A method for detecting related substances in picoprofen raw material medicine

Abstract

The invention discloses a detection method for related substances in a kind of picoprofen bulk drug, specifically: dissolve picoprofen bulk drug with mobile phase to obtain a test solution, then dilute the test solution with mobile phase to obtain a control solution; respectively measure the test solution and the control solution, and inject a liquid chromatograph for detection, compare the chromatogram of the test solution and the control solution, and the content of related substances in the picoprofen bulk drug can be calculated; wherein the stationary phase is octadecylsilane bonded silica gel, and the mobile phase is phosphate buffer (pH 2.5) acetonitrile. The detection method provided by the present invention can detect the related substances in picoprofen bulk drug in a short time, and the detection process is simple, the impurity peak separation is high, and the detection accuracy is high.

Description

Technical Field

[0001] The invention belongs to the technical field of drug quality control, and particularly relates to a method for detecting related substances in a picoprofen raw material drug. Background Art

[0002] Ibuprofen Piconol is a topical nonsteroidal anti-inflammatory drug developed by Hisamitsu Co., Ltd. of Japan. It was first launched in Japan in 1984. Ibuprofen Piconol is mainly used to treat acute eczema, contact dermatitis, atopic dermatitis, chronic eczema, rosacea, perioral dermatitis, herpes zoster, acne vulgaris, and can also treat bedsores, radiation ulcers, scald ulcers, burns, infant eczema, etc., so it has certain market prospects and application value. The chemical name of Ibuprofen Piconol is 2-methylpyridine (2RS)-2-[4-(2-methylpropyl)phenyl] propionate, and the chemical structure is as follows:

[0003]

[0004] The preparation routes of picoprofen include: using ibuprofen as the starting material, reacting thionyl chloride with 2-pyridinemethanol to obtain it; or reacting ibuprofen methyl ester with 2-pyridinemethanol sodium, or refluxing ibuprofen sodium salt in dimethylformamide with 2-pyridinemethanol to obtain it, or using ibuprofen and 2-pyridinemethanol as raw materials, N,N-dicyclohexylcarbodiimide as a dehydrator and 4-dimethylaminopyridine as a catalyst at room temperature, etc. However, no matter which preparation method is used, some related substances with similar structures to picoprofen may be produced during the synthesis process of picoprofen and the subsequent storage, transportation, and use of picoprofen, and these related substances may affect the efficacy and even safety of the drug. Therefore, for the quality control of drugs, the detection of related substances is essential.

[0005] Among the existing pharmacopoeias, only the Japanese Pharmacopoeia includes Picoprofen, and the method for detecting related substances is thin layer chromatography, which is time-consuming and insensitive, and cannot obtain the accurate content of impurities. Summary of the invention

[0006] In view of the problems in the prior art, the object of the present invention is to provide a method for detecting related substances in a picoprofen bulk drug, which method has a short detection time and can accurately determine the impurity content.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] A method for detecting related substances in a picoprofen bulk drug comprises the following steps:

[0009] Step 1. dissolving the picoprofen API with a mobile phase to obtain a test solution, and then diluting the test solution with the mobile phase to obtain a control solution;

[0010] Step 2. Measure the test solution and the control solution respectively, and inject them into the liquid chromatograph for detection respectively, compare the chromatograms of the test solution and the control solution, and calculate the content of the related substances in the picoprofen raw material.

[0011] Furthermore, in the above technical solution, the mobile phase is composed of a phosphate buffer with a pH of 2.5 and acetonitrile, and the volume ratio of the two is (450-550): (450-550), wherein the volume ratio of phosphate buffer (pH 2.5) to acetonitrile is 49:51, which is optimal, and the phosphate buffer is made of potassium dihydrogen phosphate, phosphoric acid and water.

[0012] Furthermore, the detection conditions of the liquid chromatograph are as follows: the chromatographic column is filled with octadecylsilane bonded silica gel, the column temperature is 25° C. to 35° C., the detection wavelength is 214 nm, and the elution is isocratic.

[0013] In one embodiment of the present invention, the length of the chromatographic column is 150 mm, the inner diameter is 4.6 mm, and the filler particle size is 5 μm; at this time, the flow rate is preferably 0.8-1.5 ml / min, and the injection volume is preferably 1 μl-20 μl.

[0014] In the above detection scheme, by adjusting the ratio of phosphate buffer (pH 2.5) to acetonitrile in the mobile phase, the retention time of the main peak of picoprofen in the chromatogram can be made between 25 and 30 minutes, and step 3 of collecting the chromatogram to twice the retention time of the main peak of picoprofen can meet the detection requirements.

[0015] Furthermore, in the above technical solution, the method for calculating the content of related substances in step 3 is specifically: comparing the sum of the peak areas of each impurity in the chromatogram of the test solution with the peak area of ​​the characteristic peak of picoprofen in the chromatogram of the control solution, and determining the content of the related substances based on the ratio of the two.

[0016] The beneficial effects of the present invention are as follows: compared with the existing thin layer chromatography method, the detection method provided by the present invention can detect the related substances in the picoprofen raw material within a retention time twice that of the characteristic peak of picoprofen (i.e., 50 to 60 minutes), the detection time is short, and the method of the present invention can adopt isocratic elution, the detection process is simpler, and the impurity content (i.e., the content of related substances) can be accurately determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the chromatogram of the test solution in Example 1;

[0018] Figure 2is the chromatogram of the control solution in Example 1;

[0019] Figure 3 The blank solvent chromatograms under different injection volume conditions in Example 2;

[0020] Figure 4 The chromatogram of the test solution detected by trifluoroacetic acid solution-acetonitrile mobile phase in Comparative Example 1;

[0021] Figure 5 The chromatogram of the test solution detected by phosphoric acid solution-acetonitrile mobile phase in Comparative Example 2;

[0022] Figure 6 The chromatograms of the test solution under different detection wavelength conditions in Comparative Example 3 are shown. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in combination with the embodiments and drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0024] In the following examples, unless otherwise specified, all methods are conventional methods; the reagents and materials described, unless otherwise specified, can be obtained from commercial sources.

[0025] Example 1

[0026] In this case, HPLC was used to detect the impurity content in the raw material of Picoprofen, specifically:

[0027] Mobile phase: phosphate buffer (take 2.04 g of potassium dihydrogen phosphate, dissolve it in water and dilute it to 1000 ml, and adjust the pH value to 2.5 with phosphoric acid) and acetonitrile in a volume ratio of 49:51.

[0028] Test solution: Take an appropriate amount of Picoprofen API, dissolve it in the mobile phase and dilute it to make a solution containing about 5 mg per 1 ml.

[0029] Control solution: Accurately measure an appropriate amount of the test sample solution and quantitatively dilute it with the mobile phase to make a solution containing approximately 50 μg per 1 ml.

[0030] The detection conditions are as follows: using octadecylsilane bonded silica gel as filler (4.6 mm×150 mm, 5 μm); column temperature is 30°C; detection wavelength is 214 nm; isocratic elution; flow rate is 1 ml / min, and injection volume is 5 μl.

[0031] Take the test solution and the control solution respectively, and inject them into the liquid chromatograph for detection under the above detection conditions to obtain the chromatogram of the test solution (see Figure 1) and the chromatogram of the control solution (see Figure 2 ), the impurity content is calculated according to the following formula:

[0032] Impurity content = r u / r s / 100×100%

[0033] In the formula, r u is the peak area of ​​each impurity in the test solution, r s is the main peak area in the control solution.

[0034] The calculation results are shown in the following table:

[0035]

[0036] Example 2

[0037] Different from Example 1, the injection volume of this example is 20 μl. The detection conditions of this example are used to inject blank solvent and observe the baseline. Figure 3 As shown: compared with Example 1, the baseline noise is larger after increasing the injection volume. This shows that reducing the injection volume can reduce the absorption of the blank solvent, thereby reducing the interference with the impurity peak in the test solution.

[0038] Comparative Example 1

[0039] In this example, trifluoroacetic acid solution (pH 2.5)-acetonitrile was used as the mobile phase to test the test solution in Example 1, and the ratio of trifluoroacetic acid solution and acetonitrile was adjusted to a retention time of the main peak of picoprofen at about 30 min. Other detection conditions were the same as in Example 1.

[0040] The chromatogram of the obtained test solution is shown in Figure 4 (The mobile phases of the upper and lower spectra in the figure are both trifluoroacetic acid solution-acetonitrile, but in different proportions), indicating that when the mobile phase is trifluoroacetic acid solution-acetonitrile, there are two impurity peaks in front of the main peak of picoprofen, and they cannot be separated by fine-tuning the proportion of the mobile phase.

[0041] Comparative Example 2

[0042] In this example, phosphoric acid solution (pH 2.5)-acetonitrile was used as the mobile phase to test the test solution in Example 1, and the ratio of phosphoric acid solution and acetonitrile was adjusted to a retention time of the main peak of picoprofen at about 30 min. Other detection conditions were the same as in Example 1.

[0043] Test results such as Figure 4 and Figure 5 As shown: Compared with trifluoroacetic acid solution-acetonitrile, the chromatogram obtained by phosphoric acid solution-acetonitrile mobile phase has better separation (i.e. Figure 4 After adding potassium dihydrogen phosphate to the phosphoric acid solution (i.e., the mobile phase in Example 1, corresponding to Figure 5 The impurity peaks in the chromatogram are better separated (see the lower spectrum in Figure 2).

[0044] In addition, when the aqueous phase in the mobile phase is an acetic acid solution, the baseline noise of the obtained chromatogram is large and the detection sensitivity is poor.

[0045] Comparative Example 3

[0046] The difference from Example 1 is that the detection wavelength used in this example is 254 nm (a common wavelength for liquid chromatography detection). The detection results are as follows: Figure 6 As shown: Compared with the chromatogram at 254nm wavelength ( Figure 6 The wavelength of 214 nm can analyze more impurities.

[0047] In summary, the detection method provided by the present invention can effectively separate the impurity peaks of the raw material drug in picoprofen, can be used for accurate analysis and quantification of impurities, and has a short detection time and simple operation.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for detecting related substances in a picoprofen bulk drug, characterized in that: The following steps are involved: Step 1. dissolving the picoprofen raw material drug with a mobile phase to obtain a test solution, and then diluting the test solution with the mobile phase to obtain a control solution; the mobile phase is composed of a phosphate buffer with a pH of 2.5 and acetonitrile, and the volume ratio of the two is (450-550): (450-550); Step 2. respectively measure the test solution and the control solution, and inject them into the liquid chromatograph for detection, compare the chromatograms of the test solution and the control solution, and calculate the content of the related substances in the picoprofen bulk drug; The detection conditions of the liquid chromatograph are as follows: the chromatographic column uses octadecylsilane bonded silica gel as a filler, the column temperature is 25°C~35°C, and the detection wavelength is 214nm; the length of the chromatographic column is 150mm, the diameter is 4.6mm, and the filler particle size is 5μm; the flow rate is 0.8~1.5ml / min; and the elution mode of the mobile phase is isocratic elution.

2. The method for detecting related substances in the picoprofen bulk drug according to claim 1, characterized in that: The phosphate buffer is made of potassium dihydrogen phosphate, phosphoric acid and water.

3. The method for detecting related substances in the picoprofen bulk drug according to claim 1, characterized in that: The recording time of the chromatogram is twice the retention time of the main peak.

4. The method for detecting related substances in the picoprofen bulk drug according to claim 1, characterized in that: The injection volume of the test solution or the control solution is 1 μl~20 μl.

5. The method for detecting related substances in the picoprofen bulk drug according to claim 1, characterized in that: The calculation method described in step 2 is specifically as follows: comparing the sum of the peak areas of each impurity in the chromatogram of the test solution with the peak area of ​​the characteristic peak of picoprofen in the chromatogram of the control solution, and determining the content of the related substance based on the ratio of the two.

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