Albendazole solid dispersing agent as well as preparation method and application thereof

Abstract

The invention belongs to the field of microorganisms, and discloses an albendazole solid dispersing agent and a preparation method and application thereof, and the albendazole solid dispersing agent comprises albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate; the albendazole exists in the albendazole solid dispersing agent in an amorphous state form. According to the dispersing agent, the solubility of albendazole in water can be remarkably improved by 3.15 times, drug release can be effectively avoided in an acid environment, and slow drug release can be kept in a weak alkali environment. Meanwhile, the invention also provides a preparation method and application of the albendazole solid dispersant.

Description

Technical Field

[0001] The invention relates to the field of new materials, and in particular to an albendazole solid dispersant and a preparation method and application thereof. Background Art

[0002] Solid dispersants (co-precipitated compounds) are poorly soluble drugs that are dispersed in a physiologically inert and water-soluble carrier in the form of molecules, colloids or ultrafine particles by methods such as co-dissolution or spray encapsulation. After entering the gastrointestinal tract, the water-soluble carrier dissolves rapidly, and the drug is rapidly and completely released from the carrier into particles that are much smaller than the micronized particles, thereby producing a highly efficient and rapid effect. It also has the advantages of drug stability, no gastric obstruction, masking of bitterness, and improved bioavailability.

[0003] Albendazole (ABZ) is a BCS class II alkaline drug that has therapeutic and preventive effects on whipworm disease. However, due to its poor solubility and pH sensitivity, the therapeutic rate of oral ABZ is not ideal, and high-dose use can easily cause developmental toxicity in animals.

[0004] After ABZ is orally absorbed and enters the blood, it undergoes a strong first-pass effect and is rapidly metabolized into albendazole sulfoxide (ABZSO) and albendazole sulfone (ABZSO2). The main components with insecticidal activity are ABZ and ABZSO. However, clinical evidence shows that the cure rate of oral ABZ for whipworm infection is still low, and the use of high-dose albendazole may cause developmental toxicity in animals. This may be due to the low solubility, easy crystallization and pH sensitivity of ABZ, which causes ABZ to dissolve in the gastric acid environment and be rapidly absorbed. At the same time, the unabsorbed drug enters the small intestine and large intestine (the main parasitic environment of gastrointestinal nematodes) with gastric emptying, and rapidly crystallizes and precipitates with the increase in pH, thereby affecting the efficacy of the drug. Although various formulation strategies have been explored to improve its water solubility, these include the addition of surfactants such as Tween 80 and bile salts, the development of self-microemulsifying preparations, solid lipid nanoparticles, the preparation of solid dispersions, cyclodextrin inclusion compounds and co-crystals. However, while these strategies improve the solubility of ABZ, they also seem to inevitably increase the peak concentration of the drug in the blood. This may lead to a further increase in the toxic side effects of ABZ.

[0005] The following techniques can be used to prepare solid dispersions of ABZ:

[0006] The publication number is CN114099529A, and the subject is an albendazole ivermectin premix, and a preparation method and application thereof. It records: first, the glyceryl monostearate is heated to 85-95°C, stirred until melted, and then the polyethylene glycol is added. After melting, it is kept warm at 85-95°C for 8-12 minutes, and then the activated carbon is added, and the mixture is kept warm at 85-95°C and stirred for 8-12 minutes; then, the albendazole and the ivermectin are added, and the drug suspension is condensed into spherical particles by spray drying.

[0007] The suspension prepared by this method is a solid dispersion; the peak blood concentration of the solid dispersion is 0.4 μg / ml, the peak time is 6 hours, the maintenance time is 24 hours, and the bioavailability is more than 80%. However, the pharmacokinetic experiment recorded in the protocol does not record whether the verification object is albendazole or ivermectin, and at the same time, it does not clearly inform the dosage concentration for animals.

[0008] The problem that this program needs to solve: How to reduce the peak blood concentration of albendazole and delay the peak time. Summary of the invention

[0009] The invention aims to provide an albendazole solid dispersant, which can significantly increase the solubility of albendazole in water by 3.15 times, effectively avoid drug release in an acidic environment, and maintain slow drug release in a weak alkaline environment.

[0010] At the same time, the invention also provides a preparation method and application of the albendazole solid dispersant.

[0011] To achieve the above object, the present application discloses an albendazole solid dispersant, comprising albendazole, glyceryl monostearate, and hydroxypropyl methylcellulose acetate succinate; the albendazole exists in an albendazole solid dispersant in an amorphous form.

[0012] The present invention adopts the poorly soluble auxiliary material glyceryl monostearate and the pH-sensitive reagent hydroxypropyl methylcellulose acetate succinate to achieve the purpose of solubilization of albendazole, non-release in an acidic environment, release in a slightly alkaline environment, and sustained release.

[0013] Glyceryl monostearate has a very low solubility in water and is a very good sustained-release agent. In the intestine, under the action of bile, it will slowly dissolve and release albendazole;

[0014] Hydroxypropyl methylcellulose acetate succinate is a commonly used enteric coating material, which is insoluble in gastric juice and can be slowly dissolved in the intestine;

[0015] Glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate have similar dissolution rates in the intestine, which can enable the albendazole solid dispersion to slowly dissolve in a layer-by-layer manner, releasing albendazole and avoiding excessive peak blood drug concentration.

[0016] Compared with other enteric coating materials, hydroxypropyl methylcellulose acetate succinate and albendazole can be bonded through hydrogen bonds in an alkaline environment, achieving more effective solubilization of albendazole and preventing albendazole from becoming crystals when released.

[0017] Compared with commercially available products, its peak blood concentration is lower, the peak time is prolonged, and its bioavailability is consistent with commercially available products.

[0018] In the above-mentioned albendazole solid dispersion, the mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 5-25:65-75:10-20.

[0019] In the above-mentioned albendazole solid dispersant, the particle size of the albendazole solid dispersant is 20 to 50 meshes.

[0020] In the above-mentioned albendazole solid dispersant, the particle size of the albendazole solid dispersant is 20-30 mesh, 30-40 mesh or 40-50 mesh.

[0021] In the above-mentioned albendazole solid dispersion, the mass ratio of albendazole, glyceryl monostearate, and hydroxypropyl methylcellulose acetate succinate is 10-25:65-75:10-15;

[0022] Meanwhile, the invention also discloses a method for preparing albendazole solid dispersant, which comprises melting and blending albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate, and cooling the mixture.

[0023] In the above-mentioned preparation method of albendazole solid dispersion, the mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 5-25:65-75:10-20; preferably, the mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 10-25:65-75:10-15.

[0024] Finally, the present invention also discloses the use of the albendazole solid dispersion as described above to prepare a medicine for treating whipworm disease.

[0025] The beneficial effects of this application are:

[0026] The present invention adopts the poorly soluble auxiliary material glyceryl monostearate and the pH-sensitive reagent hydroxypropyl methylcellulose acetate succinate to achieve the purpose of solubilization of albendazole, non-release in an acidic environment, release in a slightly alkaline environment, and sustained release. Compared with commercially available products, its blood drug peak concentration is reduced, the peak time is prolonged, and the bioavailability is consistent with that of commercially available products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the in vitro release curve of the first part of the sample under pH 1.2;

[0028] Figure 2 This is the in vitro release curve of the first part of the sample under pH 4.3;

[0029] Figure 3 This is the in vitro release curve of the first part of the sample under pH 6.8;

[0030] Figure 4 This is the in vitro release curve of the second part of the formulation under pH 1.2;

[0031] Figure 5 This is the in vitro release curve of the second part of the formulation under pH 4.3;

[0032] Figure 6 This is the in vitro release curve of the second part of the formulation under pH 6.8;

[0033] Figure 7a is the SEM image of ABZ;

[0034] Figure 7b SEM image of ABZ-pHs-SD;

[0035] Figure 7c is the SEM image of the physical mixture;

[0036] Figure 7d is the SEM image of GM;

[0037] Figure 7e is the SEM image of HPMC-AS;

[0038] Figure 8 PXRD results of ABZ, ABZ-pHs-SD, physical mixture, GM and HPMC-AS;

[0039] Fig. 9 DSC thermograms of ABZ, ABZ-pHs-SD, physical mixture, GM, and HPMC-AS;

[0040] Fig.10FT-IR spectra of original ABZ, ABZ-pHs-SD, physical mixture, GM, and HPMC-AS;

[0041] Fig.11a ABZ-pHs-SD, Release curve at pH 1.2;

[0042] Fig.11b ABZ-pHs-SD, Release curve at pH 4.3;

[0043] Fig.11c ABZ-pHs-SD, Release curve at pH 6.8;

[0044] Fig.11d ABZ-pHs-SD, Release curve at pH 7.4;

[0045] Fig.12a is the blood concentration-time curve of ABZ;

[0046] Figure 12b is the blood concentration-time curve of ABZSO;

[0047] Fig.12c This is the blood concentration-time curve of ABZSO2;

[0048] Figure 13a shows the relationship between ABZ-pHs-SD and Histogram of ABZ drug concentration in intestinal contents and ileal tissue;

[0049] Figure 13b shows the ABZ-pHs-SD and Bar graph of ABZSO drug concentration in intestinal contents and ileal tissue. DETAILED DESCRIPTION

[0050] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. In the description of the present invention, it should be noted that, if no specific conditions are specified in the embodiments, the conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0051] Part I Reagents and Instruments

[0052] Albendazole (batch number: 20210125) was provided by Ningxia Hui Autonomous Region Da Mo Pharmaceutical Co., Ltd.

[0053] Hydroxypropyl methylcellulose acetate succinate (Batch No.: 220603) was purchased from Anhui Shanhe Pharmaceutical Excipients Co., Ltd.

[0054] Ethyl cellulose and glyceryl monostearate (batch number: 20230501) were purchased from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd.

[0055] Polyacrylic acid resin (batch number: B220803211) was purchased from Shanghai Changwei Pharmaceutical Excipients Technology Co., Ltd.

[0056] Hydroxypropyl methylcellulose phthalate was purchased from Luofu Pharmaceutical Technology (Shanghai) Co., Ltd.

[0057] Cellulose acetate phthalate was purchased from Jiangsu Rayen Environmental Protection Technology Co., Ltd.

[0058] Albendazole standard (batch number: 2353168), albendazole sulfoxide standard (batch number: 2357608), albendazole sulfoxide standard (batch number: 2354296), and mebendazole standard (MBZ, batch number: 2204156) were purchased from Shanghai Anpu Cuishi Standard Technology Service Co., Ltd.

[0059] Albendazole granules Purchased from Shanghai Quanyu Biotechnology (Zhumadian) Animal Pharmaceutical Co., Ltd.;

[0060] Chromatographic grade acetonitrile and methanol were purchased from Thermo Fisher Scientific.

[0061] Part II In vitro release experiment of ABZ

[0062] Albendazole is an alkaline drug of BCS II class. It cannot achieve the therapeutic and preventive effects on whipworm disease when released in the stomach, and rapid release in the intestine will cause developmental toxicity in animals. Therefore, the purpose of the screening in the present invention is to obtain a composition that can load albendazole by allowing a low release of albendazole in an acidic environment and a slow release in a neutral environment.

[0063] Many enteric materials can achieve the goal of less release in the stomach and more release in the intestines. However, most enteric materials do not have the effect of sustained release in the intestines.

[0064] The relevant materials screened by the present invention are as follows:

[0065] Polyacrylic acid resin, cellulose acetate phthalate, ethyl cellulose, hypromellose phthalate, hypromellose acetate succinate;

[0066] The specific method of in vitro release experiment is as follows:

[0067] Dissolution studies were performed using a dissolution test apparatus (paddle method, RCY-808T, Haiyida, Tianjin, China) in dissolution media containing 1000 ml of solution: hydrochloric acid at pH 1.2, acetate buffer at pH 4.3, phosphate buffer at pH 6.8, except for hydrochloric acid, the remaining media contained 1% Tween. The temperature of the dissolution medium was controlled at 37 ± 0.5 °C and the stirring speed was maintained at 75 rpm. Two formulations equivalent to 4 mg of ABZ (satisfying the sink condition) were added to the dissolution bottle. The solution (5 mL) for each test was collected at 0.1, 0.25, 0.5, 1, 1.5, 2 h and 0.1, 0.25, 0.5, 1, 2, 4 h and 0.1, 0.25, 0.5, 1, 2, 4, 6, 8, 12 h, respectively. After each collection, 5 mL of isothermal medium was immediately supplemented. The collected solution was filtered through a 0.22 mm microporous membrane and analyzed by HPLC. Each test was repeated three times.

[0068] Sample formulas refer to Table 1;

[0069] Table 1 Recipe

[0070]

[0071] In vitro release curve reference of pH 1.2, pH 4.3 and pH 6.8 Figures 1 to 3 ;

[0072] pass Figures 1 to 3 It can be seen that polyacrylic acid resin and hydroxypropyl methylcellulose acetate succinate are two products with large release amounts under neutral conditions and small release amounts under acidic conditions. However, polyacrylic acid resin is released too quickly in the early stage under neutral conditions, far exceeding the animal's metabolic rate of ABZ, which can easily lead to developmental toxicity and is not sustainable for the treatment of whipworm disease.

[0073] We also evaluated two commercial products, an albendazole-ivermectin premix and albendazole granules produced by Wuhan Danongren Biotechnology Co., Ltd.

[0074] The release rate of albendazole-ivermectin premix under acidic conditions (pH 1.2) is about 40wt%, and the release rate under neutral (pH 6.8) and alkaline (pH 7.4) conditions is about 20wt%;

[0075] The release rate of albendazole granules under acidic conditions (pH 1.2) is about 80 wt %, and the release rates under neutral (pH 6.8) and alkaline (pH 7.4) conditions are both about 30 wt %.

[0076] Through the above experiments, it was screened that hydroxypropyl methylcellulose acetate succinate was the most suitable enteric material. Its release rate under acidic conditions was not less than 20%, and its release rate under neutral and alkaline conditions was about 80%. Its release was relatively slow, and it took 12 hours to achieve 80% release.

[0077] Part II Verification of the optimal ratio of glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate

[0078] The above-mentioned in vitro release experiment was used, and the formulation was referred to Table 2;

[0079] Table 2 Recipe

[0080]

[0081]

[0082] In vitro release curve reference of pH 1.2, pH 4.3 and pH 6.8 Figures 4 to 6 ;

[0083] pass Figures 4 to 6 It can be seen that the dosage of HPMC succinate is a very important parameter. Although Prescription 1 can maintain low release in an acidic environment, it is also low release in a neutral environment. When the dosage of HPMC succinate is increased to 10wt%, Prescription 2 maintains the effects of low release in an acidic environment and high release in a neutral environment. This situation shows the same rule when the dosage of glyceryl monostearate is 70wt%. When the dosage of glyceryl monostearate is 75wt%, the dosage of HPMC succinate needs to be increased to 15wt%.

[0084] In addition, the particle size of the product also has a certain influence on the release. The smaller the size, the more is released. It can be seen that under the premise of the same amount of glyceryl monostearate, Prescription 2, Prescription 4, and Prescription 9 release more.

[0085] Part III In vitro and in vivo studies of pH-sensitive solid dispersions loaded with albendazole

[0086] Preparation of ABZ-pHs-SD

[0087] Weigh the required ABZ, GM (glyceryl monostearate) and HPMC-AS (hydroxypropyl methylcellulose acetate succinate) in a mass ratio of 25:65:10 to prepare a solid dispersion. Melt GM in a water bath, then add HPCM-AS and ABZ in sequence, and stir the melt at 80°C at a certain speed until the drug is completely dispersed. Pour the melt onto a precooled glass plate and freeze it in a -20°C refrigerator overnight. Dry the frozen mixture in a watertight incubator for 24 hours, take it out, crush and sieve (40-50 mesh) to obtain ABZ-pHs-SD.

[0088] Characterization of ABZ-pHs-SD

[0089] 3.2.1.SEM

[0090] The surface morphology of ABZ, ABZ-pHs-SD, GM and HPMC-AS was studied using a Sigma 300 (ZEISS, Germany) scanning electron microscope. The samples were fixed on an aluminum sample holder and coated with a layer of gold. Subsequently, SEM images were obtained at an accelerating voltage of 10 kV to observe the surface morphology of the samples.

[0091] SEM images of ABZ, ABZ-pHs-SD, physical mixture, GM, and HPMC-AS are shown in Figures 7a to 7e The physical mixture refers to the simple physical blending of ABZ, GM and HPMC-AS in the proportions shown in Section 3.1.

[0092] ABZ presents irregular small particles with prominent edges and corners ( Figure 7a ) This may be the main reason why ABZ exhibits hydrophobicity. No ABZ crystals were detected in the solid dispersion ( Figure 7b ). However, irregular particles can still be observed in the physical mixture, indicating that the crystal structure of ABZ has not disappeared due to physical mixing ( Figure 7c ). Scanning electron microscopy shows that the surface of PM has a prominent groove shape ( Figure 7d ), HPMC-AS dispersion is in an amorphous state ( Figure 7e ). These findings confirm that ABZ can be well encapsulated in polymers via solid dispersion techniques.

[0093] 3.2.2.PXRD

[0094] PXRD analysis was performed at ambient temperature using (Empyrean) Cu Kα radiation ( Generator settings: 40 kV and 40 mA) Diffraction data were collected in a 2θ scan range between 5-40°, with a step size of 0.0084° and a counting time of 2 sec / step.

[0095] The PXRD results of ABZ, ABZ-pHs-SD, physical mixture, GM and HPMC-AS are shown in Figure 8 The spectrum of pristine ABZ exhibits a series of high-intensity peaks at 2θ values ​​of approximately 7.04°, 11.66°, 18.01°, 22.19°, and 39.18° ( Figure 8 The curve a in the figure shows that it has high crystallinity. The spectrum of HPMC-AS has no crystalline peak, which means that it is basically amorphous ( Figure 8 For GM, the PXRD spectrum shows a series of high-intensity peaks at approximately 5.62, 7.45, 19.66, and 22.85°, indicating that the carrier GM has a certain crystalline structure ( Figure 8 The PXRD patterns of the physical mixture and solid dispersion are highly consistent with GM ( Figure 8 The peak intensity is significantly reduced and the peak shape is broadened, indicating that the crystalline structure is reduced. These results indicate that ABZ may be transformed into an amorphous state in the solid dispersion.

[0096] 3.2.3.DSC

[0097] Thermal analysis of ABZ, ABZ-pHs-SD, physical mixture, GM and HPMC-AS was performed by differential scanning calorimetry (DSC25, USA). Samples (5.8 mg) were weighed, placed in a sealed aluminum pan, and scanned from 25°C to 300°C at 5°C / min under flowing nitrogen. Thermograms were recorded.

[0098] The DSC thermograms of ABZ, ABZ-pHs-SD, physical mixture, GM and HPMC-AS are shown in Fig. 9 The DSC thermogram of ABZ shows a unique sharp endothermic peak at 213.6°C, indicating its crystalline state ( Fig. 9 HPMC-AS does not show any absorption peak, indicating the absence of crystallization ( Fig. 9 GM has an obvious absorption peak at 73.4℃, which is consistent with the melting point of GM ( Fig. 9 The DSC curves of the physical mixture and ABZ-pHs-SD showed strong endothermic peaks (73.3℃, ​​69.9℃) and weak endothermic peaks (167.7℃, 168.0℃). Compared with the API, the intensity was significantly reduced and the initial position changed significantly ( Fig. 9Curves d and e in Figure 1). Generally, when the crystallinity is less than 2%, DSC usually cannot detect the melting peak of the drug. After the solid dispersion is formed, the endothermic peak of the drug substance completely disappears in the thermal spectrum, which is evidence of the phase transition of ABZ. These results further prove that the drug is highly dispersed in the solid dispersion and the drug changes from a crystalline state to an amorphous state.

[0099] 3.2.4. FTIR

[0100] FT-IR spectra of ABZ, ABZ-pHs-SD, GM and HPMC-AS were obtained using a PerkinElmer Frontier Fourier Transform Infrared Spectrometer. The data were obtained at 4000-500 cm -1 Collect between.

[0101] FT-IR spectra of original ABZ, ABZ-pHs-SD, physical mixture, GM and HPMC-AS are shown in Fig.10 The peaks of ABZ are located at 3340 (NH stretching), 2957 (CH stretching), 1632 (C=N stretching), 1443 (CH bending) and 1388 cm -1 (CN stretching)( Fig.10 The spectra of HPMC-AS are 3455 (OH stretching), 1738 (C=O stretching) and 1054 cm -1 (COC stretching)( Fig.10 The spectrum of GM appears at 2918 (CH stretching), 1732 (C=O stretching), 1469 (CH bending) and 1179 cm -1 (COC stretching)( Fig.10 The FTIR spectrum of the physical mixture is similar to that of ABZ, GM, and HPMC-AS, indicating that the chemical interactions in the physical mixture are weak ( Fig.10 In the FTIR spectrum of the solid dispersion, the absorption peaks of ABZ and HPMC-AS are from 3340 to 3455 cm -1 Start moving to 3318cm -1 The broad wavenumber shift suggests the possible hydrogen bonding between ABZ and the solid dispersion.

[0102] ABZ, ABZ-pHs-SD and Solubility studies

[0103] Excess ABZ, ABZ-pHs-SD and Add to distilled water, while excess ABZ was added to the dissolution media at pH 1.2, 4.3, 6.8 and 7.5, respectively, to obtain supersaturated solutions. The samples were shaken at 37°C for 24 hours and 100 rpm. After centrifugation, the supernatant was filtered through a 0.22 μm membrane and analyzed by HPLC.

[0104] Evaluation of ABZ, ABZ-pHs-SD and The water solubility of ABZ and the solubility of ABZ in buffer media with different pH values. The initial solubility of ABZ is 0.61±0.03ug / mL. The solubility of ABZ is 1.60±0.10ug / mL, but it increases significantly to 2.53±0.12ug / mL after being prepared into solid dispersion with HPMC-AS. Although ABZ can reach 633.50±5.23ug / mL in a buffer medium of pH 1.2, it drops sharply to 0.69±0.02ug / mL, 0.64±0.03ug / mL and 0.43±0.01ug / mL in a weakly alkaline environment of pH 4.3, pH 6.8 and pH 7.5. This shows that ABZ has the characteristics of low solubility and pH sensitivity.

[0105] 3.4. In vitro release study

[0106] Dissolution studies were performed using a dissolution test apparatus 2 (paddle method, RCY-808T, Haiyida, Tianjin, China) in dissolution media containing 1000 ml of solution: hydrochloric acid at pH 1.2, acetate buffer at pH 4.3, phosphate buffer at pH 6.8, and phosphate buffer at pH 7.5. Except for hydrochloric acid, the remaining media contained 1% Tween. The temperature of the dissolution medium was controlled at 37 ± 0.5 °C and the stirring speed was maintained at 75 rpm. Two formulations equivalent to 4 mg of ABZ (satisfying the sink condition) were added to the dissolution bottle. The solution (5 mL) for each test was collected at 0.1, 0.25, 0.5, 1, 1.5, 2 h and 0.1, 0.25, 0.5, 1, 2, 4 h and 0.1, 0.25, 0.5, 1, 2, 4, 6, 8, 12 h. After each collection, 5 mL of isothermal medium was immediately supplemented. The collected solution was filtered through a 0.22 mm microporous membrane and analyzed by HPLC. Each test was repeated three times and the dissolution rate was obtained from the standard regression curve equation.

[0107] refer to Figures 11a to 11d ; Fig.11a ABZ-pHs-SD, Release curve at pH 1.2; Fig.11b ABZ-pHs-SD, Release curve at pH 4.3; Fig.11cABZ-pHs-SD, Release curve at pH 6.8; Fig.11d ABZ-pHs-SD, Release curve at pH 7.4;

[0108] In the solutions of pH 1.2 and pH 4.3 (1% Tween 80), the total accumulation of ABZ-pHs-SD was only 13.74% and 23.21%, while the maximum release in the solutions of pH 6.8 and 7.4 (1% Tween 80) reached 82.24% and 72.85%. The maximum release amounts in these four buffers were 79.18%, 23.21%, 32.99% and 31.20% respectively. The results showed that The release is fast and complete in a strong acid environment, but not ideal in a weak acid or weak base environment. On the contrary, ABZ-pHs-SD has sufficient acid resistance and can ensure the slow release of the drug in a weak base environment. This may be due to the characteristics of HPMC-AS, which has good acid resistance and can inhibit the crystallization of ABZ in a weak base environment. At the same time, the presence of GM can delay drug release. The combination of the two can control drug release.

[0109] 3.5. In vivo pharmacokinetic studies

[0110] SD rats (280±20 g) were fasted and deprived of water for 12 h. The rats were randomly divided into two groups (n=8) and received ABZ-pHs-SD or The drug dose was 45 mg / kg (equivalent to ABZ). After administration, 0.5 mL of blood samples were collected at 0.5, 1, 2, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, and 96 h. Each blood sample was centrifuged at 4000 r / min for 10 minutes at 4°C to obtain plasma, which was then frozen in a -20°C refrigerator for further analysis.

[0111] Rats were orally treated with ABZ-pHs-SD and The mean plasma ABZ and its metabolite concentration-time curves after Figures 12a to 12c .

[0112] Fig.12a is the concentration-time curve of ABZ metabolites;

[0113] Figure 12b is the concentration-time curve of ABZSO metabolites;

[0114] Fig.12c This is the concentration-time curve of ABZSO2 metabolites;

[0115] Among them, the main active ingredients ABZ and ABZSO were lower than ABZ-pHs-SD at all time points in the first 4 hours. This indicates that solid dispersion preparations can avoid the rapid peak of ABZ and ABZSO plasma levels. Compared with ABZ, ABZ-pHs-SD decreased the Cmax and increased the Tmax after oral administration. Statistically, the Cmax of ABZ and ABZSO was 0.10±0.05 and 4.70±1.16ug / mL, respectively, which was significantly lower than that of ABZ-pHs-SD. (0.19±0.07, 6.83±0.66ug / mL) were significantly lower (47.4% and 31.2%) (p<0.01). The Tmax of ABZSO was 3.75±0.71h, which was significantly delayed by 1.75h compared with ABZ-pHs-SD (5.5±0.93h) (p<0.01). This may be due to the strong acid resistance of GM and HPMC-AS, which prevented the rapid dissolution and absorption of ABZ in gastric acid. In comparison, the AUC of ABZSO, the main active metabolite of pH-sensitive solid dispersion, was 0－t and AUC 0－∞ The values ​​of C were not statistically different. This indicates that while improving the safety of oral ABZ, it did not max The bioavailability of ABZ was affected by the decrease of the solid dispersion technology and the solubilization effect of the hydrogen bond formed between HPMC-AS and ABZ. At the same time, the MRT values ​​of ABZ, ABZSO, and ABZSO2 in ABZ-pHs-SD (3.68±1.30, 14.01±2.00, and 27.32±5.76h) were lower than those in (2.83±0.59, 11.87±0.88, 19.93±3.94h) were significantly improved (p<0.05), indicating that oral ABZ-pHs-SD has a longer residence time in the animal body, which will be beneficial for the treatment and prevention of parasitic diseases.

[0116] 3.6. Intestinal drug concentration studies

[0117] SD rats (280±20 g) were fasted and deprived of water for 12 h. The rats were randomly divided into two groups (n=5) and received ABZ-pHs-SD or The drug dose was 12.6 mg (in terms of ABZ). Rats were euthanized 24 hours after administration, and the contents of the jejunum, ileum, cecum, colon and ileum tissue were collected and then frozen in a -20°C refrigerator for further analysis.

[0118] Rats were orally treated with ABZ-pHs-SD and The drug concentrations in the intestinal contents and colon tissues after 24 h are shown in Figures 13a and 13b.

[0119] Figure 13a shows the relationship between ABZ-pHs-SD and Bar graph of ABZ drug concentration in intestinal contents and colon tissue;

[0120] Figure 13b shows the ABZ-pHs-SD and Bar graph of ABZSO drug concentration in intestinal contents and colon tissue;

[0121] Statistically, the levels of ABZ and ABZSO in ABZ-pHs-SD (234.32±38.47, 20.80±6.42ug / g) were significantly higher than those in In the colon contents, the levels of ABZ and ABZSO in ABZ-pHs-SD (221.73±37.36, 45.66±6.00ug / g) were significantly higher than those in (58.11±19.23, 2.78±0.70ug / g) (p<0.001), and the ABZ level of ABZ-pHs-SD in colon tissue (0.89±0.39ug / g) was significantly higher than that of (0.16±0.01ug / g) (p<0.01).

[0122] The results show that In comparison, ABZ-pHs-SD can significantly increase the drug level in the cecum and colon, indicating that pH-sensitive solid dispersions have stronger cecum and colon targeting, which will help improve the clinical efficacy of ABZ. At the same time, the increase in ABZ drug levels in colon tissue may provide a certain reference for improving the preventive effect of albendazole on colon cancer.

[0123] HPLC analysis

[0124] All samples were analyzed by HPLC (Agilent 1100 series) combined with a UV detector system at a wavelength of 295 nm. In the in vitro study, an Agilen Extend-C18 analytical column (250×4.6mm×5μm) was used at 35°C. The mobile phase was methanol and water (V / V=75:25). The flow rate was 1mL / min and the injection volume was 10uL.

[0125] Plasma, intestinal contents and ileal tissue samples were processed by adding 50uL NaOH (0.4M), 100uL MBZ (10ug / mL), 1.0mL acetonitrile and 1.0mL ethyl acetate to 200uL plasma sample, 100mg contents and 100mg ileal tissue, followed by vortexing for 3min and centrifuging at 12,000r / min for 10min at 4°C; the supernatant was aspirated and placed in another centrifuge tube, and 1.0mL ethyl acetate was added to the first tube, and the above operation was repeated for vortexing and centrifugation, the supernatant was combined, dried with nitrogen at 40°C, the residue was dissolved with 200uL mobile phase, and centrifuged at 12,000r / min for 10min at 4°C. The supernatant was then filtered with a 0.22μm filter for HPLC analysis. Chromatographic separation used an Agilen Extend-C18 analytical column (250×4.6mm×5μm), and ABZ and its main metabolites were separated by isocratic elution. The mobile phase was a mixture of sodium acetate solution (0.02 M) at pH 5.0 and acetonitrile (V / V=65:35), the flow rate was 1.0 mL / min, the temperature was 40° C., and the injection volume was 20 uL.

[0126] Statistical analysis

[0127] GraphPad Prism 8.0.1 (GraphPad Prism Inc., USA) was used to perform one-way ANOVA and plot the data. Phoenix WinNonlin 8.1 (Certara Inc., USA) was used to calculate the main pharmacokinetic parameters using the non-compartmental model.

[0128] 3.9 Conclusion

[0129] DSC, FTIR, PXRD, and SEM showed that the drug existed in an amorphous state in ABZ-pHs-SD, indicating that ABZ was stably dispersed in the solid dispersion. In the in vitro solubility and release study, ABZ-pHs-SD significantly increased the solubility of ABZ in water by 3.15 times ( It can effectively prevent drug release in strong acid and weak acid environments, while ensuring slow release of drugs in weak alkaline environments. In addition, in the pharmacokinetic study in rats, In comparison, ABZ-pHs-SD had a lower Cmax and a higher Tmax while having almost no effect on bioavailability, and had higher drug concentration levels in the cecum and colon. These results indicate that compared to The pH-sensitive solid dispersion prepared with GM and HPMC-AS as excipients can be used as a promising drug delivery strategy to improve the solubility, safety and efficacy of ABZ. This provides a theoretical basis and experimental guidance for the future development of new ABZ formulations.

Claims

1. An albendazole solid dispersant, characterized in that: The invention comprises albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate; the albendazole exists in the albendazole solid dispersant in a non-crystalline form.

2. The albendazole solid dispersion according to claim 1, characterized in that The mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 5-25:65-75:10-20.

3. The albendazole solid dispersion according to claim 1, characterized in that The particle size of the albendazole solid dispersant is 20 to 50 meshes.

4. The albendazole solid dispersion according to claim 3, characterized in that The particle size of the albendazole solid dispersant is 20-30 meshes, 30-40 meshes or 40-50 meshes.

5. The albendazole solid dispersion according to claim 2, characterized in that The mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 10-25:65-75:10-15.

6. A method for preparing albendazole solid dispersant, characterized in that: Albendazole, glyceryl monostearate, and hypromellose acetate succinate were melt blended and cooled.

7. The method for preparing the albendazole solid dispersion according to claim 6, characterized in that: The mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 5-25:65-75:10-20.

8. The method for preparing albendazole solid dispersion according to claim 7, characterized in that: The mass ratio of albendazole, glyceryl monostearate and hydroxypropyl methylcellulose acetate succinate is 10-25:65-75:10-15.

9. Use of the albendazole solid dispersion according to any one of claims 1 to 5 for preparing a medicament for treating whipworm disease.

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