Ciclopirox olamine nanoemulsion capable of effectively inhibiting fungi and application of ciclopirox olamine nanoemulsion

Abstract

The invention particularly discloses ciclopirox olamine nanoemulsion capable of effectively inhibiting fungi and application of the ciclopirox olamine nanoemulsion, and relates to the technical field of biological medicine. According to the ciclopirox olamine nanoemulsion provided by the invention, quaternized chitosan and ciclopirox olamine are synergistically antibacterial, and MIC can be reduced to 1 / 16 of that of a single drug when the quaternized chitosan and the ciclopirox olamine are combined for use.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and in particular to a ciclopirox olamine nanoemulsion that effectively inhibits fungi and its applications. Background Technology

[0002] Ciclopirox olamine is a broad-spectrum antifungal drug that inhibits fungal metabolism by chelating metal ions. However, it has poor water solubility and limited skin penetration, and is particularly ineffective against fungi within biofilms and drug-resistant strains. To improve its delivery efficiency, existing technologies have developed creams, nanoemulsions, and other dosage forms, and have attempted to modify it with materials such as chitosan to enhance its antibacterial activity. However, ordinary chitosan-modified nanoformulations have limited biofilm penetration ability, a high MIC value against Candida albicans, and unsatisfactory biofilm clearance effects.

[0003] Therefore, there is an urgent need to develop a ciclopirox amine nanoemulsion formulation with high positive charge and synergistic enhancement of antifungal activity to solve the problems of poor biofilm penetration and insufficient synergistic antibacterial effect in existing technologies. Summary of the Invention

[0004] (a) Technical problems to be solved Therefore, one of the main objectives of this invention is to provide an effective antifungal ciclopirox olamine nanoemulsion and its application. In the ciclopirox olamine nanoemulsion provided by this invention, quaternized chitosan and ciclopirox olamine synergistically inhibit bacterial growth, and the combined use reduces the MIC to 1 / 16 of that of a single agent.

[0005] (II) Technical Solution To achieve the above objectives, the present invention provides a ciclopirox olamine formulation comprising a nanoemulsion encapsulating ciclopirox olamine, wherein the surface of the nanoemulsion is modified with quaternized chitosan (QC).

[0006] In one embodiment, the degree of substitution of the quaternary ammonium groups in the quaternized chitosan is 40% to 50%.

[0007] Preferably, the degree of substitution of the quaternary ammonium groups in the quaternized chitosan is about 45%.

[0008] In one embodiment, the nanoemulsion core comprises an oil phase, an aqueous phase, a surfactant, and a co-surfactant.

[0009] In one embodiment, the oil phase comprises isopropyl myristate (IPM), isopropyl palmitate, and / or caprylic / capric triglycerides.

[0010] In one embodiment, the oil phase is isopropyl myristate (IPM). IPM was chosen because it has good skin penetration enhancement effects and high solubility for ciclopirox olamine.

[0011] In one embodiment, the surfactant comprises polyoxyethylene hydrogenated castor oil (Cremophor RH 40), polysorbate 80, and / or poloxamer 188.

[0012] In one embodiment, the surfactant is polyoxyethylene hydrogenated castor oil (Cremophor RH 40).

[0013] Polyoxyethylene hydrogenated castor oil has a high hydrophilic-lipophilic balance value (HLB value of about 14~16), which can effectively reduce the interfacial tension between oil and water and promote the formation and stability of nanoemulsions.

[0014] In one embodiment, the co-surfactant includes anhydrous ethanol, propylene glycol, and / or polyethylene glycol 400.

[0015] In one embodiment, the co-surfactant is anhydrous ethanol.

[0016] Ethanol, as a short-chain alcohol, can further reduce interfacial tension, increase the fluidity of the interfacial film, and help form nanoemulsions with smaller particle sizes.

[0017] In one embodiment, the aqueous phase is ultrapure water.

[0018] In another aspect, the present invention also provides a method for preparing the above-mentioned ciclopirox olamine formulation, comprising: S1: Dissolve ciclopirox olamine in the oil phase to obtain an oil phase solution; S2: Dissolve the surfactant and co-surfactant in the aqueous phase to obtain an aqueous solution; S3: Mix the oil phase solution with the aqueous phase solution to obtain the nanoemulsion encapsulating ciclopirox amine; S4: Add the quaternized chitosan solution to the nanoemulsion encapsulating ciclopirox amine and react to obtain the ciclopirox amine formulation.

[0019] In one embodiment, the mass ratio of the ciclopirox olamine to the oil phase is (0.01~0.05):1.

[0020] In one embodiment, the mass ratio of the ciclopirox olamine to the oil phase is 0.02:1.

[0021] In one embodiment, the mass ratio of the surfactant to the oil phase is 1:(1~3).

[0022] In one embodiment, the mass ratio of the surfactant to the oil phase is 1:2.

[0023] In one embodiment, the mass ratio of surfactant to co-surfactant is 1:(0.5~2).

[0024] In one embodiment, the mass ratio of surfactant to co-surfactant is 1:1.

[0025] In one embodiment, the mass ratio of the oil phase to the water phase is 1:(5~10).

[0026] In one embodiment, the mass ratio of the oil phase to the water phase is 1:8.

[0027] In one embodiment, the solvent for the quaternized chitosan solution is an aqueous acetic acid solution.

[0028] In one embodiment, the concentration of the quaternary acetic acid aqueous solution is 0.1% to 1% (v / v).

[0029] In one embodiment, the mass ratio of the quaternized chitosan to ciclopirox olamine is (1~2):1. In one embodiment, the mass ratio of the quaternized chitosan to ciclopirox olamine is 3:2.

[0030] In another aspect, the present invention also provides a ciclopirox olamine formulation obtained by the above preparation method.

[0031] In one embodiment, the dosage form of the ciclopirox olamine formulation includes creams, nanoemulsions, ointments, vaginal suppositories, vaginal soft capsules, liniments, ointments, lotions, solutions, gels, and / or powders.

[0032] In one embodiment, the ciclopirox olamine formulation is in the form of a nanoemulsion.

[0033] In another aspect, the present invention also provides a pharmaceutical product comprising the above-described ciclopirox olamine formulation.

[0034] In one embodiment, the pharmaceutical product is a vial or box.

[0035] In another aspect, the present invention also provides the use of the above-mentioned ciclopirox olamine formulations and / or pharmaceutical products in the preparation of antifungal drugs.

[0036] In one embodiment, the fungus includes Candida albicans.

[0037] (III) Beneficial Effects Compared with the prior art, the present invention has the following beneficial effects: 1. The zeta potential of the formulation of the present invention is strongly positive, which can target the surface of fungal biofilms through electrostatic attraction, thereby enhancing the accumulation and penetration of the drug at the site of infection and improving the inhibitory potential against biofilm-related infections.

[0038] 2. After modification with quaternized chitosan, the minimum inhibitory concentration (MIC) of ciclopirox olamine nanoemulsion against Candida albicans can be reduced to 0.5 μg / mL, while the MIC of unmodified ciclopirox olamine nanoemulsion is 8 μg / mL, indicating that surface modification can significantly enhance the inhibitory ability of the formulation against planktonic fungi.

[0039] 3. The MIC of quaternized chitosan alone against Candida albicans was 16 μg / mL, while the MIC of the formulation was as low as 0.5 μg / mL, which was much lower than the simple sum of the two. This indicates that quaternized chitosan and ciclopirox olamine achieved a synergistic antibacterial effect in the nanoemulsion system, and the MIC of the combined use can be reduced to 1 / 16 of that of the single drug. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a Zeta potential diagram. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Terms and Definitions As used herein, the term "oil phase" may be selected from a variety of pharmaceutically acceptable oils, including but not limited to medium-chain triglycerides, long-chain triglycerides, vegetable oils (such as olive oil and corn oil), mineral oils or silicone oils and mixtures thereof.

[0044] As used herein, the term "emulsifier" can refer to nonionic surfactants (such as polysorbates, polyoxyethylene castor oil derivatives), ionic surfactants, or amphoteric surfactants, or a combination thereof.

[0045] As used herein, the term "co-emulsifier" typically refers to short-chain alcohols (such as ethanol and propylene glycol), glycols, or other substances that can further reduce interfacial tension.

[0046] As used in this article, “containing,” “having,” or “including” includes “containing,” “mainly composed of,” “substantially composed of,” and “composed of”; “mainly composed of,” “substantially composed of,” and “composed of” are subordinate concepts of “containing,” “having,” or “including.”

[0047] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the reagents, methods and equipment used are conventional reagents, methods and equipment in this technical field.

[0048] Example 1 Preparation of ciclopirox olamine formulation #1: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion (CPX-NE).

[0049] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of quaternized chitosan (quaternary ammonium group substitution degree of 45.3%, 30 kDa) powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. After stirring until completely dissolved, a quaternized chitosan solution with a concentration of 3 mg / mL is obtained. The quaternized chitosan solution is slowly added dropwise to 50 mL of CPX-NE at a rate of about 1 mL / min, and the addition process continues for about 10 minutes. After the addition is completed, the reaction is stirred for 2 hours. Then, it is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, during which the external dialysate is replaced 3 times (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation (QC-CPX-NE).

[0050] The role of acetic acid aqueous solution is to provide a weakly acidic environment (pH≈3.5), promoting the unfolding and dissolution of QC molecular chains to form a homogeneous and transparent solution. The concentration of acetic acid should not be too high (e.g., >1.0%), so as not to introduce too many counterions (acetate ions) that will affect subsequent electrostatic adsorption; nor should it be too low (e.g., <0.1%), otherwise the dissolution may be insufficient.

[0051] The purpose of slow addition is to avoid excessive local concentration, which could lead to cross-linking or aggregation between QC molecules, thereby ensuring that QC molecules can be uniformly and monolayeredly adsorbed onto the surface of each nanodroplet.

[0052] QC allows its hydrophobic segments and positively charged groups to interact fully with the surfactants and negatively charged groups on the surface of the nanoemulsion through electrostatic and hydrophobic interactions, achieving adsorption equilibrium and forming a stable, positively charged polymer shell.

[0053] Example 2 Preparation of ciclopirox olamine formulation #2: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0054] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of quaternized chitosan (40% quaternary ammonium group substitution, 30 kDa) powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. After stirring until completely dissolved, a quaternized chitosan solution with a concentration of 3 mg / mL is obtained. The quaternized chitosan solution is slowly added dropwise to 50 mL of CPX-NE at a rate of about 1 mL / min, and the addition process continues for about 10 minutes. After the addition is completed, the reaction is stirred for 2 hours. Then, it is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, changing the dialysis fluid 3 times during the period (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation.

[0055] Example 3 Preparation of ciclopirox olamine formulation #3: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0056] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of quaternized chitosan (50% quaternary ammonium group substitution, 30 kDa) powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. After stirring until completely dissolved, a quaternized chitosan solution with a concentration of 3 mg / mL is obtained. The quaternized chitosan solution is slowly added dropwise to 50 mL of CPX-NE at a rate of approximately 1 mL / min, and the addition process continues for approximately 10 minutes. After the addition is complete, the reaction is stirred for another 2 hours. Then, the solution is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, changing the external dialysis fluid three times during this period (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation.

[0057] Example 4: Preparation of ciclopirox olamine formulation #4: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0058] Comparative Example 1: Preparation of ciclopirox olamine formulation #5: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0059] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of chitosan powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. Stir until completely dissolved to obtain a chitosan solution with a concentration of 3 mg / mL. Slowly add the chitosan solution dropwise to 50 mL of CPX-NE at a rate of about 1 mL / min, and continue the dropwise addition for about 10 minutes. After the dropwise addition is complete, continue stirring for 2 hours. Then transfer to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, changing the external dialysis fluid 3 times during this period (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation.

[0060] Comparative Example 2: Preparation of ciclopirox olamine formulation #6: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0061] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of octylated chitosan (octyl substitution degree 50%) powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. After stirring until completely dissolved, an alkylated chitosan solution with a concentration of 3 mg / mL is obtained. The alkylated chitosan solution is slowly added dropwise to 50 mL of CPX-NE at a rate of about 1 mL / min, and the addition process continues for about 10 minutes. After the addition is completed, the reaction is stirred for 2 hours. Then, it is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, changing the dialysate 3 times during the period (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation.

[0062] Comparative Example 3: Preparation of ciclopirox olamine formulation #7: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0063] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of quaternized chitosan (quaternary ammonium group substitution degree of 45.3%, 5 kDa) powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. After stirring until completely dissolved, a quaternized chitosan solution with a concentration of 3 mg / mL is obtained. The quaternized chitosan solution is slowly added dropwise to 50 mL of CPX-NE at a rate of about 1 mL / min, and the addition process continues for about 10 minutes. After the addition is completed, the reaction is stirred for 2 hours. Then, it is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, changing the dialysate 3 times during the period (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation.

[0064] Comparative Example 4: Preparation of ciclopirox olamine formulation #8: 1. Preparation of the colostrum: 20 mg of ciclopirox olamine was dissolved in 1 g of isopropyl myristate, and then added dropwise to an aqueous phase containing 0.5 g of polyoxyethylene hydrogenated castor oil and 0.5 g of anhydrous ethanol under stirring conditions (magnetic stirrer, 500 rpm). The dropping rate was controlled at approximately 1 mL / min to ensure the formation of a homogeneous colostrum. After the addition was complete, the colostrum was sheared and dispersed for 5 minutes at 15,000 rpm using an IKA T25 digital Ultra-Turrax high-speed shear disperser to form a crude emulsion. The crude emulsion was then homogenized under high pressure (800 bar) to obtain a clear or semi-clear ciclopirox olamine nanoemulsion.

[0065] 2. Preparation of ciclopirox olamine formulation: Weigh 30 mg of quaternized chitosan (quaternary ammonium group substitution degree of 45.3%, 60 kDa) powder and dissolve it in 10 mL of 0.5% (v / v) acetic acid aqueous solution. After stirring until completely dissolved, a quaternized chitosan solution with a concentration of 3 mg / mL is obtained. The quaternized chitosan solution is slowly added dropwise to 50 mL of CPX-NE at a rate of about 1 mL / min, and the addition process continues for about 10 minutes. After the addition is completed, the reaction is stirred for 2 hours. Then, it is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 12-14 kDa. Dialyze using ultrapure water for 24 hours, changing the dialysate 3 times during the period (at 0 hours, 8 hours, and 16 hours, respectively), to obtain the ciclopirox olamine formulation.

[0066] Example 5 Characterization of ciclopirox olamine formulation: 1. Zeta potential: Zeta potentials were measured using a Zetasizer Nano ZS90 instrument. The formulation samples prepared in Examples 1-4 were appropriately diluted and placed in a folded capillary electrophoretic pool. Their electrophoretic mobility was measured at 25°C, and the Zeta potential was calculated using the Smoluchowski equation.

[0067] The measurement results are as follows Figure 1 As shown, the modified nanoemulsion has a Zeta potential of +30.5±1.8 mV (Example 1), while the unmodified nanoemulsion has a Zeta potential of -12.3±1.5 mV.

[0068] Fungal biofilms typically carry a negative charge (mainly from carboxyl and phosphate groups in extracellular polysaccharides). Positively charged nanoemulsions can actively target and accumulate on the biofilm surface through electrostatic attraction, thereby disrupting the biofilm structure and enhancing drug penetration.

[0069] Example 6: Inhibition of Candida albicans by ciclopirox olamine formulation: The 24-hour minimum inhibitory concentration (MIC, unit: μg / mL) of Candida albicans ATCC 76615 was determined to evaluate the in vitro antifungal activity of the antimicrobial peptide. The strain was cryopreserved at -80℃ with glycerol and was subcultured at least twice at 35℃ on Sabouraud dextrose agar without antibiotics before the experiment to restore activity and purity. MIC determination followed the CLSI microdilution method combined with an automated liquid handling system: Five activated colonies with a diameter ≥1 mm were picked and suspended in 5 mL of sterile 0.85% physiological saline. After vortexing for 15 seconds, the turbidity was adjusted to 0.5 McFarland turbidity using a spectrophotometer (530 nm) (corresponding to a stock bacterial suspension concentration of 1×10⁻⁶). 6 ~5×10 6 (CFU / mL), then serially diluted 1:2000 in RPMI 1640 medium to prepare a final concentration of 5×10⁻⁶ CFU / mL. 3 ~2.5×10 3 CFU / mL inoculum suspension; Subsequently, the reagents prepared in Examples 1-4 and Comparative Examples 1-4, along with quaternized chitosan, were prepared into a 5.12 mg / mL stock solution. This stock solution was then serially diluted 1:1 in 17-well deep-well plates to obtain drug gradients of 2560, 1280, 640, 320, 160, 80, 40, 20, 10, 5, 2.5, 1.25, 0.6, 0.3, 0.15, 0.075, and 0 μg / mL. 10 μL of this solution was then transferred to a 96-well test plate containing 190 μL of RPMI 1640 medium, and 10 μL of inoculum suspension was added to form a 200 μL well. A final concentration gradient of μL (drug diluted 20-fold) was prepared on the test plate to cover 128, 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.0625, 0.03, 0.015, 0.0075, 0.00375, and 0 μg / mL. The test plate was sealed and incubated at 35°C for 24 hours. The growth was observed using a microplate reader. The MIC was defined as the lowest drug concentration that could completely inhibit the visible growth of the strain.

[0070] The results are shown in Table 1.

[0071] Table 1. Results of Minimum Inhibitory Concentration Test As shown in Table 1, compared with the use of quaternized chitosan or ciclopirox amine nanoemulsion alone (Example 4), quaternized chitosan modified ciclopirox amine nanoemulsion (Example 1) can significantly enhance antibacterial ability.

[0072] The degree of substitution is a key structural parameter of quaternized chitosan. If the substitution is too low, the positive charge density will be insufficient, making it difficult to provide enough electrostatic attraction for targeting and penetration (Example 2); if the substitution is too high, it may lead to changes in the water solubility of the polymer and increased steric hindrance, affecting the modification efficiency (Example 3).

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ciclopirox olamine formulation, characterized in that, The nanoemulsion includes one encapsulated with ciclopirox olamine, the surface of which is modified with quaternized chitosan.

2. The ciclopirox olamine formulation according to claim 1, characterized in that, The degree of substitution of the quaternary ammonium groups in the quaternized chitosan is 40% to 50%.

3. The ciclopirox olamine formulation according to claim 1, characterized in that, The nanoemulsion core consists of an oil phase, an aqueous phase, a surfactant, and a co-surfactant.

4. The ciclopirox olamine formulation according to claim 3, characterized in that, The oil phase includes isopropyl myristate, isopropyl palmitate, and / or caprylic / capric triglycerides.

5. The ciclopirox olamine formulation according to claim 3, characterized in that, The surfactants include polyoxyethylene hydrogenated castor oil, polysorbate 80, and / or poloxamer 188.

6. The ciclopirox olamine formulation according to claim 3, characterized in that, The co-surfactant includes anhydrous ethanol, propylene glycol, and / or polyethylene glycol 400.

7. A method for preparing the ciclopirox olamine formulation according to any one of claims 1-6, characterized in that, include: S1: Dissolve ciclopirox olamine in the oil phase to obtain an oil phase solution; S2: Dissolve the surfactant and co-surfactant in the aqueous phase to obtain an aqueous solution; S3: Mix the oil phase solution with the aqueous phase solution to obtain the nanoemulsion encapsulating ciclopirox amine; S4: Add the quaternized chitosan solution to the nanoemulsion encapsulating ciclopirox amine and react to obtain the ciclopirox amine formulation.

8. A ciclopirox olamine formulation, characterized in that, It is obtained by the preparation method described in claim 7.

9. A pharmaceutical product, characterized in that, Includes the ciclopirox olamine formulation as described in any one of claims 1-6 or 8.

10. The use of any one of claims 1-6 or the ciclopirox olamine formulation of claim 8 and / or the pharmaceutical product of claim 9 in the preparation of an antifungal drug.

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