Two-dimensional vermiculite-based drug delivery system as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of drug delivery systems, and discloses a two-dimensional vermiculite-based drug delivery system and a preparation method and application thereof. The preparation method comprises the following steps: carrying out ion exchange on expanded vermiculite, NaCl and LiCl, stripping by using a mechanical stripping sheet, centrifuging to obtain a two-dimensional vermiculite nanosheet dispersion liquid, dispersing a drug in the two-dimensional vermiculite nanosheet dispersion liquid, and forming a film to obtain the two-dimensional vermiculite-based drug delivery unit. The drug is synergistically loaded between layers and on the surface of the vermiculite; rich hydroxyl groups and interlayer cations on the end surface of the vermiculite interact with the drug, so that the drug release time is relatively long; the vermiculite-based drug delivery system can realize gradient order release of drugs according to a sequence from the surface to the interlayer through pH response of an affected part. Meanwhile, the vermiculite-based drug delivery system provides an antibacterial effect through enzyme-like catalytic activity, and avoids the problems of abuse of antibiotics and drug resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of drug delivery systems, and in particular to a two-dimensional vermiculite-based drug delivery system and a preparation method and application thereof. Background Art

[0002] Existing conventional clinical treatments for oral mucosal diseases mainly include spraying solutions and applying ointments, but they all have the disadvantages of short duration of effect, poor adhesion, and improper dosage causing local redness and swelling, resulting in unsatisfactory treatment effects. Therefore, there is an urgent need to develop a multifunctional oral "Easy Patch" with good adhesion properties to solve these problems.

[0003] Currently, most oral patches or films available on the market are external application patches for treating skin diseases, and their drug carriers mostly use organic excipients such as sodium carboxymethyl cellulose, polyvinyl pyrrolidone and glycerol. Although organic drug carriers have good biocompatibility and degradability, their drug sustained-release effect is poor and the drug release behavior is difficult to control. At the same time, most existing products contain antibiotics (rukanamycin, gentamicin) and steroid drugs (such as dexamethasone). Long-term use of antibiotics can lead to dysbiosis, increased bacterial resistance, and may cause a series of serious problems that endanger human health, such as tooth development disorders and osteoporosis. Summary of the Invention

[0004] The purpose of the present invention is to provide a two-dimensional vermiculite-based drug delivery system and its preparation method and application, so as to solve the problems of existing oral films such as poor flexibility and adhesion, short drug efficacy, and antibiotic resistance.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a two-dimensional vermiculite-based drug delivery system, comprising the following steps:

[0007] The expanded vermiculite is reacted with a NaCl solution to obtain Na-containing vermiculite;

[0008] The Na-containing vermiculite is subjected to a second reaction with a LiCl solution to obtain the Li-containing vermiculite;

[0009] Lithium-ionized vermiculite and water were mechanically crushed and then centrifuged to obtain a dispersion of two-dimensional vermiculite nanosheets.

[0010] The two-dimensional vermiculite nanosheet dispersion and the drug solution are sequentially stirred and dialyzed to remove impurities to obtain a two-dimensional vermiculite-based drug mixture;

[0011] The two-dimensional vermiculite-based drug mixture is deposited on the base material through layer-by-layer self-assembly, filtration or coating, forming a vermiculite-based drug layer with adjustable micron-level thickness on the surface of the base material to obtain a two-dimensional vermiculite-based drug delivery system.

[0012] Preferably, the mass ratio of NaCl to expanded vermiculite in the NaCl solution is 40-70:1; the mass ratio of LiCl to expanded vermiculite in the LiCl solution is 3-7:1.

[0013] Preferably, the temperature of the first reaction is 100-120° C.; the time of the first reaction is 24-48 hours.

[0014] Preferably, the temperature of the second reaction is 100-120° C.; the time of the second reaction is 24-48 hours.

[0015] Preferably, the mechanical crushing time is 60 to 100 minutes; the centrifugal speed is 5000 to 7500 rpm; and the centrifugal time is 30 to 60 minutes.

[0016] Preferably, the drug is an analgesic and / or an antibacterial drug; the analgesic is one or more of lidocaine hydrochloride, bupivacaine hydrochloride, and ropivacaine hydrochloride; the antibacterial drug is cetyltrimethylammonium bromide and / or chlorhexidine acetate.

[0017] Preferably, the mass ratio of the two-dimensional vermiculite nanosheets in the two-dimensional vermiculite nanosheet dispersion to the drug in the drug solution is 1:1-50.

[0018] The present invention also provides a two-dimensional vermiculite-based drug delivery system prepared by a preparation method of the two-dimensional vermiculite-based drug delivery system.

[0019] The present invention also provides an application of a two-dimensional vermiculite-based drug delivery system in the preparation of drugs for treating oral mucosal diseases.

[0020] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention uses two-dimensional vermiculite nanosheets as a delivery system for amide-based local analgesics and amine-based cationic antibacterial drugs. Compared with traditional oral ulcer treatment methods, the two-dimensional vermiculite-based drug delivery system has the following advantages: (1) it fully utilizes the interaction between the abundant hydroxyl groups on the end faces of vermiculite and the interlayer cations and drug molecules, and has a longer drug release time; (2) the vermiculite-based drug delivery system can respond to the pH of the affected area and realize a gradient release of drugs from the surface to the interlayer; (3) the vermiculite-based drug delivery system provides an antibacterial effect through enzyme-like catalytic activity, avoiding the abuse of antibiotics and drug resistance problems; (4) the vermiculite-based drug delivery system has multiple forms of existence, and can be sprayed on the affected area in the form of a suspension or made into a drug film, with wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0023] Figure 1 This is an atomic force microscope image of the two-dimensional vermiculite nanosheets in the two-dimensional vermiculite nanosheet dispersion obtained in step (3) of Example 1; the inset is a longitudinal dimension image;

[0024] Figure 2 This is the appearance of the CA-HL / VMT pellicle prepared in Example 1;

[0025] Figure 3 This is a water contact angle test diagram of the VMT film prepared in Comparative Example 3;

[0026] Figure 4 This is a water contact angle test diagram of the CA-HL / VMT film prepared in Example 1;

[0027] Figure 5 The drug release concentration change curve of the CA-HL / VMT film prepared in Example 1;

[0028] Figure 6 This is the drug release concentration change curve of the Debaining Lidocaine Patch of Comparative Example 2;

[0029] Figure 7 This is a graph showing the skin adhesion test of the CA-HL / VMT film prepared in Example 1;

[0030] Figure 8 The antibacterial performance test diagram of the CA-HL / VMT film of Example 1, the HL / VMT film of Example 2, and the VMT film of Comparative Example 3;

[0031] Figure 9 This is a test diagram of the catalytic antibacterial performance of the VMT film of Comparative Example 3. DETAILED DESCRIPTION

[0032] The present invention provides a method for preparing a two-dimensional vermiculite-based drug delivery system, comprising the following steps:

[0033] The expanded vermiculite is reacted with a NaCl solution to obtain Na-containing vermiculite;

[0034] The Na-containing vermiculite is subjected to a second reaction with a LiCl solution to obtain the Li-containing vermiculite;

[0035] Lithium-ionized vermiculite and water were mechanically crushed and then centrifuged to obtain a dispersion of two-dimensional vermiculite nanosheets.

[0036] The two-dimensional vermiculite nanosheet dispersion and the drug solution are sequentially stirred and dialyzed to remove impurities to obtain a two-dimensional vermiculite-based drug mixture;

[0037] The two-dimensional vermiculite-based drug mixture is deposited on the base material through layer-by-layer self-assembly, filtration or coating, forming a vermiculite-based drug layer with adjustable micron-level thickness on the surface of the base material to obtain a two-dimensional vermiculite-based drug delivery system.

[0038] In the present invention, the preparation method of the expanded vermiculite is preferably as follows: the vermiculite ore (purchased in Yuli, Xinjiang) is repeatedly washed with deionized water and anhydrous ethanol for 6 times to remove dust and organic impurities; after drying, the mixture is mixed with hydrogen peroxide and vermiculite ore in a ratio of 2:1 and stored in the dark for 24 hours, and then placed in a 750W microwave oven for expansion treatment for 2 minutes; finally, the expanded vermiculite is sieved using a 5-mesh (4mm) sieve, and then a bulk density of 1 mg / cm is selected. 3 of expanded vermiculite.

[0039] In the present invention, the NaCl solution is preferably a saturated NaCl aqueous solution.

[0040] In the present invention, the mass ratio of NaCl to expanded vermiculite in the NaCl solution is preferably 40 to 70:1, more preferably 40 to 50:1, and even more preferably 40:1.

[0041] In the present invention, the concentration of the LiCl solution is preferably 2 mol / L.

[0042] In the present invention, the mass ratio of LiCl to expanded vermiculite in the LiCl solution is preferably 3 to 7:1, more preferably 3 to 5:1, and even more preferably 3:1.

[0043] In the present invention, the temperature of the first reaction is preferably 100-120°C, more preferably 105-115°C, and more preferably 110°C; the time of the first reaction is preferably 24-48h, more preferably 24-36h, and more preferably 24h.

[0044] In the present invention, after the first reaction is completed, the process further includes washing with water and anhydrous ethanol alternately.

[0045] In the present invention, the temperature of the second reaction is preferably 100-120°C, more preferably 105-115°C, and more preferably 110°C; the time of the second reaction is preferably 24-48h, more preferably 24-36h, and more preferably 24h.

[0046] In the present invention, after the second reaction is completed, the process further includes washing with water and anhydrous ethanol alternately.

[0047] In the present invention, the mechanical crushing time is preferably 60 to 100 min, more preferably 70 to 100 min, and even more preferably 90 min.

[0048] In the present invention, the mechanical crushing instrument is preferably a mechanical crusher; the power of the mechanical crusher is preferably 150W; the working mode of the mechanical crusher is preferably: work for 5 seconds and rest for 5 seconds.

[0049] In the present invention, the centrifugal speed is preferably 5000-7500 rpm, more preferably 5000-6000 rpm, and more preferably 5000 rpm; the centrifugal time is preferably 30-60 min, more preferably 30-40 min, and more preferably 30 min.

[0050] In the present invention, the drug is preferably an analgesic and / or an antibacterial drug, and is further preferably an analgesic and an antibacterial drug; the analgesic is preferably one or more of lidocaine hydrochloride, bupivacaine hydrochloride, and ropivacaine hydrochloride, and is further preferably lidocaine hydrochloride or bupivacaine hydrochloride, and is more preferably lidocaine hydrochloride; the antibacterial drug is preferably cetyltrimethylammonium bromide and / or chlorhexidine acetate, and is further preferably cetyltrimethylammonium bromide or chlorhexidine acetate, and is more preferably chlorhexidine acetate.

[0051] In the present invention, the mass ratio of the two-dimensional vermiculite nanosheets in the two-dimensional vermiculite nanosheet dispersion to the drug in the drug solution is preferably 1:1-50.

[0052] In the present invention, when the drug is lidocaine hydrochloride, the mass ratio of the two-dimensional vermiculite nanosheets to the lidocaine hydrochloride is preferably 1:1; when the drug is bupivacaine hydrochloride, the mass ratio of the two-dimensional vermiculite nanosheets to the bupivacaine hydrochloride is preferably 1:10; when the drug is ropivacaine hydrochloride, the mass ratio of the two-dimensional vermiculite nanosheets to the ropivacaine hydrochloride is preferably 1:15.

[0053] In the present invention, the concentration of the two-dimensional vermiculite nanosheet dispersion is preferably 0.2 mg / mL.

[0054] In the present invention, the molecular cutoff of the dialysis bag for dialysis impurity removal is preferably 12-14KD, more preferably 12-13KD, and even more preferably 12KD; the time for dialysis impurity removal is preferably 24h.

[0055] In the present invention, the base material is preferably a mixed cellulose ester membrane; the pore size of the mixed cellulose ester membrane is preferably 0.45 μm, and the diameter is preferably 25 mm.

[0056] The present invention also provides a two-dimensional vermiculite-based drug delivery system prepared by a preparation method of the two-dimensional vermiculite-based drug delivery system.

[0057] The present invention also provides an application of a two-dimensional vermiculite-based drug delivery system in the preparation of drugs for treating oral mucosal diseases.

[0058] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0059] Example 1

[0060] This embodiment provides a method for preparing a two-dimensional vermiculite-based drug delivery system, comprising the following steps:

[0061] (1) Expanded vermiculite (VMT) and a saturated aqueous solution of NaCl (the mass ratio of NaCl to expanded vermiculite is 40:1) were heated at 110 °C for 24 h. After the reaction, the solution was washed alternately with water and anhydrous ethanol until no Cl was detected. - , obtain Na vermiculite;

[0062] (2) Na-dihydrated vermiculite was heated with 2 mol / L LiCl solution (the mass ratio of LiCl to expanded vermiculite was 3:1) at 110 °C for 24 h. After the reaction, the solution was washed alternately with water and anhydrous ethanol until no Cl was detected. - , obtain Li-ion vermiculite;

[0063] (3) Li-ionized vermiculite was mixed with water and mechanically exfoliated using a mechanical crusher at 150 W. The mechanical crusher worked for 5 seconds and rested for 5 seconds, with a total working time of 90 minutes. The mixture was then centrifuged at 5000 rpm for 30 minutes, and the supernatant was collected to obtain a 0.2 mg / mL two-dimensional vermiculite nanosheet dispersion.

[0064] (4) 10 mL of 0.2 mg / mL two-dimensional vermiculite nanosheet dispersion was added dropwise with 10 mg / mL lidocaine hydrochloride (HL) at a rate of 20 μL / time, with a total amount of 1 mL added; then 5 mg / mL chlorhexidine acetate (CA) was added dropwise, with a total amount of 4 mL added, and magnetic stirring was performed for 24 h; then, the mixture was dialyzed for 24 h using a dialysis bag with a molecular cutoff of 12 kD to remove impurities, and the dialyzation water was changed every 2 h to obtain a two-dimensional vermiculite-based drug mixture;

[0065] (5) A microporous filter membrane with a diameter of 25 mm and a pore size of 0.45 μm was placed on the sand core solvent filter, and then a two-dimensional vermiculite-based drug mixture was added to prepare a two-dimensional vermiculite-based drug film on the surface of the microporous filter membrane through layer-by-layer self-assembly. After removing the microporous filter membrane, a two-dimensional vermiculite-based drug delivery system was obtained, which was recorded as CA-HL / VMT drug film.

[0066] Example 2

[0067] This embodiment provides a method for preparing a two-dimensional vermiculite-based drug delivery system. For details, refer to Example 1, except that chlorhexidine acetate is not added in step (4), and is recorded as HL / VMT film.

[0068] Example 3

[0069] This embodiment provides a method for preparing a two-dimensional vermiculite-based drug delivery system, which is specifically described in Example 1, except that lidocaine hydrochloride is not added in step (4), and is referred to as CA / VMT film.

[0070] Example 4

[0071] This embodiment provides a method for preparing a two-dimensional vermiculite-based drug delivery system. For details, see Example 2, except that in step (4), lidocaine hydrochloride is replaced with bupivacaine hydrochloride (HB), which is recorded as HB / VMT film.

[0072] Example 5

[0073] This embodiment provides a method for preparing a two-dimensional vermiculite-based drug delivery system. For details, see Example 2, except that in step (4), lidocaine hydrochloride is replaced with ropivacaine hydrochloride (HR), which is recorded as HR / VMT film.

[0074] Comparative Example 1

[0075] This comparative example provides a method for preparing a two-dimensional vermiculite-based drug delivery system. For details, see Example 2, except that in step (4), lidocaine hydrochloride is replaced with sodium 3-hydroxybutyrate (3HB) (anti-inflammatory drug), which is recorded as 3HB / VMT film.

[0076] Comparative Example 2

[0077] This comparative example provides a Debaining lidocaine patch, which is a commercially available product.

[0078] Comparative Example 3

[0079] This comparative example provides a method for preparing a two-dimensional vermiculite-based film, which is specifically described in Example 1, except that step (4) is not performed, and the two-dimensional vermiculite nanosheet dispersion of step (3) is subjected to layer-by-layer self-assembly in step (5), which is recorded as a VMT film.

[0080] The drug release test was conducted on the drug films of Examples 1 to 5 and Comparative Examples 1 to 2. The specific method was as follows: the drug films were added to a PBS buffer solution with a pH of 4.5 for drug release. At the same time, in order to prevent the drug films from swelling and breaking during the drug release process, the drug films and PBS buffer solution were assembled into a whole using a dialysis bag and placed in a beaker. Then, 3 mL of the liquid outside the bag was aspirated at regular intervals and placed in a quartz dish for absorbance measurement to obtain the drug release concentration at that moment. The results are shown in Table 1. The cumulative amount of drug released was calculated according to the following formula (1).

[0081]

[0082] Where:

[0083] M t ——Cumulative amount of drug released (mg),

[0084] V——the total volume of the medium solution in the beaker (mL),

[0085] C n ——The concentration of the solution corresponding to the nth extraction (mg / mL),

[0086] C i ——Concentration of solution corresponding to the i-th extraction (mL)

[0087] V i ——The volume of each extraction solution (mL).

[0088] Table 1 Drug release concentration of the film

[0089]

[0090]

[0091] As shown in Table 1, HL, HB, and HR all exhibited excellent sustained-release properties, demonstrating the excellent compatibility of the vermiculite nanosheet structure for amide drugs. This also reveals that drug loading within the two-dimensional confined interlayer channels of vermiculite is size-dependent. The smaller lidocaine hydrochloride exhibited the most sustained sustained-release effect. Example 1 demonstrates the dual analgesic and antibacterial properties of the vermiculite-based delivery unit. Comparative Example 1 exhibited a higher sustained-release rate of 3-hydroxybutyric acid, due to its smaller size, which allows for easier entry and exit of the vermiculite space.

[0092] The two-dimensional vermiculite nanosheets in the two-dimensional vermiculite nanosheet dispersion obtained in step (3) of Example 1 were tested by atomic force microscopy. The results are as follows: Figure 1 As shown. Figure 1 It can be seen that the radial size of the two-dimensional vermiculite nanosheet is about 650nm ( Figure 1 ), with a longitudinal dimension of approximately 4 nm ( Figure 1 illustration).

[0093] The appearance of the CA-HL / VMT film prepared in Example 1 is as follows: Figure 2 shown.

[0094] The CA-HL / VMT film prepared in Example 1 and the VMT film prepared in Comparative Example 3 were tested for water contact angle. The results are as follows: Figure 3 、 Figure 4 As shown. Figure 3 、 Figure 4 It can be seen that the contact angle of CA-HL / VMT film is increased by 35.87° compared with pure vermiculite film, which shows that compared with pure vermiculite film, the surface adhesion of the film is conducive to oral adhesion and is not particularly hydrophilic.

[0095] The drug release concentration variation curve of the CA-HL / VMT film prepared in Example 1 is as follows: Figure 5 As shown. Figure 5 It can be seen that the drug release mode is rapid from 0 to 8 hours. During this stage, lidocaine hydrochloride and chlorhexidine acetate connected to the drug molecules on the vermiculite surface through van der Waals forces are first released under acidic conditions; the drug release mode is sustained from 9 to 24 hours. During this stage, lidocaine hydrochloride molecules and chlorhexidine acetate molecules that enter the vermiculite layers are gradually released into the environment.

[0096] The drug release concentration change curve of the Debaining Lidocaine patch of Comparative Example 2 is as follows: Figure 6 As shown. Figure 6 It can be seen that there is a significant difference in the concentration change of the drug release curve between the CA-HL / VMT film and the present invention.

[0097] The skin adhesion test of CA-HL / VMT film prepared in Example 1 was carried out. The results are as follows: Figure 7 As shown. Figure 7 The film exhibits excellent adhesion, significantly addressing issues such as short adherence and easy detachment of oral medications. Furthermore, the film provides analgesic and antibacterial effects through the gradient release of lidocaine hydrochloride and chlorhexidine acetate, respectively.

[0098] The antibacterial performance of the CA-HL / VMT film of Example 1, the HL / VMT film of Example 2, and the VMT film of Comparative Example 3 were tested. The results are as follows: Figure 8 As shown. Figure 8 It can be seen that the drug film of the present invention has an inhibition rate of more than 95% against Escherichia coli and Staphylococcus aureus.

[0099] In addition, in order to evaluate the catalytic antibacterial performance of vermiculite, the antibacterial performance test was conducted on the VMT film of Comparative Example 3, which was recorded as the H2O2+VMT group. On the basis of the H2O2+VMT group, near infrared irradiation was added, which was recorded as the H2O2+VMT+NIR group. The group containing only H2O2 but not the VMT film of Comparative Example 3 was recorded as the H2O2 group, and the group containing neither the VMT film of Comparative Example 3 nor H2O2 was recorded as the Control group. The results are shown in the figure. Figure 9 As shown. Figure 9 It can be seen that the iron element in the octahedral structure of vermiculite has an enhancing effect on the catalysis of H2O2 (a metabolite of oral Streptococcus) under 808nm near-infrared irradiation, and exhibits enhanced antibacterial properties.

[0100] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a two-dimensional vermiculite-based drug delivery system, characterized in that: The following steps are involved: The expanded vermiculite is reacted with a NaCl solution to obtain Na-containing vermiculite; The Na-containing vermiculite is subjected to a second reaction with a LiCl solution to obtain Li-containing vermiculite; Lithium-ionized vermiculite and water were mechanically crushed and then centrifuged to obtain a dispersion of two-dimensional vermiculite nanosheets. The two-dimensional vermiculite nanosheet dispersion and the drug solution are sequentially stirred and dialyzed to remove impurities to obtain a two-dimensional vermiculite-based drug mixture; The two-dimensional vermiculite-based drug mixture is deposited on the base material through layer-by-layer self-assembly, filtration or coating, forming a vermiculite-based drug layer with adjustable micron-level thickness on the surface of the base material to obtain a two-dimensional vermiculite-based drug delivery system.

2. The method for preparing a two-dimensional vermiculite-based drug delivery system according to claim 1, wherein: The mass ratio of NaCl to expanded vermiculite in the NaCl solution is 40-70:1; the mass ratio of LiCl to expanded vermiculite in the LiCl solution is 3-7:

1.

3. The method for preparing a two-dimensional vermiculite-based drug delivery system according to claim 2, wherein: The temperature of the first reaction is 100-120° C.; the time of the first reaction is 24-48 hours.

4. The method for preparing a two-dimensional vermiculite-based drug delivery system according to claim 3, wherein: The temperature of the second reaction is 100-120° C.; the time of the second reaction is 24-48 hours.

5. The method for preparing a two-dimensional vermiculite-based drug delivery system according to claim 3 or 4, characterized in that: The mechanical crushing time is 60 to 100 minutes; the centrifugal speed is 5000 to 7500 rpm; and the centrifugal time is 30 to 60 minutes.

6. The method for preparing a two-dimensional vermiculite-based drug delivery system according to claim 5, characterized in that: The drug is an analgesic and / or an antibacterial drug; the analgesic is one or more of lidocaine hydrochloride, bupivacaine hydrochloride, and ropivacaine hydrochloride; the antibacterial drug is cetyltrimethylammonium bromide and / or chlorhexidine acetate.

7. The method for preparing a two-dimensional vermiculite-based drug delivery system according to claim 6, characterized in that: The mass ratio of the two-dimensional vermiculite nanosheets in the two-dimensional vermiculite nanosheet dispersion to the drug in the drug solution is 1:1-50.

8. A two-dimensional vermiculite-based drug delivery system prepared by the method for preparing a two-dimensional vermiculite-based drug delivery system according to any one of claims 1 to 7.

9. Use of the two-dimensional vermiculite-based drug delivery system according to claim 8 in the preparation of drugs for treating oral mucosal diseases.

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