Triamcinolone acetonide palmitate nanoemulsion preparation as well as preparation method and application thereof

Abstract

The invention relates to the technical field of medicines, in particular to triamcinolone acetonide palmitate nano-emulsion as well as a preparation method and application thereof. The composition comprises a water phase and an oil phase, the oil phase comprises triamcinolone acetonide palmitate, a surfactant, oil and a cosurfactant; the water phase comprises an osmotic pressure regulator and a charge modifier. In the triamcinolone acetonide palmitate nano-emulsion, the content ratio of the oil to the surfactant is (3: 1)-(1: 1). According to the preparation method of the triamcinolone acetonide palmitate nano-emulsion provided by the invention, a phase transformation method is adopted, and the average particle size of the triamcinolone acetonide palmitate nano-emulsion is accurately controlled by changing the dosage of the oil phase and the surfactant, so that the triamcinolone acetonide palmitate nano-emulsion suitable for eye iontophoresis is obtained. Meanwhile, it is further found that the permeability of the triamcinolone acetonide palmitate nano-emulsion can be remarkably enhanced by adding cations into the triamcinolone acetonide palmitate nano-emulsion, and the delivery efficiency is enhanced.

Description

Technical Field

[0001] This application belongs to the field of pharmaceutical technology, and specifically relates to a triamcinolone palmitate nanoemulsion, its preparation method, and its application. Background Technology

[0002] Uveitis, also known as uveitis, is the second leading cause of blindness worldwide. Its causes are complex and varied, the condition is prone to recurrence, treatment is challenging, and complications are numerous. More than 35% of patients experience temporary or permanent vision loss. Currently, the main clinical treatment for uveitis is intravitreal / supracineal injection of triamcinolone acetonide suspension, but this requires at least four injections per year. Frequent administration leads to poor patient compliance and increases the risk of endophthalmitis. Uveitis can rapidly damage the eye and cause long-term vision-threatening complications such as macular edema, retinal damage, glaucoma, and cataracts.

[0003] Currently, the main treatments for uveitis include the following: First, corticosteroids, such as dexamethasone and triamcinolone, are administered locally or systemically. Subconjunctival injection and intravitreal implantation are commonly used clinically, achieving high local concentrations, but they carry systemic toxicity risks. While short-acting intravitreal injections are effective in treating acute posterior uveitis, they are associated with complications such as bleeding, infection, and retinal detachment, and the frequent invasive procedures significantly reduce patient compliance. Corticosteroid implants are currently used to treat active ocular inflammation and macular (the most critical part of the retina) swelling caused by uveitis. However, they may accelerate cataract formation and increase the risk of glaucoma. Immunosuppressants such as aminopterin and cyclosporine can also be used. Alternatively, biologics such as adalimumab and tocilizumab can be used. Antagonizing IL-6 and TNF-α is effective in non-infectious uveitis, but biologics have side effects such as increased infection and induction of malignant tumors, and are expensive, resulting in high treatment costs. As the most commonly used dosage form for ophthalmic diseases, eye drops have the characteristics of high compliance and good local medication safety. However, they have poor targeting and are difficult to cross the ocular barrier to deliver drugs to the posterior segment of the eye.

[0004] Currently, intraocular injection (supraclinoid injection) of triamcinolone acetonide suspension is widely used in clinical practice to treat posterior uveitis. However, supraclinoid injection is extremely difficult and requires strict precision and accuracy in operation, which reduces patient compliance. Secondly, intraocular injection of high doses of glucocorticoids may cause an increase in intraocular pressure or the risk of glaucoma. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this application provides a triamcinolone palmitate nanoemulsion suitable for iontophoresis. Iontophoresis is a physical permeation enhancement technology that promotes the absorption of drug molecules through tissues via an electric field. Combining this non-invasive method with traditional dosage forms—eye drops—can improve drug delivery to downstream applications. The specific solution is as follows: 1. A triamcinolone palmitate nanoemulsion suitable for iontophoresis, comprising: an aqueous phase and an oil phase; The oil phase comprises triamcinolone palmitate, oil, surfactant, and co-surfactant; The aqueous phase includes an osmotic pressure regulator and a charge modifier; The ratio of oil to surfactant content is 3:1 to 1:1.

[0006] 2. The triamcinolone palmitate nanoemulsion according to claim 1, wherein, in the triamcinolone palmitate nanoemulsion, the mass percentage of the triamcinolone palmitate is 0.1-0.5%, the mass percentage of the oil is 2-10%, the mass percentage of the surfactant is 2-10%, the mass percentage of the co-surfactant is 0.1-0.5%, and the mass percentage of the osmotic pressure regulator is 0.5-3%.

[0007] 3. The triamcinolone palmitate nanoemulsion according to claim 1, wherein the triamcinolone palmitate nanoemulsion further comprises a pH adjuster.

[0008] 4. The triamcinolone palmitate nanoemulsion according to claim 1, wherein the pH value of the triamcinolone palmitate nanoemulsion is 5.5 to 7.5.

[0009] 5. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein the surfactant is selected from one or more of egg yolk lecithin, polyoxyethylene-40-hydrogenated castor oil, poloxamer 188, Tween 80, and polyethylene glycol-15-hydroxystearate.

[0010] 6. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein the oil is selected from one or more of medium-chain oils, castor oil, soybean oil, and mineral oil.

[0011] 7. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein the co-surfactant is selected from one or more of soybean lecithin, polyethylene glycol 400, and propylene glycol.

[0012] 8. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein the charge modifier is selected from one or more of citrate chloride, chitosan, and sodium oleate.

[0013] 9. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein the average particle size of the nanoemulsion is 50-150 nm.

[0014] 10. A method for preparing a triamcinolone palmitate nanoemulsion suitable for iontophoresis, comprising the following steps: The surfactant, co-surfactant, and triamcinolone palmitate are dissolved in oil to obtain an oil phase, wherein the ratio of oil to surfactant is 3:1 to 1:1. An osmotic pressure regulator and a charge modifier were dissolved in water to obtain an aqueous phase. The oil phase is added dropwise to the aqueous phase and stirred.

[0015] 11. The preparation method according to item 10, wherein the surfactant is selected from one or more of egg yolk lecithin, polyoxyethylene-40-hydrogenated castor oil, poloxamer 188, Tween 80, and polyethylene glycol-15-hydroxystearate.

[0016] 12. The preparation method according to item 10, wherein the oil is selected from one or more of medium-chain oil, castor oil, soybean oil, and mineral oil.

[0017] 13. The preparation method according to item 12, wherein the co-surfactant is selected from one or more of soybean lecithin, polyethylene glycol 400, and propylene glycol.

[0018] 14. The preparation method according to item 10, wherein the charge modifier is selected from one or more of citrate chloride, chitosan, and sodium oleate.

[0019] 15. The preparation method according to item 10, wherein the step further includes: The pH value of the nanoemulsion is adjusted to be between 5.5 and 7.5 using a pH adjuster, and sterilization is achieved through a filter membrane.

[0020] 16. A method for preparing a triamcinolone palmitate nanoemulsion suitable for iontophoresis as described in any one of items 1 to 9.

[0021] 17. The use of the triamcinolone palmitate nanoemulsion suitable for iontophoresis as described in any one of items 1 to 9, or the triamcinolone palmitate nanoemulsion suitable for iontophoresis prepared by the preparation method described in any one of items 10 to 15, in the preparation of ocular drugs for iontophoresis.

[0022] Beneficial effects: The method for preparing triamcinolone palmitate nanoemulsion provided in this application employs a phase transition method. By changing the amounts of oil phase and surfactant, the average particle size of the triamcinolone palmitate nanoemulsion is precisely controlled to obtain a triamcinolone palmitate nanoemulsion suitable for ocular iontophoresis. Furthermore, it was found that the addition of cations to the triamcinolone palmitate nanoemulsion significantly enhances its permeability and delivery efficiency. Attached Figure Description

[0023] The accompanying drawings are provided to better understand this application and do not constitute an undue limitation thereof. Wherein: Figure 1 Transmission electron microscopy (A) of the nanoemulsion prepared in Example 9; Figure 2 In vitro release curves of triamcinolone palmitate nanoemulsions with different particle sizes prepared in Examples 1, 12 and 13; Figure 3 The figure shows the irritation test results of the triamcinolone palmitate nanoemulsion prepared in Example 9. In the figure, A is the rabbit eye morphology observation under slit lamp; B is the IOP measurement; and C is the eye tissue section results. Figure 4 The permeation results of the formulations prepared using nanoemulsions from different embodiments are shown in the diagrams. In this diagram, A represents the permeation of five formulations, and B represents the semi-quantitative fluorescence diagram. Figure 5 The diagram shows the iontophoresis results of the formulations prepared using the nanoemulsions prepared in Examples 1, 9, and 11. In this diagram, A represents the results of formulation introduction at different times, and B is a semi-quantitative fluorescence diagram. Figure 6 The graphs show the permeation results with and without ion introduction for different charge groups. In this graph, A represents the permeation results with and without ion introduction for different charge groups; B represents the semi-quantitative fluorescence graph. Figure 7 This includes clinical scores and before-and-after treatment comparison charts. Figure 8 Graphs showing the levels of various inflammatory factors in rabbits. TNF-α levels in tears and plasma (A&B), IL-6 levels in tears and plasma (D&E), and TNF-α and IL-6 levels in tissues (C&F). Figure 9 Image of rabbit histopathological examination (H&E staining and PAS staining). Detailed Implementation

[0024] Detailed Description of Embodiments. The following detailed description illustrates exemplary embodiments of this application in more specific terms. It should be understood in the following description that the specific embodiments described are not intended to be limiting, and other embodiments may be contemplated without departing from the scope and spirit of this application.

[0025] Unless otherwise specified, in all instances, the figures used to describe dimensions, quantities, and physical properties in this specification and claims should be understood to be modified by the term "about." Therefore, unless stated to the contrary, the figures described in this specification and claims are approximate values ​​and can vary depending on how a person skilled in the art achieves the desired properties using the methods proposed in this invention. Numerical ranges expressed using endpoints include all numbers within that range and any range within that range.

[0026] In this application, "phase transition method" is a technique that utilizes the phase transition of substances under different conditions (such as transitions between solid, liquid, and gaseous states, or transitions between different structures within the same phase) to prepare materials, regulate properties, or achieve specific functions. It is widely used in materials science, chemical engineering, biology, environmental science, and other fields. Its core logic is to obtain products with target structures, properties, or functions by controlling the phase transition process (such as temperature, pressure, concentration, and time). In this application, the phase transition method can precisely obtain nanoemulsions with smaller average particle sizes.

[0027] In this application, medium-chain triglycerides (MCT oil) are triglycerides formed by the combination of medium-chain fatty acids (MCFAs) and glycerol. They are named for their relatively short fatty acid chain length (typically containing 6–12 carbon atoms). They differ significantly from long-chain triglycerides (LCTs, containing 13–22 carbon atoms, such as the main components of vegetable oils and animal fats) commonly found in daily diets in terms of digestion, absorption, metabolism, and physiological functions. Therefore, they are widely used in nutrition, medicine, and sports.

[0028] In this application, castor oil is a plant oil extracted from castor seeds. It has a unique chemical composition and wide range of applications. It is used in traditional medicine and plays an important role in the industrial field. It has the characteristics of high viscosity, resistance to high and low temperatures, and high chemical activity.

[0029] In this application, mineral oil is a type of liquid hydrocarbon mixture extracted from petroleum (crude oil) through processes such as distillation and refining. Its main components are hydrocarbons (alkanes, cycloalkanes, etc.), and it does not contain components of plant or animal origin.

[0030] In this application, polyethylene glycol-15-hydroxystearate is a nonionic surfactant with good solubilizing and emulsifying properties.

[0031] In one specific embodiment of this application, the preparation of triamcinolone palmitate nanoemulsion requires the use of an osmotic pressure regulator, which is selected from one or more of glycerol, mannitol and sorbitol.

[0032] This application provides a triamcinolone palmitate nanoemulsion suitable for iontophoresis, comprising: an aqueous phase and an oil phase; the oil phase comprising triamcinolone palmitate, a surfactant, an oil, and a co-surfactant; and the aqueous phase comprising an osmotic pressure regulator and a charge modifier.

[0033] In one specific embodiment of this application, the ratio of oil to surfactant in the above-mentioned triamcinolone palmitate nanoemulsion is 3:1 to 1:1, for example, it can be 3:1, 2:1, 1:1, 4:3, 4.5:2.5, or 5:2.

[0034] In one specific embodiment of this application, the above-mentioned triamcinolone palmitate nanoemulsion also includes a pH adjuster.

[0035] In this application, the types of pH adjusters are not limited, and any commonly used pH adjuster can be used in the preparation of triamcinolone palmitate nanoemulsions.

[0036] In one specific embodiment of this application, the pH value of the above-mentioned triamcinolone palmitate nanoemulsion is 5.5 to 7.5, for example, pH=5.5, pH=6, pH=6.5, pH=7, or pH=7.5.

[0037] In one specific embodiment of this application, the surfactant is selected from one or more of egg yolk lecithin, polyoxyethylene-40-hydrogenated castor oil, poloxamer 188, Tween 80, and polyethylene glycol-15-hydroxystearate.

[0038] In one specific embodiment of this application, the oil is selected from one or more of medium-chain oils, castor oil, soybean oil, and mineral oil.

[0039] In one specific embodiment of this application, the aforementioned co-surfactant is selected from one or more of soybean lecithin, polyethylene glycol 400, and propylene glycol.

[0040] In one specific embodiment of this application, the charge modifier is selected from one or more of citrate chloride, chitosan, and sodium oleate.

[0041] In one specific embodiment of this application, the mass percentage of the above-mentioned triamcinolone palmitate is 0.1-0.5%, for example, it can be 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0042] In one specific embodiment of this application, the mass percentage of the oil is 2 to 10%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%.

[0043] In one specific embodiment of this application, the mass percentage of the surfactant is 2 to 10%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%.

[0044] In one specific embodiment of this application, the mass percentage of the above-mentioned co-surfactant is 0.1 to 0.5%, for example, it can be 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0045] In one specific embodiment of this application, the mass percentage of the aforementioned osmotic pressure regulator is 0.5% to 3%, for example, it can be 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.05%, 1.1%, 1.15%, 1.2%, 1.25%, 1.3%, 1.35%, 1.4%, 1.45%, 1.5%, 1.55%, 1.6%, 1.65%, 1.7%, 1.75%, 1.8%, 1.85%, 1.9%, 1.95%, 2%, 2.05%, 2.1%, 2.15%, 2.2%, 2.25%, 2.3%, 2.35%, 2.4%, 2.45%, 2.5%, 2.55%, 2.6%, 2.65%, 2.7%, 2.75%, 2.8%, 2.85%, 2.9%, 2.95%, or 3%.

[0046] This application provides a method for preparing triamcinolone palmitate nanoemulsion suitable for iontophoresis, the steps of which include: The surfactant, co-surfactant, and triamcinolone palmitate are dissolved in oil to obtain an oil phase, wherein the ratio of the oil to the surfactant is 3:1 to 1:1. An osmotic pressure regulator and a charge modifier were dissolved in water to obtain an aqueous phase. The oil phase is added dropwise to the aqueous phase and stirred.

[0047] In one specific embodiment of this application, the ratio of the oil to the surfactant can be 3:1, 2:1, 1:1, 4:3, 4.5:2.5, or 5:2.

[0048] In one specific embodiment of this application, the pH value of the above-mentioned triamcinolone palmitate nanoemulsion is adjusted to be maintained at 5.5 to 7.5, for example, pH=5.5, pH=6, pH=6.5, pH=7, pH=7.5.

[0049] In one specific embodiment of this application, the average particle size of the above-mentioned nanoemulsion is 50-150 nm, for example, it can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, or 150 nm.

[0050] In one specific embodiment of this application, adding an osmotic pressure regulator or charge modifier to the prepared triamcinolone palmitate nanoemulsion can make it more suitable for iontophoresis.

[0051] In the embodiments of this application, the triamcinolone palmitate nanoemulsion suitable for iontophoresis has at least the characteristic of a pale blue opalescence. This is because when the average particle size of the nanoemulsion is small (usually less than 50 nm), which is much smaller than the wavelength of visible light (400-700 nm), the scattering of light is mainly Rayleigh scattering. When light passes through the nanoemulsion, blue light is scattered in large quantities, while longer wavelengths such as red light pass through the system more, making the solution appear pale blue overall.

[0052] Example 1 Accurately weigh 0.3g of triamcinolone palmitate, 0.5g of egg yolk lecithin S100, and 3g of polyethylene glycol-15-hydroxystearate, and dissolve them in medium-chain oil at 60℃. The amount of medium-chain oil added is 4g. Stir to obtain a triamcinolone palmitate oil solution. Add the triamcinolone palmitate oil solution dropwise to the aqueous phase at 60℃, stir at 400 rpm for 5 min, and then make up to 100 mL. Adjust the pH of the final emulsion to 7.00 using sodium hydroxide. After sterilization by filtering through a 0.22 μm filter membrane, the nanoemulsion is obtained.

[0053] Example 2 The difference between this embodiment and Embodiment 1 is that the medium-chain oil is replaced with castor oil.

[0054] Example 3 The difference between this embodiment and Embodiment 1 is that medium-chain oil is replaced with soybean oil.

[0055] Example 4 The difference between this embodiment and Embodiment 1 is that polyethylene glycol-15-hydroxystearate is replaced with Tween 80.

[0056] Example 5 The difference between this embodiment and Example 1 is that polyethylene glycol-15-hydroxystearate is replaced with poloxamer.

[0057] Example 6 The difference between this embodiment and Embodiment 1 is that polyethylene glycol-15-hydroxystearate is replaced with polyoxyethylene-40-hydrogenated castor oil.

[0058] Example 7 The difference between this embodiment and Embodiment 1 is that egg yolk lecithin S100 is replaced with egg yolk lecithin E80.

[0059] Example 8 The difference between this embodiment and Embodiment 1 is that egg yolk lecithin S100 is replaced with egg yolk lecithin PL-100M.

[0060] Example 9 The difference between this embodiment and Embodiment 1 is that citrate chloride is added as a charge modifier.

[0061] Example 10 The difference between this embodiment and Embodiment 1 is that chitosan is added as a charge modifier.

[0062] Example 11 The difference between this embodiment and Embodiment 1 is that sodium oleate is added as a charge modifier.

[0063] Example 12 The difference between this embodiment and Example 1 is that the amount of medium-chain oil added is 5g, the amount of polyethylene glycol-15-hydroxystearate added is 2.5g, and the amount of aqueous phase is 13g.

[0064] Example 13 The difference between this embodiment and Example 1 is that the amount of medium-chain oil added is 6g, the amount of polyethylene glycol-15-hydroxystearate added is 2g, and the amount of aqueous phase is 10g.

[0065] Comparative Example 1 The preparation of triamcinolone palmitate pharmaceutical composition was carried out by replicating the scheme of Example 6 in Chinese Patent CN 101332186A.

[0066] Table 1. Components, dosages, and average particle size of nanoemulsions in each example

[0067]

[0068] Experiment Example 1: Characterization and Testing The particle size distribution (PSD), particle size distribution (PDI), and encapsulation efficiency (EE) of the nanoemulsions prepared in Examples 1-13 were tested using a Malvern laser particle size analyzer and high performance liquid chromatography. The results are shown in Table 2.

[0069] The formula for calculating the encapsulation ratio is:

[0070] In the above formula, CNE is the measured drug concentration, and Ctotal is the concentration of the drug added.

[0071] Table 2. Formulation characterization of triamcinolone palmitate nanoemulsion eye drops

[0072] Based on the experimental data in Table 2, and according to Examples 1-3, medium-chain oil is the best choice for nanoemulsions, with the lowest average particle size and the best encapsulation efficiency, resulting in a homogeneous solution with a pale blue opalescent appearance.

[0073] As can be seen from Examples 1 and 4-6, the nanoemulsion has the best effect when polyethylene glycol-15-hydroxystearate is used as the surfactant, with the lowest average particle size and the best encapsulation rate, resulting in a homogeneous solution with a pale blue opalescent appearance. Although Example 5, which uses poloxamer as the surfactant, can obtain a nanoemulsion with a high encapsulation rate, its average particle size is high and it will exhibit wall adhesion.

[0074] As shown in Examples 1, 7, and 8, egg yolk lecithin S100 was the most effective nanoemulsion as a surface-active agent, resulting in the lowest average particle size, the best encapsulation efficiency, and a homogeneous solution with a diffuse blue opalescent sheen. The nanoemulsions prepared in Examples 7 and 8 had relatively low average particle sizes, but their encapsulation efficiency was lower than that of Example 1. Nevertheless, they were still high-quality homogeneous solutions with a low average particle size and a pale blue opalescent sheen.

[0075] As shown in Examples 1 and 9-11, citalopram chloride was selected as the charge modifier, resulting in the best effect of the nanoemulsion. The average particle size was similar to that of Example 1, and the encapsulation efficiency was slightly better than that of Example 1, yielding a homogeneous solution with a pale blue opalescent luster. Its transmission electron microscopy results are as follows: Figure 1The nanoemulsions shown are uniformly distributed spherical particles that maintain their integrity even under drying conditions. Using chitosan as a charge modifier affects the average particle size of the nanoemulsion, resulting in a larger average particle size, a larger particle size distribution, and a slightly lower encapsulation efficiency than in Examples 1 and 9. When sodium oleate is used as a charge modifier, the encapsulation efficiency of the resulting nanoemulsion is slightly lower than in Examples 1, 9, and 10, but the particle size is similar to that in the above examples. Although some parameters in Examples 9-11 are slightly worse than in Example 1, all ultimately yield a homogeneous solution with a pale blue opalescent sheen.

[0076] As shown in Examples 1, 12, and 13, increasing the mass ratio of the oil phase to the surfactant significantly affects the average particle size of the nanoemulsion and, to some extent, the encapsulation efficiency. The resulting nanoemulsion is a homogeneous solution with a bluish-white or pale white opalescent luster.

[0077] Experimental Example 2: In vitro release study Drug release behavior was studied using the dialysis bag method. 500 μL of each of the triamcinolone palmitate nanoemulsions prepared in Examples 1, 12, and 13 were placed in dialysis bags (MWCO 800–14000 Da), followed by 500 μL of release medium. The dialysis bags were sealed at both ends and placed in 30 mL of release medium in a constant-temperature shaker (37°C, 100 rpm). At 1, 2, 4, 8, 12, 24, 48, 72, 120, 148, and 172 h, 10 mL samples were collected, and an equal volume of simulated artificial tears was added. The samples were filtered through a 0.22 μm filter, and the drug concentration was determined by HPLC. The cumulative release rate was calculated using the following formula.

[0078]

[0079] In the above formula, Cn is the drug concentration (μg / mL) at sampling time t, Ci is the drug concentration at the previous sampling time t, V0 is the total volume (30 mL), Vr is the sampling volume (10 mL), and W is the amount of drug added (μg). The in vitro release curve is plotted with t as the abscissa and Q as the ordinate.

[0080] The in vitro release curves of the triamcinolone palmitate nanoemulsions prepared in Examples 1, 12, and 13 are shown below. Figure 2 As shown, after 7 days of release studies, the overall release of the nanoemulsion conforms to the first-order kinetic equation.

[0081] like Figure 2 As shown, Example 9 exhibits a relatively fast release rate of approximately 30%, but the overall release rate is slow. The release rate decreases with increasing particle size. Examples 12 and 13 show lower overall release rates, indicating less drug leakage in the eye, allowing for the delivery of more intact formulations to the fundus and achieving a slow-release drug reservoir effect.

[0082] Experimental Example 3: Stimulus Evaluation Rabbits purchased from the Experimental Animal Center of Shenyang Pharmaceutical University were used as test subjects for ocular irritation evaluation. The rabbits were randomly divided into three groups: Saline, TAP-NE, and Ion-NE, with three rabbits in each group. Before administration, the condition of the conjunctiva, cornea, and other tissues in each rabbit's eye was observed and recorded. 50 μL of the triamcinolone palmitate nanoemulsion prepared in Example 9 was administered to one eye of each rabbit. Ocular reactions were recorded at 1, 2, 4, 24, 48, and 72 hours. Scoring was performed according to the National Medical Products Administration's "Scoring Standard for Ocular Irritation Reactions," and the results are as follows: Figure 3 As shown.

[0083] Figure 3 The following figures illustrate the irritation test results of the triamcinolone palmitate nanoemulsion prepared in Example 9 (A. Rabbit eye morphology observation under slit lamp; B. IOP determination; C. Eye tissue section results). Figure 3 It was found that the triamcinolone palmitate nanoemulsion eye drops group showed no obvious irritation. The Draize test results indicated that the nanoemulsion, after local instillation, was non-irritating, and no significant irritation reaction was observed in the rabbit eyes. With the addition of iontophoresis, no obvious irritation reaction was observed in the eyes; except for slight reddish discoloration of the ears, all other group scores were 0. To reduce the risk of increased intraocular pressure from high-dose glucocorticoid use, this application monitored intraocular pressure changes before and after administration. The results showed no significant difference, indicating that the nanoemulsion is a biosafety-assured delivery system. HE staining of tissue sections showed that the cornea, conjunctiva, and posterior segment of the eye remained intact after administration, with no fibrous deposition of inflammatory cells, and the tissues were not damaged. This demonstrates that the nanoemulsion supplemented with iontophoresis in this invention has good safety and biocompatibility and will not damage the ocular surface tissues.

[0084] Experiment Example 4: In vivo fluorescence penetration experiment - verification of iontophoresis penetration effect and promoting effect DIR was added to the oil phase during the preparation processes of Examples 1, 9, and 11-13, respectively, to obtain the corresponding DIR nanoemulsions. Six rabbits were used, and the DIR nanoemulsions prepared according to the respective examples or the blank control group DIR solution were instilled into the conjunctival sac of the left eye of each rabbit. The eyelids were gently closed for 30 seconds. The iontophoresis time was set to 15 minutes, the current to 0.6 mA, and the administration was protected from light. One hour after administration, the rabbits were sacrificed, the eyeballs were removed, rinsed with physiological saline, excess muscle was removed, and tissue samples were immersed in 4% paraformaldehyde solution, frozen sections were prepared, nuclei were stained with DAPI, and fluorescence intensity was observed under a confocal microscope.

[0085] Examples of the absorption and penetration effects of each formulation group are as follows: Figure 4As shown, nanoemulsion formulations have a significant delivery advantage over DIR solutions, indicating that nanoemulsion formulations can improve delivery efficiency in the posterior segment of the eye.

[0086] Charge screening showed that positive charge and eye attraction increased retention time, while anion repulsion reduced delivery efficiency. Furthermore, small particle size resulted in strong permeability. Therefore, the cationic formulation (Example 9) was selected for subsequent efficacy evaluation.

[0087] Experimental Example 5: In vivo fluorescence penetration experiment - verification of the iontophoresis-enhancing effect The procedures in Example 5 were repeated using the nanoemulsions prepared in Examples 1, 9, and 11, and the fluorescence intensity was observed using a confocal microscope. The results are as follows: Figure 6 As shown, the cation group exhibited enhanced penetration, while the anion group showed no difference. Because iontophoresis relies on the attraction and repulsion of charges, anions repel the eye, while cations attract it. Combined with the non-invasive delivery of iontophoresis, this results in a stronger accumulation of the cation group within the choroid-retina. This demonstrates that iontophoresis can enhance the accumulation of drug formulations within the choroid-retina.

[0088] Experimental Example 6: In vivo fluorescence permeation experiment - determination of iontophoresis time Rabbits were fixed in place, and the nanoemulsion prepared in Example 1 was processed into a DIR nanoemulsion. The DIR nanoemulsion was instilled into the conjunctival sac of the left eye of the rabbit, and the eyelid was gently closed for 30 seconds. Observations and records were made at 10 min, 15 min, and 20 min of iontophoresis, with a current of 0.6 mA, and administration was protected from light. One hour after administration, the rabbits were sacrificed, the eyeballs were removed and rinsed with physiological saline, excess muscle was removed, and tissue samples were immersed in 4% paraformaldehyde solution, frozen sections were prepared, nuclei were stained with DAPI, and fluorescence intensity was observed under a confocal microscope.

[0089] according to Figure 5 As shown, increasing iontophoresis time enhances retinal-choroidal delivery efficiency, with significant differences between 10 min and 15 min (P<0.01), and some difference between 15 min and 20 min (P<0.05). Considering the feasibility of rabbit experiments, 15 min was selected as the optimal iontophoresis time.

[0090] Experimental Example 7: Pharmacodynamic Study Experimental grouping: The eye health status of Japanese White rabbits was screened using a handheld slit lamp to exclude rabbits with eye injuries. After eye health screening and independent samples t-tests showing no statistically significant differences (all P>0.05), 20 rabbits were enrolled. They were randomly divided into 4 groups of 5 rabbits each: Blank control group, Model control group, Ion-NE (iontophoresis nanoemulsion) treatment group, and SCS-TAsuspension group.

[0091] Construction of an experimental autoimmune uveitis model: Bovine serum albumin (BSA) was used as a foreign antigen, and experimental uveitis was induced by a two-stage injection method via the vitreous body and marginal ear vein. Rabbits were anesthetized by injecting 8% chloral hydrate (3 mL / kg) into the marginal ear vein. One to two drops of 0.5% promecaine hydrochloride were then instilled locally to induce short-term corneal anesthesia. Using a disposable 1 mL 29G sterile insulin syringe, the syringe was obliquely inserted into the anterior chamber 0.5 mm from the corneal limbus, and 0.1 mL of aqueous humor was aspirated. Then, using the same syringe, 0.25 mL of 4% BSA was injected into the vitreous body. Successful injection was indicated by the diffusion of yellow fluid within the vitreous cavity. Then, levofloxacin and recombinant bovine basic fibroblast growth factor ophthalmic gel were administered as eye drops. One week later, a second immunization was performed. After trimming the rabbit fur and disinfecting with 75% alcohol, 2.5 mL of 2% BSA was injected through the marginal ear vein. Successful modeling was indicated by the appearance of a significant inflammatory reaction in the anterior segment and vitreous body of the rabbit.

[0092] Dosage regimen: Drug administration began 14 days after EAU model induction. The Blank group received no treatment; the Model group received 50 μL of physiological saline; the Ion-NE group received 50 μL of the nanoemulsion from Example 9 followed by treatment with a current intensity of 0.6 mA for 15 min; and the SCS-TA group received 10 μL of triamcinolone acetonide suspension. Rabbits were sacrificed on day 28, and their eyeballs were harvested for subsequent experimental procedures. During this period, starting on day 8, inflammatory factors such as TNF-α and IL-6 in blood and tears were measured every 5 days, and inflammation scores were assessed.

[0093] Clinical scoring: At the start of the experiment, scores were assigned based on the extent of ocular damage and recorded. The results are as follows: Figure 7 As shown, the clinical symptoms in the treatment group were less severe than those in the model group. The results of slit-lamp observation before and after modeling were the same as above.

[0094] Inflammatory factor scoring: The levels of TNF-α and IL-6 in rabbit eye tissue, plasma, and tears were detected using an ELISA kit. The results are as follows: Figure 8 Both treatment regimens shown exhibited a clear downregulation of pro-inflammatory factors, and their dynamic changes were significantly positively correlated with the degree of improvement in clinical scores. It is speculated that triamcinolone acetonide may achieve its therapeutic effect by inhibiting the production or expression of TNF-α and IL-6, thereby regulating the body's immune function and alleviating the inflammatory response of uveitis.

[0095] Histopathological examination: Rabbits were euthanized 28 days after modeling, and H&E and PAS staining was performed to observe the condition of the eye tissue. The results are shown in […]. Figure 9 Compared with the model group, the treatment group had relatively intact retinal results, higher cell density, and more orderly cell arrangement, and the overall damage was milder.

[0096] pass Figures 7-9 It has been shown that non-invasive delivery of triamcinolone palmitate nanoemulsion eye drops via iontophoresis has a certain therapeutic effect on posterior uveitis. Experimental results indicate that, except for differences in IL-6 inflammation levels, other indicators showed no significant differences compared to the SCS-TA suspension treatment group. Increasing the dosing frequency to once a week may achieve efficacy comparable to, or even better than, the SCS-TA suspension treatment group. In conclusion, non-invasive delivery of triamcinolone palmitate nanoemulsion eye drops via iontophoresis can replace suprachoroidal injection and represents a promising new treatment method for uveitis.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit the application in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the protection scope of this application.

Claims

1. A triamcinolone palmitate nanoemulsion suitable for iontophoresis, wherein, include: Aqueous phase and oil phase; The oil phase comprises triamcinolone palmitate, oil, surfactant, and co-surfactant; The aqueous phase includes an osmotic pressure regulator and a charge modifier; The ratio of oil to surfactant content is 3:1 to 1:

1.

2. The triamcinolone palmitate nanoemulsion according to claim 1, wherein, In the triamcinolone palmitate nanoemulsion, the triamcinolone palmitate has a mass percentage of 0.1-0.5%, the oil has a mass percentage of 2-10%, the surfactant has a mass percentage of 2-10%, the co-surfactant has a mass percentage of 0.1-0.5%, and the osmotic pressure regulator has a mass percentage of 0.5-3%.

3. The triamcinolone palmitate nanoemulsion according to claim 1, wherein, The triamcinolone palmitate nanoemulsion also includes a pH adjuster.

4. The triamcinolone palmitate nanoemulsion according to claim 1, wherein, The pH value of the triamcinolone palmitate nanoemulsion is 5.5 to 7.

5.

5. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein, The surfactant is selected from one or more of egg yolk lecithin, polyoxyethylene-40-hydrogenated castor oil, poloxamer 188, Tween 80, and polyethylene glycol-15-hydroxystearate.

6. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein, The oil is selected from one or more of medium-chain oils, castor oil, soybean oil, and mineral oil.

7. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein, The co-surfactant is selected from one or more of soybean lecithin, polyethylene glycol 400, and propylene glycol.

8. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein, The charge modifier is selected from one or more of citrate chloride, chitosan, and sodium oleate.

9. The triamcinolone palmitate nanoemulsion suitable for iontophoresis according to claim 1, wherein, The average particle size of the nanoemulsion is 50–150 nm.

10. A method for preparing a triamcinolone palmitate nanoemulsion suitable for iontophoresis, comprising the following steps: The surfactant, co-surfactant, and triamcinolone palmitate are dissolved in oil to obtain an oil phase, wherein the ratio of oil to surfactant is 3:1 to 1:

1. An osmotic pressure regulator and a charge modifier were dissolved in water to obtain an aqueous phase. The oil phase is added dropwise to the aqueous phase and stirred.

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