A bpa pharmaceutical composition for boron neutron capture therapy and a preparation method and application thereof

Abstract

The application discloses a BPA pharmaceutical composition for boron neutron capture therapy and a preparation method and application thereof, and belongs to the technical field of tumor treatment drugs. The pharmaceutical composition is an injection preparation, which is composed of an active ingredient BPA and a complexing ligand 1,2-dihydroxybenzene-3,5-disulfonic acid disodium salt, and the two form a stable five-membered ring borate complex under a physiological pH condition. The complex has a strong negative charge, can double block passive diffusion and active uptake of blood cells to the drug, effectively reduces drug accumulation in normal tissues, and reduces bone marrow suppression toxicity; meanwhile, the complex has a pH response characteristic, is stable in a normal blood circulation of a body, can specifically dissociate and release free BPA after entering an acid microenvironment of a tumor, improves a drug enrichment amount of the tumor site, prolongs a residence time, and effectively widens a treatment window. The preparation process condition is mild, does not need organic solvents and high-temperature treatment, is simple and easy to operate and industrialized mass production, the obtained preparation has excellent solubility, stable and controllable quality, and can be widely applied to boron neutron capture therapy of various LAT1 high-expression malignant tumors.

Description

Technical Field

[0001] This invention relates to the field of tumor therapeutic drug technology, and in particular to a BPA pharmaceutical composition for boron neutron capture therapy, its preparation method and application. Background Technology

[0002] Boron neutron capture therapy (BNCT) utilizes thermal neutrons to bombard tumor cells with neutrons that are enriched within them. 10 Element B produces alpha particles with high energy transfer linear density and 7 Li ions are used to precisely kill cancer cells. 10 Element B undergoes a nuclear reaction after capturing a neutron, producing alpha particles and... 7 Li ions have the characteristics of short range (only about 5-10 μm, covering about 1-2 cell diameters) but high energy, which can achieve precise attack on tumors at the cellular level and theoretically minimize damage to surrounding normal tissues.

[0003] 4-Dihydroxyboron-L-phenylalanine (BPA) is currently the most widely used and mainstream approved small-molecule boron carrier for BNCTs in clinical practice. It can achieve active targeted uptake through L-amino acid transporter 1 (LAT1), which is highly expressed in tumor cells. However, BPA has extremely poor water solubility under physiological neutral pH conditions and must rely on excipients for complexation and solubilization to meet the requirements for intravenous administration.

[0004] Currently, clinically marketed BPA formulations have undergone two generations of technological iterations: the first generation used fructose as a complexing and solubilizing excipient, which had core drawbacks such as easy browning, poor storage stability, high production difficulty, and contraindication for patients with hereditary fructose intolerance; the second generation used D-sorbitol as a complexing and solubilizing excipient, which only solved the storage stability and patient contraindication issues of fructose formulations, but failed to address the following inherent defects in the clinical application of BPA formulations: BPA itself has extremely poor water solubility and limited solubility in aqueous solutions. It is difficult to achieve stable high-concentration dissolution under simple hydration conditions. Even when sorbitol is introduced as a solubilizing excipient in the formulation of compound systems, the solubilizing effect is limited and cannot significantly increase the saturated dissolution concentration of BPA. High-concentration solutions are prone to drug molecule association and aggregation, which can lead to BPA precipitation, solution turbidity and stratification. The formulation has poor stability and cannot meet the requirements for high-dose, long-term intravenous infusion in clinical practice, which seriously limits the drug loading capacity of boron drugs and the therapeutic effect of BNCT. The massive uptake of free BPA by blood cells is the core dose-limiting source of myelosuppressive toxicity in existing formulations. Free BPA is electrically neutral and can be absorbed via passive diffusion and by highly expressed LAT2 and γ-aminobutyric acid (γ-PA) on the surface of blood cells. +The LAT1 transporter actively takes up blood cells, accumulating in large quantities and forming a non-targeted reservoir. During neutron irradiation, the LAT1 transporter... 10 B-reactive protein (BPA) undergoes a nuclear reaction that directly damages circulating blood cells and bone marrow hematopoietic tissue, leading to severe bone marrow suppression. Simultaneously, the continuous dissociation and release of BPA stored within blood cells further exacerbates non-specific exposure to normal tissues. This toxicity directly limits the upper limit of clinical dosage, making it difficult for tumor tissue boron concentrations to reach the effective therapeutic threshold for BNCT, severely restricting clinical efficacy. Therefore, a novel formulation that can simultaneously improve BPA solubility and block blood cell uptake is urgently needed.

[0005] In existing technologies, Tiron (titanium iron reagent) has only been used for the quantitative detection of borate ions and the complexation and scavenging of heavy metal ions, and has never been used in the development of BPA formulations for BNCT. In summary, a BPA formulation that simultaneously possesses solubilizing and hematopoietic uptake blocking properties has not yet been developed in this field, which has become a major technical bottleneck restricting the improvement of clinical efficacy and widespread application of BNCT. Summary of the Invention

[0006] This invention provides a BPA pharmaceutical composition for boron neutron capture therapy, its preparation method, and its application, which can solve the defects of existing BPA preparations such as poor solubility and high blood cell uptake.

[0007] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a BPA pharmaceutical composition for boron neutron capture therapy, the pharmaceutical composition being an injectable formulation comprising the active ingredient BPA and the complexing ligand disodium 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron); wherein the disodium 1,2-dihydroxybenzene-3,5-disulfonic acid forms a stable five-membered cyclic borate ester complex with BPA at physiological pH.

[0008] Furthermore, the molar ratio of BPA to disodium 1,2-dihydroxybenzene-3,5-disulfonic acid is (0.1~10):1, preferably 2:1.

[0009] Furthermore, the final concentration of BPA in the injectable formulation is 1~200 mg / mL.

[0010] Furthermore, the pharmaceutical composition also includes an isotonic adjuster, a pH adjuster, and water for injection.

[0011] Furthermore, the isotonic regulator is one or more of sodium chloride, mannitol, and glycerol.

[0012] Furthermore, the pH adjuster is one or more of phosphate buffer, acetic acid, hydrochloric acid, and sodium hydroxide.

[0013] Furthermore, the pH of the injectable formulation is 6.8 to 7.4.

[0014] In a second aspect, the present invention provides a method for preparing a BPA pharmaceutical composition for boron neutron capture therapy, comprising the following steps: S1. Add the sodium salt of complexed ligand 1,2-dihydroxybenzene-3,5-disulfonic acid to 80% of the prescribed amount of water for injection and stir until completely dissolved to obtain the ligand solution. S2. Add BPA to the ligand solution obtained in S1, stir well, adjust the pH to 6.8~7.4 with a pH adjuster, stir at room temperature in the dark to obtain a complex solution; S3. Add isotonic regulator to complexing solution and stir until completely dissolved. Add water for injection to the total volume to obtain crude solution. Test the complexation rate, pH value, osmotic pressure and related substances of crude solution. Proceed to the next step after the key quality attributes meet the preset requirements. S4. The qualified crude liquid is filtered through a sterile filter membrane under light-protected conditions, sterilized and dispensed to obtain an injectable preparation, which is the BPA drug composition.

[0015] Furthermore, in step S2, the stirring time at room temperature in the dark is 15-30 minutes.

[0016] Furthermore, in step S4, the sterile filter membrane is a 0.22 μm filter membrane.

[0017] Thirdly, the present invention provides the use of a BPA pharmaceutical composition for boron neutron capture therapy in the preparation of an antitumor drug for boron neutron capture therapy.

[0018] Furthermore, the tumor is a malignant tumor with high expression of the LAT1 transporter, including any one of malignant glioma, recurrent head and neck tumors, colon cancer, triple-negative breast cancer, non-small cell lung cancer, liver cancer, gastric cancer, ovarian cancer, and prostate cancer.

[0019] The beneficial effects of this invention are: 1. Significantly improves BPA solubility: This invention uses Tiron as a functional solubilizing component to form a stable five-membered ring borate ester complex with BPA, which has a stronger complexing and solubilizing ability for BPA. This can significantly improve the saturated solubility of BPA in aqueous solution, enabling the formulation to maintain the uniformity and transparency of the system under higher dosing concentrations, thus meeting the clinical needs for high-dose administration.

[0020] 2. Dual Blocking of Blood Cell Uptake: The BPA-Tiron complex prepared in this invention carries a strong negative charge. Through a dual mechanism of electrostatic repulsion and transporter recognition blocking, it significantly inhibits the passive diffusion and active uptake of BPA by blood cells. In vitro whole blood incubation experiments show that one hour after administration, the proportion of boron in blood cells is reduced by more than 50% compared to fructose preparations, fundamentally alleviating the dose-limiting myelosuppressive toxicity of BPA preparations and significantly increasing the upper limit of clinical dosage.

[0021] 3. Precise release in response to the tumor microenvironment: The complex of this invention remains stable under physiological pH conditions, which ensures its structural integrity during in vivo circulation. It is expected to further achieve precise release of free BPA in the tumor microenvironment, which can then be efficiently taken up by the LAT1 transporter highly expressed by tumor cells, prolonging the tumor retention time and broadening the therapeutic window.

[0022] 4. The preparation process is mild and easy to industrialize: The preparation method of this invention uses water for injection as the only solvent throughout the entire process, without the need for organic solvents or high temperature and high pressure treatment. It only requires conventional pharmaceutical-grade stirring and filtration equipment, which greatly reduces the cost of production line construction. The process parameter window is wide, the quality is highly controllable, and it is very easy to achieve industrial scale-up production, which has extremely high clinical translation and commercialization value. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the BPA pharmaceutical composition obtained in this invention; Figure 2 The results of in vitro administration of different BPA formulations of this invention show the detection results of blood cell and plasma boron content. Figure 3 Effect of different molar ratios of Tiron on the solubility of BPA. (a) Pure BPA aqueous solution; (b) BPA to Tiron molar ratio 5:1; (c) BPA to Tiron molar ratio 4:1; (d) BPA to Tiron molar ratio 3:1; (e) BPA to Tiron molar ratio 2:1; (f) Pure Tiron aqueous solution; Figure 4 The UV absorption spectra of Tiron, BPA solution, and Tiron-BPA complex are shown. Figure 5 High-performance liquid chromatograms of Tiron, BPA solution, and Tiron-BPA complex; Figure 6 The stability of the BPA-Tiron complex under different pH conditions: (a) pH 3.0; (b) pH 4.0; (c) pH 5.0; (d) pH 6.0; (e) pH 7.0. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0025] In a first aspect, the present invention provides a BPA pharmaceutical composition for boron neutron capture therapy, the pharmaceutical composition being an injectable formulation comprising the active ingredient BPA and the complexing ligand disodium 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron); wherein the disodium 1,2-dihydroxybenzene-3,5-disulfonic acid forms a stable five-membered cyclic borate ester complex with BPA at physiological pH.

[0026] This invention provides a BPA pharmaceutical composition for boron neutron capture therapy. By using Tiron as a complexing ligand to form a stable five-membered cyclic boron ester complex with BPA, the saturated solubility of BPA in aqueous solution is significantly improved, allowing the formulation to remain clear and homogeneous at high concentrations, meeting the needs of high-dose intravenous administration in clinical practice. Simultaneously, the strong negative charge carried by this complex effectively inhibits the passive diffusion and active uptake of BPA by blood cells through a dual mechanism of electrostatic repulsion and transporter recognition blocking, thereby fundamentally alleviating dose-limiting myelosuppressive toxicity and increasing the upper limit of clinical dosage. Furthermore, this complex remains stable in the bloodstream at physiological pH, while specifically dissociating and releasing free BPA in the weakly acidic microenvironment of tumors, achieving precise tumor-targeted release, prolonging the drug's residence time at the tumor site, and broadening the therapeutic window. The composition of this invention has a mild preparation process, uses only water for injection as a solvent, and requires no organic solvents or high-temperature and high-pressure treatment, exhibiting extremely high industrial feasibility and clinical translational value.

[0027] In some embodiments, the molar ratio of BPA to disodium 1,2-dihydroxybenzene-3,5-disulfonic acid is (0.1~10):1, preferably 2:1. Within this molar ratio range, Tiron and BPA can form a highly stable five-membered ring borate ester complex, achieving efficient solubilization of BPA and dual blocking of blood cell uptake. If the Tiron ratio is too low (molar ratio <0.1:1), the complexation is insufficient, the increase in BPA solubility is limited, and the negative charge shielding is insufficient, leading to increased blood cell uptake. If the Tiron ratio is too high (molar ratio >10:1), the excessive ligand will competitively occupy BPA binding sites or introduce too much negative charge, which may affect the stability of the complex or the isotonic adjustment of the formulation, and cause waste of raw materials.

[0028] In some embodiments, the final concentration of BPA in the injectable formulation is 1-200 mg / mL. Within this concentration range, the formulation can balance an effective therapeutic dose of BPA with good solubility and stability, ensuring a clear and homogeneous system when administered at high concentrations. If the concentration is below 1 mg / mL, it is difficult to achieve the tumor boron concentration required for BNCT, resulting in insufficient clinical efficacy. If it is above 200 mg / mL, it may exceed the complexation and solubilization limit of Tiron, leading to BPA precipitation, turbidity of the solution, and increased risks associated with intravenous administration.

[0029] In some embodiments, the pharmaceutical composition further comprises an isotonic adjuster, a pH adjuster, and water for injection. By adjusting the osmotic pressure and pH to the physiological range and using water for injection as a solvent, the biocompatibility, stability, and safety of intravenous administration of the formulation are significantly improved.

[0030] In some embodiments, the isotonic adjuster is one or more of sodium chloride, mannitol, and glycerol. This allows for precise adjustment of the formulation's osmotic pressure to an isotonic level, preventing blood cell damage or injection site irritation caused by osmotic imbalance, and exhibits good compatibility with the Tiron-BPA complex.

[0031] In some embodiments, the pH adjuster is one or more selected from phosphate buffer, acetic acid, hydrochloric acid, and sodium hydroxide. This allows the pH of the formulation to be stably controlled within the physiologically neutral range of 6.8 to 7.4, thereby maintaining the structural stability of the five-membered ring borate ester complex and ensuring the consistency of the formulation's quality during storage and use.

[0032] In some embodiments, the pH of the injectable formulation is 6.8 to 7.4. Maintaining the pH of the injectable formulation within the physiologically neutral range of 6.8 to 7.4 ensures the stability of the BPA-Tiron pentagonal borate ester complex during storage and blood circulation, preventing hydrolysis and inactivation under acidic / alkaline conditions, while also ensuring good compatibility with the isotonic environment of human blood, reducing vascular irritation and adverse reactions during intravenous injection.

[0033] In a second aspect, the present invention provides a method for preparing a BPA pharmaceutical composition for boron neutron capture therapy, comprising the following steps: S1. Add the sodium salt of complexed ligand 1,2-dihydroxybenzene-3,5-disulfonic acid to 80% of the prescribed amount of water for injection and stir until completely dissolved to obtain the ligand solution. The above steps involve dissolving the complexing ligand Tiron in 80% of the prescribed volume of water for injection. This ensures the ligand is fully dispersed and has high dissolution efficiency, while also providing a uniform complexing environment for the subsequent addition of BPA. Additionally, 20% of the water volume is reserved for precise volume adjustment, facilitating accurate control of the final concentration.

[0034] S2. Add BPA to the ligand solution obtained in S1, stir well, adjust the pH to 6.8~7.4 with a pH adjuster, stir at room temperature in the dark to obtain a complex solution; Under physiological conditions of pH 6.8–7.4, the above steps involve a coordination reaction between the ortho-dihydroxyl group in the Tiron molecule and the boric acid group in BPA, resulting in dehydration and the formation of a stable five-membered ring borate ester complex. This process achieves solubilization of BPA and shielding against its negative charge. Stirring at room temperature in the dark promotes the efficient formation of a stable five-membered ring borate ester complex between Tiron and BPA, while avoiding oxidative degradation caused by high temperature and light, ensuring a complete complexation reaction and a homogeneous product.

[0035] S3. Add isotonic regulator to complexing solution and stir until completely dissolved. Add water for injection to the total volume to obtain crude solution. Test the complexation rate, pH value, osmotic pressure and related substances of crude solution. Proceed to the next step after the key quality attributes meet the preset requirements. The above steps involve adding an isotonic regulator to the complexing solution and replenishing it with water for injection to the full volume, thereby obtaining a crude solution that meets the physiological osmotic pressure requirements of the human body. After testing for key quality attributes (complexation rate, pH, osmotic pressure, and related substances), the semi-finished product is ensured to be qualified before proceeding to the next process, effectively guaranteeing the safety and quality control of the final product.

[0036] S4. The qualified crude liquid is filtered through a sterile filter membrane under light-protected conditions, sterilized and dispensed to obtain an injectable preparation, which is the BPA drug composition.

[0037] The above steps involve filtering the qualified crude liquid through a 0.22μm sterile filter membrane under light-protected conditions and then sterilizing and dispensing it. This effectively removes microorganisms and any particles that may be present. At the same time, the light-protected operation prevents the degradation of photosensitive components, ultimately resulting in a sterile, clear, and stable injectable formulation.

[0038] In some embodiments, in step S2, the stirring time at room temperature in the dark is 15-30 minutes. This time range ensures that Tiron and BPA fully complex to form a stable five-membered borate ester structure, while avoiding the decrease in production efficiency or photo-oxidation side reactions caused by excessive stirring; if the stirring time is too short, the complexation will be incomplete and the solubilization and blocking effects will decrease, while if the time is too long, the process time will increase and there will be no additional benefits.

[0039] In some embodiments, in step S4, the sterile filter membrane is a 0.22 μm filter membrane. This pore size can effectively trap microorganisms (including bacteria and fungi) to ensure the sterility of the formulation, while not affecting the passage of complexes and excipients, thus ensuring the safety and efficacy of the final product; if the pore size of the filter membrane is too large, sterility cannot be guaranteed, and if the pore size is too small, it is easy to clog and filter is difficult.

[0040] Thirdly, the present invention provides the use of a BPA pharmaceutical composition for boron neutron capture therapy in the preparation of an antitumor drug for boron neutron capture therapy.

[0041] In some embodiments, the tumor is a malignant tumor that highly expresses the LAT1 transporter, including any one of malignant glioma, recurrent head and neck tumors, colon cancer, triple-negative breast cancer, non-small cell lung cancer, liver cancer, gastric cancer, ovarian cancer, and prostate cancer.

[0042] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0043] Example 1: BPA-Tiron injection formulation with a molar ratio of 2:1 This embodiment provides a method for preparing a BPA pharmaceutical composition for boron neutron capture therapy, comprising the following steps: Take 0.2 mmol of Tiron, add 4 mL of water for injection, and stir to dissolve; add 0.1 mmol of BPA, stir to mix well, add acetic acid to adjust the pH to 6.8; stir at room temperature in the dark for 15 min; add sodium chloride to adjust to isotonicity, and add water for injection to 5 mL; filter aseptically at 0.22 μm and dispense to obtain the injection formulation.

[0044] Example 2: BPA-Tiron injection formulation with a molar ratio of 3:1 This embodiment provides a method for preparing a BPA pharmaceutical composition for boron neutron capture therapy, comprising the following steps: Take 0.3 mmol of Tiron, add 4 mL of water for injection, and stir to dissolve; add 0.1 mmol of BPA, stir to mix well, and adjust the pH to 7.2 with acetic acid and sodium hydroxide; stir at room temperature in the dark for 20 min; add mannitol to adjust to isotonicity, and add water for injection to 5 mL; filter aseptically at 0.22 μm and dispense to obtain the injection formulation.

[0045] Example 3: BPA-Tiron injection formulation with a molar ratio of 5:1 This embodiment provides a method for preparing a BPA pharmaceutical composition for boron neutron capture therapy, comprising the following steps: Take 0.5 mmol of Tiron, add 4 mL of water for injection, and stir to dissolve; add 0.1 mmol of BPA, stir to mix well, and adjust the pH to 7.4 with hydrochloric acid and sodium hydroxide; stir at room temperature in the dark for 30 min; add glycerol to adjust to isotonicity, and add water for injection to 5 mL; filter aseptically at 0.22 μm and dispense to obtain the injection formulation.

[0046] Example 4: In vitro blood cell uptake inhibition experiment Fresh mouse whole blood was taken and the injectable formulation and fructose-BPA formulation obtained in Example 1 were added respectively. The mixtures were incubated at 37°C for 1 h and 1.5 h. Blood cells and plasma were separated. The blood cells were digested, diluted, and filtered. The boron content was determined by ICP-OES.

[0047] Test results are as follows Figure 2 As shown, by Figure 2 As can be seen, the intracellular boron absorption intensity of the fructose-BPA formulation group (blue line) increased with incubation time, while the injection formulation group obtained in Example 1 (red line) did not show a significant increase. Furthermore, after 1.5 hours, the intracellular boron absorption intensity of the fructose-BPA formulation group was twice that of the formulation group of this invention. This indicates that the BPA-Tiron complex prepared in this invention carries a strong negative charge and significantly inhibits the passive diffusion and active uptake of BPA by blood cells through a dual mechanism of electrostatic repulsion and transporter recognition blocking. This fundamentally alleviates the dose-limiting myelosuppressive toxicity of BPA formulations and can significantly increase the upper limit of clinical dosage.

[0048] Example 5: In vivo blood cell uptake inhibition experiment Mice were injected intravenously with the injectable formulation obtained in Example 1 and the fructose-BPA formulation, respectively. Samples were taken at 1 hour, and blood cells and plasma were separated, digested, diluted, and filtered. The boron content of blood cells and plasma was determined by ICP-MS. The test results are shown in Table 1. Table 1

[0049] As shown in Table 1, the ratio of boron uptake by blood cells to boron uptake by whole blood in the injectable formulation group obtained in Example 1 of this invention was 16.13%, which was significantly lower than the 46.41% ratio in the fructose-BPA formulation group. This indicates that the BPA-Tiron complex prepared in this invention can significantly reduce the proportion of BPA uptake by blood cells, thereby effectively alleviating bone marrow suppression toxicity.

[0050] Example 6: Effect of different molar ratios of Tiron on the solubility of BPA Prepare the following 6 groups of samples, with a fixed BPA dosage of 0.1 mmol. Add water for injection to 1 mL, adjust the pH of the system to 7.2 using 1 mol / L sodium hydroxide, stir at room temperature in the dark for 30 min, and observe the clarity of the solution after standing for 1 h: (a) Blank control group 1: pure BPA aqueous solution; (b) Experimental group 1: BPA to Tiron molar ratio 5:1; (c) Experimental group 2: BPA to Tiron molar ratio 4:1; (d) Experimental group 3: BPA to Tiron molar ratio 3:1; (e) Experimental group 4: BPA to Tiron molar ratio 2:1; (f) Blank control group 2: pure Tiron aqueous solution; Experimental results are as follows Figure 3 As shown: The pure BPA aqueous solution group was obviously turbid, and a large amount of white undissolved precipitate could be seen at the bottom, indicating that BPA has extremely poor water solubility under physiological pH conditions.

[0051] The BPA to Tiron molar ratio of 2:1 solution was completely clear and transparent, without any visible turbidity, opalescence or precipitation, indicating that Tiron can significantly increase the saturated solubility of BPA at this molar ratio.

[0052] The turbidity of the solutions with BPA to Tiron molar ratios of 3:1, 4:1, and 5:1 was significantly reduced compared to the pure BPA solution, and a small amount of loose white precipitate was visible in the solution.

[0053] Pure Tiron aqueous solution is a colorless, clear, and transparent solution without any turbidity or precipitation.

[0054] Experimental results show that Tiron can significantly increase the saturated solubility of BPA.

[0055] Example 7: Validation of BPA by UV Spectroscopy and High Performance Liquid Chromatography Tiron complexation reaction This embodiment uses ultraviolet light. Visible absorption spectrum (UV) Vis) and high performance liquid chromatography (HPLC) were used to verify that BPA and Tiron undergo a complexation reaction under physiological pH conditions to form a stable complex.

[0056] Prepare separately: 1. BPA control solution (0.1 mmol / 5 mL, pH 7.2); 2. Tiron control solution (0.1 mmol / 5 mL, pH 7.2); 3. BPA Tiron mixed solution (molar ratio 2:1, pH 7.2).

[0057] Ultraviolet spectroscopy determination: Using pH 7.2 phosphate buffer as a blank, the absorption curve was scanned in the range of 190–900 nm.

[0058] High performance liquid chromatography (HPLC) conditions: C18 column (4.6 mm × 250 mm, 5 μm), mobile phase is methanol-water solution (15:85, v / v) isocratic elution, flow rate 1.0 mL / min, column temperature 30℃, detection wavelength 300 nm, injection volume 50 μL, and chromatograms of BPA, Tiron and mixed system were recorded respectively.

[0059] like Figure 4 As shown, the Tiron solution exhibits a strong characteristic absorption peak at approximately 210 nm; extremely weak absorption in the 250-300 nm wavelength range; and no significant absorption above 300 nm. The BPA control solution has a strong terminal absorption peak at 220 nm, a weak characteristic absorption peak at 260 nm, and no obvious absorption after 290 nm. The absorption spectrum of the BPA-Tiron mixed solution differs from both Tiron and BPA. Compared to the single component, the main absorption peak in the short wavelength region exhibits a red shift and a change in absorption intensity; the characteristic absorption peak of the original BPA at 260 nm disappears; and a novel strong absorption peak, not present in either of the single components, appears at approximately 310 nm, with an intensity much higher than the weak absorption of Tiron at 290 nm. This indicates that a specific coordination reaction occurred between BPA and Tiron, forming a new chemical species.

[0060] like Figure 5 The results showed that the Tiron solution exhibited a single, sharp characteristic chromatographic peak at a retention time of 1.195 min; The BPA solution showed a very weak chromatographic peak at a retention time of approximately 1.699 min; Compared with the single component, the BPA-Tiron mixed solution showed a new single sharp chromatographic peak at a retention time of approximately 1.298 min. This peak is a characteristic peak of the BPA-Tiron complex, proving that BPA and Tiron underwent a quantitative complexation reaction under physiological pH conditions to form a stable five-membered cyclic boron ester complex.

[0061] Conclusion: The results of UV-Vis absorption spectroscopy and high performance liquid chromatography consistently demonstrate that BPA and Tiron can undergo a specific complexation reaction under physiological pH 7.2 to form a stable BPA-Tiron five-membered ring borate ester complex.

[0062] Example 8 pH Response Stability Verification Experiment A mixed solution of BPA and Tiron in a 2:1 molar ratio was prepared, and the pH was adjusted to 3.0, 4.0, 5.0, 6.0, and 7.0 respectively using 1 mol / L sodium hydroxide and 10% acetic acid solutions. The solutions were then allowed to stand at room temperature in the dark for 30 minutes. The stability of the system was evaluated by observing the strength of the Tyndall effect and the turbidity of the solution when the solution was illuminated from the side with a red laser pointer.

[0063] Experimental results are as follows Figure 6 As shown: At pH 7.0, the solution is completely clear and transparent, with no obvious scattered light when irradiated by laser, and the light path is invisible, indicating that BPA... Tiron complexes are highly stable under physiological pH conditions, with no free BPA precipitated. At pH 6.0, the solution exhibits the most significant turbidity. Laser irradiation produces a strong Tyndall effect, and the red scattered light path is clear, sharp, and penetrates the entire solution, indicating that the complex dissociates to the highest degree under this pH condition, resulting in the precipitation of a large number of free BPA particles. At pH 5.0, the turbidity of the solution was significantly reduced compared to pH 6.0, and a clear but weakened scattered light path could be seen when irradiated with laser, indicating that the degree of dissociation of the complex had decreased. At pH 4.0, the turbidity of the solution further decreased, becoming only slightly translucent, and the scattered light path under laser irradiation weakened, indicating a reduction in the content of free BPA particles. At pH 3.0, the solution again showed a milky white and heavily turbid state. The strong Tyndall effect was observed when irradiated with laser, indicating that free BPA precipitated out in large quantities under strongly acidic conditions due to its extremely poor water solubility.

[0064] Experiments have shown that BPA Tiron complexes exhibit significant pH-responsive properties, remaining stable under normal human physiological conditions (pH 7.0–7.4), while specifically dissociating and releasing free BPA in the typical weakly acidic microenvironment of tumor tissue (pH 5.0–6.5), thus meeting the targeted release requirements for BNCT therapy.

[0065] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A BPA pharmaceutical composition for boron neutron capture therapy, characterized in that, The pharmaceutical composition is an injectable formulation, consisting of the active ingredient BPA and the complexing ligand disodium salt of 1,2-dihydroxybenzene-3,5-disulfonic acid; the disodium salt of 1,2-dihydroxybenzene-3,5-disulfonic acid and BPA form a stable five-membered cyclic borate ester complex at physiological pH.

2. The BPA pharmaceutical composition for boron neutron capture therapy according to claim 1, characterized in that, The molar ratio of BPA to disodium 1,2-dihydroxybenzene-3,5-disulfonic acid is (0.1~10):

1.

3. The BPA pharmaceutical composition for boron neutron capture therapy according to claim 1, characterized in that, The final concentration of BPA in the injectable formulation is 1~200 mg / mL.

4. The BPA pharmaceutical composition for boron neutron capture therapy according to claim 1, characterized in that, The pharmaceutical composition further comprises an isotonicity regulator, a pH regulator, and water for injection; The isotonic regulator is one or more of sodium chloride, mannitol, and glycerin; The pH adjuster is one or more of phosphate buffer, acetic acid, hydrochloric acid, and sodium hydroxide.

5. The BPA pharmaceutical composition for boron neutron capture therapy according to claim 1, characterized in that, The pH of the injectable formulation is 6.8 to 7.

4.

6. A method for preparing a BPA pharmaceutical composition for boron neutron capture therapy, comprising the method for preparing the BPA pharmaceutical composition for boron neutron capture therapy according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Add the sodium salt of complexed ligand 1,2-dihydroxybenzene-3,5-disulfonic acid to 80% of the prescribed amount of water for injection and stir until completely dissolved to obtain the ligand solution. S2. Add BPA to the ligand solution obtained in S1, stir well, adjust the pH to 6.8~7.4 with a pH adjuster, stir at room temperature in the dark to obtain a complex solution; S3. Add isotonic regulator to complexing solution and stir until completely dissolved. Add water for injection to the total volume to obtain crude solution. Test the complexation rate, pH value, osmotic pressure and related substances of crude solution. Proceed to the next step after the key quality attributes meet the preset requirements. S4. The qualified crude liquid is filtered through a sterile filter membrane under light-protected conditions, sterilized and dispensed to obtain an injectable preparation, which is the BPA drug composition.

7. The method for preparing the BPA pharmaceutical composition for boron neutron capture therapy according to claim 6, characterized in that, In step S2, the stirring time at room temperature in the dark is 15-30 minutes.

8. The method for preparing the BPA pharmaceutical composition for boron neutron capture therapy according to claim 6, characterized in that, In step S4, the sterile filter membrane is a 0.22 μm filter membrane.

9. The use of a BPA pharmaceutical composition for boron neutron capture therapy in the preparation of an antitumor drug for boron neutron capture therapy.

10. The application according to claim 9, characterized in that, The tumor is a malignant tumor that highly expresses the LAT1 transporter, including any one of malignant glioma, recurrent head and neck tumors, colon cancer, triple-negative breast cancer, non-small cell lung cancer, liver cancer, gastric cancer, ovarian cancer, and prostate cancer.

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