Method for adsorbing bile acid by hydrotalcite chewable tablets and method for measuring bile acid

Abstract

The invention provides a method for adsorbing bile acid by hydrotalcite chewable tablets, which comprises the following steps: mixing hydrotalcite chewable tablet fine powder and a hydrochloric acid solution of bile salt to obtain a mixed solution; incubating the mixed solution, uniformly mixing and centrifuging at set intervals, and taking supernate, so as to obtain a hydrotalcite solution for adsorbing bile acid. The invention also provides a determination method of bile acid in the hydrotalcite solution for adsorbing bile acid prepared by the method. The adsorption method provided by the invention is good in repeatability and durability, the detection method is strong in specificity and high in accuracy, bile acid and preparation auxiliary materials can be effectively separated, and the amount of bile acid can be more accurately detected; the in-vitro adsorption capacity of the hydrotalcite chewable tablets on bile acid is investigated, so that a certain basis is provided for clinical reasonable medication.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing methods, and particularly relates to a method for adsorbing bile acids by chewable tablets of hydrotalcite and a method for determining bile acids. More specifically, it relates to a method for adsorbing bile acids by chewable tablets of hydrotalcite. After the bile acids are adsorbed, they are centrifuged and separated, and the high performance liquid chromatography method is used for determination to calculate the adsorption rate of the chewable tablets of hydrotalcite to bile acids. Background Art

[0002] Erosive gastritis and peptic ulcer are related to bile reflux and the concentration of bile acids in gastric juice. Bile acids in bile play an important role in the damage of gastric mucosa. Bile acids include two categories: free type and conjugated type. Conjugated bile acids are the main substances that cause damage to the gastric mucosa in bile reflux.

[0003] Hydrotalcite has a unique layered network structure in its chemical structure and is a compound containing aluminum hydroxide, magnesium hydroxide, and carbonate. It can adsorb and bind bile acids, thereby weakening the attack of mucosal damage factors and improving the blood flow of the local mucosa; regulating the pH value, changing the acid-base environment on its mucosal surface, etc., and participating in the protection of the mucosa.

[0004] The commonly used detection methods for bile acids mainly include thin layer chromatography, gas chromatography, and high performance liquid chromatography. The high performance liquid chromatography method is widely used due to its characteristics of accuracy, sensitivity, and good stability.

[0005] Currently, there is no national standard for the method of adsorbing bile acids by chewable tablets of hydrotalcite, nor is there a national standard for the detection method of bile acids. It is necessary to study an analytical method for the adsorption of bile acids by chewable tablets of hydrotalcite to investigate the in vitro adsorption ability of chewable tablets of hydrotalcite to bile acids and provide a certain basis for rational clinical drug use. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for adsorbing bile acids by chewable tablets of hydrotalcite and a method for determining bile acids. The method has good specificity, good resolution, high sensitivity and is ready, and can be used for the determination of bile acids.

[0007] The present invention provides a method for adsorbing bile acids by chewable tablets of hydrotalcite, including the following steps:

[0008] Mix the fine powder of chewable tablets of hydrotalcite and the hydrochloric acid solution of bile salt to obtain a mixed solution;

[0009] Incubate the mixed solution, mix it evenly at regular intervals, centrifuge, and take the supernatant to obtain the solution of hydrotalcite adsorbing bile acids.

[0010] Preferably, the bile salt in the hydrochloric acid solution of bile salt is selected from sodium glycocholate, sodium taurocholate, sodium glycochenodeoxycholate, sodium taurochenodeoxycholate, or sodium taurodeoxycholate.

[0011] Preferably, the incubation temperature is 37 ± 0.5 °C, and the incubation time is 50 - 70 min; during the incubation process, mix well every 5 - 15 min.

[0012] Preferably, the centrifugation speed is 1500 - 2500 rpm, and the centrifugation time is 13 - 17 min.

[0013] The present invention provides a method for determining bile acids in the magnesium aluminum silicate solution adsorbed with bile acids prepared by the above technical solution, including the following steps:

[0014] Take the magnesium aluminum silicate solution adsorbed with bile acids as the test solution;

[0015] Take the hydrochloric acid solution of bile salts as the reference solution;

[0016] Adopt high performance liquid chromatography, detect with an ultraviolet detector, and use octadecylsilane chemically bonded silica gel as the filler for the chromatographic column; use a mixed solution of methanol, acetonitrile and phosphate solution as the mobile phase.

[0017] Preferably, the column temperature is 25 - 35 °C, and the flow rate is 0.9 - 1.1 ml / min;

[0018] The detection wavelength is 200 nm, and the injection volume is 10 - 20 μl.

[0019] Preferably, in the mixed solution of methanol, acetonitrile and 0.05 mol / L phosphate solution, the volume ratio of methanol, acetonitrile and phosphate solution is (38:38:54) - (42:42:46).

[0020] Preferably, the pH value of the mixed solution of methanol, acetonitrile and phosphate solution is 2.8 - 3.2.

[0021] Preferably, accurately measure 20 μl of each of the test solution and the reference solution, inject them into the liquid chromatograph, record the chromatogram, and calculate the adsorption rate of bile acids.

[0022] The present invention provides a method for adsorbing bile acids by magnesium aluminum silicate chewable tablets, including the following steps: mixing the fine powder of magnesium aluminum silicate chewable tablets and the hydrochloric acid solution of bile salts to obtain a mixed solution; incubating the mixed solution, mixing well every once in a while, centrifuging, and taking the supernatant to obtain the magnesium aluminum silicate solution adsorbed with bile acids. It also provides a method for determining bile acids in the magnesium aluminum silicate solution adsorbed with bile acids prepared by the above method. The adsorption method provided by the present invention has good repeatability and durability, the detection method has strong specificity, high accuracy, can effectively separate bile acids from preparation excipients, and can more accurately detect the amount of bile acids; by investigating the in vitro adsorption ability of magnesium aluminum silicate chewable tablets to bile acids, it provides a certain basis for rational clinical medication. Description of the Drawings

[0023] Figure 1 This is the chromatogram of the mixed reference solution under the system suitability of the present invention;

[0024] Figure 2 This is the chromatogram of the blank sample solution under the specificity of the present invention. Detailed Description of the Invention

[0025] The present invention provides a method for adsorbing bile acids by magnesium aluminum carbonate chewable tablets, which comprises the following steps:

[0026] Mix the fine powder of magnesium aluminum carbonate chewable tablets and the hydrochloric acid solution of bile salts to obtain a mixed solution;

[0027] Incubate the mixed solution, mix it evenly at regular intervals, centrifuge it, and take the supernatant to obtain the magnesium aluminum carbonate solution adsorbed with bile acids.

[0028] In the present invention, the fine powder of magnesium aluminum carbonate chewable tablets and the hydrochloric acid solution of bile salts are mixed to obtain a mixed solution. The bile salts in the hydrochloric acid solution of bile salts are selected from sodium glycocholate, sodium taurocholate, sodium glycochenodeoxycholate, sodium taurochenodeoxycholate or sodium taurodeoxycholate. The concentration of the hydrochloric acid solution of bile salts is 0.1 mol / L. Specifically, in the present invention, an appropriate amount of the fine powder of magnesium aluminum carbonate chewable tablets, approximately equivalent to 25 mg of magnesium aluminum carbonate, is accurately weighed in 5 portions and placed in centrifuge tubes respectively; 5 ml of the hydrochloric acid solution (0.1 mol / L) containing approximately 0.5 mmol / L (0.25 mg / ml) of a single bile salt (sodium glycocholate, sodium taurocholate, sodium glycochenodeoxycholate, sodium taurochenodeoxycholate, sodium taurodeoxycholate) is added to each centrifuge tube respectively.

[0029] After obtaining the mixed solution, in the present invention, the mixed solution is incubated, mixed evenly at regular intervals, centrifuged, and the supernatant is taken to obtain the magnesium aluminum carbonate solution adsorbed with bile acids. The incubation temperature is 37 ± 0.5 °C, and the incubation time is 50 - 70 min, preferably 60 min; during the incubation process, it is mixed evenly every 5 - 15 min, preferably every 10 min.

[0030] After incubation, the solution is centrifuged at 1500 rpm - 2500 rpm, preferably 2000 rpm; the centrifugation time is 13 min - 17 min, preferably 15 min.

[0031] The applicant found in the research that the repeatability of the adsorption of bile acids by hydrotalcite chewable tablets is poor; the excipient peaks of hydrotalcite chewable tablets are likely to interfere with the determination of bile acids and the resolution of each bile acid is poor. Through the screening of adsorption conditions and determination methods, the inventor provided a method of using fine powder of hydrotalcite chewable tablets for adsorption and shaking during the incubation process, so that hydrotalcite chewable tablets can better adsorb bile acids and have good repeatability and durability. The inventor also provided a method for analyzing and detecting bile acids by HPLC, enabling the separation of each bile acid from the excipient peaks and the effective separation between each bile acid peak, which can more accurately determine the amount of bile acids. At the same time, the method is simple, rapid, highly specific and accurate.

[0032] The present invention provides a method for determining bile acids in a hydrotalcite solution that adsorbs bile acids prepared by the method of the above technical solution, comprising the following steps:

[0033] Take the hydrotalcite solution that adsorbs bile acids as the test solution;

[0034] Take the hydrochloric acid solution of bile salt as the reference solution;

[0035] Adopt high performance liquid chromatography, detect with an ultraviolet detector, and use octadecylsilane chemically bonded silica gel as the filler for the chromatographic column; use a mixed solution of methanol, acetonitrile and phosphate solution as the mobile phase.

[0036] Measure 5 ml of hydrochloric acid solution (0.1 mol / L) containing about 0.5 mmol / L (0.25 mg / ml) of a single bile salt (sodium glycocholate, sodium taurocholate, sodium glycochenodeoxycholate, sodium taurochenodeoxycholate, sodium taurodeoxycholate) respectively, place them in centrifuge tubes, incubate at 37 ± 0.5 °C for 1 hour, shake and mix well every 10 min during the incubation process, and then centrifuge at 2000 revolutions per minute for 15 minutes as the reference solution.

[0037] In the present invention, the chromatographic column uses octadecylsilane chemically bonded silica gel as the filler, Diamonsil C18, 4.6 mm × 250 mm, 5 μm or a chromatographic column with equivalent column efficiency.

[0038] In the present invention, the column temperature is 25 - 35 °C, preferably 30 °C; the flow rate is 0.9 - 1.1 ml / min, preferably 1 ml / min; the detection wavelength is 200 nm, and the injection volume is 10 - 20 μL, preferably 20 μL.

[0039] In the present invention, in the mixed solution of methanol, acetonitrile and phosphate solution, the volume ratio of methanol, acetonitrile and 0.05 mol / L phosphate solution is (38:38:54) - (42:42:46), preferably 40:40:50. In specific embodiments, the phosphate solution is sodium dihydrogen phosphate solution, and the concentration of the sodium dihydrogen phosphate solution is 0.045 mol / L - 0.055 mol / L, preferably 0.05 mol / L.

[0040] In the present invention, the pH value of the mixed solution of methanol, acetonitrile and phosphate solution is 2.8 - 3.2, preferably 3.0.

[0041] In the present invention, accurately measure 20 μl of each of the test solution and the reference solution, inject them into the liquid chromatograph, record the chromatogram, and calculate the adsorption rate of bile acids.

[0042] Under this method, for each component of bile acids, within the concentration range of 1.25×10 -3 mg / ml - 2.51×10 -1 mg / ml, the linearity is good, r = 0.9997 - 1.0000. The quantitative limit of each bile acid under this method is lower than the limit injection volume of 50 ng, meeting the requirements for bile acid detection; this method has a high response to each bile acid and can accurately detect the amount of each bile acid. The adsorption rate of hydrotalcite chewable tablets to five bile acids is between 35.6% and 97.9%, and the RSD values are between 0.41% and 2.26%; the results show that this method has good precision and accuracy (absolute recovery rate of the method). The recovery rates of each bile acid are between 93.91% and 103.31%, and the RSD values are between 0.43% and 2.98%. The results show that the adsorption process has no interference on the determination of bile acid concentration, and the accuracy of the HPLC method meets the determination requirements. The reference solution and the test solution after adsorption are placed at room temperature for 30 h, and injected for determination at 0 h, 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 48 h, 60 h, and 72 h. The results show that the RSD values of the peak areas of each bile acid are between 0.18% and 1.80%, and the RSD values of the retention times are between 0.20% and 0.80%. The results show that the reference solution and the test solution are stable within 72 h.

[0043] To further illustrate the present invention, the following describes in detail a method for a hydrotalcite chewable tablet to adsorb bile acids and a method for determining bile acids provided by the present invention in combination with examples, but they should not be construed as limiting the protection scope of the present invention.

[0044] Example 1

[0045] To confirm the adsorption effect of the hydrotalcite chewable tablets on bile acids in the present invention, the applicant conducted a large number of screening and optimization experiments, as follows:

[0046] (1) Selection of bile acid types: According to the chemical structure, bile acids can be divided into free bile acids and conjugated bile acids. Free bile acids include cholic acid, deoxycholic acid, and chenodeoxycholic acid; conjugated bile acids are mainly the products of free bile acids combined with glycine or taurine, including glycocholic acid, taurocholic acid, glycochenodeoxycholic acid, taurochenodeoxycholic acid, glycodeoxycholic acid, and taurodeoxycholic acid. Free bile acids are unstable and are easily oxidized in the presence of acid and Ca. 2+ When present, it is easy to precipitate; conjugated bile acids are stable and are in the presence of acid and Ca 2+ It is not easy to precipitate when it exists. Conjugated bile acid is the main substance that causes damage to the gastric mucosa in bile reflux. Therefore, conjugated bile acid was selected for the adsorption test of aluminum carbonate magnesium chewable tablets.

[0047] (2) Selection of bile salt concentration: Based on literature data and the bile acid concentration that may damage the gastric mucosa, the bile salt concentration was selected to be 0.5 mmol / L (the molecular weight of each bile salt is about 500), that is, the concentration was 0.25 mg / ml.

[0048] (3) Selection of medium: Bile salts can only damage the gastric mucosa under low pH conditions. Medically, the pH value of gastric acid is approximately 0.9-1.2 (approximately equivalent to the pH value of 0.1 mol / L hydrochloric acid solution). The main component of gastric acid is hydrochloric acid, which also contains pepsin. In the pharmacopoeia, artificial gastric juice is prepared using dilute hydrochloric acid and pepsin. Therefore, 0.1 mol / L hydrochloric acid and artificial gastric juice were selected for comparative testing. The results are shown in Table 1.

[0049] Table 1 Media selection results

[0050]

[0051] From the results in Table 1 above, it can be seen that there is no significant difference in the adsorption rates of the five bile acid salts in artificial gastric juice and 0.1 mol / L hydrochloric acid (the absolute difference in adsorption rate is <5%), and all of them can be used as media for bile acid adsorption tests. Considering the simplicity and feasibility of the operation, 0.1 mol / L hydrochloric acid was selected as the medium.

[0052] (4) Selection of adsorption form of aluminum carbonate chewable tablets: The adsorption of bile acid by aluminum carbonate chewable tablets after swallowing the whole tablet and chewing the tablet was investigated. The results are shown in Table 2.

[0053] Table 2 Adsorption results of bile acid by different forms

[0054]

[0055] As can be seen from the above results, in the bile acid adsorption test with whole tablets and powders, there was no significant difference in the adsorption rates of the five bile salts, and the deviation was less than 5.0%.

[0056] (5) Investigation of incubation time and shaking interval during incubation: The effects of incubation times of 50 min, 60 min, 70 min and shaking intervals of 5 min, 10 min, 15 min on the adsorption rate were investigated respectively, and the results are shown in Table 3.

[0057] Table 3 Results of investigation of incubation time and shaking interval

[0058]

[0059] (6) Investigation of centrifugation speed and centrifugation time: The effects of centrifugation speeds of 1500 rmp, 2000 rmp, 2500 rmp and centrifugation times of 13 min, 15 min, 17 min after incubation on the adsorption rate were investigated respectively, and the results are shown in Table 4.

[0060] Table 4 Results of investigation of centrifugation speed and centrifugation time

[0061]

[0062] (7) Conclusion: Under the changes of sample treatment methods including incubation time (50 min - 70 min), shaking time (13 min - 17 min), centrifugation speed (1500 rpm - 2500 rpm), and centrifugation time (13 min - 17 min), the RSD values of the adsorption rates of each bile acid were less than 5.0%.

[0063] To further confirm the accuracy of bile acid detection in the present invention, the present invention provides an HPLC detection method. Through the screening and optimization of chromatographic conditions, each bile acid can be effectively separated, as follows:

[0064] Chromatographic column: DIKMA Diamonsil C18 (4.6 mm * 150 mm, 5 μm) chromatographic column.

[0065] To achieve the separation effect, the effects of changes in the proportion of the mobile phase, changes in the pH value of the mobile phase, and changes in the concentration of salts in the mobile phase components on the separation of bile acids were investigated. Methanol, acetonitrile and phosphate solution were used as the mobile phase, with ratios of 38:38:54, 40:40:50, 42:42:46 respectively, the pH values of the mobile phase were 2.8, 3.0, 3.2 respectively, and the concentrations of phosphate were 0.045 mol / L, 0.050 mol / L, 0.055 mol / L respectively.

[0066] To further achieve the separation effect, the effects of changes in column temperature and flow rate on the separation of bile acids were investigated. The column temperatures were 25°C, 30°C, and 35°C, and the flow rates were 0.9 ml per minute, 1.0 ml per minute, and 1.1 ml per minute, respectively.

[0067] To further achieve the separation effect, chromatographic columns of the same brand and different brands were investigated, namely DIKMA Diamonsil C18 (4.6 mm * 150 mm, 5 μm) chromatographic column and Ultimate LP-C18 (250 * 4.6 mm, 5 μm) chromatographic column.

[0068] The results of the durability investigation of the chromatographic conditions for the bile acid detection method are shown in Table 5.

[0069] Table 5 Results of the durability investigation of chromatographic conditions

[0070]

[0071]

[0072] Remark 1: The chromatographic column is DIKMA Diamonsil C18 (4.6 mm * 150 mm, 5 μm), the mobile phase ratio is 40:40:50, the pH value of the mobile phase is 3.0, the buffer salt concentration in the mobile phase is 0.05 mol / L, the flow rate is 1.0 ml / min, and the column temperature is 30°C.

[0073] Conclusion: Under the changes of chromatographic conditions such as column temperature (25°C - 35°C), flow rate (0.9 ml / min - 1.1 ml / min), chromatographic column, mobile phase ratio (38:38:54 - 42:42:56), mobile phase pH value (2.8 - 3.2), and phosphate concentration (0.045 M - 0.055 M), the RSD values of the adsorption rates of the five bile salts are all less than 5.0%.

[0074] To verify the technical solution of the present invention, scientific verification was carried out on the finally determined adsorption method and determination method.

[0075] System suitability

[0076] Take the bile salt mixed reference solution (weigh appropriate amounts of each of the 5 bile salt reference substances, dissolve with 0.1 M hydrochloric acid solution and dilute to 100 ml, mix well, filter) as the system suitability solution, accurately measure 20 μl and inject it. The results are shown in Table 6, and the chromatogram is shown in Figure 1 .

[0077] Table 6 Results of the system suitability test

[0078]

[0079] Conclusion: As can be seen from the results in Table 6 above, in the system suitability test, all bile acids were completely separated within 25 minutes, the theoretical plate numbers were all greater than 2000, the tailing factors were all less than 2.0, and the resolution between adjacent peaks was all greater than 1.5. The results of the system suitability verification met the requirements.

[0080] Specificity

[0081] Take blank solvent, control solutions of each bile acid, test solution and blank sample solution (without bile salts), accurately measure 20 μl and inject them. The results are shown in Table 7, and the chromatogram of the blank sample solution is shown in Figure 2 .

[0082] Table 7 Results of specificity test

[0083]

[0084]

[0085] Conclusion: The blank solvent and the blank sample solution did not interfere with the determination of the bile acid peaks, and the results of the specificity verification met the requirements.

[0086] Linearity and range

[0087] Accurately weigh the reference substances of five bile acid components, place them in 100-ml volumetric flasks respectively, and prepare reference stock solutions with concentrations of 0.25 mg / ml by adding 0.1 mol / L hydrochloric acid solution; prepare 6 solutions with different concentrations, inject them respectively, take the peak area as the abscissa and the concentration as the ordinate, and perform linear regression analysis to obtain the linear regression equations of each bile acid. The results are shown in Table 8.

[0088] Table 8 Linear equations and correlation coefficients

[0089] Bile acid components Linear equation Correlation coefficient Range (mg / ml) Sodium taurocholate <![CDATA[y = 1.524×10 -4 x - 1.030×10 -3 > 0.9999 <![CDATA[1.257×10 -3 ~2.514×10 -1 > Sodium glycocholate <![CDATA[y = 2.014×10 -4 x - 1.186×10 -3 > 0.9999 <![CDATA[1.252×10 -3 ~2.504×10 -1 > Sodium taurochenodeoxycholate <![CDATA[y = 1.257×10 -4 x + 2.329×10 -4 > 1.000 <![CDATA[2.452×10 -3 ~2.452×10 -1 > Sodium taurodeoxycholate <![CDATA[y = 1.210×10 -4 x - 3.804×10 -4 > 1.000 <![CDATA[2.396×10 -3 ~2.396×10 -1 > Sodium glycochenodeoxycholate <![CDATA[y = 2.031×10 -4 x - 6.254×10 -4 > 0.9997 <![CDATA[2.412×10 -3 ~2.412×10 -1 >

[0090] Conclusion: Under this method, each component of bile acid had good linearity in the concentration range of 1.25×10 -3 mg / ml to 2.51×10 -1 mg / ml, and r = 0.9997 - 1.0000.

[0091] Quantitation limit and precision of quantitation limit

[0092] The quantitation limits of each bile acid were determined by the signal-to-noise ratio method. Prepare the stock solutions of each bile acid respectively, dilute them to a certain concentration and inject them, calculate the ratio of the peak height to the noise (signal-to-noise ratio). The detected amount of the sample with a signal-to-noise ratio (S / N) of about 10 was the quantitation limit. The results are shown in Table 9 and Table 10.

[0093] Table 9 Results of quantitation limit test

[0094]

[0095]

[0096] Table 10 Quantitation Limit Precision

[0097]

[0098] Conclusion: The quantitation limits of each bile acid under this method are all lower than the limit injection volume of 50 ng, meeting the requirements for bile acid detection; this method has a high response to each bile acid and can accurately detect the amount of each bile acid.

[0099] Precision

[0100] Repeatedly determined 6 times by the same experimenter to calculate the adsorption rate of magnesium aluminum silicate chewable tablets to five bile acids; the experiment was carried out by another experimenter on different dates and repeated 6 times; calculate the adsorption rate of magnesium aluminum silicate chewable tablets to five bile acids in 12 experiments, and the results are shown in Table 11.

[0101] Table 11

[0102]

[0103]

[0104] Conclusion: The adsorption rates of magnesium aluminum silicate chewable tablets to five bile acids in 12 experiments are between 35.6% and 97.9%, and the RSD values are between 0.41% and 2.26%; the results show that this method has good precision and accuracy (method absolute recovery rate).

[0105] Due to the unique bile acid adsorption effect of this product, after taking this product, the bile acid refluxing into the stomach will only decrease in concentration but not increase due to being adsorbed. Therefore, three concentrations of 80%, 50%, and 20% are selected for quality control to evaluate the recovery level of bile salts for the treatment method without adding samples.

[0106] Prepare sample solutions with high, medium, and low three concentrations from each bile acid reference stock solution, operate according to the adsorption process of the sample, and determine the absolute recovery rate of the method. Each concentration is measured in parallel 3 times, and the results are shown in Table 12.

[0107] Table 12 Test Results of Accuracy (Method Absolute Recovery Rate)

[0108]

[0109]

[0110] Conclusion: The recovery rates of each bile acid were between 93.91% and 103.31%, and the RSD values were between 0.43% and 2.98%. The results showed that the adsorption process had no interference on the determination of bile acid concentration, and the accuracy of the HPLC method met the requirements of the determination.

[0111] Solution stability

[0112] The control solution and the test solution after adsorption were taken respectively and placed at room temperature for 30 h, and then injected for determination at 0 h, 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 48 h, 60 h, and 72 h. The results showed that the RSD values of the peak areas of each bile acid were between 0.18% and 1.80%, and the RSD values of the retention times were between 0.20% and 0.80%. The results indicated that the control solution and the test solution were stable within 72 h.

[0113] As can be seen from the above examples, the present invention provides a method for adsorbing bile acid by hydrotalcite tablets, which includes the following steps: mixing the fine powder of hydrotalcite tablets and the hydrochloric acid solution of bile salt to obtain a mixed solution; incubating the mixed solution, mixing evenly at regular intervals, centrifuging, and taking the supernatant to obtain the hydrotalcite solution adsorbed with bile acid. A method for determining bile acid in the hydrotalcite solution adsorbed with bile acid prepared by the above method is also provided. The adsorption method provided by the present invention has good repeatability and durability, the detection method has strong specificity and high accuracy, can effectively separate bile acid from the preparation excipients, and can more accurately detect the amount of bile acid; by investigating the in vitro adsorption ability of hydrotalcite tablets to bile acid, it provides a certain basis for rational clinical drug use.

[0114] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for adsorbing bile acids by magnesium aluminum carbonate chewable tablets, comprising the following steps: Mix the fine powder of magnesium aluminum carbonate chewable tablets and the hydrochloric acid solution of bile salt to obtain a mixed solution; Incubate the mixed solution, mix it evenly at regular intervals, centrifuge, and take the supernatant to obtain a magnesium aluminum carbonate solution adsorbed with bile acids.

2. The method according to claim 1, wherein The bile salt in the hydrochloric acid solution of bile salt is selected from sodium glycocholate, sodium taurocholate, sodium glycochenodeoxycholate, sodium taurochenodeoxycholate or sodium taurodeoxycholate.

3. The method according to claim 1, wherein The incubation temperature is 37 ± 0.5 °C, and the incubation time is 50 - 70 min; mix it evenly every 5 - 15 min during the incubation process.

4. The method according to claim 1, characterized in that The centrifugation speed is 1500 - 2500 rpm, and the centrifugation time is 13 - 17 min.

5. A method for determining bile acids in a magnesium aluminum carbonate solution adsorbed with bile acids prepared by the method according to any one of claims 1 - 4, comprising the following steps: Take the magnesium aluminum carbonate solution adsorbed with bile acids as the test sample solution; Take the hydrochloric acid solution of bile salt as the reference sample solution; Use high performance liquid chromatography, detect with an ultraviolet detector, and use octadecylsilane chemically bonded silica gel as the filler for the chromatographic column; Use a mixed solution of methanol, acetonitrile and phosphate solution as the mobile phase.

6. The measurement method according to claim 5, characterized in that, The column temperature is 25 - 35 °C, and the flow rate is 0.9 - 1.1 ml / min; The detection wavelength is 200 nm, and the injection volume is 10 - 20 μl.

7. The measurement method according to claim 5, characterized in that, In the mixed solution of methanol, acetonitrile and 0.05 mol / L phosphate solution, the volume ratio of methanol, acetonitrile and phosphate solution is (38:38:54) - (42:42:46).

8. The measurement method according to claim 5, characterized in that, The pH value of the mixed solution of methanol, acetonitrile and phosphate solution is 2.8 - 3.

2.

9. The measurement method according to claim 5, wherein Precisely measure 20 μl of each of the test sample solution and the reference sample solution, inject them into the liquid chromatograph, record the chromatogram, and calculate the adsorption rate of bile acids.

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