Method for determining content of polydimethylsiloxane and silicon dioxide in simethicone emulsion

Abstract

The invention belongs to the technical field of compound content determination, and particularly discloses a method for determining the content of polydimethylsiloxane and silicon dioxide in simethicone emulsion, which comprises the following steps of: preparing a test solution for determining the content of polydimethylsiloxane by using methanol, normal hexane and anhydrous sodium sulfate; according to the present invention, the polydimethylsiloxane and the silicon dioxide are extracted through the test solution, the extraction accuracy is high, the methanol and the n-hexane are the common solvents, the use is safe, the cost is low, and the provided detection method has characteristics of high accuracy and good repeatability.

Description

Technical Field

[0001] The present invention relates to the technical field of compound content determination, and in particular to a method for determining the contents of polydimethylsiloxane and silicon dioxide in a simethicone emulsion. Background Art

[0002] Simethicone emulsion is a stable nonionic surfactant used to treat discomfort caused by excessive gas accumulation in the gastrointestinal tract and to assist with abdominal imaging examinations. Simethicone is a mixture of polydimethylsiloxane and silicon dioxide. Therefore, the content of polydimethylsiloxane and silicon dioxide in the emulsion directly affects the quality of the simethicone emulsion.

[0003] Methods for detecting the dimethicone and silicon dioxide content in orally dissolving simethicone films are already available in the prior art, such as the invention patent publication number CBN116625971A. However, due to the differences between orally dissolving film preparations and emulsion preparations, simethicone emulsions contain a complex variety of excipients. The method of preparing a test solution using dimethyl sulfoxide, n-hexane, and sodium lauryl sulfate is not suitable for detecting the content of simethicone emulsions. Using this method for testing simethicone emulsions will result in incomplete extraction of polydimethylsiloxane, leading to inaccurate results for the simethicone emulsion content. Summary of the Invention

[0004] The object of the present invention is to address the above-mentioned problems and provide a method for determining the content of polydimethylsiloxane and silicon dioxide in simethicone emulsion. A test solution for determining the content of polydimethylsiloxane is prepared by using methanol, n-hexane, and anhydrous sodium sulfate. Methanol and n-hexane are both commonly used solvents, safe to use, and low in cost. The provided detection method has high accuracy and good repeatability.

[0005] The technical solution adopted in the present invention is as follows: A method for determining the contents of polydimethylsiloxane and silicon dioxide in simethicone emulsion, the method specifically comprising: Determination of polydimethylsiloxane content: Preparation of test solution A: Take simethicone emulsion and add methanol to mix, then mix with n-hexane and anhydrous sodium sulfate, and extract the supernatant; Preparation of reference solution A: Add polydimethylsiloxane reference solution to water and mix well, and operate in the same way as the test solution; Preparation of blank solution A: Take water and operate in the same way as the test solution; The test solution A, reference solution A and blank solution A were detected by infrared spectrophotometry to calculate the content of polydimethylsiloxane; Determination of silicon dioxide content: Preparation of test solution B: Mix simethicone emulsion with n-hexane and anhydrous sodium sulfate, and take the n-hexane layer; Preparation of reference solution B: Prepare simethicone reference solution and test solution B in the same manner; Preparation of blank solution B: add n-hexane and anhydrous sodium sulfate and mix with the test solution B; The test solution B, reference solution B and blank solution B were detected by infrared spectrophotometry to calculate the content of silicon dioxide.

[0006] Furthermore, in the determination of the polydimethylsiloxane content, the preparation process of the test solution A is specifically as follows: Accurately weigh an appropriate amount of simethicone emulsion, place it in a stoppered container, add an appropriate amount of methanol, mix well and ultrasonicate, then accurately add an appropriate amount of n-hexane, mix well and ultrasonicate, separate the n-hexane layer, add an appropriate amount of anhydrous sodium sulfate, mix well and centrifuge, take the supernatant to obtain the test solution A.

[0007] Furthermore, the reference solution A is prepared as follows: an appropriate amount of precision polydimethylsiloxane reference substance is placed in a stoppered container, water is added and mixed, then an appropriate amount of precisely added n-hexane is mixed and ultrasonically treated, the n-hexane layer is separated, an appropriate amount of anhydrous sodium sulfate is added, the mixture is mixed and centrifuged, and the supernatant is taken to obtain the reference solution A.

[0008] Furthermore, the content of polydimethylsiloxane was determined by infrared spectrophotometry at a wavelength of 1260 cm -1 ±4cm -1 Measure the absorbance.

[0009] Furthermore, the content of polydimethylsiloxane is calculated specifically by the following formula: (1) (2) Where A r is the absorbance of the test solution A; A R is the absorbance of reference solution A; W r W is the sample weight of the test sample (mg); R is the sample weight of the reference substance (mg); ρ is the relative density of the emulsion; C R is the content of polydimethylsiloxane in the reference substance (%); 38.38 is the labeled amount of polydimethylsiloxane in the emulsion (mg / ml); 0.9982 is the density of water at 20°C (g / ml).

[0010] Furthermore, the preparation of the test solution B specifically includes: Accurately weigh an appropriate amount of simethicone emulsion and place it in a stoppered container. Accurately add appropriate amounts of n-hexane and anhydrous sodium sulfate, mix well, and ultrasonically treat. Let stand and separate the n-hexane layer to obtain the test solution B.

[0011] Furthermore, the preparation process of the reference solution B is as follows: Accurately weigh an appropriate amount of simethicone reference substance, place it in a stoppered container, accurately add appropriate amounts of n-hexane and anhydrous sodium sulfate, mix well, ultrasonicate, let stand, and separate the n-hexane layer to obtain reference substance B.

[0012] Furthermore, in the determination of silicon dioxide content, the infrared spectrophotometry method is specifically carried out at 1400 cm -1 ~600cm -1 The infrared absorption spectrum was measured in the wavelength range. The signal range corresponding to the polydimethylsiloxane concentration in the test solution B was 1280 cm -1 ~1230cm -1 , i.e. range 1, the signal range corresponding to the sum of polydimethylsiloxane and silica in the test solution B is 1160 cm -1 ~950cm -1 , that is, range 2.

[0013] Furthermore, the content of silicon dioxide is calculated as follows: (3) Where, α R1 is the signal area of ​​"range 1" of the spectrum of simethicone reference substance, α R2 is the signal area of ​​"Range 2" of the spectrum of simethicone reference substance, m R is the sample weight of simethicone oil reference substance (mg), α T1 is the signal area of ​​"range 1" of the spectrum of test solution B, α T2 is the signal area of ​​"Range 2" of the spectrum of test solution B, m T is the sample weight of the test solution B (mg), C R SiO2 is the silicon dioxide content in the simethicone reference substance (%), C 聚二甲基硅氧烷 is the polydimethylsiloxane content in the test solution B (%), C R 聚二甲基硅氧烷 is: the content of polydimethylsiloxane in simethicone reference substance (%), D is the polydimethylsiloxane content of simethicone emulsion labeled, U f is the conversion coefficient of silica content.

[0014] Furthermore, the content of simethicone in the simethicone emulsion is specifically: simethicone content (mg / ml) = polydimethylsiloxane (mg / ml) + silicon dioxide content (mg / ml).

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The method of the present invention uses methanol, n-hexane and anhydrous sodium sulfate to prepare a test solution for determining the content of polydimethylsiloxane. The test solution provided by the present invention is used to extract polydimethylsiloxane and silicon dioxide, and the extraction accuracy is high. Methanol and n-hexane are both commonly used solvents, which are safe to use and low in cost. The provided detection method has high accuracy and good repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a linear detection graph of polydimethylsiloxane in the detection of an embodiment of the present invention; Figure 2 is a linear detection diagram of silicon dioxide signal range 1 in the detection of an embodiment of the present invention; Figure 3 This is a linear detection diagram of silicon dioxide signal range 2 in the detection of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings.

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Example The method for determining the simethicone content in the simethicone emulsion provided in this embodiment specifically includes detecting the polydimethylsiloxane content, detecting the silicon dioxide content, and calculating the simethicone content.

[0020] Determination of polydimethylsiloxane content: Test solution A: Take about 1 g of simethicone emulsion, place it in a stoppered conical flask, add 10 ml of methanol, mix well, and ultrasonicate for 5 minutes. Accurately add 25 ml of n-hexane, mix well, and ultrasonicate for 5 minutes. Let it stand, separate the n-hexane layer, add 3 g of anhydrous sodium sulfate, mix well, and centrifuge at 4000 rpm for 5 minutes. Take the supernatant.

[0021] Reference solution A: Take about 38.38 mg of polydimethylsiloxane reference substance, accurately weigh it, place it in a stoppered conical flask, add 1 ml of water, mix well, and then operate in the same way as test solution A, and take the supernatant.

[0022] Blank solution A: Take 1 ml of water, then operate in the same way as test solution A, and take the supernatant.

[0023] Determination method: Take the above three solutions respectively, select a 0.5mm absorption cell, and then-1 ±4cm -1 The absorbance is measured at the wavelength and calculated according to the following formula.

[0024] (1) (2) A r is the absorbance of the test solution A; A R is the absorbance of reference solution A; W r W is the sample weight of the test sample (mg); R is the sample weight of the reference substance (mg); ρ is the relative density of the emulsion; C R is the content of polydimethylsiloxane in the reference substance (%); 38.38 is the labeled amount of polydimethylsiloxane in the emulsion (mg / ml); 0.9982 is the density of water at 20°C (g / ml).

[0025] Determination of silicon dioxide content: Both test solution and reference solution should be prepared on the same day.

[0026] Test solution B: Take about 0.25 g of this product and place it in a 20 ml stoppered vial. Accurately add 10 ml of n-hexane and 3 g of anhydrous sodium sulfate, mix well, sonicate for 15 minutes, let it stand, and separate the n-hexane layer.

[0027] Reference solution B: Take about 10 mg of simethicone reference solution, accurately weigh it, and operate in the same way as test solution B.

[0028] Blank solution B: In another 20 ml stoppered vial, accurately add 10 ml of n-hexane and 3 g of anhydrous sodium sulfate, and operate in the same manner as for test solution B.

[0029] Determination method: Take the above three solutions respectively, select 0.5mm absorption cell, and -1 ~600cm -1 The infrared absorption spectrum was measured in the wavelength range. The signal range corresponding to the concentration of polydimethylsiloxane in the test solution B was 1280 cm -1 ~1230cm -1 (Range 1), the signal range corresponding to the sum of polydimethylsiloxane and silica in the test solution B is 1160 cm -1 ~950cm -1 (Range 2), calculated according to the following formula, the silicon dioxide SiO2 content in each 1 ml of simethicone emulsion shall not exceed 2.7 mg.

[0030] (3) Where, α R1is the signal area of ​​"range 1" of the spectrum of simethicone reference substance, α R2 is the signal area of ​​"Range 2" of the spectrum of simethicone reference substance, m R is the sample weight of simethicone oil reference substance (mg), α T1 is the signal area of ​​"range 1" of the spectrum of test solution B, α T2 is the signal area of ​​"Range 2" of the spectrum of test solution B, m T is the sample weight of the test solution B (mg), C R SiO2 is the silicon dioxide content in the simethicone reference substance (%), C 聚二甲基硅氧烷 is the polydimethylsiloxane content in the test solution B (%), C R 聚二甲基硅氧烷 is: the content of polydimethylsiloxane in simethicone reference substance (%), D is the polydimethylsiloxane content of simethicone emulsion labeled, fixed value: 38.38 mg / ml, U f is the conversion coefficient of silica content, fixed value: 100.

[0031] Calculate the content of simethicone in each 1 ml: simethicone content (mg / ml) = polydimethylsiloxane (mg / ml) + silicon dioxide content (mg / ml).

[0032] Example detection Precision testing: Six test solutions were prepared in parallel and tested according to the infrared spectrophotometry method. The spectra were recorded and the contents of polydimethylsiloxane and silicon dioxide were calculated according to the external standard method, as shown in Table 1.

[0033] Table 1 Precision test results

[0034] The results in Table 1 show that the RSD of the polydimethylsiloxane content detected six times was 1.7%, and the RSD of the silicon dioxide content was 1.1%, which proves that the method of this embodiment has good injection precision.

[0035] Linear relationship and range: Prepare a series of linear solutions equivalent to 50%, 75%, 100%, 125% and 150% of the polydimethylsiloxane concentration in the test sample, and then test according to the conditions of infrared spectrophotometry, such as Figure 1 As shown, with the concentration of polydimethylsiloxane (mg / ml) as the horizontal coordinate and the absorbance as the vertical coordinate, the linear regression equation of polydimethylsiloxane is y=0.2774x-0.0305, r=0.999.

[0036] Prepare a series of linear solutions equivalent to 50%, 75%, 100%, 125% and 150% of the silica concentration in the test sample, and then test them according to the infrared spectrophotometric detection conditions, such as Figure 2 and Figure 3 As shown, with the concentration of silica (mg / ml) as the horizontal coordinate and the signal area of ​​"range 1" and "range 2" as the vertical coordinates, the linear regression equation of silica "range 1" is y=47.491x+0.0788, r=0.999, and the linear regression equation of silica "range 2" is y=346.92x+0.1979, r=0.999.

[0037] Durability testing: The effects of slight changes in the amounts of methanol, n-hexane, and anhydrous sodium sulfate in the sample preparation method on the determination of polydimethylsiloxane and silicon dioxide contents were investigated. The specific test results are shown in Table 2 below.

[0038] Table 2 Contents under different amounts of methanol, n-hexane and anhydrous sodium sulfate

[0039] There was no significant difference in the contents of dimethicone and silicon dioxide under different conditions, which proved that the detection method of this embodiment had good durability.

[0040] The key to determining the polydimethylsiloxane content in simethicone emulsion in this application is to pre-treat the sample with methanol to break the emulsion, allowing the polydimethylsiloxane to be completely extracted into n-hexane for determination. Two samples prepared in parallel using 5 ml of methanol, with other conditions unchanged, showed polydimethylsiloxane contents of 97.5% and 96.9%, respectively. These results are slightly lower than those obtained using 10 ml of methanol; therefore, the methanol content selected in this example is optimal.

[0041] The principles and implementation methods of the present invention are described herein using specific embodiments. The description of the above embodiments is intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for determining the contents of polydimethylsiloxane and silicon dioxide in simethicone emulsion, characterized in that: The method specifically includes: Determination of polydimethylsiloxane content: Preparation of test solution A: Take simethicone emulsion and add methanol to mix, then mix with n-hexane and anhydrous sodium sulfate, and extract the supernatant; Preparation of reference solution A: Add polydimethylsiloxane reference solution to water and mix well, and operate in the same way as the test solution; Preparation of blank solution A: Take water and operate in the same way as the test solution; The test solution A, reference solution A and blank solution A were detected by infrared spectrophotometry to calculate the content of polydimethylsiloxane; Determination of silicon dioxide content: Preparation of test solution B: Mix simethicone emulsion with n-hexane and anhydrous sodium sulfate, and take the n-hexane layer; Preparation of reference solution B: Prepare simethicone reference solution and test solution B in the same manner; Preparation of blank solution B: add n-hexane and anhydrous sodium sulfate and mix with the test solution B; The test solution B, reference solution B and blank solution B were detected by infrared spectrophotometry to calculate the content of silicon dioxide.

2. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein In the determination of the polydimethylsiloxane content, the preparation process of the test solution A is specifically as follows: Accurately weigh an appropriate amount of simethicone emulsion, place it in a stoppered container, add an appropriate amount of methanol, mix well and ultrasonicate, then accurately add an appropriate amount of n-hexane, mix well and ultrasonicate, separate the n-hexane layer, add an appropriate amount of anhydrous sodium sulfate, mix well and centrifuge, take the supernatant to obtain the test solution A.

3. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein The reference solution A is prepared as follows: an appropriate amount of precision polydimethylsiloxane reference substance is placed in a stoppered container, water is added and mixed, then an appropriate amount of precision n-hexane is added, mixed and ultrasonicated, the n-hexane layer is separated, an appropriate amount of anhydrous sodium sulfate is added, mixed and centrifuged, and the supernatant is taken to obtain the reference solution A.

4. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein The content of polydimethylsiloxane was determined by infrared spectrophotometry at a wavelength of 1260 cm -1 ±4cm -1 Measure the absorbance.

5. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein The content of polydimethylsiloxane is calculated specifically by the following formula: （1） （2） Where A r is the absorbance of the test solution A; A R is the absorbance of reference solution A; W r W is the sample weight of the test sample (mg); R is the sample weight of the reference substance (mg); ρ is the relative density of the emulsion; C R is the content of polydimethylsiloxane in the reference substance (%); 38.38 is the labeled amount of polydimethylsiloxane in the emulsion (mg / ml); 0.9982 is the density of water at 20°C (g / ml).

6. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein The preparation of the test solution B specifically includes: Accurately weigh an appropriate amount of simethicone emulsion and place it in a stoppered container. Accurately add appropriate amounts of n-hexane and anhydrous sodium sulfate, mix well, and ultrasonically treat. Let stand and separate the n-hexane layer to obtain the test solution B.

7. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein The preparation process of the reference solution B is as follows: Accurately weigh an appropriate amount of simethicone reference substance, place it in a stoppered container, accurately add appropriate amounts of n-hexane and anhydrous sodium sulfate, mix well, ultrasonicate, let stand, and separate the n-hexane layer to obtain reference substance B.

8. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein In the determination of silicon dioxide content, the infrared spectrophotometry method is specifically carried out at 1400 cm -1 ~600cm -1 The infrared absorption spectrum was measured in the wavelength range. The signal range corresponding to the polydimethylsiloxane concentration in the test solution B was 1280 cm -1 ~1230cm -1 , i.e. range 1, the signal range corresponding to the sum of polydimethylsiloxane and silica in the test solution B is 1160 cm -1 ~950cm -1 , that is, range 2.

9. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 8, wherein: The silica content is calculated as follows: （3） Where, α R1 is the signal area of ​​"range 1" of the spectrum of simethicone reference substance, α R2 is the signal area of ​​"Range 2" of the spectrum of simethicone reference substance, m R is the sample weight of simethicone reference substance (mg), α T1 is the signal area of ​​"range 1" of the spectrum of test solution B, α T2 is the signal area of ​​"Range 2" of the spectrum of test solution B, m T is the sample weight of the test solution B (mg), C R SiO2 is the silicon dioxide content in the simethicone reference substance (%), C 聚二甲基硅氧烷 is the polydimethylsiloxane content in the test solution B (%), C R 聚二甲基硅氧烷 is: the content of polydimethylsiloxane in simethicone reference substance (%), D is the polydimethylsiloxane content of simethicone emulsion labeled, U f is the conversion coefficient of silica content.

10. The method for determining the contents of polydimethylsiloxane and silicon dioxide in the simethicone emulsion according to claim 1, wherein: The specific content of simethicone in simethicone emulsion is: simethicone content (mg / ml) = polydimethylsiloxane (mg / ml) + silicon dioxide content (mg / ml).

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