A pretreatment method for sustained-release drug content detection and its detection method and application

Abstract

The present invention belongs to the technical field of chemical analysis, and discloses a pretreatment method for detecting the content of a sustained-release drug, wherein an ionic salt or a pharmaceutical excipient with a swelling effect is added to a sample solution of an aqueous solvent for extraction. The present invention first optimizes the sample pretreatment process, improves the recovery rate, shortens the sample preparation time and reduces the viscosity of the sample solution, establishes high-performance liquid chromatography conditions, and detects the content of pregabalin sustained-release tablets by a high-performance liquid chromatograph, and the detection method has the advantages of high specificity and high sensitivity.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis, and in particular relates to a pretreatment method for detecting the content of a sustained-release drug, a detection method and an application thereof. Background Art

[0002] Drugs are generally used in the form of preparations for the prevention, treatment and diagnosis of diseases. Their effectiveness, safety, rationality and precision reflect the level of medicine and determine the effect of the drug. The first generation of drugs are simply processed into pastes, pills, tablets, injections, capsules and aerosols for oral and external use. The activity of the second generation of drugs has been greatly improved and is now widely used in clinical practice. The third generation of drugs uses new drug excipients to control the release rate of tablets and capsules through membrane control technology, skeleton blocking technology and coating technology, so as to release at a fixed time and speed, which can effectively delay the duration of blood drug concentration, provide safety of medication and reduce adverse reactions; sustained-release preparations can continuously release drugs for a long time after medication to achieve a sustained effect. Its advantages include fewer dosing times, small fluctuations in peak and trough blood drug concentrations, reduced gastrointestinal adverse reactions, slow release, reduced absorption rate, safety and economy, etc.

[0003] However, due to the application of new sustained-release materials in sustained-release preparations, such as sustained-release skeleton materials and high-viscosity excipients, it is difficult to determine the content of the main drug and related substances in the later sustained-release preparations. For example, pregabalin sustained-release tablets, trade name Lyrica CR, pregabalin is a newly developed drug for the treatment of chronic pain, mainly used to treat neuropathic pain (DPN) associated with diabetic peripheral neuropathy and postherpetic neuralgia (PHN). Its characteristics are that it can greatly improve the quality of life of patients with chronic pain, especially neuropathic pain. It is generally welcomed by clinicians and patients for its excellent efficacy and fewer adverse reactions. The first dosage form of pregabalin to be marketed was capsules. Because capsules need to be administered multiple times a day, the blood drug concentration in the body fluctuates greatly, so there are more adverse reactions. Because of the frequent administration, the patient's compliance is poor. Therefore, Pfizer has developed pregabalin sustained-release tablets. Sustained-release tablets administered once a day can effectively reduce the occurrence of adverse reactions and increase patient compliance.

[0004] However, pregabalin sustained-release tablets are a type of sustained-release preparation that contains both a hydrophilic gel skeleton and high-viscosity excipients. Its characteristic is that after taking the drug, gastrointestinal fluid enters the skeleton, causing it to swell and form a gel barrier, and the active drug slowly dissolves and is released through the barrier to achieve a long-term sustained-release effect. However, due to the swelling of the hydrophilic gel skeleton material in water and the presence of high-viscosity excipients, compared with ordinary sustained-release tablets containing only a hydrophilic gel skeleton, its matrix system has a higher viscosity, resulting in poor fluidity. It is difficult to disperse or centrifuge during the pretreatment process of drug testing, and it is impossible to perform related tests on the content and related substances of the active drug. The current "Chinese Pharmacopoeia" does not include relevant analytical methods for pregabalin sustained-release tablets, nor does it have import registration standards for reference.

[0005] Therefore, providing a simple and efficient pretreatment method and detection method for sustained-release drug content detection is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] In view of this, the present invention provides a pretreatment method for sustained-release drug content detection and a detection method thereof, which effectively solves the problems that the main drug recovery rate of the test solution prepared in the prior art is low and the solution viscosity is high, which easily causes clogging of the chromatographic column during high-performance liquid chromatography analysis.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A pretreatment method for detecting the content of a sustained-release drug includes adding ionic salts or pharmaceutical excipients with swelling effects into a sample solution for extraction.

[0009] In the prior art, carbomer and other polymer excipients become gel-like when in contact with water, and other polymer excipients make the solution too viscous, so that the raw material drug cannot be completely dissolved. The present invention can effectively reduce the viscosity of the polymer solution by adding electrolytes to precipitate the polymer, and different salts have an improving effect on the dissolution of the drug; or add insoluble excipients that swell when in contact with water, so that the precipitate in the tablet powder solution becomes fluffy, which is more conducive to the extraction of the active ingredient.

[0010] Preferably, the ionic salt includes at least one of hydrochloride, sulfate, nitrate, citrate, tartrate, phosphate and acetate.

[0011] Preferably, the hydrochloride comprises at least one of sodium chloride, potassium chloride and ammonium chloride;

[0012] The sulfate includes sodium sulfate and / or ammonium sulfate;

[0013] The nitrate includes sodium nitrate and / or potassium nitrate;

[0014] The citrate comprises at least one of sodium citrate, potassium citrate and ammonium citrate;

[0015] The tartrate includes ammonium tartrate and / or potassium sodium tartrate;

[0016] The phosphate includes at least one of sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, ammonium phosphate, diammonium hydrogen phosphate and ammonium dihydrogen phosphate;

[0017] The acetate includes at least one of sodium acetate, potassium acetate and ammonium acetate.

[0018] Preferably, the dosage of the ionic salt is: based on the total amount of the high molecular weight polymer in the sample solution, each portion of the high molecular weight polymer requires 28-885 portions of the ionic salt.

[0019] Preferably, 57-115 parts of the ionic salt are required for each part of the high molecular weight polymer.

[0020] Preferably, the dosage of the ionic salt is: based on the total amount of the polymer, each part of the polymer requires 28-207 parts of sodium chloride, 28-197 parts of potassium chloride, 28-213 parts of ammonium chloride, 28-161 parts of sodium sulfate, 28-434 parts of ammonium sulfate, 28-506 parts of sodium nitrate, 28-190 parts of potassium nitrate, 28-885 parts of sodium citrate, 28-187 parts of potassium citrate, 28-140 parts of ammonium citrate, and ...0 parts of ammonium tartrate. 28-222 parts, 28-315 parts of potassium sodium tartrate, 28-36 parts of sodium phosphate, 28-44 parts of sodium monohydrogen phosphate, 28-50 parts of sodium dihydrogen phosphate, 28-57 parts of potassium phosphate, 28-79 parts of dipotassium hydrogen phosphate, 28-130 parts of potassium dihydrogen phosphate, 28-150 parts of ammonium phosphate, 28-394 parts of diammonium hydrogen phosphate, 28-215 parts of ammonium dihydrogen phosphate, 28-190 parts of sodium acetate, 28-56 parts of potassium acetate, and 28-44 parts of ammonium acetate.

[0021] Preferably, the pharmaceutical excipient having a swelling effect includes at least one of cross-linked polyvinyl pyrrolidone, low-substituted hydroxypropyl cellulose, cross-linked sodium carboxymethyl cellulose and sodium carboxymethyl starch.

[0022] Preferably, the dosage of the pharmaceutical excipient with swelling effect is: based on the total amount of the high molecular weight polymer in the sample solution, each portion of the high molecular weight polymer requires 0.5-4 portions of the pharmaceutical excipient with swelling effect.

[0023] Preferably, each portion of the high molecular weight polymer requires 1-3 portions of the pharmaceutical excipient having a swelling effect.

[0024] Preferably, the aqueous solvent is an acidic aqueous solution with a pH of 1-5.

[0025] Preferably, the pH value of the acidic aqueous solution is 1-3.

[0026] Preferably, the acidic aqueous solution includes at least one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, citric acid and tartaric acid.

[0027] Preferably, the specific steps of the extraction are: grinding the sustained-release drug, mixing it evenly with an ionic salt or a pharmaceutical excipient with a swelling effect, adding it to an aqueous solvent, stirring and extracting it, and filtering it.

[0028] Preferably, the pH value of the hydrochloric acid solution is 1.2.

[0029] A method for detecting the content of a sustained-release drug adopts the pretreatment method described above.

[0030] Preferably, the HPLC conditions of the detection method are:

[0031] Chromatographic column: Octadecylsilane bonded silica gel as filler Inertsil ODS-3, or other chromatographic columns with similar polarity;

[0032] Mobile phase: 3.4 g / L potassium dihydrogen phosphate-methanol 85:15

[0033] Flow rate: between 0.8-1.2ml / min;

[0034] Injection volume: 50 μl;

[0035] Detection wavelength: 210nm;

[0036] Column temperature: between 25-35℃.

[0037] Application of the above-mentioned detection method in the content determination of pregabalin sustained-release tablets.

[0038] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) The present invention first optimizes the sample pretreatment process, shortens the sample preparation time and reduces the viscosity of the sample solution, improves the recovery rate of the active substance, establishes high performance liquid chromatography conditions, and detects the content of pregabalin sustained-release tablets by high performance liquid chromatography. The detection method has the advantages of high specificity and high sensitivity;

[0040] (2) The present invention selects different extraction solvents, optimizes the pretreatment process, reduces the viscosity of the test solution, reduces the damage to the high performance liquid chromatography column, prepares a stable sample solution, improves experimental efficiency, avoids the harm caused by organic reagents, and reduces the detection cost. The detection method of the present invention can effectively detect the content of pregabalin sustained-release tablets, and the sample pretreatment method can be extended and applied to auxiliary material samples containing high molecular weight polymers. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] A method for detecting the content of a sustained-release drug, comprising the following steps:

[0043] Reference solution: Take about 10 mg of pregabalin reference substance, weigh accurately, place in a 10 ml volumetric flask, dissolve in pH 1.2 hydrochloric acid solution and quantitatively dilute;

[0044] Test solution: Take 20 pregabalin sustained-release tablets, accurately weigh, grind, accurately weigh an appropriate amount of tablet powder 460 mg and place it in a 100 ml volumetric bottle, add an appropriate amount of salt or excipients, stir magnetically for about 1 min to mix, add 50 ml of pH 1.2 hydrochloric acid solution, stir magnetically, dilute to the scale with pH 1.2 hydrochloric acid solution, shake well, filter, and take the filtrate;

[0045] Instrument: Thermo Fisher UltiMate 3000 HPLC

[0046] The HPLC conditions were:

[0047] Chromatographic column: octadecylsilane bonded silica gel as filler Inertsil ODS-3 (4.6mm*0.25m, 5μm);

[0048] Mobile phase: 3.4 g / L potassium dihydrogen phosphate (adjust pH to 6.3 with ammonia)-methanol (85:15)

[0049] Flow rate: 1.0ml / min

[0050] Injection volume: 50 μl

[0051] Detection wavelength: 210nm

[0052] Column temperature: 30°C

[0053] Example 1

[0054] Example 1 The amount of salt added and the magnetic stirring time are shown in Table 1 below.

[0055] Table 1 Related parameters of Example 1

[0056] Salt Name Addition amount (g) Magnetic stirring time (h) Recovery rate (%) Potassium chloride 15 4 100.09 Sodium sulfate 15 4 99.98 Sodium chloride 15 4 99.85

[0057] It can be seen from the data in Table 1 that under the same conditions of the addition amount of the above three salts and the same stirring time, the three salts can effectively improve the recovery rate of the active ingredient and improve the viscosity of the solution.

[0058] Example 2

[0059] Example 2 The amount of salt added and the magnetic stirring time are shown in Table 2 below.

[0060] Table 2 Related parameters of Example 2

[0061] Salt Name Addition amount (g) Magnetic stirring time (h) Recovery rate (%) Potassium chloride 5 0.5 93.63 Potassium chloride 5 1 95.58 Potassium chloride 10 0.5 97.23 Potassium chloride 10 1 99.86 Sodium sulfate 5 0.5 92.36 Sodium sulfate 5 1 94.38 Sodium sulfate 10 0.5 97.03 Sodium sulfate 10 1 100.01 Sodium chloride 5 0.5 91.23 Sodium chloride 5 1 93.01 Sodium chloride 10 0.5 95.27 Sodium chloride 10 1 99.47

[0062] It can be seen from the data in the above table that when the amount of salt used is not less than 10g and the magnetic stirring time is not less than 1h, the sample recovery rate can meet the requirements (98.0% to 102.0%).

[0063] Example 3

[0064] The amount of auxiliary materials added and the magnetic stirring time of Example 3 are shown in Table 3 below.

[0065] Table 3 Related parameters of Example 3

[0066] Excipient name Addition amount (g) Magnetic stirring time (h) Recovery rate (%) Crospovidone 0.46 4 99.63 Low substituted hydroxypropyl cellulose 0.46 4 98.52 Croscarmellose Sodium 0.46 4 98.87

[0067] It can be seen from the above table that the above three excipients with swelling effect can effectively improve the recovery rate of active ingredients under the same conditions of addition amount and stirring time. Because there are suspended matter in the three test solutions, they need to be centrifuged before entering the high performance liquid chromatograph for detection.

[0068] Example 4

[0069] The amount of auxiliary materials added and the magnetic stirring time of Example 4 are shown in Table 4 below.

[0070] Table 4 Related parameters of Example 4

[0071] Excipient name Addition amount (g) Magnetic stirring time (h) Recovery rate (%) Crospovidone 0.23 0.5 92.41 Crospovidone 0.23 1 98.49 Crospovidone 0.46 0.5 91.25 Crospovidone 0.46 1 99.05 Low substituted hydroxypropyl cellulose 0.23 0.5 89.63 Low substituted hydroxypropyl cellulose 0.23 1 98.77 Low substituted hydroxypropyl cellulose 0.46 0.5 92.40 Low substituted hydroxypropyl cellulose 0.46 1 98.43 Croscarmellose Sodium 0.23 0.5 87.47 Croscarmellose Sodium 0.23 1 98.49 Croscarmellose Sodium 0.46 0.5 90.08 Croscarmellose Sodium 0.46 1 98.81

[0072] It can be seen from the data in the above table that when the amount of auxiliary materials used is not less than 0.23g and the magnetic stirring time is not less than 1h, the sample recovery rate can meet the requirements (98.0% to 102.0%).

[0073] Method validation by salt treatment of samples:

[0074] (1) Linear test:

[0075] The pregabalin reference substance was prepared into a concentration gradient of 0.3, 0.5, 6.6, 0.8, and 1 mg / ml for determination, and the regression equation and correlation coefficient were calculated according to the chromatogram, with the concentration of the reference solution as the abscissa and the peak area as the ordinate, and a good linear relationship was obtained, with a correlation coefficient of 0.9996, which met the content detection requirements of pregabalin sustained-release tablets;

[0076] (2) Precision test:

[0077] Prepare 0.66 mg / ml test solution (add appropriate amount of salt) and reference solution, inject 6 times in succession. Another person uses other instruments and the same method to test 6 times, and the RSD of sample recovery is 0.63%.

[0078] (4) Repeatability test:

[0079] Weigh 9 portions of the same flake powder, treat the samples according to the steps of the salting-out method, and detect them using the present chromatographic conditions. The repeatability of this method is tested by calculating the RSD of the peak area of ​​each sample test result. The measurement results show that the RSD of the peak area is 0.37%, indicating that the repeatability of this method is good.

[0080] (5) Solution stability test:

[0081] The samples were treated with salt and measured under the same chromatographic conditions. The samples were injected and measured at 0, 3, 6, 9, 12, and 24 hours. The RSD of the peak area of ​​each sample was 0.27, indicating that the sample solution was stable within 24 hours.

[0082] Comparative Example 1

[0083] Patent CN111999157A discloses a method for pre-treatment of hydrophilic gel skeleton sustained-release solid preparations, which describes the use of organic solvents as dispersion solvents and the precipitation of inorganic salts to improve the fluidity of the solution system. The method of patent CN111999157A was used to conduct experiments, first using organic solvents methanol and acetonitrile for dispersion, and then calcium salt precipitation. The results are as follows:

[0084] The amount of salt added and the ultrasonic time of Comparative Example 1 are shown in Table 5 below.

[0085] Table 5 Related parameters of comparative example 1

[0086] Organic solvents Salt Name Addition amount (g) Ultrasonic time (min) Recovery rate (%) Methanol Calcium chloride 10 15 89.02 Acetonitrile Calcium chloride 10 15 88.67

[0087] The recovery rate of the sample treated by the method of patent CN111999157A is low. Organic solvents are used for dispersion, but pregabalin is insoluble in organic solvents, and the use of organic solvents is harmful to the human body and the environment. The precipitation effect of calcium salt is not ideal, the viscosity of the solution is not reduced, the solution is not easy to filter, and centrifugation is required before entering the high-performance liquid phase for sample detection. This method has cumbersome steps and an unsatisfactory recovery rate. The present invention does not use organic solvents and can effectively reduce the viscosity of the test solution.

[0088] Comparative Example 2

[0089] The solvent used in the present invention was replaced with water to process the sample, while other conditions remained unchanged.

[0090] The amount of salt added and the magnetic stirring time of Comparative Example 2 are shown in Table 6 below.

[0091] Table 6 Related parameters of comparative example 2

[0092] Salt Name Addition amount (g) Magnetic stirring time (h) Recovery rate (%) Potassium chloride 10 1 93.67 Sodium sulfate 10 1 94.12 Sodium chloride 10 1 92.84

[0093] It can be seen from the data in Table 2 that when water is used as a solvent, the recovery rate is low. This may be because pregabalin has both acidic and basic groups and its solubility in water is not as good as in a slightly acidic solvent. It may also be because the viscosity of high molecular weight compounds such as carbomer can also be reduced under acidic conditions.

[0094] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pretreatment method for detecting the content of pregabalin sustained-release tablets, characterized in that: A pharmaceutical excipient having a swelling effect is added to a sample solution of an aqueous solvent for extraction; The specific steps of the extraction are: grinding the pregabalin sustained-release tablets, mixing them evenly with the pharmaceutical excipients having a swelling effect, adding the aqueous solvent, stirring and extracting, filtering, and using them for high performance liquid chromatography detection; The pharmaceutical excipient with swelling effect is at least one of cross-linked polyvinyl pyrrolidone, low-substituted hydroxypropyl cellulose, cross-linked sodium carboxymethyl cellulose and sodium carboxymethyl starch; The dosage of the pharmaceutical excipient with swelling effect is as follows: based on the total amount of the high molecular weight polymer in the sample solution, each portion of the high molecular weight polymer requires 0.5-4 portions of the pharmaceutical excipient with swelling effect; The aqueous solvent is an acidic aqueous solution with a pH of 1-5.

2. The pretreatment method for detecting the content of pregabalin sustained-release tablets according to claim 1, characterized in that: The aqueous solvent is a hydrochloric acid solution with a pH value of 1.

2.

3. A method for detecting the content of pregabalin sustained-release tablets, characterized in that: The pretreatment method according to any one of claims 1 to 2 is adopted.

4. The method for detecting the content of pregabalin sustained-release tablets according to claim 3, characterized in that: The HPLC conditions of the detection method are: Chromatographic column: octadecylsilane bonded silica gel as filler Inertsil ODS-3; Mobile phase: 3.4 g / L potassium dihydrogen phosphate-methanol 85:15; Flow rate: 0.8-1.2ml / min; Injection volume: 50 μl; Detection wavelength: 210nm; Column temperature: 25-35℃.