Preparation of a targeted formulation containing oxaliplatin and its use in the treatment of colon cancer

Abstract

This invention discloses the preparation of an oxaliplatin-containing targeted formulation and its application in the treatment of colorectal cancer, belonging to the field of pharmaceutical formulation technology. The formulation consists of an active ingredient and a coating carrier; the active ingredient is oxaliplatin and a compound extracted from reed rhizome (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D The formulation consists of a covalently coupled oxaliplatin-glucopyranoside formed via amide bonds, with a mass ratio of 1:1 to 1:2. The coating carrier is a chitosan-sodium alginate composite microsphere, with a mass ratio of its suspension to the covalently coupled sphere of 10:1 to 15:1. This structure forms a stable protective layer in the acidic environment of the stomach, preventing premature release of the active ingredient. The preparation method involves three steps: first, preparing the oxaliplatin covalently coupled sphere; second, preparing the chitosan-sodium alginate composite microsphere suspension; and finally, ultrasonically dispersing, centrifuging, washing, and freeze-drying the coupling sphere and microsphere suspension to obtain a formulation with a particle size of 100-500 nm. This formulation utilizes a natural polysaccharide carrier, exhibiting good biocompatibility, non-toxicity, and strong targeting. It protects the active ingredient, ensuring its smooth passage through the stomach to the colon for release, enhancing drug efficacy and reducing toxic side effects, thus demonstrating promising clinical application prospects.

Description

Technical Field

[0001] This invention relates to the preparation of an oxaliplatin-containing targeted formulation and its application in the treatment of colon cancer, belonging to the field of novel drug preparation technology. Background Technology

[0002] Colorectal diseases, especially colorectal cancer, are among the most common malignant tumors worldwide, and drug therapy is an important means of clinical treatment. Oxaliplatin, a commonly used platinum-based chemotherapy drug, has a good inhibitory effect on colorectal cancer. However, this drug lacks tissue targeting, is widely distributed in the body, and is prone to producing toxic side effects on normal tissues such as the gastrointestinal tract and bone marrow, leading to adverse reactions such as nausea, vomiting, and bone marrow suppression in patients, which seriously affects treatment compliance and efficacy. Therefore, the development of colon-targeted oxaliplatin formulations has become a research hotspot in the field of pharmaceutical formulation.

[0003] Currently available oxaliplatin formulations are mostly available as injectable or oral preparations. Oral preparations are prone to premature drug release in the acidic environment of the stomach, which not only reduces the effective drug concentration in the colon but also exacerbates gastrointestinal irritation. While injectable preparations offer rapid onset of action, they suffer from inconvenient administration and significant side effects. Furthermore, existing targeted therapies often use chemically synthesized carriers, which have poor biocompatibility and are prone to triggering immune responses, thus limiting their clinical application.

[0004] As a traditional Chinese medicinal herb, reed rhizome contains a substance (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D -Glucuronyl pyranoside has adjuvant anti-inflammatory and anti-tumor effects; conjugation with oxaliplatin can synergistically enhance its anti-tumor efficacy. Chitosan and sodium alginate, as natural polysaccharides, possess good biocompatibility, non-toxicity, and biodegradability, and are often used as drug carriers. Based on this, a colon-targeted formulation using natural polysaccharides as the coating carrier and oxaliplatin conjugated with reed rhizome extract as the active ingredient is developed, which can effectively solve the problems of poor targeting, high toxicity, and poor carrier biocompatibility in existing oxaliplatin formulations. Summary of the Invention

[0005] This invention aims to provide a preparation of an oxaliplatin-containing targeted formulation and its application in the treatment of colorectal cancer. Specifically, it constructs a targeted delivery system of "oxaliplatin-containing covalent conjugates coated with chitosan-sodium alginate composite microspheres", which combines the solubilizing effect of alkaline substances metabolized by colonic flora with the drug targeting effect to achieve precise release of oxaliplatin around tumor cells.

[0006] Reed rhizome, the rootstock of the grass reed (Phragmites communis), possesses properties such as clearing heat and purging fire, promoting body fluid production and quenching thirst, relieving irritability and moisturizing dryness. Studies have shown that reed rhizome exhibits multiple activities including hypotensive, antipyretic, anti-inflammatory, analgesic, immune-enhancing, and antioxidant effects. Su Yanfang et al. isolated several compounds from reed rhizome, one of which caught our attention. In subsequent studies, we unexpectedly discovered that it did not show significant cytotoxicity, exhibited a certain degree of targeted binding to ulcerative colitis-associated colon cancer cells, and could also promote the remodeling of gut microbiota in ulcerative colitis-associated colon cancer.

[0007] The new compound is (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D -Glucopyranoside, its structural formula is as follows:

[0008] The invention team unexpectedly discovered that it has great application potential in the field of anti-tumor treatment of colon cancer and can be used to treat colon cancer.

[0009] During the research and practice of this invention, due to the extremely poor oral bioavailability of oxaliplatin, our team continuously developed new conjugate drugs for coating. We accidentally discovered that oxaliplatin, along with (1'... R ,2' S )-Eugenol-based glycerol 3'- O -β- D - Glucono-pyranoside conjugation can better shrink colon cancer tumors induced by ulcerative colitis, alleviate symptoms in rats, and improve gut microbiota. Through chitosan-sodium alginate composite microsphere coating, this effect can be achieved orally. It is speculated that the finished drug prepared by this method can target and kill tumor cells, increase anti-inflammatory effects, reduce damage to gut microbiota, and regulate the gut microbiota microecological environment, which is of great significance for the treatment of colon cancer associated with ulcerative colitis.

[0010] The oxaliplatin used in this invention was purchased from MedChemExpress, CAS number 61825-94-3; Other key substances used in this invention include (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D- Glucuronyl pyranoside (reed rhizome extract compound, purity ≥98%), dimethyl sulfoxide (DMSO, analytical grade), condensing agent EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, Sigma-Aldrich, CAS No. 25952-53-8), catalyst DMAP (4-dimethylaminopyridine, analytical grade), deionized water; The core innovation of this invention lies in constructing a targeted delivery system of "oxaliplatin covalently coupled with chitosan-sodium alginate composite microspheres", which, combined with the solubilizing effect of alkaline substances metabolized by colonic flora, achieves precise release of oxaliplatin around tumor cells. The specific technical solution is as follows: 1. Formulation composition This formulation consists of two parts: the active ingredient and the coating carrier. The composition and proportion of each component are as follows: Active ingredient: a covalently coupled compound formed by oxaliplatin and a reed rhizome extract via an amide bond, wherein the mass ratio of oxaliplatin to the reed rhizome extract is 1:1-1:2; the name of the reed rhizome extract is (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D -Glucopyranoside, with the following structural formula:

[0011] The coating carrier is a chitosan-sodium alginate composite microsphere, which is coated on the surface of the covalently coupled material to enhance the stability of the formulation in the stomach. The mass ratio of the chitosan-sodium alginate composite microsphere suspension to the covalently coupled material is 10:1-15:1. It is a natural polysaccharide with good biocompatibility and non-toxicity. It can form a stable protective layer in the acidic environment of the stomach to prevent premature release of active ingredients.

[0012] The preparation method of the drug: Step 1: Preparation of oxaliplatin-containing covalent conjugates: Mix 5 parts oxaliplatin with 5 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D 1-Gluconopyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 hours. After the reaction was completed, a certain amount of deionized water was added to precipitate the compound. The precipitate was collected by centrifugation and then freeze-dried to obtain the covalent conjugate of oxaliplatin-reed rhizome extract. Step Two: Preparation of chitosan-sodium alginate composite microsphere suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution and 1 part of sodium alginate in 80 parts of deionized water. Stir each until completely dissolved. Slowly add the sodium alginate solution dropwise to the chitosan solution and stir for 30 min. During this time, slowly add 10 parts of 5% calcium chloride solution. Crosslink at room temperature for 30 min to obtain composite microsphere suspension. Step 3: Formulation: Add 1 part of the oxaliplatin-containing covalent conjugate prepared in step one to 10-15 parts of the composite microsphere suspension prepared in step two, and ultrasonically disperse at 200-250W power for 40 minutes to ensure that the covalent conjugate is uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing oxaliplatin covalent conjugate coated with chitosan-sodium alginate composite microspheres is obtained, with the particle size controlled at 100-500nm.

[0013] Advantages of this invention: During their research and practice, the invention team discovered that oxaliplatin and (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D - Glucono-pyranoside conjugation can better shrink colon cancer tumors induced by ulcerative colitis, slow down the rate of body weight loss and fecal occult blood symptoms in rats, and improve intestinal flora imbalance and dysbiosis, reversing the inflammatory response in vivo. The preparation method using chitosan-sodium alginate composite microspheres can achieve these effects through oral administration. It is speculated that the finished drug prepared by this method can target and kill tumor cells, increase anti-inflammatory effects, reduce damage to intestinal flora, and regulate the intestinal microecological environment, which is of great significance for the treatment of ulcerative colitis-related colon cancer. Detailed Implementation

[0014] The embodiments of the present invention are described in detail below. These embodiments are only used to explain the present invention and should not be construed as limiting the present invention.

[0015] Specific embodiments of the present invention are described below.

[0016] Example 1 Preparation of a targeted formulation containing oxaliplatin: Step 1: Preparation of oxaliplatin-containing covalent conjugates: Mix 5 parts oxaliplatin with 5 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D- pyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 h. After the reaction was completed, a certain amount of deionized water was added to precipitate the compound. The precipitate was collected by centrifugation and then freeze-dried to obtain the covalently coupled compound of oxaliplatin-reed rhizome extract. Step Two: Preparation of chitosan-sodium alginate composite microsphere suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution and 1 part of sodium alginate in 80 parts of deionized water. Stir each until completely dissolved. Slowly add the sodium alginate solution dropwise to the chitosan solution and stir for 30 min. During this time, slowly add 10 parts of 5% calcium chloride solution. Crosslink at room temperature for 30 min to obtain composite microsphere suspension. Step 3: Formulation: 1 part of the oxaliplatin-containing covalent conjugate prepared in step one was added to 10 parts of the composite microsphere suspension prepared in step two. The mixture was ultrasonically dispersed at 200W for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing oxaliplatin covalent conjugate and coated with chitosan-sodium alginate composite microspheres was obtained, with the particle size controlled at 100-500nm.

[0017] Example 2 Preparation of a targeted formulation containing oxaliplatin: Step 1: Preparation of oxaliplatin-containing covalent conjugates: Mix 5 parts oxaliplatin with 5 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D - pyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 h. After the reaction was completed, a certain amount of deionized water was added to precipitate the compound. The precipitate was collected by centrifugation and then freeze-dried to obtain the covalently coupled compound of oxaliplatin-reed rhizome extract. Step Two: Preparation of chitosan-sodium alginate composite microspheres: 2 parts of chitosan were dissolved in 150 parts of 1% acetic acid solution, and 1 part of sodium alginate was dissolved in 80 parts of deionized water. The mixture was stirred until completely dissolved. The sodium alginate solution was slowly added dropwise to the chitosan solution and stirred for 30 min. During this time, 10 parts of 5% calcium chloride solution were slowly added. The mixture was crosslinked at room temperature for 30 min to obtain a composite microsphere suspension. Step 3: Formulation: 1 part of the oxaliplatin-containing covalent conjugate prepared in step one was added to 15 parts of the composite microsphere suspension prepared in step two. The mixture was ultrasonically dispersed at 250W for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing oxaliplatin covalent conjugate and coated with chitosan-sodium alginate composite microspheres was obtained, with the particle size controlled at 100-500nm.

[0018] Example 3 Comparative Example 1 The preparation method is the same as in Example 1, but it contains only oxaliplatin and does not contain (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D -Gluranoside: Preparation of a targeted formulation containing oxaliplatin: Step 1: Preparation of oxaliplatin-containing conjugates: 10 parts of oxaliplatin were dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 hours. After the reaction was completed, a certain amount of deionized water was added to precipitate the product. The precipitate was collected by centrifugation and then freeze-dried to obtain the oxaliplatin conjugates. Step Two: Preparation of chitosan-sodium alginate composite microsphere suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution and 1 part of sodium alginate in 80 parts of deionized water. Stir each until completely dissolved. Slowly add the sodium alginate solution dropwise to the chitosan solution and stir for 30 min. During this time, slowly add 10 parts of 5% calcium chloride solution. Crosslink at room temperature for 30 min to obtain composite microsphere suspension. Step 3: Formulation: 1 part of the oxaliplatin-containing conjugate prepared in step one was added to 10 parts of the composite microsphere suspension prepared in step two. The mixture was ultrasonically dispersed at 200W for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing oxaliplatin conjugate coated with chitosan-sodium alginate composite microspheres was obtained, with the particle size controlled at 100-500nm.

[0019] Comparative Example 2 The preparation method is the same as in Example 1, but it only contains (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D-Glucopyranoside, does not contain oxaliplatin: Preparation of a targeted formulation: Step 1: Preparation of the coupling compound: 10 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D - pyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 hours. After the reaction was completed, a certain amount of deionized water was added to precipitate the mixture. The precipitate was collected by centrifugation and then freeze-dried to obtain the conjugate. Step Two: Preparation of chitosan-sodium alginate composite microsphere suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution and 1 part of sodium alginate in 80 parts of deionized water. Stir each until completely dissolved. Slowly add the sodium alginate solution dropwise to the chitosan solution and stir for 30 min. During this time, slowly add 10 parts of 5% calcium chloride solution. Crosslink at room temperature for 30 min to obtain composite microsphere suspension. Step 3: Formulation: 1 part of the conjugate prepared in step one was added to 10 parts of the composite microsphere suspension prepared in step two, and ultrasonically dispersed at 200W power for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing and freeze-drying, a colon-targeted formulation of the conjugate coated with chitosan-sodium alginate composite microspheres was obtained, with the particle size controlled at 100-500nm.

[0020] Comparative Example 3: The preparation method is the same as in Example 1, but without the chitosan-sodium alginate composite microsphere coating: Preparation of a targeted formulation containing oxaliplatin: Mix 5 portions of oxaliplatin with 5 portions of (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D 1-Glucopyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 hours. After the reaction was completed, a certain amount of deionized water was added to precipitate the precipitate. The precipitate was collected by centrifugation and then freeze-dried to obtain a targeted formulation containing oxaliplatin.

[0021] Comparative Example 4 The preparation method is the same as in Example 1, but (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D - Replace glucopyranoside with commercially available n-octylβ-D-glucopyranoside: Preparation of a targeted formulation containing oxaliplatin: Step 1: Preparation of oxaliplatin-containing covalent conjugates: 5 parts of oxaliplatin and 5 parts of n-octylβ-D-glucopyranoside were dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 h. After the reaction was completed, a certain amount of deionized water was added to precipitate the mixture, the precipitate was collected by centrifugation, and the precipitate was obtained by freeze-drying. Step Two: Preparation of chitosan-sodium alginate composite microsphere suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution and 1 part of sodium alginate in 80 parts of deionized water. Stir each until completely dissolved. Slowly add the sodium alginate solution dropwise to the chitosan solution and stir for 30 min. During this time, slowly add 10 parts of 5% calcium chloride solution. Crosslink at room temperature for 30 min to obtain composite microsphere suspension. Step 3: Formulation: 1 part of the oxaliplatin-containing covalent conjugate prepared in step one was added to 10 parts of the composite microsphere suspension prepared in step two. The mixture was ultrasonically dispersed at 200W for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing oxaliplatin covalent conjugate and coated with chitosan-sodium alginate composite microspheres was obtained, with the particle size controlled at 100-500nm.

[0022] Comparative Example 5: The preparation method is the same as in Example 1, but only chitosan is used in the preparation of the coated particles, instead of sodium alginate: Preparation of a targeted formulation containing oxaliplatin: Step 1: Preparation of oxaliplatin-containing covalent conjugates: Mix 5 parts oxaliplatin with 5 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D- pyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 h. After the reaction was completed, a certain amount of deionized water was added to precipitate the compound. The precipitate was collected by centrifugation and then freeze-dried to obtain the covalently coupled compound of oxaliplatin-reed rhizome extract. Step Two: Preparation of chitosan suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution, stir for 30 min, slowly add 10 parts of 5% calcium chloride solution during the process, crosslink at room temperature for 30 min to obtain chitosan microsphere suspension; Step 3: Formulation: 1 part of the oxaliplatin-containing covalent conjugate prepared in step one was added to 10 parts of the chitosan microsphere suspension prepared in step two. The mixture was ultrasonically dispersed at 200W for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing the oxaliplatin covalent conjugate and coated with chitosan microspheres was obtained, with a particle size controlled between 100-500nm.

[0023] Comparative Example 6: The preparation method is the same as in Example 1, but the sodium alginate in the preparation of the coated particles is replaced with commercially available fucoidan: Preparation of a targeted formulation containing oxaliplatin: Step 1: Preparation of oxaliplatin-containing covalent conjugates: Mix 5 parts oxaliplatin with 5 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D 1-Gluconopyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, EDC) and 0.3 parts of catalyst (4-dimethylaminopyridine, DMAP) were added, and the mixture was stirred at room temperature for 8 hours. After the reaction was completed, a certain amount of deionized water was added to precipitate the compound. The precipitate was collected by centrifugation and then freeze-dried to obtain the covalent conjugate of oxaliplatin-reed rhizome extract. Step Two: Preparation of chitosan-fucose polysaccharide composite microsphere suspension: 2 parts of chitosan were dissolved in 150 parts of 1% acetic acid solution, and 1 part of fucoidan was dissolved in 80 parts of deionized water. The mixture was stirred until completely dissolved. The fucoidan solution was slowly added dropwise to the chitosan solution and stirred for 30 min. During the stirring, 10 parts of 5% calcium chloride solution were slowly added. The mixture was crosslinked at room temperature for 30 min to obtain the composite microsphere suspension. Step 3: Formulation: 1 part of the oxaliplatin-containing covalent conjugate prepared in step one was added to 10 parts of the composite microsphere suspension prepared in step two. The mixture was ultrasonically dispersed at 200W for 40 minutes to ensure that the covalent conjugate was uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing the oxaliplatin covalent conjugate and coated with chitosan-fucose composite microspheres was obtained, with the particle size controlled at 100-500nm.

[0024] Example 4 SPF-grade healthy male C57BL / 6J mice, 5-6 weeks old and weighing (20±2) g, were selected. Ten mice were placed in each experimental group. The groups included a normal group, a model group, Example 1-2 groups, and Comparative Examples 1-6 groups. The model mice were acclimatized for 7 days, and each mouse was given AOM (10 mg·kg⁻¹) on days 1 and 5 within one week. -1 Mice were injected with 2.5% DSS solution and given free access to drinking water for 7 days, followed by 14 days of sterile water. This constituted one cycle, and a total of 3 cycles were performed to successfully model the disease. Mice with successful modeling exhibited tumor-like changes and visible "cauliflower-like" sarcomas on the surface of the colon. Normal mice received an intraperitoneal injection of the same volume of AOM saline and free access to water. The example and comparative groups were modeling mice, which were simultaneously administered the corresponding formulation prepared in the example (6 mg / kg) by gavage on day 1 after the end of the third cycle of DSS administration. -1 Mice were administered the medication once daily for 21 consecutive days, followed by evaluation. The normal control group and the model group were given pure water via gavage. After evaluation, the mice in each group were sacrificed, and the number of tumors was counted. The results are shown in Table 1. Table 1 Tumor counts after treatment in different groups , Note: t-test, l: P<0.05 (compared with the normal group); 2: P<0.05 (compared with the model group).

[0025] Oxaliplatin exhibits a significant tumor-killing effect, and its targeted killing effect is even better when combined with novel reed rhizome compounds, resulting in a significant reduction in the number of tumors. However, its effect is not very good when combined with other similar glucosides, suggesting that the compound (1') R ,2' S )-Eugenol-based glycerol 3'- O -β- D -Glucopyranoside has a better affinity for tumor cells and is targeted. Chitosan alone can protect targeted drugs from reaching the intestines, but cross-linking with other sugars and chitosan does not provide good protection, resulting in very poor bioavailability. Only oxaliplatin combined with (1' R ,2' S)-Eugenol-based glycerol 3'- O -β- D Examples 1 and 2, which were obtained by coupling with glucopyranoside and coating the formulation with chitosan-sodium alginate composite microspheres, showed the best results and were able to exert their effects on colon cancer cells. The targeted formulations prepared in this way have unexpected and innovative anti-tumor effects.

[0026] Example 5 The Disease Activity Index (DAI) was observed in each group of mice constructed in Example 4: the mice's body weight loss rate, fecal characteristics, and fecal occult blood were evaluated respectively. Evaluation criteria for body weight loss rate: less than 1% is 0 points; less than 5% is 1 point; more than 5% and less than 10% is 2 points; more than 10% is 3 points. Stool evaluation criteria: 0 points for moderate particle size and consistency; 1 point for having particles, soft texture but not sticking to the anus; 2 points for soft stool sticking to the anus; 3 points for no particle feel, unformed stool, sticking to the anus or diarrhea. Evaluation criteria for fecal occult blood: 0 points for no abnormalities in stool; 1 point for visible dark red spots; 2 points for visible dark red spots and bleeding visible from the anus; 3 points for visible dark red stool and obvious blood adhering around the anus.

[0027] The DAI score is the average of the three scores. The results are shown in Table 2: Table 2 DAI scores for different groups , Note: t-test, l: P<0.05 (compared with the normal group); 2: P<0.05 (compared with the model group).

[0028] Ulcerative colitis-associated colon cancer not only contains tumor cells but also severe inflammation; uncoated oxaliplatin conjugate formulations have poor oral bioavailability and do not provide good therapeutic effects; however, formulations containing only oxaliplatin also have limited efficacy, suggesting that the inflammatory response is not reversed; oral efficacy using other sugar coatings is also reduced, indicating that the chitosan-sodium alginate composite microspheres in the coating formulation have excellent stability at low pH values; furthermore, the use of oxaliplatin with (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D The conjugate obtained by β-glucopyranoside conjugate can reduce DAI scores as expected. We speculate that while killing tumors, it may also achieve a dual therapeutic effect by regulating the gut microbiota and altering the inflammatory microenvironment in the gut.

[0029] Example 6 After the mice with colon cancer in Example 4 were sacrificed at the end of the experiment, fecal samples were collected from their intestines. The detection indicators included *Escherichia coli*, *Enterococcus*, *Lactobacillus*, and *Bifidobacterium*. After the last administration, 0.1 g of fecal sample from each group of rats was collected and diluted with physiological saline to prepare a 100-fold dilution. This dilution was then serially diluted 10-fold, and the diluted samples were added to selective culture media corresponding to the respective bacterial groups. Culture was performed strictly according to the standard culture conditions for each bacterium. After culture, the number of colonies on each plate was counted using the plate count method to calculate the colony level of the corresponding bacterial group. Finally, the raw data were converted into logarithmic values ​​for statistical calculation. The results are shown in Table 3. Table 3. Effects on gut microbiota levels in CAC mice (CFU / g)

[0030] The results show that (1') R ,2' S )-Eugenol-based glycerol 3'- O -β- D -Glucopyranoside has a certain inhibitory effect on miscellaneous bacteria and can promote the growth of probiotics, thus playing a role in regulating the colonic microecology of model mice; while other glucosides are not very effective. Among them, the chitosan-sodium alginate composite microsphere coating and protective conjugates have the best effect, while oxaliplatin and (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D The conjugates obtained by β-glucopyranoside conjugates may achieve the dual purpose of disease treatment by simultaneously killing tumors and regulating the gut microbiota, thereby altering the inflammatory microenvironment within the gut.

[0031] Example 7 This study found that a chitosan-sodium alginate composite microsphere-coated oxaliplatin coupled with (1'R,2'S)-eugenol-based glycerol 3'-O-β-D-glucopyranoside can be used to treat colorectal cancer.

[0032] In summary, during our research and practice, our team discovered that coupling oxaliplatin with (1'R, 2'S)-eugenol glycerol 3'-O-β-D-glucopyranoside can better shrink colon cancer tumors induced by ulcerative colitis, slow down the rate of weight loss in rats, and alleviate symptoms of fecal occult blood. It can also improve intestinal flora imbalance and reverse inflammatory responses. By coating the prepared product with chitosan-sodium alginate composite microspheres, this effect can be effectively achieved orally. We speculate that the finished drug prepared by this method can target and kill tumor cells, increase anti-inflammatory effects, reduce damage to intestinal flora, and regulate the intestinal microecological environment, which is of great significance for the treatment of ulcerative colitis-related colon cancer.

[0033] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0034] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A targeted formulation comprising oxaliplatin, characterized in that, The formulation consists of two parts: an active ingredient and a coating carrier. Active ingredient: covalent conjugate of oxaliplatin and Phragmites communis extract compound formed by amide bond, wherein the mass ratio of oxaliplatin to Phragmites communis extract compound is 1:1-1:2; the Phragmites communis extract compound is named (1 R ,2' S )-syringyl glycerol 3'- O -β- D -glucopyranoside, and the structural formula is as follows: ， The coating carrier is a chitosan-sodium alginate composite microsphere, which is coated on the surface of the covalently coupled material to enhance the stability of the formulation in the stomach. The mass ratio of the chitosan-sodium alginate composite microsphere suspension to the covalently coupled material is 10:1-15:

1. It is a natural polysaccharide with good biocompatibility and non-toxicity. It can form a stable protective layer in the acidic environment of the stomach to prevent premature release of active ingredients.

2. The targeted formulation according to claim 1, characterized in that, The preparation method of the formulation includes the following steps: Step 1: Preparation of oxaliplatin-containing covalent conjugates: Mix 5 parts oxaliplatin with 5 parts (1' R ,2' S )-Eugenol-based glycerol 3'- O -β- D 1-Gluconopyranoside was dissolved in 25 parts of dimethyl sulfoxide (DMSO), 1 part of condensing agent 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and 0.3 parts of catalyst 4-dimethylaminopyridine (DMAP) were added, and the mixture was stirred at room temperature for 8 h. After the reaction was completed, deionized water was added to precipitate the compound, the precipitate was collected by centrifugation, and the compound was freeze-dried to obtain the covalent coupling of oxaliplatin-reed rhizome extract. Step 2: Preparation of chitosan-sodium alginate composite microsphere suspension: Dissolve 2 parts of chitosan in 150 parts of 1% acetic acid solution and 1 part of sodium alginate in 80 parts of deionized water. Stir each solution until completely dissolved. Slowly add the sodium alginate solution dropwise to the chitosan solution and stir for 30 minutes. During this time, slowly add 10 parts of 5% calcium chloride solution. Crosslink at room temperature for 30 minutes to obtain the composite microsphere suspension. Step 3: Formulation: Add 1 part of the oxaliplatin-containing covalent conjugate prepared in Step 1 to 10-15 parts of the composite microsphere suspension prepared in Step 2, and ultrasonically disperse at 200-250W power for 40 minutes to ensure that the covalent conjugate is uniformly loaded inside and on the surface of the composite microspheres. After centrifugation, washing, and freeze-drying, a colon-targeted formulation containing oxaliplatin covalent conjugate coated with chitosan-sodium alginate composite microspheres is obtained, with the particle size controlled at 100-500nm.

3. The targeted formulation according to claim 2, characterized in that... In step three of the preparation method of the formulation, the ultrasonic dispersion power is 200-250W and the dispersion time is 40min to ensure uniform particle size of the formulation.

4. The oxaliplatin-containing targeted formulation according to any one of claims 1-3, and its use in the preparation of medicaments for treating colorectal cancer.

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