The diclofenac prodrug of EX6 was determined to have the following characteristics: 11H NMR (CDCl3, 500 MHz) δ 1.35 (s, 3H), 1.42 (s, 3H), 3.77 - 3.79 (m, 1H), 3.88 (s, 2H), 4.05 - 4.07 (m, 1H), 4.20 (br s, 2H), 4.32 - 4.34 (m, 1H), 5.81 (s, 2H), 6.56 (d, J = 8.0 Hz, 1H), 6.62 (br s, 1H), 6.95 - 6.99 (m, 2H), 7.12 - 7.15 (m, 1H), 7.12 - 7.15 (m, 1H), 7.2 - 7.25 (m, 1H), 7.34 (d, J = 8.5 Hz, 2H); 13 13C NMR (CDCl3, 125 MHz) δ 25.29, 26.64, 38.09, 66.15, 68.42, 73.02, 82.44, 110.11, 118.65, 122.30, 123.55, 124.11, 128.31, 129.44, 130.98, 137.75, 142.68, 153.72, 170.69。 Example 7 (EX7)

[0094] The procedure for preparing the diclofenac prodrug of EX7 involves the following steps A to C.

[0095] In step A, 0.8 mL (10.7 mmol) of trifluoroacetic acid was added dropwise at 25 °C to a solution containing ((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)carbonyloxy)methyl 2-(2-((2,6-dichlorophenyl)amino)phenyl)acetate as described in Example 6, 15 mL of methanol, and 3 mL of deionized water to form a mixture.

[0096] In step B, the mixture was stirred and the reaction was continued at room temperature for 16 hours. After confirming the completion of the reaction by reverse-phase HPLC, the mixture was evaporated to obtain a dry product.

[0097] In Step C, the dried product was diluted with 4.0 mL of an acetonitrile / water solvent and subjected to preparative reverse-phase HPLC to measure its purity. The preparative reverse-phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS-3 column (size: 30×250 mm, 10 μm), flow rate 32.5 mL / min, stepwise gradient elution from 43% acetonitrile / water to 70% acetonitrile / water (water containing 0.1% trifluoroacetic acid), UV detection at a wavelength of 254 nm. The collected peak-containing fractions were lyophilized to obtain a colorless oil diclofenac prodrug of EX7 with a weight of 198 mg, a purity of 96%, and a yield of 58.9%. Additionally, the colorless oil may be further recrystallized using ethyl acetate and n-hexane in a volume ratio ranging from 1:5 to 1:8 to obtain a crystalline product.

[0098] The chemical formula of the diclofenac prodrug of EX7 [Chemical formula] (((2,3-Dihydroxypropoxy)carbonyl)oxy)methyl 2-(2-((2,6-dichlorophenyl)amino)phenyl)acetate having the following was subjected to NMR spectroscopic analysis using the procedure described in EX1.

[0099] The diclofenac prodrug of EX7 was determined to have the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 3.33 (br s, 3H), 3.54 - 3.56 (m, 1H), 3.66 (br s, 3H), 3.86 (s, 2H), 3.92 (br s, 1H), 4.16 - 4.23 (m, 2H), 4.16 - 4.23 (m, 2H), 5.78 (s, 2H), 6.54 (d, J = 7.5 Hz, 1H), 6.58 (br s, 1H), 6.94 - 6.97 (m, 2H), 7.10 - 7.13 (m, 1H), 7.20 - 7.22 (m, 1H), 7.32 (d, J = 8.5 Hz, 2H); 1313C NMR (CDCl3, 125 MHz) δ 38.02, 63.03, 69.24, 69.71, 82.56, 118.55, 122.29, 123.46, 124.24, 128.35, 128.89, 129.48, 131.03, 137.69, 142.65, 153.90, 170.97. Example 8 (EX8)

[0100] The procedure for preparing the diclofenac prodrug of EX8 involves the following steps A to E.

[0101] In step A, a first solution containing 771 μL (8.5 mmol) of chloromethyl chloroformate and 10 mL of dichloromethane was cooled to 0 °C and mixed with a second solution containing 1.52 (8 mmol) of 3-((tert-butyldimethylsilyl)oxy)propanol, 683 μL of pyridine, and 4 mL of dichloromethane to form a first mixture. After stirring the first mixture at 0 °C for 2 hours, it was stirred overnight at room temperature, then 20 mL of water and 20 mL of dichloromethane were added for the first extraction. The resulting aqueous layer and organic layer were collected separately, and 20 mL of dichloromethane was added to the aqueous layer. Then, a second extraction was performed on the aqueous layer with added dichloromethane, and the resulting organic layer was collected. The organic layers collected in the first extraction and the second extraction were combined, washed with 20 mL of brine, dried over anhydrous sodium sulfate, and then filtered to obtain a dehydrated organic layer. Thereafter, the dehydrated organic layer was evaporated and concentrated under reduced pressure to obtain 3-((tert-butyldimethylsilyl)oxy)propan-1-ol as an intermediate oily product with a weight of 2.17 g and a yield of 96%. When 3-((tert-butyldimethylsilyl)oxy)propan-1-ol was subjected to NMR spectroscopic analysis, its 1 1H NMR (CDCl3, 500 MHz) spectrum has the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 0.5 (s, 6H), 0.89 (s, 9H), 1.88 - 1.92 (m, 2H), 3.72 (t, J = 6.0 Hz, 2H), 4.34 (t, J = 6.5 Hz, 2H), 5.73 (s, 2H).

[0102] In step B, 2.16 g (7.3 mmol) of diclofenac dissolved in 20 mL of acetone was mixed with 1.31 mL (7.3 mmol) of N,N - diisopropylethylamine under a nitrogen atmosphere, and then 2.16 g (7.69 mmol) of 3 - ((tert - butyldimethylsilyl)oxy)propan - 1 - ol dissolved in 40 mL of acetone and 100 mg (0.67 mmol) of sodium iodide were added to form a second mixture.

[0103] In step C, the second mixture was stirred at 65 °C for 26 hours and then concentrated by evaporation to remove the solvent therein, obtaining a concentrated product. Thereafter, the concentrated product was mixed with 30 mL of isopropyl ether, stirred for 30 minutes, filtered, and concentrated to obtain an oily crude product.

[0104] In step D, the oily crude product was subjected to flash chromatography using hexane and ethyl acetate with a volume ratio of 10:1 to measure its purity. The collected elution fractions were lyophilized to obtain 9,9,10,10 - tetramethyl - 3 - oxo - 2,4,8 - trioxa - 9 - siladecyl 2 - (2 - ((2,6 - dichlorophenyl)amino)phenyl)acetate with a weight of 1.62 g and a yield of 41%.

[0105] 9,9,10,10 - tetramethyl - 3 - oxo - 2,4,8 - trioxa - 9 - siladecyl 2 - (2 - ((2,6 - dichlorophenyl)amino)phenyl)acetate was subjected to NMR spectroscopic analysis using the procedure described in EX1 and had the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 0.01 (s, 6H), 0.89 (s, 9H), 1.86 - 1.90 (m, 2H), 3.69 (t, J = 6.0 Hz, 2H), 3.88 (s, 2H), 4.29 (t, J = 6.5, 2H), 5.81 (s, 2H), 6.57 (d, J = 8.0 Hz, 1H), 6.64 (bs, 1H), 6.96 - 6.99 (m, 2H), 7.12 - 7.15 (m, 2H), 7.12 - 7.15 (m, 1H), 7.23 (bs, 1H), 7.34 (d, J = 8.0 Hz, 2H);13 13C NMR (CDCl3, 125 MHz) δ 25.64, 31.53, 38.13, 58.91, 65.85, 82.30, (C, -OCH2O-), 118.64, 122.28, 123.63, 124.07, 128.27, 128.84, 129.44, 130.96, 137.78, 142.68, 153.86 (C, -OCOO-), 170.78 (C, -OCOCH2-).

[0106] In step E, 1 mL of trifluoroacetic acid was added to a solution containing 1.62 g (2.99 mmol) of 9,9,10,10 - tetramethyl - 3 - oxo - 2,4,8 - trioxa - 9 - siladecyl 2-(2 - ((2,6 - dichlorophenyl)amino)phenyl)acetate and 16 mL of acetonitrile at 0 °C to form a mixture. Then, the mixture was warmed to 18 °C and left for 3 hours. The resulting reaction product was directly purified by preparative HPLC under the following conditions: step - gradient elution from 50% acetonitrile / water to 75% acetonitrile / water (water containing 0.1% trifluoroacetic acid). The collected peak - containing fractions were lyophilized to obtain a white crystalline solid of the diclofenac prodrug of EX8 with a weight of 1.16 g, a purity of 99%, and a yield of 91%.

[0107] The chemical formula of the diclofenac prodrug of EX8

Chemical formula

[0108] The diclofenac prodrug of EX8 was determined to have the following characteristics: 11H NMR (CDCl3, 500 MHz) δ 1.70 (s, 2H), 1.89 - 1.93 (m, 2H), 3.72 (t, J = 6.0 Hz, 2H), 3.88 (s, 2H), 4.34 (t, J = 6.5 Hz, 2H), 5.81 (s, 2H), 6.56 (d, J = 8.0 Hz, 1H), 6.56 (d, J = 8.0 Hz, 1H), 6.64 (bs, 1H), 6.96 - 6.99 (m, 2H), 7.12 - 7.15 (m, 2H), 7.12 - 7.15 (m, 2H), 7.23 (bs, 1H), 7.34 (d, J = 8.0 Hz, 2H); 13 13C NMR (CDCl3, 125 MHz) δ 31.41, 38.11, 58.84, 65.77, 82.38, (C, -OCH2O-), 118.63, 122.29, 123.57, 124.13, 128.29, 129.44, 130.98, 137.75, 142.68, 154.05 (C, -OCOO-), 170.78 (C, -OCOCH2-). Example 9 (EX9)

[0109] The procedure for preparing the diclofenac prodrug of EX9 includes the following steps A to E.

[0110] In step A, a first solution containing 185 μL (2 mmol) of chloromethyl chloroformate and 2 mL of dichloromethane was cooled to 0 °C, and then mixed with a second solution containing 318 mg (3 mmol) of diethylene glycol, 210 μL of pyridine, and 3 mL of dichloromethane to form a first mixture. After stirring the first mixture at 0 °C for 2 hours, it was stirred overnight at room temperature, and then 30 mL of water and dichloromethane were added for extraction twice to form an organic layer. Then, the collected organic layer was dried over anhydrous magnesium sulfate and filtered to obtain a dehydrated organic layer. Thereafter, the dehydrated organic layer was concentrated to obtain ((2-(2-hydroxyethoxy)ethoxy)carbonyl)oxymethyl chloride as an intermediate oily product with a weight of 286 mg and a yield of 72%.

[0111] In step B, 426 mg (1.44 mmol) of diclofenac dissolved in 4.5 mL of acetone was mixed with 275 μL (1.44 mmol) of N,N - diisopropylethylamine, and then 286 mg (1.44 mmol) of (((2 - (2 - hydroxyethoxy)ethoxy)carbonyl)oxy)methyl chloride dissolved in 2 mL of acetone and 216 mg (1.44 mmol) of sodium iodide were added little by little to form a second mixture.

[0112] In step C, the second mixture was heated and stirred at 55 °C for 24 hours, and then concentrated under reduced pressure to obtain a concentrated product.

[0113] In step D, 30 mL of water was added to dilute the concentrated product, and then dichloromethane was added for extraction twice (20 mL each time) to form an organic layer. The collected organic layer was washed with 20 mL of brine, dried over anhydrous magnesium sulfate, and then filtered to obtain a dehydrated organic layer.

[0114] In step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. The crude product was diluted with 4.0 mL of acetonitrile / water solvent and then subjected to preparative reverse - phase HPLC to measure its purity. The preparative reverse - phase HPLC was carried out under the following conditions: GL Sciences Inertsil ODS - 3 column (size: 30×250 mm, 10 μm), flow rate 32.5 mL / min, step - gradient elution from 55% acetonitrile / water to 60% acetonitrile / water (water containing 0.1% trifluoroacetic acid), UV detection at a wavelength of 275 nm. The collected peak - containing fractions were lyophilized to obtain a colorless oil of the diclofenac prodrug of EX9 with a weight of 283 mg, a purity of 96%, and a yield of 42.9%.

[0115] The chemical formula of the diclofenac prodrug of EX9

Chemical formula

[0116] The diclofenac prodrug of EX9 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 3.33 (br s, 3H), 3.54 - 3.56 (m, 1H), 3.66 (br s, 3H), 3.86 (s, 2H), 3.92 (br s, 1H), 4.16 - 4.23 (m, 2H), 4.16 - 4.23 (m, 2H), 5.78 (s, 2H), 6.54 (d, J = 7.5 Hz, 1H), 6.58 (br s, 1H), 6.94 - 6.97 (m, 2H), 7.10 - 7.13 (m, 1H), 7.20 - 7.22 (m, 1H), 7.32 (d, J = 8.5 Hz, 2H); 13 C NMR (CDCl3, 125 MHz) δ 38.02, 63.03, 69.24, 69.71, 82.56, 118.55, 122.29, 123.46, 124.24, 128.35, 128.89, 129.48, 131.03, 137.69, 142.65, 153.90, 170.97. Example 10 (EX10)

[0117] The procedure for preparing the diclofenac prodrug of EX10 includes the following steps A to E.

[0118] In step A, a first solution containing 185 μL (2 mmol) of chloromethyl chloroformate and 2 mL of dichloromethane was cooled to 0 °C, and then mixed with a second solution containing 360 mg (3 mmol) of diethylene glycol monomethyl ether, 210 μL of pyridine, and 3 mL of dichloromethane to form a first mixture. Next, the first mixture was stirred at 0 °C for 2 hours, then stirred overnight at room temperature, and subsequently 30 mL of water and 10 mL of dichloromethane were added for extraction twice to form an organic layer. Thereafter, the collected organic layer was dried over anhydrous magnesium sulfate and filtered to obtain a dehydrated organic layer. Then, the dehydrated organic layer was concentrated to obtain an intermediate oily product of (((2-(2-methoxyethoxy)ethoxy)carbonyl)oxy)methyl chloride with a weight of 329 mg and a yield of 77%.

[0119] In step B, 458 mg (1.54 mmol) of diclofenac dissolved in 10 mL of acetone was mixed with 295 μL (1.64 mmol) of N,N-diisopropylethylamine, and then 329 mg (1.54 mmol) of (((2-(2-methoxyethoxy)ethoxy)carbonyl)oxy)methyl chloride dissolved in 2 mL of acetone and 231 mg (1.54 mmol) of sodium iodide were added little by little to form a second mixture.

[0120] In step C, the second mixture was heated and stirred at 65 °C for 24 hours, and then concentrated under reduced pressure to obtain a concentrated product.

[0121] In step D, 30 mL of water was added to dilute the concentrated product, and then dichloromethane was added for extraction twice (20 mL each time) to form an organic layer. The collected organic layer was washed with 20 mL of brine, dried over anhydrous magnesium sulfate, and then filtered to obtain a dehydrated organic layer.

[0122] In step E, the solvent of the dehydrated organic layer was removed under reduced pressure to obtain a crude product. The crude product was diluted with 4.0 mL of an acetonitrile / water solvent and then subjected to preparative reverse-phase HPLC to measure its purity. The preparative reverse-phase HPLC was performed under the following conditions: GL Sciences Inertsil ODS-3 column (size: 30 × 250 mm, 10 μm), flow rate 32.5 mL / min, stepwise gradient elution from 55% acetonitrile / water to 75% acetonitrile / water (water containing 0.1% trifluoroacetic acid), UV detection at a wavelength of 254 nm. The collected peak-containing fractions were lyophilized to obtain a colorless oil diclofenac prodrug of EX10 with a weight of 283 mg, a purity of 98%, and a yield of 52.7%.

[0123] The chemical formula of the diclofenac prodrug of EX10

Chem.

[0124] The diclofenac prodrug of EX10 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 1.70 (s, 2H), 1.89 - 1.93 (m, 2H), 3.72 (t, J = 6.0 Hz, 2H), 3.88 (s, 2H), 4.34 (t, J = 6.5 Hz, 2H), 5.81 (s, 2H), 6.56 (d, J = 8.0 Hz, 1H), 6.64 (bs, 1H), 6.96 - 6.99 (m, 2H), 7.12 - 7.15 (m, 2H), 7.12 - 7.15 (m, 1H), 7.23 (bs, 1H), 7.34 (d, J = 8.0 Hz, 2H); 1313C NMR (CDCl3, 125 MHz) δ 31.41, 38.11, 58.84, 65.77, 82.38, (C, -OCH2O-), 118.63, 122.29, 123.57, 124.13, 128.29, 129.44, 130.98, 137.75, 142.68, 154.05 (C, -OCOO-), 170.78 (C, -OCOCH2-). Example 11 (EX11)

[0125] The procedure for preparing the diclofenac prodrug of EX11 includes the following steps A to D.

[0126] In step A, a first solution containing 360 μL (4 mmol) of chloromethyl chloroformate and 3 mL of acetonitrile was cooled to 0 °C, and then a second solution containing 0.4 mL (4 mmol) of piperidine, 0.73 mL of N,N-diisopropylethylamine, and 6 mL of acetonitrile was added dropwise to the cooled first solution over 15 minutes. After stirring at 0 °C for 2 hours and then stirring overnight at room temperature, a first mixture was obtained.

[0127] In step B, a third solution containing 1.13 g (3.81 mmol) of diclofenac and 10 mL of acetonitrile was stirred and mixed with 0.73 mL (4 mmol) of N,N-diisopropylethylamine to dissolve diclofenac and form a second mixture. Next, the second mixture was added to the first mixture, followed by the addition of 627 mg (4.18 mmol) of sodium iodide to form a third mixture.

[0128] In step C, the third mixture was heated and stirred at 70 °C for 3.5 hours, cooled to room temperature, and then extracted by mixing 40 mL of ethyl acetate and 40 mL of water to form an organic layer. The collected organic layer was washed twice with 20 mL of water and then concentrated under reduced pressure to obtain a concentrated product weighing 1.72 g.

[0129] In step D, the concentrated product was purified by silica gel chromatography using a stationary phase containing silica gel (Merck, size 40 μm to 63 μm, 60 Å) and a mobile phase containing n - hexane and ethyl acetate in a volume ratio ranging from 1:2 to 1:5, thereby obtaining a diclofenac prodrug of EX11 in the form of an oily product weighing 1.02 g and having a yield of 61%.

[0130] The chemical formula of the diclofenac prodrug of EX11 [Chemical formula] (2 - (2 - ((2,6 - dichlorophenyl)amino)phenyl)acetoxymethylpiperidine - 1 - carboxylate having [the chemical formula] was subjected to NMR spectroscopic analysis using the procedure described in EX1.

[0131] The diclofenac prodrug of EX11 was determined to have the following characteristics: 1 H NMR(CDCl3, 500 MHz) δ 1.66(s, 2H), 1.83 - 1.86(m, 4H), 3.30(t, J = 7.0, 2H), 3.40(t, J = 7.0, 2H), 3.87(s, 2H), 5.82(s, 2H), 6.55(d, J = 8.0 Hz, 1H), 6.75(bs, 1H), 6.96 - 6.99(m, 2H), 7.14 - 7.16(m, 2H), 7.23 - 7.25(m, 1H), 7.33(d, J = 8.5 Hz, 2H); 13 C NMR(CDCl3, 125 MHz) δ 24.82, 25.58, 38.36, 45.93, 46.31, 80.64, (C, - OCH2O - ), 118.45, 122.14, 123.87, 124.03, 128.12, 128.83, 129.47, 130.99, 137.81, 142.73, 152.89(C, - OCOO - ), 171.33(C, - OCOCH2 - ). Example 12 (EX12)

[0132] The procedure for preparing the diclofenac prodrug of EX12 includes the following steps A to D.

[0133] In step A, a first solution containing 360 μL (4 mmol) of chloromethyl chloroformate and 3 mL of acetonitrile was cooled to 0 °C, and then a second solution containing 350 mg (4 mmol) of pyrrolidine, 210 μL of N,N - diisopropylethylamine, and 3 mL of acetonitrile was added dropwise to the cooled first solution over 12 minutes. After stirring at 0 °C for 2 hours and then at room temperature overnight, a first mixture was obtained.

[0134] In step B, a third solution containing 1.13 g (3.81 mmol) of diclofenac and 10 mL of acetonitrile was stirred and mixed with 0.66 mL (3.81 mmol) of N,N - diisopropylethylamine to dissolve diclofenac and form a second mixture. Next, the second mixture was added to the first mixture, and subsequently 627 mg (4.18 mmol) of sodium iodide was added to form a third mixture.

[0135] In step C, the third mixture was heated and stirred at a temperature in the range of 65 °C to 70 °C for 4 hours, cooled to room temperature, and then extracted by mixing 30 mL of ethyl acetate and 30 mL of water to form an organic layer. The collected organic layer was washed three times with 30 mL of water and then concentrated under reduced pressure to obtain a concentrated product weighing 1.58 g.

[0136] In step D, the concentrated product was recrystallized using ethyl acetate and n - hexane with a volume ratio of 1:1.5, thereby obtaining a diclofenac prodrug of EX12 as a white solid powder weighing 1.11 g with a yield of 69%.

[0137] The (2 - (2 - ((2,6 - dichlorophenyl)amino)phenyl)acetoxy)methylpyrrolidine - 1 - carboxylate having the chemical formula

Chemical formula

[0138] The diclofenac prodrug of EX12 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 1.43 (s, 2H), 1.44 - 1.60 (br s, 4H), 3.36 - 3.43 (m, 2H), 3.86 (s, 2H), 5.82 (s, 2H), 6.55 (d, J = 8.0 Hz, 1H), 6.75 (bs, 1H), 6.95 - 7.11 (m, 2H), 7.14 - 7.16 (m, 2H), 7.23 - 7.25 (m, 1H), 7.33 (d, J = 8.0 Hz, 2H); 13 C NMR (CDCl3, 125 MHz) δ 25.37, 38.34, 46.03, 80.79, (C, -OCH2O-), 118.44, 122.15, 123.84, 124.04, 128.13, 128.83, 129.49, 130.98, 137.80, 142.72, 153.35 (C, -OCOO-), 171.37 (C, -OCOCH2-). Example 13 (EX13)

[0139] The procedure for preparing the diclofenac prodrug of EX13 includes the following steps A to D.

[0140] In step A, a first solution containing 360 μL (4 mmol) of chloromethyl chloroformate and 3 mL of acetonitrile was cooled to 0 °C, and then a second solution containing 0.46 mL (4 mmol) of 3 - methylmorpholine, 0.86 mL of N,N - diisopropylethylamine, and 3 mL of acetonitrile was added dropwise to the cooled first solution over 15 minutes. After stirring at 0 °C for 2 hours and then stirring overnight at room temperature, a first mixture was obtained.

[0141] In step B, a third solution containing 1.13 g (3.81 mmol) of diclofenac and 10 mL of acetonitrile was stirred and mixed with 0.73 mL (4 mmol) of N,N - diisopropylethylamine to dissolve diclofenac and form a second mixture. Next, the second mixture was added to the first mixture, and subsequently 627 mg (4.18 mmol) of sodium iodide was added to form a third mixture.

[0142] In Step C, the third mixture was heated and stirred at a temperature of 70 °C for 4 hours. After cooling to room temperature, 30 mL of ethyl acetate and 30 mL of water were mixed for extraction to form an organic layer. The collected organic layer was washed three times with 30 mL of water and then concentrated under reduced pressure to obtain a concentrated product weighing 1.87 g.

[0143] In Step D, the concentrated product was purified by silica gel chromatography using a stationary phase containing silica gel (manufactured by Merck) with a size of 40 μm to 63 μm and 60 Å, and a mobile phase containing ethyl acetate and n - hexane with a volume ratio in the range of 1:1 to 1:5. Thereby, a diclofenac prodrug of EX13 in the form of an oily product weighing 1.18 g with a yield of 68% was obtained.

[0144] The diclofenac prodrug of EX13, the chemical formula [Chemical formula] 2-(2-((2,6-dichlorophenyl)amino)phenyl)acetoxy)methyl 2-methylmorpholine-4-carboxylate having the formula was subjected to NMR spectroscopic analysis using the procedure described in EX1.

[0145] The diclofenac prodrug of EX13 was determined to have the following characteristics: 1 H NMR (CDCl3, 500 MHz) δ 1.12 - 1.17 (m, 3H), 3.41 - 3.60 (m, 2H), 3.40 - 3.59 (m, 2H), 3.87 (s, 2H), 3.78 - 3.98 (m, 3H), 6.55 (d, J = 8.0 Hz, 1H), 6.75 (bs, 1H), 6.96 - 6.99 (m, 2H), 7.13 - 7.16 (m, 2H), 7.24 - 7.26 (m, 1H), 7.34 (d, J = 8.5 Hz, 2H); 1313C NMR (CDCl3, 125 MHz) δ 17.51, 38.31, 48.78, 49.03, 49.37, 71.56, 80.73 (C, -OCH2O-), 118.44, 122.19, 123.69, 124.13, 128.22, 128.86, 129.47, 130.94, 137.74, 142.69, 153.09 (C, -OCOO-), 171.28 (C, -OCOCH2-). Example 14 (EX14)

[0146] The procedure for preparing the diclofenac prodrug of EX14 includes the following steps A to D.

[0147] In step A, a first solution containing 360 μL (4 mmol) of chloromethyl chloroformate and 3 mL of acetonitrile was cooled to 0 °C, and then a second solution containing 0.46 mL (4 mmol) of 2,6-dimethylmorpholine, 0.86 mL of N,N-diisopropylethylamine, and 3 mL of acetonitrile was added dropwise to the cooled first solution over 15 minutes. After stirring at 0 °C for 2 hours and then at room temperature overnight, a first mixture was obtained.

[0148] In step B, a third solution containing 1.13 g (3.81 mmol) of diclofenac and 10 mL of acetonitrile was mixed with 0.73 mL (4 mmol) of N,N-diisopropylethylamine with stirring to dissolve diclofenac and form a second mixture. Next, the second mixture was added to the first mixture, followed by the addition of 627 mg (4.18 mmol) of sodium iodide to form a third mixture.

[0149] In step C, the third mixture was heated and stirred at a temperature of 70 °C for 4 hours, cooled to room temperature, and then extracted by mixing with 30 mL of ethyl acetate and 30 mL of water to form an organic layer. The collected organic layer was washed three times with 30 mL of water and then concentrated under reduced pressure to obtain a concentrated product weighing 1.89 g.

[0150] In step D, the concentrated product was purified by silica gel chromatography using a stationary phase containing silica gel (Merck, size 40 μm to 63 μm, 60 Å) and a mobile phase containing ethyl acetate and n - hexane in a volume ratio ranging from 1:1 to 1:5, thereby obtaining a diclofenac prodrug of EX14 in the form of an oily product weighing 1.21 g with a yield of 68%.

[0151] The chemical formula of the diclofenac prodrug of EX14 [Chemical formula] (2 - (2 - ((2,6 - dichlorophenyl)amino)phenyl)acetoxy)methyl - 2,6 - dimethylmorpholine - 4 - carboxylate having the formula was subjected to NMR spectroscopic analysis using the procedure described in EX1.

[0152] The diclofenac prodrug of EX14 was determined to have the following characteristics: 1 H NMR(CDCl3, 500 MHz) δ 1.12(d, J = 6.0 Hz, 3H), 1.18(d, J = 6 Hz, 3H), 2.48 - 2.53(m, 2H), 3.41 - 3.56(m, 2H), 3.81(d, J = 13 Hz, 1H), 3.87(s, 2H), 3.87(d, J = 13 Hz, 1H), 5.84(s, 2H), 6.56(d, J = 8.0 Hz, 1H), 6.75(bs, 1H), 6.96 - 7.02(m, 2H), 7.11 - 7.15(m, 2H), 7.24 - 7.27(m, 1H), 7.35(d, J = 8.5 Hz, 2H); 13 C NMR(CDCl3, 125 MHz) δ 18.62, 38.33, 49.01, 49.36, 71.46, 71.59, 80.71(C, -OCH2O-), 118.43, 122.19, 123.66, 124.16, 128.25, 128.88(2C), 129.46, 130.99, 137.71, 142.69, (C, -OCOO-), 153.14, 171.36(C, -OCOCH2 -). Example 15 (EX15)

[0153] The procedure for preparing the diclofenac prodrug of EX15 includes the following steps A to D.

[0154] In step A, a first solution containing 360 μL (4 mmol) of 1-chloroethyl chloroformate and 3 mL of acetonitrile was cooled to 0 °C, and then a second solution containing 0.38 mL (4 mmol) of morpholine, 0.86 mL of N,N-diisopropylethylamine, and 3 mL of acetonitrile was added dropwise to the cooled first solution over 15 minutes. After stirring at 0 °C for 2 hours and then stirring overnight at room temperature, a first mixture was obtained.

[0155] In step B, a third solution containing 1.13 g (3.81 mmol) of diclofenac and 10 mL of acetonitrile was stirred and mixed with 0.73 mL (4 mmol) of N,N-diisopropylethylamine to dissolve the diclofenac and form a second mixture. Next, the second mixture was added to the first mixture, and subsequently 625 mg (4.18 mmol) of sodium iodide was added to form a third mixture.

[0156] In step C, the third mixture was heated and stirred at a temperature of 70 °C for 4 hours, cooled to room temperature, and then extracted by mixing with 30 mL of ethyl acetate and 30 mL of water to form an organic layer. The collected organic layer was washed three times with 30 mL of water and then concentrated under reduced pressure to obtain a concentrated product weighing 1.89 g.

[0157] In step D, the concentrated product was purified by silica gel chromatography using a stationary phase containing silica gel (manufactured by Merck) with a size of 40 μm to 63 μm and 60 Å, and a mobile phase containing ethyl acetate and n-hexane in a volume ratio ranging from 1:3 to 1:5, thereby obtaining an oil-like product with a brownish color weighing 0.98 g. Subsequently, the oil-like product with a brownish color was recrystallized using ethyl acetate and n-hexane to obtain a yellow solid diclofenac prodrug of EX15 weighing 0.80 g with a yield of 52%.

[0158] The chemical formula of the diclofenac prodrug of EX15 [Chemical formula] (2-(2-((2,6-Dichlorophenyl)amino)phenyl)acetoxy)methyl-2,6-dimethylmorpholine-4-carboxylate having the following was subjected to NMR spectroscopy using the procedure described in EX1.

[0159] The diclofenac prodrug of EX15 was determined to have the following characteristics: 1 1H NMR (CDCl3, 500 MHz) δ 1.53 (d, J = 5 Hz, 3H), 1.76 (br s, 2H), 3.38 - 3.56 (m, 2H), 3.81 (d, J = 13 Hz, 1H), 3.85 - 3.45 (m, 4H), 3.46 - 3.65 (m, 4H), 3.83 (dd, J = 14.5, 20.5 Hz, 2H), 6.56 (d, J = 7.5 Hz, 1H), 6.71 (bs, 1H), 6.89 (q, J = 6.0 Hz, 1H), 6.98 - 7.01 (m, 3H), 7.15 - 7.18 (m, 2H), 7.23 - 7.26 (m, 1H), 7.35 (d, J = 8.5 Hz, 2H); 13 13C NMR (CDCl3, 125 MHz) δ 19.79, 38.41, 43.80, 44.36, 66.29, 66.52, 90.56 (C, -OCH2O-), 118.54, 122.18, 124.05, 128.07, 128.87 (2C), 129.43, 130.90, 137.86, 142.67, (C, -OCOO-), 152.91, 170.41 (C, -OCOCH2-). Comparative Example (CE)

[0160] Sodium 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetate (hereinafter referred to as diclofenac sodium) purchased from Combi-Blocks was used as the comparative example as it was. Characteristic Evaluation 1. X-ray powder diffraction analysis

[0161] The diclofenac prodrugs of EX5 and EX8 are each solid crystals, and it should be noted that such diclofenac prodrugs were prepared using highly polar solvents such as methanol, ethanol, isopropanol, ethyl acetate, acetonitrile, etc., and anti-solvents such as hexane, heptane, isopropyl ether, etc. The diclofenac prodrugs of EX5 and EX8 were subjected to X-ray diffraction analysis using an X-ray diffractometer (manufacturer: PANalytical, model: Empyrean, scan range: 5° to 60°, scan step size: 0.04°) to measure their crystallographic molecular structure. The results are shown as plots of the X-ray diffraction patterns and are presented in Figures 1 and 2.

[0162] As shown in Figure 1, the diclofenac prodrug of EX5 showed sharp diffraction peaks at 2θ degrees of 13.04, 15.92, 17.14, 18.68, 19.86, 20.35, 21.39, 21.65, 22.42, 23.65, 25.12, 25.68, 28.47, and 28.96.

[0163] As shown in Figure 2, the diclofenac prodrug of EX8 showed sharp diffraction peaks at 2θ degrees of 9.62, 9.87, 17.96, 19.37, 19.77, 20.35, 21.16, 21.68, 22.15, 24.11, 24.60, 25.70, 27.59, 27.86, 29.17, and 34.96. 2. Solubility and Hydrolysis Tests A. Solubility Test Using Potassium Phosphate Buffer at pH 7.4

[0164] First, each of the diclofenac prodrugs of EX5 to EX8 and EX12 was mixed with a potassium phosphate buffer (containing 50 mM potassium phosphate, sodium chloride, and water; pH 7.4), and then placed in a constant temperature shaker at 37 °C for 24 hours to dissolve the diclofenac prodrug and obtain a test sample. Thereafter, the test sample was filtered through a filter with a pore size of 0.22 μm to obtain a filtrate. Next, the filtrate was mixed with an equal volume of acetonitrile, and vibration and centrifugation were performed in sequence. The obtained supernatant fraction was subjected to HPLC, and UV detection was performed at a wavelength of 254 nm. The results are shown in Table 1 below.

[0165]

Table 1

[0166] The concentration of each of the diclofenac prodrugs of EX5 to EX8 and EX12 was lower than the detection limit (LoD) of HPLC after 24 hours of dissolution. As shown in Table 1, each of the diclofenac prodrugs of EX5, EX6, EX8, and EX12 has low solubility in a potassium phosphate buffer at pH 7.4, suggesting that the diclofenac prodrug of the present disclosure dissolves and is released slowly after administration, and thus has a long half-life. B. Hydrolysis test using 80% rat serum

[0167] First, 1 mg of each of the diclofenac prodrugs of EX5 and EX8 was mixed in a vial with 0.2 mL of potassium phosphate buffer (containing 50 mM potassium phosphate, sodium chloride, and water; pH 7.4), and then 0.8 mL of rat serum (purchased from BioLASCO Co., Ltd., model: CD(SD) rat serum) was added. Next, the vial was placed in a thermostatic shaker to dissolve the diclofenac prodrug at 37°C. The contents of the vial were taken out after 24 hours and 96 hours to obtain two test samples containing diclofenac. Then, each test sample was filtered through a filter with a pore size of 0.22 μm to obtain a filtrate. Next, the filtrate was mixed with an equal volume of acetonitrile, followed by shaking and centrifugation in sequence. The obtained supernatant fraction was subjected to HPLC with UV detection at a wavelength of 254 nm. The results are shown in Table 2 below.

[0168]

Table 2

[0169] As shown in Table 2, each of the diclofenac prodrugs of EX5 and EX8 has low solubility in rat serum, suggesting that the diclofenac prodrugs of the present disclosure dissolve and are released slowly after administration, and thus have a long half-life. 3. Measurement of particle size

[0170] The solid particles of the diclofenac prodrugs of EX5 and EX8 were milled to formulate them into a soluble liquid suspension suitable for intra-articular injection. Generally, first, the solid particles of the diclofenac prodrug and deionized water were mixed to form a liquid suspension. Next, the liquid suspension was milled using a homogenizer and subjected to vibration treatment to obtain test samples. Then, the particle size distribution of the test samples was measured. Thereafter, the test samples containing solid particles having a particle size in the range of 20 μm to 30 μm were centrifuged, freeze-dried, and then the purity was measured using HLPC. Note that solid particles having a relatively large particle size, that is, a particle size in the range of 60 μm to 90 μm, need to be pre-milled using a mortar in the presence of a milling medium containing a dispersant (for example, Pluronic® F-68, Tween 20, Tween 80, and Triton X-100), water, and physiological saline.

[0171] Specifically, 100 mg of the diclofenac prodrug of EX5 having an initial particle size of about 60 μm was manually milled using a mortar, and then mixed with 2.0 mL of an aqueous solution containing 0.125 wt% of Tween 20 and deionized water to obtain a slurry. Next, the slurry was milled with a homogenizer and vibrated at a rotational speed of 29 Krpm for 15 minutes, and then the particle size D90 was measured 3 times using a particle size analyzer (manufacturer: Beckman Coulter, model: Multisizer™ 3), and 20 μL was measured each time. The average particle size D90 of the measured diclofenac prodrug of EX5 was 8.4 μm.

[0172] On one hand, the diclofenac prodrug of EX8 having an initial particle size of about 60 μm and a weight of 102 mg was manually ground using a mortar, and then mixed with 2.0 mL of an aqueous solution containing 0.125 wt% of Tween 20 and physiological saline to obtain a slurry. Next, the slurry was ground with a homogenizer and vibrated at a rotational speed of 29 Krpm for 15 minutes, then placed in an ice bath every 5 minutes for 1 minute for a total of 33 minutes. Subsequently, the particle size D90 was measured 3 times using a particle size analyzer (manufacturer: Beckman Coulter, model: Multisizer (trademark) 3), and 20 μL was measured each time. The average particle size D90 of the measured diclofenac prodrug of EX8 was 18.2 μm. 4. Pharmacokinetic study

[0173] Three liquid suspensions each having a concentration of 70 mmol / mL were prepared using CE's sodium diclofenac, the diclofenac prodrug of EX5 ground to an average particle size D90 of 8.4 μm, and the diclofenac prodrug of EX8 ground to an average particle size D90 of 18.2 μm, and used in the pharmacokinetic study described below.

[0174] To prepare a liquid suspension containing CE's sodium diclofenac, 3 mL of a hyaluronic acid solution containing 0.1 wt% of hyaluronic acid (molecular weight: 2000 kDa, purchased from Aldrich) and sterile physiological saline (purchased from Taiwan Biotech Co., Ltd.) was added to 66 mg of CE's sodium diclofenac, and then vibration treatment was performed.

[0175] To prepare a liquid suspension containing the diclofenac prodrug of EX5, 3 mL of a hyaluronic acid solution containing 0.1 wt% of hyaluronic acid (Aldrich) and sterile physiological saline (Taiwan Biotech Co., Ltd.) was added to 92 mg of the diclofenac prodrug of EX5, and then vibration treatment was performed.

[0176] To prepare a liquid suspension containing the diclofenac prodrug of EX8, 3 mL of a hyaluronic acid solution containing 0.1 wt% hyaluronic acid (Aldrich) and sterile physiological saline (Taiwan Biotech Co., Ltd.) was added to 92 mg of the diclofenac prodrug of EX8, and then vibration treatment was performed.

[0177] The experimental subjects used in the pharmacokinetic study were male Lewis rats (10 to 12 weeks old), which were housed in an animal room equipped with an independent air conditioning system under the following experimental conditions: a light-dark cycle of 12 hours light / 12 hours dark, a temperature maintained at 25°C ± 2°C, and a relative humidity maintained at 40% to 70%. The rats were given free access to water and food. All experimental procedures related to the experimental rats complied with the legal regulations of Taiwan, China, and were carried out in accordance with the animal breeding guidelines of Taiwan, China.

[0178] The rats were randomly divided into three groups: experimental group 1 (EG1), experimental group 2 (EG2), and control group (CG), with 3 rats in each of the EG1, EG2, and CG groups.

[0179] Note that each of the aforementioned liquid suspensions was prepared on the same day and administered to the rats in each group within 4 hours.

[0180] Specifically, the rats in EG1 were administered an intra-articular injection of a liquid suspension containing the diclofenac prodrug of EX5, the rats in EG2 were administered an intra-articular injection of a liquid suspension containing the diclofenac prodrug of EX8, and the rats in CG were administered an intra-articular injection of a liquid suspension containing diclofenac sodium of CE. The intra-articular injection was performed by using a 29G needle to administer each liquid suspension once into the joint cavity of the rats. For the rats in EG1, EG2, and CG, samples were collected from the blood, synovial tissue, and meniscus of each rat on the 1st, 3rd, 7th, 14th, and 28th days after administration, processed into plasma samples, meniscus samples, and synovial tissue samples respectively, and then the concentration of diclofenac (i.e., the parent drug) in them was measured.

[0181] The plasma collected from each rat as described above was uniformly mixed with a diluent (containing acetonitrile and 0.1 wt% formic acid) at a ratio of 1:3, mixed with 50 ng / mL of glybenzcyclamide (used as an internal standard) at a constant temperature using a shaker (brand: ThermoMixer), and then centrifuged to obtain a supernatant fraction as a plasma sample.

[0182] The meniscus collected from each rat as described above was mixed with a diluent (containing 0.1% formic acid, 20% acetonitrile, and phosphate-buffered saline) at a ratio of 1:10, pulverized using a homogenizer (manufacturer: Qiagen, model: TissueLyser), and then centrifuged at a speed of 12,000 rpm for 5 minutes to obtain a first supernatant fraction. Subsequently, the first supernatant fraction was uniformly mixed with a diluent (containing acetonitrile and 0.1 wt% formic acid) at a ratio of 1:3, mixed with 50 ng / mL of glybenzcyclamide (used as an internal standard) at a constant temperature using a shaker (brand: ThermoMixer), and then centrifuged to obtain a second supernatant fraction as a meniscus sample.

[0183] The synovial tissue collected from each rat as described above was mixed with a diluent (containing 0.1% formic acid, 20% acetonitrile, and phosphate-buffered saline) at a ratio of 1:10, pulverized using a homogenizer (manufacturer: Qiagen, model: TissueLyser), and then centrifuged at a speed of 12,000 rpm for 5 minutes to obtain a first supernatant fraction. Subsequently, the first supernatant fraction was uniformly mixed with a diluent (containing acetonitrile and 0.1 wt% formic acid) at a ratio of 1:3, mixed with 50 ng / mL of glybenzcyclamide (used as an internal standard) at a constant temperature using a shaker (brand: ThermoMixer), and then centrifuged to obtain a second supernatant fraction as a synovial tissue sample.

[0184] Each of the plasma sample, the meniscus sample, and the synovial tissue sample was subjected to a liquid chromatography tandem mass spectrometer (LC-MS / MS) to measure the concentration of diclofenac (i.e., the parent drug) therein. LC-MS / MS was performed using an ACQUITY UPLC BEH C18 column (size: 1.7 μm, 2.1×50 mm). The first eluent was an aqueous formic acid solution containing 0.1 wt% formic acid and water, and the second eluent was a formic acid solution containing 0.1 wt% formic acid and acetonitrile. The elution conditions were as follows: the flow rate of each of the first eluent and the second eluent was 0.4 mL / min. At 0 minute of elution, 50% of the first eluent and 50% of the second eluent were used. At 0.5 minute of elution, 50% of the first eluent and 50% of the second eluent were used. At 6 minutes, only the first eluent was used. At 7 minutes, only the first eluent was used. At 7.5 minutes, 50% of the first eluent and 50% of the second eluent were used. At 8.5 minutes, 50% of the first eluent and 50% of the second eluent were used. The results are shown in FIGS. 3 to 5.

[0185] As shown in FIG. 3, the drug exposure amounts of diclofenac (i.e., the parent drug) detected from the plasma of the rats in EG1 and EG2 on the first day were 40.6±3.2 ng / mL and 9.7±4.8 ng / mL, respectively. In these groups, the concentration of diclofenac decreased as the number of days after administration increased. In contrast, the concentration of diclofenac detected from the plasma of the rats in CG on the first day was only 0.2±0.1 ng / mL. The concentrations of diclofenac detected from the plasma of the rats in EG1 and EG2 on the first day, the third day, the seventh day, the fourteenth day, and the twenty-eighth day were all within the lower limit of quantification (LoQ). The LoQs of diclofenac of CE, the diclofenac prodrug of EX5, and the diclofenac prodrug of EX8 in each plasma sample were 0.05 ng / mL, 0.05 ng / mL, and 0.05 ng / mL, respectively.

[0186] As shown in Figure 4, the drug exposure levels of diclofenac (i.e., the parent drug) detected from the menisci of rats in EG1 and EG2 were the highest on the 7th day after administration compared to other time points after administration, being 2484.2 ± 935.9 ng / g and 42.9 ± 67.5 ng / g respectively. In these groups, the drug exposure level of diclofenac decreased as the number of days after administration increased. In contrast, the drug exposure level of diclofenac detected from the menisci of rats in CG on the 7th day was only 30.1 ± 55.9 ng / g. Furthermore, on the 7th day after administration, the maximum values of the drug exposure levels of diclofenac detected from the menisci of rats in EG1 and EG2 reached 70283.3 ± 31746.4 ng / g and 4.1 ± 1.4 ng / g respectively. The LoQs of CE diclofenac, EX5 diclofenac prodrug, and EX8 diclofenac prodrug in each meniscus sample were 1.0 ng / g, 0.5 ng / g, and 0.5 ng / g respectively.

[0187] As shown in Figure 5, the drug exposure levels of diclofenac (i.e., the parent drug) detected from the synovial tissues of rats in EG1 and EG2 were the highest on the 7th day after administration compared to other time points after administration, being 16236.7 ± 10516.7 ng / g and 13.3 ± 13.1 ng / g respectively. In these groups, the drug exposure level of diclofenac decreased as the number of days after administration increased. In contrast, the drug exposure level of diclofenac detected from the synovial tissues of rats in CG on the 7th day was only 1.3 ng / g. Furthermore, on the 7th day after administration, the maximum values of the drug exposure levels of diclofenac detected from the synovial tissues of rats in EG1 and EG2 reached 2584666.7 ± 1387275.7 ng / g and 2.1 ± 0.8 ng / g respectively. The LoQs of CE diclofenac, EX5 diclofenac prodrug, and EX8 diclofenac prodrug in each synovial tissue sample were 0.5 ng / g, 0.5 ng / g, and 0.5 ng / g respectively.

[0188] In summary, these results demonstrate that when the diclofenac prodrug of the present disclosure is administered by intra-articular injection, it can slowly dissolve and hydrolyze, and slowly release diclofenac in the joint cavity, and thus is expected to be useful for alleviating arthritis.

[0189] In the above description, for the purpose of explanation, numerous specific details have been set forth to provide a complete understanding of the embodiments. However, it will be apparent to those skilled in the art that one or more other embodiments may be practiced without these specific details. Also, in the description indicating "one embodiment" or "an embodiment" in this specification, it should be understood that all descriptions accompanied by indications such as ordinal numbers may be included in specific implementations of the present disclosure having specific aspects, structures, and features. Furthermore, in this specification, although multiple variations are sometimes incorporated into one embodiment, drawing, or their descriptions, this is for rationalizing this specification and for the purpose of understanding the multifaceted nature of the present disclosure, and one or more features or specific examples in one embodiment may, where appropriate, be implemented together with one or more features or specific examples in other embodiments in the implementation of the present disclosure.

[0190] As described above, the embodiments and variations of the present disclosure have been explained, but the present disclosure is not limited thereto, and shall include all modifications and equivalent configurations as various configurations included within the spirit and scope of the broadest interpretation.

Claims

1. A diclofenac prodrug represented by formula (I), Formula (I) 【Chemical Formula 1】 , In formula (I), R ０ represents hydrogen, a linear alkyl group, or a branched alkyl group, X is R １ , 【Chemical Formula 2】 represents, R １ and R ２ are independently selected from the group consisting of a linear alkyl group, a branched alkyl group, a substituted heterocyclic group, an unsubstituted heterocyclic group, and 【Chemical Formula 3】 and are selected from the group consisting of, R ３ is a substituted phenyl group, an unsubstituted phenyl group, a substituted cycloalkyl group, an unsubstituted cycloalkyl group, a substituted heterocyclic group, an unsubstituted heterocyclic group, an alkyl group having a heterocyclic group, an alkyl group having a hydroxyl group, and (R ３１ O) ｎ - R ３２ and is selected from the group consisting of, R ３１ represents an alkylene group, R ３２ represents hydrogen or an alkyl group, and n is an integer of 2 or more, A diclofenac prodrug.

2. R ０ represents hydrogen, and X is 【Chemical Formula 4】 represents, and R ２ is a linear alkyl group, a substituted heterocyclic group, an unsubstituted heterocyclic group, and 【Chemical Formula 5】 and is selected from the group consisting of, The diclofenac prodrug according to claim 1.

3. R ０ represents hydrogen, and X is 【Chemical Formula 6】 represents, and R ２ is, -CH ２ CH ２ CH ３ , 【Chemical Formula 7】 selected from the group consisting of, the diclofenac prodrug according to claim 1.

4. R ０ represents hydrogen, and X is, 【Chemical Formula 8】 represents, and R ３ is, 【Chemical Formula 9】 , -CH ２ CH ２ OH, -CH ２ CH ２ CH ２ OH, -CH ２ CH ２ OCH ２ CH ２ OH, and CH ２ CH ２ OCH ２ CH ２ OCH ３ selected from the group consisting of, the diclofenac prodrug according to claim 1.

5. 【Chemical Formula 10】 is crystalline 【Chemical Formula 11】 and, 【Chemical Formula 12】 The X-ray diffraction pattern of shows characteristic peaks at 2θ degrees of 13.04, 15.92, 17.14, 18.68, 19.86, 20.35, 21.39, 21.65, 22.42, 23.65, 25.12, 25.68, 28.47, and 28.96, the diclofenac prodrug according to claim 1.

6. 【Chemical Formula 13】 is crystalline [Chemical Formula 14] and [Chemical Formula 15] The X-ray diffraction pattern of shows characteristic peaks at 2θ degrees of 9.62, 9.87, 17.96, 19.37, 19.77, 20.35, 21.16, 21.68, 22.15, 24.11, 24.60, 25.70, 27.59, 27.86, 29.17, and 34.96 The diclofenac prodrug according to claim 1.

7. A method for relieving arthritis, comprising administering the diclofenac prodrug according to claim 1 to a subject in need thereof method.

8. The diclofenac prodrug is in a dosage form for intra-articular administration The method according to claim 7.

9. The arthritis is selected from the group consisting of osteoarthritis, rheumatoid arthritis, gouty arthritis, psoriatic arthritis, infectious arthritis, and combinations thereof The method according to claim 7.

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