Octreotide sustained-release formulation

Abstract

Provided is an octreotide sustained-release formulation, comprising octreotide acetate, glyceryl dioleate, phosphatidylcholine, an organic solvent such as ethanol, and a pH regulator, for treating neuroendocrine system-related diseases. The active pharmaceutical ingredient octreotide acetate is used to prepare the octreotide sustained-release formulation, and the pH regulator is used to regulate the pH of the octreotide sustained-release formulation to a suitable range, thereby improving the stability of octreotide in the formulation. The formulation system has good stability during long-term storage at 2-8 °C.

Description

An octreotide sustained-release formulation

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Chinese patent application No. 202510380066.6, filed with the China National Intellectual Property Administration on March 28, 2025, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This application belongs to the pharmaceutical field, specifically relating to an octreotide sustained-release formulation, its preparation method, and its uses. Background Technology

[0004] Octreotide is a synthetic octapeptide derivative of natural somatostatin, retaining the same pharmacological effects as somatostatin but with a longer duration of action. It inhibits the increased pharmacological secretion of growth hormone (GH) and peptides and serotonin produced by the gastrointestinal pancreas (GEP) endocrine system, and is clinically used to treat acromegaly, carcinoid tumors, and vasoactive intestinal peptide tumors. Currently, there are three commercially available octreotide formulations globally: octreotide acetate injection (brand name SANDOSTATIN), developed by Novartis; octreotide acetate microspheres for injection (brand name SANDOSTATIN LAR), also developed by Novartis; and oral octreotide sustained-release capsules (brand name MYCAPSSA), developed by Chiasma in June 2020, which received FDA approval. Several domestic Chinese companies have also launched octreotide acetate injection or octreotide acetate microspheres for injection.

[0005] However, all marketed formulations of octreotide have some shortcomings, as detailed in the table below.

[0006] To address the shortcomings of the aforementioned formulations, the Swedish company Camurus developed... (Also known as fluid crystal) preparations. It is a specially formulated combination of endogenous polar lipids, an autoadaptive drug delivery system that combines ease of manufacture, processing, and injection with long-lasting release. Upon contact with tissue fluid, the injection solution transforms into a gel-like crystal, forming a drug reservoir and exerting a sustained release effect. CN101014319B discloses... The composition of the formulation. The company utilizes... This product achieves long-acting delivery of buprenorphine, becoming the first marketed product in this dosage form. Camurus AB's octreotide hydrochloride fluid crystals were approved for marketing in the EU on June 30, 2025, under the trade name... The indication is acromegaly.

[0007] The key excipients are diacyl esters and phospholipids. These excipients are characterized by high safety but are easily degraded and have poor compatibility with peptide drugs. Therefore, there are currently no peptide drugs on the market delivered using this dosage form. Consequently, many researchers are dedicated to improving the stability of peptide liquid crystal formulations.

[0008] Camurus's Chinese patent CN101842082B and its aforementioned products Relatedly, a composition for delayed delivery of a peptide activator is disclosed, wherein the peptide activator exists in salt form and comprises at least one positively charged peptide ion and at least one negatively charged counterion. The at least one negatively charged counterion is a halide ion, preferably a chloride or bromide ion. Specifically, this patent prepares octreotide hydrochloride (OCT(Cl)) by passing an aqueous solution of octreotide acetate (OCT(Ac)) through an ion exchange column, and prepares a fluid crystal formulation using OCT(Cl) as a raw material. The technical solution of this patent does not involve pH adjustment and control.

[0009] Example 5 of CN101842082B compares the in vitro release of OCT(Cl) and OCT(Ac) formulations, showing that the release rate of hydrochloride is up to about 4 times slower than that of acetate.

[0010] Example 6 of CN101842082B compares the stability of OCT(Ac) fluid crystals and OCT(Cl) fluid crystals after 4 weeks at 40°C / 75% relative humidity. The results show that the OCT(Cl) formulation showed only a slight decrease in content at 40°C for 4 weeks, decreasing from 100.45% to 98.41%, while the decomposition products increased from 0.19% to 0.35%. In contrast, the OCT(Ac) formulation exhibited significant degradation of octreotide, with its content decreasing from 95.72% to 60.33%, and the decomposition products increasing from 1.88% to 32.39%.

[0011] While this patent yields a slow-release, relatively stable octreotide formulation, neither China nor the US currently has a registered pharmaceutical-grade octreotide hydrochloride. The process involves converting octreotide acetate into octreotide hydrochloride and then preparing fluid crystal samples, which increases the complexity of the raw material preparation process. Furthermore, the patent does not disclose data on the quality and stability of the octreotide hydrochloride raw material, leaving it unclear whether the octreotide hydrochloride meets pharmaceutical requirements. Summary of the Invention

[0012] This application provides an octreotide sustained-release formulation, which uses a registered and readily available octreotide acetate raw material to prepare a fluid crystal formulation. A pH adjuster is used to adjust the pH of the fluid crystal formulation to a suitable range, thereby increasing the stability of octreotide in the formulation. This formulation system exhibits good stability during long-term storage at 2–8°C. Pharmacokinetic and pharmacodynamic results of this application's formulation indicate that it can achieve once-every-four-weeks or once-monthly dosing with efficacy superior to commercially available formulations.

[0013] In a first aspect, this application provides an octreotide acetate sustained-release formulation comprising the following components in parts by weight: 10-30 parts octreotide acetate, 200-600 parts dioleoglyceride, 200-600 parts phosphatidylcholine, 50-150 parts organic solvent, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 4.5-7.0.

[0014] In some embodiments, the sustained-release formulation comprises 13-28 parts by weight of octreotide acetate, preferably 18-26 parts by weight, more preferably 20-24 parts by weight, more preferably 21-23 parts by weight, and more preferably 22-23 parts by weight.

[0015] In some embodiments, the pH of the formulation is 5.0-6.0, 5.1-6.0, 5.5-6.0, 5.6-6.0, or 5.7-6.0. More preferably, the pH of the formulation is 5.6-5.8. In some embodiments, the pH of the formulation is 5.7.

[0016] In some embodiments, the pH adjuster is acetic acid, sulfuric acid, or hydrogen chloride. More preferably, the pH adjuster is hydrogen chloride.

[0017] In some embodiments, the organic solvent is ethanol, propylene glycol, or a mixture of both. More preferably, the organic solvent is ethanol.

[0018] In some embodiments, the organic solvent is 75-150 parts by weight, 80-120 parts by weight, 80-110 parts by weight, 90-110 parts by weight, or 100-110 parts by weight. More preferably, the organic solvent is 105 parts by weight.

[0019] In some implementations, phosphatidylcholine is soybean phosphatidylcholine, i.e., SPC.

[0020] In some embodiments, the weight ratio of soybean phosphatidylcholine (SPC) to glyceryl dioleate (GDO) is 4:6 to 6:4. More preferably, the weight ratio of SPC to GDO is 5:5.

[0021] In some embodiments, the phosphatidylcholine is 300-550 parts by weight, or 350-500 parts by weight, or 400-450 parts by weight, or 430-440 parts by weight.

[0022] In some embodiments, the dioleoyl glyceride is 300-550 parts by weight, or 350-500 parts by weight, or 400-450 parts by weight, or 430-440 parts by weight.

[0023] In some embodiments, this application provides an octreotide acetate sustained-release formulation comprising the following components in parts by weight: 13-28 parts octreotide acetate, 300-550 parts dioleoglyceride, 300-550 parts soybean phosphatidylcholine, 70-140 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.0-6.0.

[0024] In some embodiments, this application provides an octreotide acetate sustained-release formulation comprising the following components in parts by weight: 18-26 parts octreotide acetate, 350-500 parts dioleoglyceride, 350-500 parts soybean phosphatidylcholine, 80-120 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.5-6.0.

[0025] In some embodiments, this application provides an octreotide acetate sustained-release formulation comprising the following components in parts by weight: 20-24 parts octreotide acetate, 400-450 parts dioleoglyceride, 400-450 parts soybean phosphatidylcholine, 90-110 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.6-5.8.

[0026] In some embodiments, this application provides an octreotide acetate sustained-release formulation comprising the following components in parts by weight: 22-23 parts octreotide acetate, 430-440 parts dioleoglyceride, 430-440 parts soybean phosphatidylcholine, 100-110 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.6-5.8.

[0027] In some embodiments, the sustained-release formulation of octreotide acetate comprises the following components in parts by weight: 23 parts octreotide acetate, 436 parts phosphatidylcholine, 436 parts dioleoyl glyceride, 105 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.6-5.8.

[0028] In some embodiments, the sustained-release formulation of octreotide acetate comprises the following components in parts by weight: 21 parts octreotide acetate, 436 parts phosphatidylcholine, 436 parts dioleoyl glyceride, 105 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.6-5.8.

[0029] In some embodiments, the sustained-release formulation of octreotide acetate comprises the following components in parts by weight: 23 parts octreotide acetate, 425 parts phosphatidylcholine, 447 parts dioleoglycerate, 105 parts anhydrous ethanol, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 5.6-5.8.

[0030] Secondly, this application provides a method for preparing the above-mentioned octreotide acetate sustained-release formulation, comprising the following steps: mixing octreotide acetate, an organic solvent (anhydrous ethanol), soybean phosphatidylcholine (SPC), glyceryl dioleate (GDO), and a pH adjuster, and stirring to dissolve; optionally comprising a filtration and / or filling step.

[0031] In some embodiments, the preparation method includes the following steps:

[0032] Step 1: Mix octreotide acetate with an organic solvent (anhydrous ethanol), stir to dissolve, and obtain the raw material solution;

[0033] Step 2: Mix soybean phosphatidylcholine (SPC) and glyceryl dioleate (GDO) with the raw material solution from Step 1, stir and dissolve to obtain a mixture of raw and auxiliary lipids;

[0034] Step 3: Add a pH adjuster to the raw material lipid mixture obtained in Step 2 to adjust the pH value to 4.5-7.0.

[0035] Preferably, step 3 may optionally include a filtration and / or filling step.

[0036] In some embodiments, the preparation method includes the following steps:

[0037] Step 1: Mix octreotide acetate with a portion of an organic solvent (anhydrous ethanol), stir to dissolve, and obtain the raw material solution;

[0038] Step 2: Mix soybean phosphatidylcholine (SPC) and glyceryl dioleate (GDO) with the raw material solution from Step 1, stir and dissolve to obtain a mixture of raw and auxiliary lipids;

[0039] Step 3: Mix the pH adjuster with the remaining organic solvent (anhydrous ethanol) and add it to the raw material lipid mixture obtained in Step 2 to adjust the pH value to 4.5-7.0.

[0040] Preferably, step 3 may optionally include a filtration and / or filling step.

[0041] In step 1, the organic solvent used accounts for 67-96% of the total organic solvent, preferably 83-89%.

[0042] The above preparation method provides only an exemplary preparation approach. Those skilled in the art should understand that other conventional preparation methods are also applicable to this application, and that other preparation methods that ultimately yield a clarified system can be obtained by adjusting the order of some steps or replacing conventional processes. These applicable solutions obtained by adjusting the order of some steps or replacing conventional processes also fall within the scope of protection of this application.

[0043] Thirdly, this application also provides the use of the above-mentioned octreotide acetate sustained-release formulation in the preparation of a medicament for treating neuroendocrine system-related diseases.

[0044] Fourthly, this application also provides a method for treating neuroendocrine system-related diseases, comprising: administering a therapeutically effective amount of the octreotide acetate sustained-release formulation to a subject or patient in need. In some embodiments, the administration is performed once every 2-6 weeks, preferably once every 3-5 weeks, once every 4 weeks, or once a month.

[0045] Fifthly, this application also provides the above-mentioned octreotide acetate sustained-release formulation for the treatment of neuroendocrine system-related diseases.

[0046] This application achieves the following beneficial technical effects:

[0047] The formulation of this application uses readily available pharmaceutical-grade octreotide acetate as a raw material to directly prepare a fluid crystal formulation. Stable octreotide sustained-release formulations can be obtained without the need for complex salt conversion processes, which greatly reduces the difficulty and cost of the preparation process.

[0048] Compared with existing octreotide formulations, the main advantages of the formulation in this application include: 1) rapid onset of action after injection, eliminating the need for maintenance therapy with short-acting injections; 2) higher bioavailability; 3) natural excipients, resulting in better safety; 4) simpler manufacturing process and better sterility; 5) subcutaneous injection using small-gauge needles, resulting in less pain; 6) pre-filled syringe packaging, eliminating the need for complex drug preparation before administration, allowing for immediate injection after drug preparation, making clinical use simple and convenient; 7) pharmacokinetic and pharmacodynamic studies in animals show that, compared with commercially available formulations, the sustained-release octreotide formulation in this application can maintain efficacy for a longer period of time, demonstrating superior efficacy potential.

[0049] Terminology Definition

[0050] Phosphatidylcholine

[0051] Phosphatidylcholine (PC) is an amphipathic molecule consisting of a hydrophilic head and a hydrophobic tail. It is a type of phospholipid with a choline group inserted into the head. PC can be derived from natural sources, including animal sources such as eggs, hearts (e.g., bovine hearts), brains, and livers (e.g., bovine livers), as well as plant sources such as soybeans. Any single PC or mixture of PCs from these or other sources can be used, preferably soybean PC (SPC), egg PC, or a mixture containing soybean PC (SPC) or egg PC. The PC component preferably contains at least 50% soybean PC or egg PC, more preferably at least 75% soybean PC or egg PC, and most preferably substantially pure soybean PC or egg PC. The PC component can be a commercially available product, such as FDA or CDE-registered phosphatidylcholine, preferably soybean phosphatidylcholine and egg yolk phosphatidylcholine with a purity of 94% or higher.

[0052] Dioleoglyceride

[0053] Dioleoglycerate (GDO), also known as the diester of (Z)-9-octadecenoic acid and 1,2,3-propanetriol, dioleoglycerate 9C 18:1, or glyceryl dioleate, can be prepared by esterification of oleic acid and glycerol to obtain a mixture of monoglycerides, diglycerides, and triglycerides in different proportions.

[0054] pH adjuster

[0055] The amount of the pH adjuster can be adjusted according to its acidity to adjust the pH value of the octreotide acetate sustained-release formulation to a suitable range.

[0056] Unless otherwise stated, the amount of API (octreotide or its pharmaceutically acceptable salt) described in this application is calculated based on octreotide.

[0057] Unless otherwise stated, the ethanol described in this application is anhydrous ethanol.

[0058] Unless otherwise stated, percentages and parts as described in this application are by weight.

[0059] For the sake of brevity, the term "about" is not used for some quantitative data herein. It should be understood that, whether the term "about" is explicitly used or not, every numerical value given herein includes not only the actual given value (the given value), but also an approximation of such a given value based on reasonable deduction by one of ordinary skill in the art, including equivalents and approximations of such a given value due to experimental and / or measurement conditions. These approximations are preferably ±20%, ±15%, ±10%, ±8%, ±6%, ±5%, ±4%, ±3%, 2%, or ±1% of the given value. In some embodiments, the approximations are obtained by rounding. Attached Figure Description

[0060] Figure 1. Pharmacokinetics of rats with different ethanol contents

[0061] Figure 2. Magnified view of the pharmacokinetic profile of rats with different ethanol concentrations.

[0062] Figure 3. In vitro release of SPC and GDO samples with different proportions.

[0063] Figure 4. PK behavior in rats with different prescriptions

[0064] Figure 5. Magnified view of pharmacokinetic behavior in rats with different prescriptions.

[0065] Figure 6. Comparison results of the formulation of this application and the marketed product in rats via in vivo pharmacokinetic analysis.

[0066] Figure 7. Enlarged view of the in vivo pharmacokinetic comparison results of the formulation of this application and the marketed product in rats.

[0067] Figure 8. In vivo pharmacokinetic comparison results of the formulation applied for in this application and the marketed product in Beagle dogs.

[0068] Figure 9. Enlarged view of the in vivo pharmacokinetic comparison results of the formulation of this application and the marketed product in Beagle dogs. Detailed Implementation

[0069] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to one skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this application. The preferred embodiments and materials described herein are for illustrative purposes only.

[0071] 1. Content determination

[0072] Determined by high performance liquid chromatography (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0512).

[0073] Chromatographic conditions: Octadecylsilane-bonded silica gel was used as the stationary phase (e.g., Welchrom C18, 4.6 × 250 mm, 5 μm or equivalent column); 0.02% trifluoroacetic acid aqueous solution was used as mobile phase A; acetonitrile was used as mobile phase B; the flow rate was 1 mL per minute; gradient elution was performed according to the table below; the detection wavelength was 220 nm; and the column temperature was 30 °C.

[0074] 2. Determination of related substances (total impurities)

[0075] According to the high performance liquid chromatography method (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0512).

[0076] The column was packed with octadecylsilane-bonded silica gel (e.g., Welchrom C18, 4.6 × 250 mm, 5 μm or equivalent performance column); mobile phase A was tetramethylammonium hydroxide solution (8 ml of 25% tetramethylammonium hydroxide solution, 2.72 g of anhydrous potassium dihydrogen phosphate, 880 ml of water, and pH adjusted to 2.0 with phosphoric acid) - acetonitrile (900:100); mobile phase B was tetramethylammonium hydroxide solution (8 ml of 25% tetramethylammonium hydroxide solution, 390 ml of water, and pH adjusted to 2.5 with phosphoric acid) - acetonitrile (400:600); the flow rate was 1 ml per minute, and gradient elution was performed according to the table below; the detection wavelength was 220 nm; the column temperature was 35 °C.

[0077] 3. In vitro release rate

[0078] Release conditions: Take about 0.1g of the formulation of this application, and use a phosphate buffer solution containing surfactant as the release medium. Take samples at 30 minutes, 3 hours and 24 hours respectively as test solutions.

[0079] The content of the test solution was determined using the assay method.

[0080] 4. Monooleic glycerides and free fatty acids

[0081] According to size exclusion chromatography (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0514).

[0082] Chromatographic conditions: Styrene-divinylbenzene copolymer was used as the packing material (e.g., two 7.8 mm × 300 mm, 5 μm columns in series or columns with equivalent performance); tetrahydrofuran was used as the mobile phase; the flow rate was 1.0 mL per minute; the column temperature was 40 °C; a differential refractive index detector was used with a detector temperature of 40 °C; and the injection volume was 40 μL.

[0083] 5. Lysophosphatidylcholine

[0084] According to the high performance liquid chromatography method (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0512).

[0085] Chromatographic conditions: Silica gel was used as the packing material (e.g., Alltima silica, 4.6 × 250 mm, 5 μm or equivalent column); mobile phase A was methanol-water-glacial acetic acid-triethylamine (85:15:0.45:0.05); mobile phase B was n-hexane-isopropanol-mobile phase A (20:48:32); flow rate was 1 mL / min; gradient elution was performed according to the table below; column temperature was 40 °C; injection volume was 20 μL; evaporative light scattering detector was used.

[0086] 6. Injectability assay method

[0087] Equipment: HAK-3132WJ push-pull force testing machine;

[0088] Push rate: 100 mm / min;

[0089] Pushing distance: 1cm;

[0090] Measurement temperature: 20℃.

[0091] 7. Methods for testing the properties of gelling agents

[0092] Weigh 0.1g of sample and inject it into PBS solution (pH=7.40) to form a spherical shape in the medium. Remove the gel at the specified time, cut it open and observe it, and record the time when there is no obvious liquid.

[0093] Example 1: Preparation of Octreotide sustained-release formulation

[0094] Prepare octreotide sustained-release formulations according to the following prescription:

[0095] Table 1. Prescriptions for Octreotide sustained-release formulations

[0096] The preparation method of prescription 1 is as follows:

[0097] Step 1: Mix octreotide acetate with a portion of anhydrous ethanol, stir to dissolve, and obtain the raw material solution;

[0098] Step 2: Mix soybean phosphatidylcholine (SPC) and glyceryl dioleate (GDO) with the raw material solution from Step 1, stir and dissolve to obtain a mixture of raw and auxiliary lipids;

[0099] Step 3: Take an appropriate amount of hydrogen chloride and mix it with the remaining anhydrous ethanol. Add the mixture to the raw material lipid mixture obtained in Step 2, adjust the pH value to 5.7, filter and fill.

[0100] All three formulations can yield sustained-release octreotide acetate formulations that meet appearance requirements and exhibit good stability.

[0101] Example 2: Effect of different solvents on formulation performance

[0102] The effect of different solvents on the performance of the formulation was investigated according to Formulation 1-1 of Example 1. The different solvents are listed in Table 2. "Anhydrous ethanol" was replaced with various solvents in the table below, while the remaining raw materials and amounts were the same as in Formulation 1-1. The preparation was carried out according to the preparation method described in Example 1, and the results are shown in Table 2.

[0103] Table 2. Investigation of solvent types and usage.

[0104] The results show that, under the same solvent volume, using propylene glycol or a mixture of propylene glycol and ethanol as the solvent is inferior to ethanol in terms of process time, sample viscosity, and gelation performance (prolonged gelation time will increase the risk of gel deformation due to external factors after injection).

[0105] Example 3: Effect of different amounts of the same solvent on formulation performance

[0106] As shown in Example 2, ethanol is a good solvent for octreotide sustained-release formulations. The amount of anhydrous ethanol is set as listed in Table 3, and the remaining raw materials and amounts are the same as in Formulation 1-1. Formulations 3-4 to 3-7 are prepared according to the preparation method described in Example 1. In Formulations 3-1 to 3-3, since ethanol content ≤7.5% cannot dissolve octreotide and lipid excipients, it is necessary to first dissolve them with excess ethanol (approximately 10%), and then use rotary evaporation to achieve the target solvent content. Other preparation processes are consistent with those previously described.

[0107] Table 3. Investigation of solvent types and usage. Note: N / A indicates that the sample was not tested for gelation properties.

[0108] The results show that:

[0109] 1. When the ethanol content in the formulation is ≤7.5%, it is insufficient to dissolve all the raw materials and excipients. Excess ethanol must be added first, and then the ethanol content must be evaporated to reach the target value. The process is complicated and the viscosity is high, which is not conducive to preparation and injection.

[0110] 2. Using ethanol as a solvent, as the amount of ethanol increases, the formed gel changes from spherical to ellipsoidal, and the gelation time gradually decreases. This indicates that the surface tension between the fluid crystal interfaces and water is uneven, the surface area gradually increases, accelerating the diffusion of ethanol and increasing the risk of burst release. Based on the above results, anhydrous ethanol was selected as the solvent, and the amount was initially determined to be 7.5% to 15% (i.e., 75-150 parts by weight).

[0111] 3. Animal testing methods are as follows: Referring to the clinical dosage of Sannin and Sanlon, the dosage of short-acting octreotide injection (octreotide acetate for injection, i.e., Sannin) was set at 0.2 mg / kg, and the dosage of the long-acting octreotide injection of this application (samples with different ethanol contents of 7.5%, 10%, and 15%, i.e., prescriptions 3-3, 3-4, and 3-6) was set at 20 mg / kg. Male SD rats, weighing 180–220 g, were randomly divided into four groups of four rats each. Three groups of rats were subcutaneously injected with long-acting octreotide injection with different ethanol contents of 7.5%, 10%, and 15%. Blood was collected from the orbital venous plexus before administration and at 15 min, 1, 2, 4, 6, and 24 h after administration, and at 4, 7, 14, 16, 21, 24, and 28 days after administration. Plasma was obtained by centrifugation. The fourth group of rats were subcutaneously injected with short-acting octreotide acetate injection. Blood samples were collected from the orbital venous plexus before administration and at 5, 10, 20, and 30 minutes and 1, 2, 4, 6, and 24 hours after administration. Plasma was obtained by centrifugation. The concentration of octreotide in the plasma samples was determined by LC-MS / MS.

[0112] For formulations with ethanol content ≥7.5%, pharmacokinetic parameters in rats were further investigated. The results are shown in Figures 1 and 2. As can be seen from Figures 1 and 2, the pharmacokinetic diagrams of rats for samples with different ethanol contents were not significantly different. Compared with the marketed short-acting injectable octreotide acetate (ordinary injection), the fluid crystal samples of this application with different ethanol contents showed a good long-acting advantage. The AUC of samples with different ethanol contents was basically the same. Therefore, the solvent of this application is ethanol, and a solvent content of 7.5%-15% can achieve sustained release and long-acting effect. The Cmax of the 10% ethanol sample is lower than that of the 15% ethanol sample, indicating better safety. Therefore, an ethanol content of 7.5%-10% (g / g) is preferred, and 10% (g / g) is more preferred.

[0113] Example 4: Effect of different SPC / GDO ratios on formulation performance

[0114] Samples with different SPC / GDO ratios were prepared according to Table 4. Different ratios of SPC, GDO, and anhydrous ethanol were mixed and dissolved to investigate the effect of different SPC / GDO ratios on the performance of the blank formulation. The results are shown in Table 4.

[0115] Table 4. Solubility and viscosity of SPC at different ratios to GDO.

[0116] The results show that as the SPC ratio increases, the viscosity also increases. When the SPC:GDO ratio is 70:30, the viscosity of the sample is as high as 840 mPa·s, resulting in poor injectability. When the SPC:GDO ratio is 30:70, the injectability of the sample is very poor and it cannot completely gel within 24 hours. When the SPC:GDO ratio is 40:60, 50:50, or 60:40, the SPC can be dissolved, and the injectability is good. Therefore, the SPC:GDO ratio in the formulation of this application is 40:60 to 60:40.

[0117] The in vitro release of octreotide sustained-release formulations with different SPC / GDO ratios was further investigated. As shown in Figure 3, the in vitro release curves were basically consistent when the SPC / GDO ratio was 40:60, 50:50, or 60:40. The release rate was slightly slower at a ratio of 50:50, suggesting that it had the best sustained-release effect in vivo. Therefore, the optimal SPC / GDO ratio in the formulation of this application is 50:50 (w / w).

[0118] Example 5: Effect of pH on formulation stability

[0119] The effect of pH on the performance of the formulation was investigated according to Formulation 1-1 of Example 1. The pH was set to different values ​​as shown in the table below, while the remaining raw materials and amounts were the same as in Formulation 1-1. The preparation was carried out according to the method described in Example 1, with hydrogen chloride used to adjust the pH in step 3. After preparation, the formulation was stored at 40°C for 3 months, and its stability was monitored. The results are shown in Table 5.

[0120] Table 5. Stability study of sustained-release formulations at different pH values Note: The stability time point content is calculated with D0 content as 100%.

[0121] Octreotide sustained-release formulations, prepared without pH adjustment, had a sample pH of approximately 8.5. After being stored at 40°C for 3 months, the content decreased significantly. However, formulations with added pH adjusters to different pH values ​​(4.0-7.0) showed significantly improved stability. But the content data showed that formulations with pH values ​​deviating from 5.0-6.0 experienced a faster decrease in content. Therefore, it is speculated that an inappropriate pH is one of the reasons for the instability of octreotide.

[0122] Example 6: Effect of different types of pH adjusters on formulation performance

[0123] The effects of different types of pH adjusters on formulation performance were investigated according to Formulation 1-1 in Example 1. The pH adjusters were set to the different types listed in the table below, while the remaining raw materials and dosages were the same as in Formulation 1-1. Formulation 6-1 was not acid-adjusted; the acetic acid used in Formulation 6-2 was commercially available glacial acetic acid; the hydrogen chloride used in Formulation 6-3 was commercially available concentrated hydrochloric acid; and the sulfuric acid used in Formulation 6-4 was commercially available concentrated sulfuric acid, diluted with anhydrous ethanol before use.

[0124] The preparation was carried out according to the method described in Example 1, with different types of acids used in step 3 to adjust the pH value in a basically consistent manner. After preparation, the solution was placed at 40°C for one month to monitor stability. The results are shown in Table 6.

[0125] Table 6. Effects of different pH adjusters on formulation performance Note: The stability time point content is calculated with D0 content as 100%.

[0126] The results showed that when the pH of the formulation was basically the same, the stability of octreotide after one month at 40°C varied slightly when different types of acids were used as pH adjusters. However, compared with the formulation without pH adjustment, the stability of octreotide was significantly improved. Therefore, the formulation of this application uses readily available octreotide acetate as a raw material to prepare fluid crystals, and obtains a more stable sustained-release formulation of octreotide by adjusting the pH value. The types of acids used to adjust the pH value include, but are not limited to, acetic acid, hydrogen chloride, and sulfuric acid.

[0127] The CN101842082B patent mentions that the role of chloride and counterions enhances the stability of octreotide sustained-release formulations. However, this study can improve the stability of octreotide sustained-release formulations by adjusting the pH value, which is obviously beyond the expectations of researchers in this field.

[0128] Rats were subcutaneously injected with the same doses of formulations 6-2, 6-3, and 6-4 from Example 6, and the skin condition of the rats was observed to investigate the skin irritation of different acid-containing sustained-release formulations. The results are shown in Table 7.

[0129] Table 7. Skin irritation in rats

[0130] The results above show that samples adjusted with acetic acid or sulfuric acid caused varying degrees of irritation to rat skin, but the skin condition recovered after a period of administration. Samples adjusted with hydrogen chloride had no significant effect on the rat skin condition. Therefore, hydrogen chloride is the preferred acid for adjusting pH.

[0131] Example 7: Effect of different pH values ​​on formulation performance

[0132] Referring to Formulation 1-1 of Example 1, the effect of different pH values ​​on the performance of the formulation was investigated using hydrogen chloride as a pH adjuster. The pH was set to different values ​​as shown in the table below. Preparation was carried out according to the method described in Example 1. After preparation, the formulation was stored at 40°C for 3 months, and its stability was monitored. The results are shown in Table 8.

[0133] Table 8. Effects of different pH values ​​on formulation performance Note: The content is calculated based on a D0 content of 100% after being stored at 40℃ for 3 months.

[0134] The results showed that under the experimental conditions, a pH value above 6.3 led to a significant decrease in content; below 4.5, the content decreased, while the contents of lipid degradation products lysophosphatidylcholine, monoglycerides, and free fatty acids all increased significantly, and total impurities also increased significantly. Comprehensive analysis indicated that a pH range of 5.1–6.0 was more favorable for the stability of the formulation. The imported drug registration standard for the already marketed octreotide acetate injection shows a pH value of 3.9–4.5, while the stable pH range of the octreotide sustained-release formulation of this invention is 5.1–6.0, which clearly exceeds the expectations of those skilled in the art.

[0135] Example 8: Refinement of pH Value Formulation Stability

[0136] The stability of the formulation with a pH value between 5.1 and 6.0 was refined according to Formulation 1-1 of Example 1. The pH was set to different pH values ​​as shown in the table below, and the preparation was carried out according to the preparation method described in Example 1. After preparation, the stability was monitored by storing the product at 40°C and refrigerating it at 2-8°C for 2 months, respectively. The results are shown in Table 9.

[0137] Table 9. Stability Study of Samples Note: Content is calculated with D0 content as 100%.

[0138] The results above show that under conditions of 40℃ high-temperature storage for 2 months, the content of octreotide and related substances are slightly better at pH 5.7-6.0 than at other pH values; under refrigerated storage conditions, there is no significant difference in the content and total impurities of samples at different pH values. Therefore, considering the results under both high-temperature and refrigerated conditions, octreotide exhibits better stability in samples with pH 5.7-6.0, and the preferred pH range for the formulation of this application is determined to be 5.7-6.0.

[0139] Example 9: Stability of the formulation of this application

[0140] The sample prepared according to Formula 1-1 in Example 1 was pH 5.7 with hydrogen chloride as a pH adjuster, and its stability under different conditions was measured. The results are shown in Table 10.

[0141] Table 10 Stability of the formulation of this application Note: Content is calculated with D0 content as 100%.

[0142] When the formulation of this application is stored at 25°C for 3 months, the API content decreases by less than 4%, while the total impurities increase slightly faster. When stored at 2–8°C for 12 months, the API content decreases by less than 2%, and the content change is clearly stabilizing. The total impurities content increases by less than 0.3%, and the content of lipid degradation products remains basically unchanged. In summary, the formulation of this application has the potential for long-term storage under refrigeration conditions.

[0143] Example 10: Stability of the formulation of this application and the formulation for preparing octreotide hydrochloride.

[0144] According to Formulation 10-1 in Table 11 (octreotide acetate raw material, total impurities 0.11%, content 99.1%), the sample was prepared according to the method described in Example 1. The pH value of the sample was adjusted to 5.7 using hydrogen chloride as a pH adjuster to obtain the formulation of this application.

[0145] Meanwhile, the applicant commissioned Jiangsu Nuotai Aosainuo Biotechnology Co., Ltd. to customize laboratory-grade octreotide hydrochloride (total impurities of 0.11%, purity of 99.8%), and used octreotide hydrochloride as raw material to prepare octreotide hydrochloride preparations according to Formula 10-2.

[0146] The stability of the two formulations was investigated after 3 months at 40°C. Except for the starting materials, the formulation composition and preparation process were identical (an acid adjustment process was involved in the preparation of fluid crystals from octreotide acetate) to compare their stability. Formulation information is shown in Table 11, and results are shown in Table 12.

[0147] Table 11 Formulation Information Note: 2.1% in the prescription is calculated as octreotide.

[0148] Table 12 Stability of the two salt formulations Note: Content is calculated with D0 content as 100%.

[0149] The results above show that, under the condition of being placed at 40℃ for 3 months, the fluid crystal preparation prepared from octreotide acetate raw material has a higher content of impurities. The total impurity change trends of the two are basically the same. However, under the condition of being placed at 40℃ for 3 months, the increase in the degradation products of the two lipid excipients, SPC and GDO, namely lysophosphatidylcholine, monoglycerides and free fatty acids, of the octreotide hydrochloride preparation is much greater than that of the preparation prepared from octreotide acetate raw material. Therefore, the fluid crystal preparation prepared from octreotide acetate has better stability after adjusting the appropriate pH range.

[0150] Example 11: Comparison of the release characteristics of the formulation of this application and the formulation prepared from octreotide hydrochloride in rats.

[0151] Samples were prepared according to formulations 10-1 and 10-2 in Example 10 to compare their pharmacokinetic characteristics in rats.

[0152] The experimental method is as follows: Male SD rats, weighing 180–220 g, were randomly divided into two groups of three rats each. They were subcutaneously injected with a dose of 20 mg / kg. Blood samples were collected from the orbital venous plexus before administration and at 15 min, 1, 2, 4, 6, and 24 h after administration, and on days 4, 7, 14, 16, 21, 24, and 28 after administration. Plasma was obtained by centrifugation. The concentration of octreotide in the plasma samples was determined by LC-MS / MS. The pharmacokinetic (PK) results are shown in Figures 4-5.

[0153] In Example 5 of CN101842082B, the formulations prepared using OCT(Cl) and OCT(Ac) show that, compared to the acetate formulation, the hydrochloride formulation has an in vitro release rate that is up to approximately 4 times slower, potentially providing a reservoir composition with an effective duration of up to 4 times longer. In other words, based on the in vitro release effects described in CN101842082B, it is reasonable to infer in the art that the in vivo pharmacokinetic parameters of fluid crystal formulations prepared using OCT(Cl) and OCT(Ac) respectively will be significantly different, with the sustained-release duration (t) of the OCT(Cl) formulation being longer. 1 / 2 It will be approximately 4 times that of OCT(Ac).

[0154] However, as can be seen from Figures 4 and 5 of this application, under the same dosage, the PK behavior of Formulation 10-2 prepared from octreotide hydrochloride and Formulation 10-1 prepared from octreotide acetate in this application is basically the same in rats. This is obviously an unexpected result and also exceeds the expectations of those skilled in the art.

[0155] Example 12: Release characteristics of the formulation of this application compared with the marketed formulation in rats.

[0156] The pharmacokinetic characteristics of the sample of formulation 1-1 in Example 1 of this application were compared with those of octreotide acetate injection (Shanning) and octreotide acetate microspheres for injection (Shanlong) already marketed in China in rats.

[0157] The experimental method is as follows: Male SD rats, weighing 180-220g, were randomly divided into three groups of 5 rats each. Subcutaneous injections were administered. The first group was injected with octreotide acetate microspheres for injection (Shanlong) at a dose of 20mg / kg. The second group was injected with the formulation of this application (product code: SYHX2008) at a dose of 20mg / kg. The third group was injected with octreotide acetate injection (Shanning) at a dose of 0.2mg / kg. Blood samples were collected from the orbital venous plexus before administration and at 15min, 1, 2, 4, 6, 24h, and 4, 7, 14, 16, 21, 24, and 28d after administration. Plasma was obtained by centrifugation, and the octreotide concentration in the plasma samples was determined by LC-MS / MS.

[0158] The PK results are shown in Figures 6 and 7. As can be seen from the results, compared with octreotide acetate injection, the formulation of this application can slowly release octreotide, exhibiting a significant advantage in long-acting properties. The dosing frequency is once a month, far lower than that of commercially available octreotide acetate injection, which requires dosing once or several times daily, thereby improving patient compliance.

[0159] Compared with the same dose of octreotide acetate microsphere formulation, the formulation of this application achieved higher Cmax and AUC levels in rats. 0-28d It is approximately 6 times that of microsphere formulations, greatly increasing in vivo exposure and resulting in better bioavailability.

[0160] Example 13: Release characteristics and pharmacodynamics of the formulation of this application compared with the marketed formulation in a large animal, the Beagle dog.

[0161] The pharmacokinetic and pharmacodynamic characteristics of the sample of formulation 1-1 in Example 1 of this application and the domestically marketed octreotide acetate injection (Shanning) were compared in Beagle dogs.

[0162] 1. Pharmacokinetic studies

[0163] The experimental method is as follows: Beagle dogs, weighing 8-12 kg, were divided into 4 groups according to sex and weight, with 6 dogs in each group. (1) Groups 1-2 were the group of this invention (product code: SYHX2008): subcutaneous injection, with doses of 0.6 and 1.8 mg / kg, respectively. The 0.6 mg / kg dose group was given as a single subcutaneous injection, and the 1.8 mg / kg dose group was given once every 4 weeks for 2 consecutive times. (2) Groups 3-4 were commercially available octreotide acetate injection ( In the control group, subcutaneous injections were administered at doses of 0.009 and 0.0225 mg / kg, respectively, for three consecutive doses every 8 hours. In the experimental group, blood samples (1–1.5 ml / spot) were collected from the forelimb veins of animals at 0 h before administration, and at 15 min, 30 min, 1 h, 6 h, 24 h after administration, and at 3 d, 7 d, 10 d, 14 d, 17 d, 21 d, 24 d, 26 d, and 28 d after administration. In the control group, which received commercially available octreotide acetate injection, blood samples (1–1.5 ml / spot) were collected from the forelimb veins at 0 h before administration, and at 5 min, 15 min, 0.5 h, 1 h, 4 h, 6 h, 8 h, 16 h, and 24 h after administration. The concentration of octreotide in Beagle dog plasma was determined using a validated LC-MS / MS analytical method. Based on the obtained blood drug concentrations, the WinNonlin non-compartmental model was used to process the plasma concentrations of the target compound, and the relevant pharmacokinetic parameters were calculated using the linear logarithmic trapezoidal method.

[0164] The PK results are shown in Figures 8 and 9. It is evident that the formulation of this application can slowly release octreotide, with a single injection providing sustained drug release for more than 28 days. Compared with commercially available octreotide acetate injection, there was no significant difference in maximum plasma concentration (Cmax), but the mean residence time (MRT) was significantly prolonged. Furthermore, compared to the trough concentration (Ctrough) of commercially available octreotide acetate injection administered once every 8 hours, the trough concentration of the formulation of this application administered once every 4 weeks is higher. This suggests that the formulation of this application, administered once every 4 weeks, is equivalent to or superior to the efficacy of commercially available octreotide acetate injection administered once every 8 hours, demonstrating a significantly longer duration of efficacy.

[0165] 2. Pharmacodynamic studies

[0166] The experimental method is as follows: Six Beagle dogs, weighing 8–12 kg, were subcutaneously injected with the drug of this invention (product code: SYHX2008) at a dose of 1.8 mg / kg, administered once every 4 weeks for a total of 2 times. Blood samples were collected before administration and at 7, 14, 21, and 28 days after the first and second administrations to determine the IGF-1 content in the Beagle dogs' plasma to evaluate the efficacy. The results are shown in Table 13.

[0167] Table 13 Effect of subcutaneous administration of the formulation of this application on the change rate (%) of plasma IGF-1 in dogs (Mean±SD, n=6) Note: **P < 0.01 compared with pre-drug administration.

[0168] The results showed that, compared with the pre-administration level, subcutaneous injection of the formulation of this application at 1.8 mg / kg could reduce the IGF-1 content in Beagle dogs plasma by 12% to 17% within 3-4 weeks after the first administration and 4 weeks after the second administration, demonstrating certain pharmacological activity.

[0169] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An octreotide acetate sustained-release formulation comprising the following components in parts by weight: 10-30 parts octreotide acetate, 200-600 parts dioleoglyceride, 200-600 parts phosphatidylcholine, 50-150 parts organic solvent, and an appropriate amount of pH adjuster, wherein the pH of the formulation is 4.5-7.

0.

2. The sustained-release formulation as described in claim 1, characterized in that... It contains 13-28 parts by weight of octreotide acetate, preferably 18-26 parts by weight, and more preferably 20-24 parts by weight.

3. The sustained-release formulation as described in claim 1, characterized in that... The sustained-release formulation has a pH of 5.0-6.0, 5.1-6.0, 5.5-6.0, or 5.6-6.0; preferably, the pH of the formulation is 5.6-5.8, and / or The pH adjuster is acetic acid, sulfuric acid, or hydrogen chloride, preferably hydrogen chloride.

4. The sustained-release formulation as described in claim 1, characterized in that... The organic solvent is ethanol, propylene glycol, or a mixture of the two, preferably ethanol, and / or The organic solvent is 75-150 parts by weight, 80-120 parts by weight, 80-110 parts by weight, 90-110 parts by weight, or 100-110 parts by weight, preferably 105 parts by weight.

5. The sustained-release formulation as described in claim 1, characterized in that, The weight ratio of phosphatidylcholine to dioleoylglycerol is 4:6-6:4, preferably 5:

5.

6. The sustained release formulation according to claim 1, wherein The formulation comprises the following components in parts by weight: octreotide acetate 13-28 parts by weight, dioleoglyceride 300-550 parts by weight, soybean phosphatidylcholine 300-550 parts by weight, anhydrous ethanol 70-140 parts by weight, and a suitable amount of pH adjuster. The pH of the formulation is 5.0-6.0, or... The formulation comprises the following components in parts by weight: octreotide acetate 18-26 parts by weight, dioleoglyceride 350-500 parts by weight, soybean phosphatidylcholine 350-500 parts by weight, anhydrous ethanol 80-120 parts by weight, and a suitable amount of pH adjuster. The pH of the formulation is 5.5-6.0, or... The formulation comprises the following components in parts by weight: octreotide acetate 20-24 parts by weight, dioleoglyceride 400-450 parts by weight, soybean phosphatidylcholine 400-450 parts by weight, anhydrous ethanol 90-110 parts by weight, and a suitable amount of pH adjuster. The pH of the formulation is 5.6-5.8, or... The formulation comprises the following components in parts by weight: octreotide acetate 22-23 parts by weight, dioleoglyceride 430-440 parts by weight, soybean phosphatidylcholine 430-440 parts by weight, anhydrous ethanol 100-110 parts by weight, and a suitable amount of pH adjuster. The pH of the formulation is 5.6-5.8, or... The preparation contains the following components in parts by weight: 23 parts octreotide acetate, 436 parts phosphatidylcholine, 436 parts dioleoyl glyceride, 105 parts anhydrous ethanol, and an appropriate amount of pH adjuster. The pH of the preparation is 5.6-5.

8.

7. The method for preparing the sustained-release formulation of octreotide acetate according to any one of claims 1-6, comprising the following steps: mixing octreotide acetate, an organic solvent, phosphatidylcholine, dioleoyl glycerol, and a pH adjuster, and stirring to dissolve; optionally comprising a filtration and / or filling step. Preferably, the preparation method includes the following steps: Octreotide acetate was mixed with anhydrous ethanol and stirred to dissolve, yielding a raw material solution. Soybean phosphatidylcholine and dioleoyl glycerol were mixed with the above raw material solution and stirred to dissolve, yielding a raw material-excipient lipid mixture. A pH adjuster was added to the raw material-excipient lipid mixture to adjust the pH to 4.5-7.

0. Alternatively, the preparation method includes the following steps: mixing octreotide acetate with a portion of an organic solvent, stirring and dissolving to obtain a raw material solution; mixing soybean phosphatidylcholine and dioleoylglycerol with the raw material solution, stirring and dissolving to obtain a raw material lipid mixture; mixing a pH adjuster with the remaining organic solvent and adding it to the raw material lipid mixture to adjust the pH value to 4.5-7.

0. Preferably, the portion of the organic solvent accounts for 67-96% of the total organic solvent, more preferably 83-89%.

8. Use of the sustained-release formulation of octreotide acetate as described in any one of claims 1-6 in the preparation of a medicament for treating neuroendocrine system-related diseases.

9. A method for treating a neuroendocrine system-related disease, comprising administering to a subject or patient in need a therapeutically effective amount of the octreotide acetate sustained-release formulation as described in any one of claims 1-6.

Images