Method for Preserving P1, P4-di(uridine 5′)-tetraphosphate Crystals

Abstract

The present invention provides a method for easily and stably storing P1, P4-di(uridine 5')-tetraphosphate crystals for a long period of time; the method is a method for storing packaged P1, P4-di(uridine 5')-tetraphosphate crystals or pharmaceutically acceptable salts thereof, characterized by selecting any one of the following storage conditions (1) to (3) and storing the crystals under the conditions; (1) the storage temperature is above 0°C and below 25°C, (2) the storage temperature is above 25°C and below 40°C and the crystal pH is 4.5 to 8.0, and (3) the storage temperature is above 40°C and below 60°C and the crystal pH is 5.0 to 6.4.

Description

Technical Field

[0001] The present invention relates to a method for stably preserving P1, P4-di(uridine 5')-tetraphosphate crystals. Background Art

[0002] P1,P4-di(uridine 5')-tetraphosphate (common name "UP4U") or its salt represented by the following formula (1) is used as a therapeutic drug for corneal epithelial disorders associated with dry eye disease. In addition, the compound has an expectorant effect and is expected to be developed as an expectorant or a pneumonia therapeutic drug.

[0003] (Chemistry 1)

[0004]

[0005] In order to stably store P1, P4-di(uridine 5′)-tetraphosphate (hereinafter sometimes referred to as “UP4U”), crystals of the compound or its salt have been obtained (Patent Document 1). However, although previous documents have shown that crystals are more stable than freeze-dried products, there has been no research on the conditions under which crystals can be stably stored.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2000 / 020430 Summary of the invention

[0009] UP4U is a compound used as a raw material for pharmaceuticals. When used as a raw material for pharmaceuticals, in order to minimize the generation of byproducts caused by impurities contained in it, it is necessary to use an extremely high-purity intermediate product. Sometimes there are such strict specifications that even 0.1% of impurities can become a problem. Therefore, when storing the manufactured intermediate products, it is necessary to set conditions that minimize decomposition. When storing UP4U crystals, what conditions will help decomposition, or what conditions can be set to suppress decomposition, it was previously completely unknown.

[0010] Therefore, an object of the present invention is to provide a method for easily and stably storing UP4U crystals for a long period of time.

[0011] The inventors of the present invention conducted intensive research to solve the above-mentioned problems and found that the stability of UP4U varies greatly depending on the storage temperature and pH of the crystals. Further research revealed that when UP4U crystals are stored under any of the following storage conditions (1) to (3), the rate of change in HPLC purity after 4 weeks of storage is suppressed to less than 0.15%, and the rate of decrease in HPLC purity during storage can be reduced, thereby completing the present invention. (1) The storage temperature is between 0°C and 25°C; (2) The storage temperature is between 25°C and 40°C, and the pH of the crystals is between 4.5 and 8.0; (3) The storage temperature is between 40°C and 60°C, and the pH of the crystals is between 5.0 and 6.4.

[0012] Effects of the Invention

[0013] By using the storage method of the present invention, UP4U is hardly decomposed and can be stored for a long time in a stable state. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The graph shows the purity change rate (%) of HPLC when UP4U crystals showing various crystal pHs were packaged in containers and stored at 5°C to 60°C for 4 weeks.

[0015] As an example, * represents 5°C, x represents 25°C, △ represents 40°C, and ● represents 60°C, and their respective approximate curves are also shown. DETAILED DESCRIPTION

[0016] The storage method of the present invention relates to a storage method for UP4U crystals. The UP4U used in the crystals may be a free body or a pharmaceutically acceptable salt. Specific salts include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, and pharmaceutically acceptable salts such as ammonium salts. The number of substitutions in the salts may include 1 to 4 metal substitutions.

[0017] In the storage method of the present invention, in order to suppress the change rate of HPLC purity of the crystals after 4 weeks of storage to less than 0.15%, the crystals of UP4U are stored under any one of the following conditions (1) to (3). (1) The storage temperature is 0°C to 25°C; (2) The storage temperature is 25°C to 40°C and the crystal pH is 4.5 to 8.0; (3) The storage temperature is 40°C to 60°C and the crystal pH is 5.0 to 6.4.

[0018] In addition, in the storage method of the present invention, in order to suppress the change rate of HPLC purity of the crystals after 4 weeks of storage to less than 0.10%, the crystals of UP4U are stored under any one of the following conditions (4) to (6). (4) The storage temperature is 0°C to 25°C; (2) The storage temperature is 25°C to 40°C and the crystal pH is 4.5 to 7.4; (3) The storage temperature is 40°C to 60°C and the crystal pH is 5.2 to 6.2.

[0019] In addition, in the storage method of the present invention, in order to suppress the change rate of HPLC purity of the crystals after 4 weeks of storage to less than 0.05%, the UP4U crystals are stored under any one of the following conditions (7) to (8): (7) the storage temperature is 0°C to 25°C; (8) the storage temperature is 25°C to 40°C, and the crystal pH is 4.6 to 6.6.

[0020] In the present invention, the pH of the crystal refers to the pH value when 1 g of the crystal is dissolved in 20 ml of water. In order to adjust the pH of the UP4U crystal within the desired range, for example, the pH of the stock solution used for crystallization can be adjusted. In order to adjust the pH, any acid or base that can be used in the manufacture of pharmaceutical raw materials can be used as needed. As an acid, any acid such as hydrochloric acid, nitric acid, phosphoric acid, etc. can be used; as an alkali, any alkali such as sodium hydroxide, sodium carbonate, sodium bicarbonate, etc. can be used.

[0021] The UP4U used in the present invention can be synthesized by a known method (such as Patent Document 1) and crystallized. A specific example is to purify the crude UP4U synthesized by any method such as chemical synthesis or enzyme synthesis by anion exchange chromatography and activated carbon chromatography, and add a hydrophilic organic solvent to the refined UP4U solution to obtain UP4U crystals. As long as the crystal can be obtained, it can also be a crystal obtained by other methods. In addition, the obtained crystals can be appropriately dried by common methods such as reduced pressure drying, ventilation drying, heating drying, etc.

[0022] Considering that the obtained UP4U crystals are used for pharmaceutical purposes, the purity is preferably 95% or more, more preferably 97% or more, and further preferably 99% or more. In addition, these crystals can be attached with or adsorbed water, and can also be hydrated. More specifically, for one molecule of UP4U, 3 to 8 molecules of water can be bound or adsorbed.

[0023] In the method of the present invention, the UP4U crystals are packaged in any container for storage. The container used for storage can be any container of any shape such as a bag, a bottle, a can, a box, a small glass tube, etc.

[0024] As the material of the container, unstretched films and uniaxial or biaxially stretched films of polyolefin resins such as low-density polyethylene, high-density polyethylene, and polypropylene, ethylene resins such as polystyrene and polyvinyl chloride, polyamide resins such as nylon 6 and nylon 66, and polyester resins such as polyethylene terephthalate and polybutylene terephthalate can be used.

[0025] These film materials can be used in a single layer or two or more layers, and can also be used after lamination of metal films such as aluminum, metal or metal oxide vapor deposition films, etc. In addition, the container can also be stored in two or more layers. The state of loading into the container is preferably loaded in a closed, airtight, sealed or other non-open state, and more preferably in a sealed or airtight state.

[0026] When UP4U is stored under conditions where the crystal pH or temperature is outside the above range, UP4U is easily decomposed, and there is a risk that it will be unsuitable for use as a pharmaceutical raw material or the like.

[0027] According to the method of the present invention, the decrease rate of UP4U purity by high performance liquid chromatography (HPLC) after storage for 4 weeks can be controlled to 0.15% or less, or 0.10% or less, or further 0.05% or less, which is extremely suitable for suppressing decomposition.

[0028] That is, when storing UP4U, for example, when the HPLC purity is required to be reduced to 0.15% or less as a raw material for manufacturing a drug, it can be stored in a sealed, airtight or airtight state under any of the following storage conditions: (1) the storage temperature is 0°C or higher and 25°C or lower; (2) the storage temperature is 25°C or higher and 40°C or lower and the crystal pH is 4.5 to 8.0; (3) the storage temperature is 40°C or higher and 60°C or lower and the crystal pH is 5.0 to 6.4. If the storage environment can control the storage temperature to be 0°C or higher and 25°C or lower, it is not necessary to adjust the crystal pH. However, if the storage environment temperature is unstable and may reach 25°C or higher and 40°C or lower, it is necessary to adjust the crystal pH to 4.5 to 7.4 in order to control the HPLC purity reduction to less than 0.15% after 4 weeks of storage. If the temperature is 40°C or higher and 60°C or higher and may be higher, the crystal pH is adjusted to the range of 5.2 to 6.2.

[0029] Similarly, in order to control the reduction of HPLC purity of UP4U to below 0.10%, it is necessary to store it under any one of the following storage conditions: (4) storage temperature is above 0°C and below 25°C; (5) storage temperature is above 25°C and below 40°C, and crystal pH is between 4.5 and 7.4; (6) storage temperature is above 40°C and below 60°C, and crystal pH is between 5.2 and 6.2.

[0030] Furthermore, in order to control the decrease in HPLC purity of UP4U to below 0.05%, it is necessary to store it under any one of the following storage conditions: (7) the storage temperature is above 0°C and below 25°C; (8) the storage temperature is above 25°C and below 40°C, and the crystal pH is between 4.6 and 6.6.

[0031] To summarize the above, (A) if the storage temperature can be maintained at 0°C or above and 25°C or below, the HPLC purity of the UP4U crystals will hardly decrease regardless of the pH of the crystals, making it suitable for long-term storage. On the other hand, in order to store UP4U crystals in an environment where temperature control is difficult, it is necessary to adjust the pH of the crystal stock solution to a specified range.

[0032] (B) When the storage temperature is likely to reach 25°C to 40°C, it is appropriate to set the crystal pH to 4.5-8.0, preferably 4.5-7.4, and more preferably 4.6-6.6, so that the HPLC purity of the crystals after 4 weeks of storage can be controlled to be less than 0.15%, 0.10%, and 0.05%, respectively.

[0033] (C) When the storage temperature may reach 40°C or higher and 60°C or lower, by setting the crystal pH to 5.0 to 6.4, preferably 5.2 to 6.2, the decrease in HPLC purity of the crystals after 4 weeks of storage can be controlled to be less than 0.15% and 0.10%, respectively. When it is necessary to control the decrease in HPLC purity to less than 0.05%, a storage temperature exceeding 40°C is not preferred.

[0034] (D) If the storage temperature is higher than 60°C, the HPLC purity of the crystals may be greatly reduced regardless of the pH of the crystals, which is not preferred.

[0035] In addition, when UP4U crystals are stored for more than 4 weeks (2 to 3 months), in order to control the decrease in HPLC purity to below the desired value, the storage temperature can be set to above 0°C and below 25°C, and the crystal pH can be set within a range that is more preferred than the range of necessary crystal pH recorded in the respective temperature ranges described in (B) or (C) above.

[0036] Example

[0037] The following examples are given to explain the present invention in detail, but the present invention is not limited to these examples.

[0038] (Example 1) Modulation of UP4U crystals at different pH values

[0039] UP4U crystals prepared by a known method are dissolved in deionized water. Phosphoric acid aqueous solution or sodium hydroxide aqueous solution is added to the liquid in which UP4U is dissolved to prepare solutions with different pH values ​​(hereinafter referred to as "stock solutions").

[0040] Ethanol was added to each stock solution to make it slightly cloudy, and a small amount of UP4U crystals was added and stirred for more than ten hours. After confirming the precipitation of crystals, ethanol was further added, stirred, and then separated by centrifugation. The obtained crystals were dried in a ventilation dryer to adjust the UP4U crystals with different pH.

[0041] (pH measurement) Prepare distilled water that has been fully boiled and then cooled with a carbon dioxide absorption tube attached. Dissolve 1.0 g of the test sample in 20 mm of distilled water using the prepared distilled water. Measure the pH of the solution (crystal pH). The following Table 1 shows the correspondence between the pH of the stock solution and the crystal pH before crystallization.

[0042] Table 1

[0043]

[0044] (Example 2) About 20 mg of the test specimen for the stability test (packaging of the test specimen) was placed in a bag made of low-density polyethylene and sealed by heat sealing. The bag was placed in a bag made of low-density polyethylene and sealed by heat sealing. The bag was placed in a bag made of low-density polyethylene again and sealed by heat sealing. The bag was then placed in a bag of an aluminum-plated film and sealed by heat sealing to prepare a specimen for the stability test.

[0045] (Stability Test) The packaged samples were placed in a constant temperature chamber at 5°C, 25°C, 40°C, and 60°C and stored for 4 weeks.

[0046] (Analysis) The sealed packages of the specimens at day 0 of the stability test and the specimens stored at various temperatures for 4 weeks were opened, and the test specimens were dissolved in deionized water. The solution was analyzed by HPLC, and the stability was evaluated based on the results. In addition, the HPLC measurement conditions for this analysis are as follows.

[0047] Table 2

[0048]

[0049] In the evaluation, the value of the HPLC purity (%) of the crystals on the 0th day of the stability test was subtracted from the HPLC purity (%) of the crystals after 4 weeks of storage as the change rate, and the evaluation was performed. The change rate (%) under each condition is shown in Table 3 and Figure 1 .

[0050] Table 3

[0051] pH 4.60 5.16 5.54 5.64 5.97 6.32 6.66 6.91 7.12 7.43 7.97 5℃ 0.01 0.00 0.00 0.00 0.00 0.00 -0.01 0.00 0.00 0.01 0.03 25℃ -0.01 -0.02 -0.02 -0.01 -0.02 -0.01 -0.03 -0.02 -0.02 -0.01 -0.01 40℃ -0.05 -0.04 -0.03 -0.02 -0.03 -0.02 -0.04 -0.04 -0.08 -0.15 -0.12 60℃ -0.25 -0.08 -0.07 -0.07 -0.08 -0.14 -0.18 -0.24 -0.46 -0.50 -0.87

[0052] From Table 3 and Figure 1 It can be seen from the results that the storage conditions for UP4U crystals are as follows: (1) the storage temperature is above 0°C and below 25°C; (2) the storage temperature is above 25°C and below 40°C, and the crystal pH is between 4.5 and 8.0; (3) the storage temperature is above 40°C and below 60°C, and the crystal pH is between 5.0 and 6.4. The change rate of HPLC purity can be suppressed to below 0.15%.

[0053] In addition, as for the storage conditions, as long as any one of the following conditions is met: (4) the storage temperature is above 0°C and below 25°C; (2) the storage temperature is below 25°C and below 40°C, and the crystal pH is between 4.5 and 7.4; (6) the storage temperature is above 40°C and below 60°C, and the crystal pH is between 5.2 and 6.2, the change rate of HPLC purity can be suppressed to below 0.10%.

[0054] Furthermore, as for the storage conditions, as long as any one of the following conditions is met: (7) the storage temperature is above 0°C and below 25°C; (8) the storage temperature is above 25°C and below 40°C, and the crystal pH is between 4.6 and 6.6, the change rate of HPLC purity can be suppressed to below 0.05%.

[0055] In addition, Table 3 and Figure 1 The storage conditions for UP4U crystals are clearly described in the reference, where it can be clearly seen that when the storage temperature is 5°C, the change rate is 0.01 when the crystal pH is 4.60, 0.00 when the crystal pH is 5.16, 0.00 when the crystal pH is 5.54, 0.00 when the crystal pH is 5.64, 0.00 when the crystal pH is 5.97, 0.00 when the crystal pH is 6.32, 0.00 when the crystal pH is 6.66, -0.01 when the crystal pH is 6.91, 0.00 when the crystal pH is 7.12, 0.00 when the crystal pH is 7.43, 0.01, and 0.03 when the crystal pH is 7.97. This clearly shows that when the storage temperature is above 0°C and below 25°C and the crystal pH is 5.16 to 6.32, the decrease rate of HPLC purity after 4 weeks of storage is 0.00. It is also clear that when the storage temperature is between 0°C and 25°C and the crystal pH is 6.66, the decrease rate of HPLC purity after 4 weeks of storage is 0.01. It is also clear that when the storage temperature is between 0°C and 25°C and the crystal pH is between 6.91 and 7.12, the decrease rate of HPLC purity after 4 weeks of storage is 0.00.

Claims

1. A method for preserving P1, P4-di(uridine 5′)-tetraphosphate crystals, characterized in that: In order to suppress the decrease rate of HPLC purity of the packaged crystals to less than 0.15% when stored for 4 weeks, any one of the following storage conditions was selected and stored under the condition: (1) Crystal pH is 4.60, 5℃; (2) Crystal pH is 5.16, 5℃; (3) Crystal pH is 5.54, 5℃; (4) Crystal pH is 5.64, 5℃; (5) Crystal pH is 5.97, 5℃; (6) Crystal pH is 4.60, 25℃; (7) Crystal pH is 5.16, 25℃; (8) Crystal pH is 5.54, 25℃; (9) Crystal pH is 5.64, 25℃; (10) Crystal pH is 5.97, 25℃; (11) Crystal pH is 4.60, 40℃; (12) Crystal pH is 5.16, 40℃; (13) Crystal pH is 5.54, 40℃; (14) Crystal pH is 5.64, 40℃; (15) Crystal pH is 5.97, 40℃; The crystal pH is the pH value measured when 1 g of crystals is dissolved in 20 ml of water.

2. A method for preserving P1, P4-di(uridine 5′)-tetraphosphate crystals, characterized in that: In order to suppress the decrease rate of HPLC purity of the packaged crystals to less than 0.00 when stored for 4 weeks, any one of the following storage conditions was selected and stored under the condition: (2) Crystal pH is 5.16, 5°C; (3) Crystal pH is 5.54, 5°C; (4) Crystal pH is 5.64, 5°C; (5) Crystal pH is 5.97, 5°C; The crystal pH is the pH value measured when 1 g of crystals is dissolved in 20 ml of water.

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