JP2007145767A - Method for stabilizing sirolimus derivative or paclitaxel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize a sirolimus derivative or paclitaxel by preventing its deterioration/degradation, to prolong the effective period of the medicine or a pharmaceutical product mixed with the medicine, to keep a medicine stable until the medicine is eluted and to improve its effectiveness in a sustained-release preparation or a medicine-release type intracorporeal implant structure. <P>SOLUTION: The method for stabilizing a sirolimus derivative or paclitaxel comprises dissolving edaravone, a sirolimus derivative or paclitaxel and another additive to be added, if necessary, in a solvent such as ethanol or tetrahydrofuran or suspending them in a solvent to give a solution or a slurry, optically distilling away the solvent and drying the resultant substance to give an edaravone-containing sirolimus derivative or an edaravone-containing paclitaxel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for stabilizing a sirolimus derivative or paclitaxel. Sirolimus derivatives or paclitaxel are mainly used as an active ingredient of drug-releasing in vivo implant structures. Hereinafter, the drug-releasing in-vivo implant structure will be described as a stent, but the present invention is not limited to the stent and includes a drug delivery system and the like.

Sirolimus derivatives such as sirolimus, biolimus, everolimus, tacrolimus, and paclitaxel are used as active ingredients in anti-restenosis agents in drug-releasing stents for the treatment of percutaneous coronary arteries. Among them, it was difficult to store and handle due to deterioration and deterioration within a short period of time. Further, even when these compounds are incorporated into a drug-releasing stent, the rate of deterioration and deterioration is large, and a rapid decrease in the active ingredient content of the drug-releasing stent is inevitable.

For this reason, the shelf life of sirolimus derivatives or paclitaxel-containing drug-releasing stents is short, and they cannot be altered or deteriorated even when stored in a sealed container that is blocked from oxygen. It was what was done.

In addition, the alteration / degradation of sirolimus derivatives or paclitaxel in drug-releasing stents continues even after the stent placement in the human body, so the sirolimus derivative or paclitaxel dissolves and exhibits efficacy over a long period of 6 months in the body. In drug-release stents designed as described above, attenuation of pharmacological action is unavoidable, which is a very serious problem in such sustained-release preparations.

Thus, a technique for stabilizing a sirolimus derivative or paclitaxel is required, and many stabilizers have been proposed, but an effective stabilization method has not been put to practical use.・ The sirolimus content decreased by about 15% in 5 months, and its effective period was limited to 3 months at room temperature. In other words, even a sirolimus-containing drug-releasing stent manufactured using existing technology cannot be used in three months after manufacturing, and has to be discarded.
JP 2005-296665 A Review Report No. 2372 from Eiken February 18, 2004 7 c. Stability documentation Review Report No. 2372 from Eiken February 18, 2004 20 Approval conditions

Since stents having an optimal size are selected and used depending on the size of the lesion, it is necessary to prepare a variety of stents having different lengths and diameters. Therefore, when the effective period is as short as 3 months, the number of stents to be discarded increases, and the economic loss is very large.

The object of the present invention is to stabilize and stabilize the sirolimus derivative or paclitaxel by preventing alteration and deterioration thereof, and to extend the effective period of these drugs and pharmaceuticals containing these drugs, as well as sustained-release preparations and drug-release types. In the case of an in-vivo implant structure, it is necessary to keep the drugs stable and improve their effectiveness until the elution of these drugs is completed.

The present inventor has studied the alteration / degradation of sirolimus derivatives or paclitaxel, the rapamycin ring of sirolimus derivatives or the double bond part of paclitaxel is oxidized to change to other compounds, and active oxygen is the direct causative substance. The mechanism of alteration / degradation of sirolimus derivatives or paclitaxel has been elucidated, including that iron ions are involved in the generation of active oxygen and that the alteration / degradation reaction proceeds easily in the presence of residual solvent.

In addition, oxygen is a source of active oxygen, but it is essentially a radical inhibitor and suppresses the production of active oxygen. Therefore, storing a drug-releasing stent in a sealed container from which oxygen has been removed conversely causes sirolimus derivatives or paclitaxel. In some cases, alteration / degradation was accelerated, and it was found that removal of oxygen is not always effective for stabilizing sirolimus derivatives or paclitaxel.

Based on these findings, a radical scavenger for active oxygen, a chelating agent with an ion scavenging action for iron ions, and a surface activity with a drying promoting action for residual solvents As a result of searching for various compounds to incorporate the agent, it was found that edaravone has these multiple actions and, in addition, has an action to prevent thrombosis.
JP 2004-203820 Iron chelating agent Pharmaceutical for preventing and / or treating arterial wall disorder

As a result of studying the stabilization effect of edaravone on sirolimus derivative or paclitaxel, it was found that edalavone was added to sirolimus derivative or paclitaxel by coexisting with sirolimus derivative or paclitaxel. However, the present invention was completed by confirming that a sufficient stabilizing effect was exhibited, and that safety to the human body was sufficiently ensured at doses exhibiting the stabilizing effect.

In the present invention, edaravone is dissolved in a solvent such as ethanol or tetrahydrofuran (THF) and added to a sirolimus derivative or paclitaxel to obtain a uniform mixed solution or slurry, followed by drying to remove the solvent and adding edaravone-added sirolimus derivative or edaravone This is a method for stabilizing sirolimus derivatives or paclitaxel that prevents alteration and deterioration by the method of paclitaxel.

By carrying out the present invention, (1) a sirolimus derivative or paclitaxel having a long effective period at room temperature (2) a drug-releasing in vivo implant structure containing these drugs can be obtained. In particular, in a drug release stent containing a sirolimus derivative or paclitaxel, the effective period can be extended from room temperature of 3 months to 1 year or more.

In addition, after the sirolimus derivative or paclitaxel-containing drug-releasing stent is inserted and placed at the lesion site in the body, it remains stable without deterioration or deterioration until the sirolimus derivative or paclitaxel is completely eluted, so treatment is performed at the lesion site. A sufficient drug concentration required for the drug can be obtained, and the effectiveness of the drug release stent can be remarkably improved.

In addition, edaravone suppresses cultured vascular endothelial cell damage caused by active oxygen, thus preventing the formation of thrombus due to vascular endothelium damage, thus preventing stent thrombosis and improving the safety of drug-releasing stents Is expected to do.

Edaravone is made into an ethanol or THF solution and added to the sirolimus derivative or paclitaxel and other additives added as needed to form a uniform mixture or slurry. This is dried to remove the solvent to obtain edaravone-added sirolimus derivative or paclitaxel. In the case of a drug-releasing stent, a mixed solution or slurry is applied to the stent and then dried to remove the solvent to form an edaravone-added sirolimus derivative or paclitaxel-containing coating.

The upper limit of the amount of edaravone is not required to be set chemically and is limited from the viewpoint of safety to the human body. For example, in the case of a drug release stent, the total number of stents used in one stent placement is 60 mg. This amount is derived from the results of edaravone intravascular single dose toxicity test. When the number of single stents used is 3, the amount is 20 mg per stent. However, it can be further increased if the maximum blood concentration of edaravone that appears after in-stent placement of the stent is suppressed by a method such as applying a coating that does not contain edaravone on the surface of the drug-releasing stent.

In order to stabilize the sirolimus derivative or paclitaxel, it is preferable that the amount of coexisting edaravone is large, but conversely, in order to reduce the influence of edaravone on the human body, it is necessary to reduce it. The lower limit of the amount added in such a case is about 0.003% with respect to the sirolimus derivative or paclitaxel, but it is further reduced when used in combination with other stabilizers such as dibutylhydroxytoluene or vitamin E. be able to.

Next, the present invention will be described in detail with reference to examples. Prior to the examples, a method for quantifying the sirolimus derivative or paclitaxel used in each example will be described.

Quantitative determination method of sirolimus derivative or paclitaxel in the preparation: Take 0.5 g of sample and accurately weigh the mass. Precisely measure the amount corresponding to 0.03 g as sirolimus derivative or paclitaxel, add 50 mL of THF accurately, shake for 1 hour and then centrifuge. Pipet 5 mL of the supernatant and add 5 mL of the internal standard solution accurately to make the sample solution. Separately, weigh accurately 5 mL of sirolimus derivative or paclitaxel standard solution, and add exactly 5 mL of internal standard solution to make a standard solution. It was tested by HPLC method under the following conditions per sample solution and standard solution 10 [mu] L, determining the ratio A _T and A _S of the peak area of sirolimus derivatives or paclitaxel to the peak area of internal standard. Amount of sirolimus derivative or paclitaxel (mg) = amount of sirolimus derivative or paclitaxel standard product (mg) × A _T / A _S × 1/2

Sirolimus derivative or paclitaxel standard solution: About 0.25 g of sirolimus derivative or paclitaxel standard product (previously measured for moisture) is accurately weighed and dissolved in THF to make exactly 100 mL. Internal standard solution: acetonitrile solution of butyl paraoxybenzoate (1 → 80000). HPLC detector: ultraviolet absorptiometer (measurement wavelength: 220 nm). Column: A stainless steel tube having an inner diameter of about 4 mm and a length of about 25 cm is packed with octadecylsilylated silica gel for liquid chromatography having a particle size of 5 μm. Column temperature: constant temperature around 25 ° C. Mobile phase: acetonitrile. Flow rate: Adjust the flow rate so that the retention time of sirolimus derivative or paclitaxel is about 7 minutes. Selection of column: When operating under the above conditions per 10 μL of standard solution, use a sirolimus derivative or paclitaxel and butyl paraoxybenzoate having a resolution of 3 or more.

Dissolve 5.4 mg each of (A) sirolimus, (B) biolimus, (C) everolimus, (D) tacrolimus, (E) paclitaxel in 500 mL of THF from which peroxide and the like have been removed by distillation to obtain an active ingredient solution (A) To (E).

Separately, 5.4 mg of polyethylene vinyl acetate (PEVA) and 5.4 mg of polybutyl methacrylate (PBMA) were dissolved in 500 mL of THF from which peroxides and the like were removed by distillation to obtain a polymer solution (X) containing no edaravone.

1 mg or 600 mg of edaravone was added to 500 mL of the polymer solution (X) and dissolved to prepare a polymer solution (Y) containing 1 mg of edaravone and a polymer solution (Z) containing 600 mg of edaravone.

Add 500 mL of the polymer solution (X) containing 1 mg of edaravone, the polymer solution (Y) containing 1 mg of edaravone or the polymer solution (Z) containing 600 mg of edaravone to 500 mL of each of the active ingredient solutions (A) to (E). Comparative active ingredient polymer solutions (AX) to (EX), test active ingredient polymer solutions (AY) to (EY), and test active ingredient polymer solutions (AZ) to (EZ).

Comparative active ingredient polymer solutions (AX) to (EX), test active ingredient polymer solutions (AY) to (EY), test active ingredient polymer solutions (AZ) to (EZ) are 3 cm × 5 cm 316L stainless steel pieces After spraying and applying uniformly on one side of the sample, it is air-dried at room temperature, and the active component polymer-coated test pieces for comparison (AX) to (EX) are tested for effective component polymer-coated test pieces (AY) to (EY), which are effective for testing Six component polymer-coated test pieces (AZ) to (EZ) were prepared. Three of these were immediately subjected to the test, and the film was collected and the content of sirolimus derivative or paclitaxel was measured by HPLC.

Remaining comparative active ingredient polymer-coated test pieces (AX) to (EX), test active ingredient polymer-coated test pieces (AY) to (EY), test active ingredient polymer-coated test pieces (AZ) to (EZ) Three sheets were stored in a constant temperature / humidity bath at 40 ° C ± 2 ° C / 75% RH ± 5% RH for 1 month, and then the coating was collected and the content of sirolimus derivative or paclitaxel was measured by the HPLC method. I saw.

As a result, the proportion of the remaining amount of sirolimus derivative or paclitaxel after one month was the average (AX) 84.7%, (BX) 83.2%, (CX) 82.4%, (DX ) 82.7%, (EX) 83.8%, (AY) 92.6%, (BY) 90.9%, (CY) 90.1%, (DY) 90.4%, (EY) 91 Edaravone was coexisted at .6%, (AZ) 98.0%, (BZ) 96.3%, (CZ) 95.3%, (DZ) 95.7%, (EZ) 96.9%. In all cases, 90% or more remained.

(F) Sirolimus, (G) Biolimus, (H) Everolimus, (I) Tacrolimus, (J) Paclitaxel 5.4 mg each dissolved in 500 mL of N, N-dimethylformamide (DMF) (J). Separately, it was dissolved in 500 mL of DMF at a ratio of 10.8 mg of poly L-lactic acid (PLLA) to obtain a polymer solution (V) containing no edaravone. To 500 mL of the polymer solution (V), 0.10 mg of edaravone was added and dissolved to obtain a polymer solution (W).

To each 500 mL of the active ingredient solutions (F) to (J), 500 mL of a polymer solution (V) containing no edaravone or 500 mL of a polymer solution (W) containing 0.1 mg of edaravone was added and mixed. FV) to (JV), test active ingredient polymer solutions (FW) to (JW).

The active ingredient polymer solutions (FV) to (JV) for comparison and the active ingredient polymer solutions (FW) to (JW) for testing were uniformly sprayed and applied to one side of a 3 cm × 5 cm piece of 316L stainless steel, and then aerated at room temperature. The dried active test polymer coated test pieces for comparison (FV) to (JV) and test active polymer coated test pieces (FW) to 6 (JW) were prepared. Three of these were immediately subjected to the test, and the film was collected and the content of sirolimus derivative or paclitaxel was measured by HPLC.

Remaining comparative active ingredient polymer-coated test pieces (FV) to (JV) and test active ingredient polymer-coated test pieces (FW) to (JW), each of 3 sheets, 25 ° C. ± 2 ° C./60% RH ± 5% After being stored in a RH constant temperature and humidity chamber for 12 months, the film was collected and the content of sirolimus derivative or paclitaxel was measured by HPLC method to see the change with time.

As a result, the ratio of the remaining amount of the sirolimus derivative or paclitaxel after 12 months was an average (FV) 62.8%, (GV) 59.6%, (HV) 58.0%, (IV ) 58.7%, (JV) 60.8%, (FW) 87.0%, (GW) 86.0%, (HW) 85.5%, (IW) 85.7%, (JW) 86 In all cases where edaravone coexisted at 4%, the standard value of 85% or more remained, and the effect of edaravone coexistence was recognized.

The method of the present invention, in which edaravone is stabilized in the presence of chemically unstable sirolimus derivative or paclitaxel, is easily oxidized by other chemically active drug substances and chemicals such as ether bonds. The present invention can also be applied to THF that generates peroxide.

In addition, the occurrence of acute / subacute thrombosis, which is considered to be caused by active oxygen generated at the time of stent placement, has become a major problem along with restenosis.
Review Report No. 2372 from Eiken February 18, 2004 20 Approval conditions

If the method of coexisting edaravone of the present invention is applied to an implantable drug delivery system, the other coexisting drug is stabilized and its effectiveness is improved, and at the same time, the active oxygen scavenging action of edaravone is used for implanting the drug delivery system. The accompanying thrombosis is prevented and safety is improved.

Structural formula of edaravone

Claims (3)

A method for stabilizing a sirolimus derivative or paclitaxel, characterized by preventing the alteration or deterioration of a sirolimus derivative or paclitaxel by causing edaravone to coexist with a sirolimus derivative or paclitaxel. The method for stabilizing a sirolimus derivative or paclitaxel according to claim 1, wherein the sirolimus derivative of claim 1 is sirolimus, biolimus, everolimus, or tacrolimus. The method for stabilizing a sirolimus derivative or paclitaxel according to claim 1, wherein the sirolimus derivative according to claim 1 is a compound obtained by chemically modifying a rapamycin ring.

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