Diaminopyrimidine oxide nanomicelles, a preparation method thereof and application thereof in anti-hair loss cosmetics

Abstract

This invention provides a diaminopyrimidine oxide nanomicelle, its preparation method, and its application in anti-hair loss cosmetics. It relates to the field of cosmetic technology. The nanomicelle comprises, by mass percentage: 1%~1.5% amphoteric surfactant and 0.1%~0.5% glycyrrhizic acid, with the remainder being a solvent. The amphoteric surfactant and glycyrrhizic acid are combined to form nanomicelles, which optimizes the drug loading concentration of glycyrrhizic acid while ensuring the stability of the micelle structure, achieving a balance of synergistic effects. The glycyrrhizic acid content is controlled to not exceed 0.5%, meeting the requirement that the total glycyrrhizic acid concentration in cosmetics should not exceed 0.5%. Furthermore, it promotes hair growth, has follicle targeting, accumulates in the hair follicle, and encapsulates diaminopyrimidine oxide, improving the water solubility and transdermal properties of the diaminopyrimidine oxide.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and in particular to a diaminopyrimidine oxide nanomicelle, its preparation method, and its application in anti-hair loss cosmetics. Background Technology

[0002] Hair loss is a common skin condition, with androgenetic alopecia (AGA) being the most common type worldwide. The etiology and mechanisms of hair loss are not fully understood, but it is generally believed to be caused by a combination of genetic and environmental stimuli. The pathogenesis of androgenetic alopecia is the result of multiple interacting factors, including genetics, androgens, environment, and lifestyle. Currently, marketed treatments for AGA include minoxidil, finasteride, and dutasteride. Minoxidil is a topical vasodilator; its exact mechanism of action in treating hair loss is not fully understood, but it is generally believed to stimulate the proliferation of hair follicle epithelial cells, prolong the growth phase of hair follicles, and potentially increase blood flow to the hair follicles. Finasteride is an oral 5α-reductase inhibitor that specifically inhibits type II 5α-reductase, preventing the conversion of testosterone to dihydrotestosterone (DHT), thereby fundamentally addressing the attack of DHT on hair follicles. Despite continuous advancements in treatment methods, hair loss treatment still faces many problems and challenges. For example, many patients experience a temporary, rapid increase in hair loss, known as the "hair loss spree," within 2-8 weeks of starting minoxidil. Common side effects may include scalp itching, dryness, flaking, erythema, and contact dermatitis. Finasteride is absolutely contraindicated in women of reproductive age, pregnant, or breastfeeding women, as it may cause male genital malformations in the fetus. It is only effective in postmenopausal women, and its effectiveness is less than in men; long-term use may cause side effects such as decreased libido, erectile dysfunction, and reduced sperm count. Dutasteride is also an oral 5α-reductase inhibitor, but its key difference from finasteride is that it simultaneously inhibits both type I and type II 5α-reductase isoenzymes, thus having a stronger inhibitory effect on DHT, but the risk and severity of some side effects may be higher.

[0003] Diaminopyrimidine oxide is a chemically synthesized hair growth ingredient, belonging to the same potassium channel opener class as minoxidil. Its mechanism of action is highly similar to minoxidil, but through molecular structure optimization, it aims to retain its core efficacy while overcoming some of minoxidil's major drawbacks, significantly reducing irritation and allergic reactions compared to minoxidil. However, diaminopyrimidine oxide is a poorly water-soluble compound, with low solubility in water, directly affecting its concentration and bioavailability in formulations. Although hair follicles are an important channel for drug delivery to the skin, the large molecular structure and high polarity of diaminopyrimidine oxide limit its passive diffusion ability, making it difficult to efficiently penetrate the stratum corneum barrier to reach the hair follicle target. To overcome these limitations, developing novel drug delivery systems has become an emerging direction for enhancing the application value of diaminopyrimidine oxide.

[0004] Glycyrrhizic acid (GA) is a triterpenoid saponin compound derived from the plant *Glycyrrhiza glabra* L. It exhibits amphiphilic properties similar to surfactants, with its hydrophilic and hydrophobic units being glucuronic acid and glycyrrhizic acid residues, respectively. It can aggregate and self-assemble in water to form micelles. Current literature reports that glycyrrhizic acid has follicle-targeting activity, possibly due to its lipophilic nature, allowing it to penetrate the stratum corneum barrier. Hair follicles are important "channels" for the skin, and their funnel structure has a strong affinity for lipophilic molecules. Therefore, glycyrrhizic acid may penetrate through the follicle and accumulate within it. Its structure and follicle-targeting ability make glycyrrhizic acid an ideal carrier molecule for diaminopyrimidine oxides. However, at higher concentrations, glycyrrhizic acid may cause skin irritation such as stinging and redness in some individuals, and it may be unstable in strongly acidic or alkaline environments, affecting its activity. Therefore, the EU has clearly stated that the total concentration, calculated based on the amount of glycyrrhizic acid, cannot exceed 0.5%, and Japan and South Korea should also adhere to this requirement when submitting or obtaining approvals. These regulations on glycyrrhizic acid concentrations in cosmetics significantly limit its application.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] One of the objectives of this invention is to provide a nanomicelle to address the technical problem of the lack of a carrier in the prior art that can be used to deliver diaminopyrimidine oxide, improve its water solubility, and promote its penetration through the stratum corneum barrier to reach the hair follicle target.

[0007] A second objective of this invention is to provide a method for preparing the aforementioned nanomicelles.

[0008] The third objective of this invention is to provide a diaminopyrimidine oxide nanomicelle.

[0009] The fourth objective of this invention is to provide a method for preparing the above-mentioned diaminopyrimidine oxide nanomicelles.

[0010] The fifth objective of this invention is to provide the application of the above-mentioned diaminopyrimidine oxide nanomicelles or the diaminopyrimidine oxide nanomicelles prepared by the above-mentioned preparation method in the preparation of anti-hair loss products.

[0011] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0012] In a first aspect, the present invention provides a nanomicelle comprising, by mass percentage: 1% to 1.5% amphoteric surfactant and 0.1% to 0.5% glycyrrhizic acid, with the balance being solvent.

[0013] Furthermore, by mass percentage, it comprises the following components: 1% amphoteric surfactant and 0.1% glycyrrhizic acid, with the balance being solvent.

[0014] Furthermore, the amphoteric surfactant includes at least one of cocamidopropyl betaine, disodium lauroyl amphiphilic diacetate, sodium cocoyl ethanesulfonate, lauryl dimethylamine oxide, disodium cocamidopropyl diacetate, or sodium methyl cocoyl taurate.

[0015] Furthermore, the particle size of the nanomicelles is 20~100 nm.

[0016] Secondly, the present invention provides a method for preparing the above-mentioned nanomicelles, wherein amphoteric surfactant, glycyrrhizic acid and solvent are mixed according to the formulation to obtain nanomicelles.

[0017] Thirdly, the present invention provides a diaminopyrimidine oxide nanomicelle, comprising a diaminopyrimidine oxide and nanomicelles encapsulated outside the diaminopyrimidine oxide, wherein the nanomicelles are the above-described nanomicelles or nanomicelles prepared by the above-described preparation method.

[0018] Furthermore, by mass percentage, it comprises the following components: 1%~1.5% amphoteric surfactant, 0.1%~0.5% glycyrrhizic acid and ≤3% diaminopyrimidine oxide, with the balance being solvent.

[0019] Fourthly, the present invention provides a method for preparing the above-mentioned diaminopyrimidine oxide nanomicelles, wherein an amphoteric surfactant, glycyrrhizic acid, diaminopyrimidine oxide and solvent are mixed according to the formulation to obtain diaminopyrimidine oxide nanomicelles.

[0020] Furthermore, this includes the following steps:

[0021] A. Mix the amphoteric surfactant, glycyrrhizic acid and solvent according to the formula to obtain a nano micelle solution;

[0022] B. The diaminopyrimidine oxide solution was subjected to rotary evaporation according to the formula, and then mixed with the nanomicelle solution to obtain diaminopyrimidine oxide nanomicelles.

[0023] Fifthly, the present invention provides the application of the above-mentioned diaminopyrimidine oxide nanomicelles or the diaminopyrimidine oxide nanomicelles prepared by the above-mentioned preparation method in the preparation of anti-hair loss products.

[0024] This invention provides a nanomicelle formed by combining an amphoteric surfactant with glycyrrhizic acid. This allows for the optimization of the drug loading concentration of glycyrrhizic acid while maintaining the stability of the micelle structure, achieving a balance in the synergistic effect of the two. The glycyrrhizic acid content is controlled to not exceed 0.5%, meeting the requirement that the total concentration of glycyrrhizic acid in cosmetics should not exceed 0.5%. Furthermore, it can promote hair growth, has follicle targeting, accumulates in the hair follicle, and encapsulates diaminopyrimidine oxide, improving the water solubility and transdermal properties of the diaminopyrimidine oxide. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 The different micelle sizes of diaminopyrimidine oxides encapsulated in nanomicelles provided in Example 1 of this invention;

[0027] Figure 2 The micelle dispersion coefficients of different nanomicelles encapsulating diaminopyrimidine oxides provided in Example 1 of this invention;

[0028] Figure 3 The absolute values ​​of the micelle zeta potential of different nanomicelles encapsulating diaminopyrimidine oxides provided in Example 1 of this invention;

[0029] Figure 4 This is a comparison chart of drug loading in nanomicelles encapsulating diaminopyrimidine oxide provided in Example 3 of the present invention;

[0030] Figure 5 This is the result of the transdermal permeation of diaminopyrimidine oxide encapsulated in nanomicelles provided in Example 6 of the present invention.

[0031] Figure 6 This is the second result of the transdermal permeation of diaminopyrimidine oxide encapsulated in nanomicelles provided in Example 6 of the present invention;

[0032] Figure 7 The third result is the transdermal permeation result of the nanomicelle-encapsulated diaminopyrimidine oxide provided in Example 6 of this invention;

[0033] Figure 8 The results of the effect of nanomicelle-encapsulated diaminopyrimidine oxide on hair growth in androgenic alopecia model mice provided in Example 7 of the present invention;

[0034] Figure 9 The image shows the HE section of the back of a mouse model of androgenetic alopecia under the action of diaminopyrimidine oxide encapsulated in nanomicelles provided in Example 7 of this invention, where a is a longitudinal section and b is a transverse section. Detailed Implementation

[0035] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0036] Unless otherwise stated, the methods and techniques of the present invention are generally carried out according to conventional methods well known in the art and as described in various general and more specific references, which are cited and discussed throughout this specification.

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0038] One aspect of the present invention provides a nanomicelle comprising, by mass percentage: 1%~1.5% amphoteric surfactant and 0.1%~0.5% glycyrrhizic acid, with the balance being solvent.

[0039] By using amphoteric surfactants in combination with glycyrrhizic acid to form nanomicelles, the drug loading concentration of glycyrrhizic acid can be optimized while ensuring the stability of the micelle structure, achieving a balance of synergistic effects between the two. The glycyrrhizic acid content is controlled to not exceed 0.5%, meeting the requirement that the total concentration of glycyrrhizic acid in cosmetics should not exceed 0.5%. Furthermore, it can promote hair growth, has follicle targeting, accumulates in the hair follicle, and can encapsulate diaminopyrimidine oxide, improving the water solubility and transdermal properties of diaminopyrimidine oxide.

[0040] The mass percentage of the amphoteric surfactant in the nanomicelles can be, but is not limited to, 1%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5%, or any value between 1% and 1.5%, preferably 1%.

[0041] The mass percentage of glycyrrhizic acid in the nanomicelles can be, but is not limited to, 0.1%, 0.2%, 0.3%, 0.4% or 0.5%, or any value between 0.1% and 0.5%, preferably 0.1%.

[0042] In some specific embodiments, the product comprises the following components by mass percentage: 1% amphoteric surfactant and 0.1% glycyrrhizic acid, with the balance being solvent.

[0043] In some specific embodiments, the amphoteric surfactant includes at least one of cocamidopropyl betaine, disodium lauroyl amphiphilic diacetate, sodium cocoyl hydroxyethanesulfonate, lauryl dimethylamine oxide, disodium cocamidopropyl diacetate, or sodium methyl cocoyl taurate, preferably disodium lauroyl amphiphilic diacetate.

[0044] In some specific embodiments, the particle size of the nanomicelles is 20~100 nm. In some specific embodiments, the PDI of the nanomicelles is ≤0.35. In some specific embodiments, the absolute value of the Zeta potential of the nanomicelles is ≥29mV. The obtained nanomicelles are not prone to aggregation, have optimal stability, and possess good transdermal efficacy.

[0045] It should be noted that the solvent can be water, alcohol solution or other preservative system, as long as it can dissolve amphoteric surfactants and glycyrrhizic acid to provide a solution environment for the formation of nanomicelles.

[0046] According to another aspect of the present invention, a method for preparing the above-mentioned nanomicelles is also provided, wherein an amphoteric surfactant, glycyrrhizic acid and solvent are mixed in the prescribed amounts to obtain nanomicelles.

[0047] According to another aspect of the present invention, a diaminopyrimidine oxide nanomicelle is also provided, comprising a diaminopyrimidine oxide and nanomicelles encapsulated outside the diaminopyrimidine oxide, wherein the nanomicelles are the above-described nanomicelles or nanomicelles prepared by the above-described preparation method.

[0048] By encapsulating diaminopyrimidine oxide in the above-mentioned nanomicelles, its stability and hair follicle targeting are improved, and its transdermal properties are enhanced. Animal experiments show that it can improve the symptoms of testosterone-induced androgenetic alopecia, promote hair growth, and has no significant damage to the body weight or organs of mice.

[0049] In some specific embodiments, the product comprises the following components by mass percentage: 1% to 1.5% amphoteric surfactant, 0.1% to 0.5% glycyrrhizic acid and ≤3% diaminopyrimidine oxide, with the balance being solvent.

[0050] The mass percentage of the amphoteric surfactant in the diaminopyrimidine oxide nanomicelles can be, but is not limited to, 1%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5%, or any value between 1% and 1.5%, preferably 1%.

[0051] The mass percentage of glycyrrhizic acid in the diaminopyrimidine oxide nanomicelles can be, but is not limited to, 0.1%, 0.2%, 0.3%, 0.4% or 0.5%, or any value between 0.1% and 0.5%, preferably 0.1%.

[0052] The mass percentage of the diaminopyrimidine oxide in the diaminopyrimidine oxide nanomicelles can be, but is not limited to, 0.5%, 1%, 1.5%, 2%, 2.5% or 3%, or any value ≤3%.

[0053] According to another aspect of the present invention, a method for preparing the above-mentioned diaminopyrimidine oxide nanomicelles is also provided, wherein an amphoteric surfactant, glycyrrhizic acid, diaminopyrimidine oxide and solvent are mixed according to the formulation amount to obtain diaminopyrimidine oxide nanomicelles.

[0054] The preparation method is simple and feasible, requires no special equipment, and is easy to carry out on a large scale for industrial production.

[0055] In some specific implementations, the following steps are included:

[0056] A. Mix the amphoteric surfactant, glycyrrhizic acid and solvent according to the formula to obtain a nano micelle solution;

[0057] B. The diaminopyrimidine oxide solution was subjected to rotary evaporation according to the formula, and then mixed with the nanomicelle solution to obtain diaminopyrimidine oxide nanomicelles.

[0058] Rotary evaporation slowly removes the alcohol solvent, forming a uniform diaminopyrimidine oxide film, which facilitates rapid redispersibility and avoids the technical problems of precipitation, exudation, and uneven distribution caused by the poor water solubility of diaminopyrimidine oxide. The addition of a nanomicelle solution hydrates and dissolves the diaminopyrimidine oxide film, which then self-assembles into stable diaminopyrimidine oxide nanomicelles, achieving efficient encapsulation of the diaminopyrimidine oxide.

[0059] According to another aspect of the present invention, the application of the above-described diaminopyrimidine oxide nanomicelles or the diaminopyrimidine oxide nanomicelles prepared by the above-described preparation method in the preparation of anti-hair loss products is also provided.

[0060] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0061] Example 1

[0062] 1. Preparation of nanomicelles

[0063] Nano micelles were prepared by dissolving 0.1% glycyrrhizic acid and 1% carrier in water at 60°C. The carriers were selected from various surfactants, including a high molecular weight surfactant (chitosan), a nonionic surfactant (Tween-80), an anionic surfactant (sodium lauroyl ether sulfate), a cationic surfactant (cocamidopropylamine oxide), and an amphiphilic surfactant (disodium lauroyl amphiphilic diacetate). A control group without 1% carrier was also included.

[0064] 2. Preparation of diaminopyrimidine oxide nanomicelles

[0065] Alternatively, 3% diaminopyrimidine oxide is dissolved in an alcohol solution by ultrasonication, the solvent is recovered in a rotary evaporator, a mixed carrier is added to dissolve the oxide, and the diaminopyrimidine oxide on the wall of the round-bottom flask is hydrated and dissolved to obtain the final product. The alcohol solution is one of ethanol, methanol, propylene glycol, or a mixture of these solutions; in this example, methanol is used.

[0066] 3. Results

[0067] 1) A white precipitate appeared at the bottom of the solution using the molecular surfactant (chitosan), indicating that the diaminopyrimidine oxide could not be encapsulated; all other solutions yielded clear, transparent, and colorless diaminopyrimidine oxide nanomicelle solutions.

[0068] 2) A clear, transparent, and colorless diaminopyrimidine oxide nanomicelle solution was diluted 2 times with water. The particle size, zeta potential, and distribution were measured using a particle size analyzer (Zetasizer Nano ZS, purchased from Malvern, UK). The results are as follows: Figures 1-3 As shown.

[0069] Figure 1 The results showed that different surfactants could significantly reduce the particle size of micelles.

[0070] Figure 2 The results show that different surfactants affect the dispersion coefficient of micelles. The dispersion coefficient of micelles is as follows: anionic surfactant > cationic surfactant > nonionic surfactant > amphoteric surfactant. Only amphoteric surfactants have a dispersion coefficient <0.35, indicating that amphoteric surfactants can reduce the dispersion coefficient of micelles and make the nanoparticles more uniformly dispersed in the solution.

[0071] Figure 3 The results show that surfactants have a significant impact on the absolute value of the micelle zeta potential. The absolute value of the micelle zeta potential is ranked as follows: amphoteric surfactants > anionic surfactants > nonionic surfactants > cationic surfactants. This indicates that cationic surfactants significantly reduce the absolute value of the potential, resulting in micelles with lower stability. In contrast, micelles formed by amphoteric surfactants and glycyrrhizic acid have the highest absolute value of the zeta potential, which is greater than 29, giving the micelles higher stability.

[0072] Example 2

[0073] Unlike Example 1, four different amphiphilic surfactants, namely disodium lauroyl diacetate (LAD), cocamidopropyl betaine (CAB), sodium cocoyl hydroxyethanesulfonate (SCI), and acetyl tetrapeptide-2, were selected to form a carrier with glycyrrhizic acid (GA) to encapsulate diaminopyrimidine oxide (AW).

[0074] The results showed that a white precipitate appeared at the bottom of the acetyl tetrapeptide-2 solution, and the diaminopyrimidine oxide could not be encapsulated. All others yielded clear, transparent, and colorless diaminopyrimidine oxide nanomicelle solutions. The particle size, zeta potential, and dispersion coefficient were determined according to the method in Example 1, and the results are shown in Table 1.

[0075] Table 1

[0076]

[0077] It can be seen that the particle size of formulations 1 to 3 is between 20 and 100 nm, and the PDI < 0.35 and the absolute value of the Zeta potential > 29, indicating that any of the three amphoteric surfactants, LAD, CAB and SCI, can be used to obtain nanomicelles that stably encapsulate diaminopyrimidine oxides.

[0078] Example 3

[0079] In this embodiment, disodium lauroyl amphiphilic diacetate (LAD), which showed the best performance in Example 2, was used to co-encapsulate diaminopyrimidine oxide (AW) with glycyrrhizic acid as a carrier to investigate the maximum amount of drug that nanomicelles can dissolve and carry.

[0080] Weigh 0.1% glycyrrhizic acid and measure 1% disodium lauroyl amphiphilic diacetate (LAD), and dissolve them in water at 60°C with stirring to obtain a mixed carrier solution. Separately weigh 1%, 3%, and 5% diaminopyrimidine oxides, dissolve them in alcohol solutions by sonication, recover the solvent in a rotary evaporator, add the mixed carrier solution and dissolve it, and hydrate and dissolve the diaminopyrimidine oxides on the wall of the round-bottom flask to obtain diaminopyrimidine oxide nanomicelles.

[0081] The results are as follows Figure 4As shown, when the concentration of diaminopyrimidine oxide is 5%, a white precipitate appears at the bottom of the solution, and a clear and transparent solution can be obtained when the concentration is less than 3%.

[0082] Weigh diaminopyrimidine oxide according to sample quantities 1-6 as shown in Table 2. Prepare a 10 mL nanomicelle system according to formulation 1. Dilute to 7 times. Using a mobile phase of methanol:0.1% phosphoric acid aqueous solution = 20:80, column temperature 35℃, detection wavelength 290 nm, flow rate 1.0 mL / min, and injection volume of 10 μL, determine the drug loading and encapsulation efficiency of the micelles. A control was set up with 0.1% glycyrrhizic acid encapsulating 3% diaminopyrimidine oxide. The results are shown in Table 2. Drug loading refers to the weight of the weighed drug divided by (carrier weight + drug weight).

[0083] Table 2

[0084]

[0085] Example 4

[0086] In this embodiment, different concentrations of disodium lauroyl amphiphilic diacetate (LAD) and glycyrrhizic acid (GA) were used to form a carrier (LG) to co-encapsulate diaminopyrimidine oxide (AW).

[0087] 0.1% glycyrrhizic acid was weighed, and 1%, 1.5%, 2%, and 3% amphoteric surfactants (LAD) were measured and dissolved in water at 60°C with stirring to obtain a mixed carrier solution. Separately, 3% diaminopyrimidine oxide was weighed and dissolved in an alcohol solution by ultrasonication. The solvent was recovered in a rotary evaporator, and the mixed carrier solution was added and dissolved. The diaminopyrimidine oxide on the wall of the round-bottom flask was then hydrated and dissolved to obtain diaminopyrimidine oxide nanomicelles. The particle size, zeta potential, and dispersion coefficient were determined according to the method in Example 1, and the results are shown in Table 3.

[0088] Table 3

[0089]

[0090] The results showed that when the LAD concentration was 1% to 1.5%, the micelle size ranged from 20 to 100 nm, PDI < 0.35, and the absolute value of the Zeta potential ≥ 29 mV, which was the optimal concentration. Among them, formulation 1 had the lowest particle size and dispersion coefficient, and the highest absolute value of the Zeta potential, making it the most stable.

[0091] Example 5

[0092] In this embodiment, disodium lauroyl amphiphilic diacetate (LAD) and glycyrrhizic acid (GA) of different concentrations were used to form a carrier (LG) to co-encapsulate diaminopyrimidine oxide (AW).

[0093] Glycyrrhizic acid (0.1%, 0.25%, 0.5%, 0.75%, and 1% in total) and a 1% amphoteric surfactant were weighed and dissolved in water at 60°C with stirring to obtain a mixed carrier solution. Separately, 3% diaminopyrimidine oxide was weighed and dissolved in an alcohol solution by ultrasonication. The solvent was recovered in a rotary evaporator, and the mixed carrier solution was added to dissolve it. The diaminopyrimidine oxide on the wall of the round-bottom flask was then hydrated and dissolved to obtain diaminopyrimidine oxide nanomicelles. The particle size, zeta potential, and dispersion coefficient were determined according to the method in Example 1, and the results are shown in Table 4.

[0094] Table 4

[0095]

[0096] The results showed that as the concentration of glycyrrhizic acid increased, the particle size of the micelles gradually increased. When the concentration of glycyrrhizic acid was between 0.1% and 0.5%, the particle size ranged from 20 to 100 nm, PDI < 0.35, the absolute value of zeta potential > 29, the particle size was small and uniform, and the stability was good. Among them, the micelles of formulation 1 showed the best characterization results and were the most stable.

[0097] Example 6

[0098] This embodiment investigates the transdermal permeation of diaminopyrimidine oxide before and after preparation into micelles. The specific steps are as follows:

[0099] Prepared pigskin was used for transdermal micelle experiments. Excess diaminopyrimidine oxide was dissolved in distilled water to obtain the AW group. 0.1% glycyrrhizic acid was used to encapsulate 3% diaminopyrimidine oxide to obtain the LG group. Following the above formulations and processes, nano-micelles encapsulating diaminopyrimidine oxide (diaminopyrimidine oxide) were prepared as formulations 1-3, 5, 9, and the LG-AW group (diaminopyrimidine oxide concentration 3%) using nonionic surfactant (Tween-80) and anionic surfactant (sodium lauroyl ether sulfate) as carriers in Example 1. 300 μl of sample was added to each supply cell, and the receiving cell was filled with receiving solution. Transdermal infiltration was performed for 36 h. At 2 h, 4 h, 8 h, 12 h, 24 h, and 36 h, 1 ml of receiving solution (PBS:PEG 400 = 8:2) was collected and stored at 4°C. Receiving solution was then added to the receiving cell. The receiving solution was diluted 1:1 with methanol, filtered through a 0.45 μm filter membrane, and the content was determined.

[0100] like Figure 5As shown, after preparing diaminopyrimidine oxide into micelles, the permeation rate of the encapsulated diaminopyrimidine oxide within 12 h was higher than that of diaminopyrimidine oxide administered alone, and the permeation rate gradually increased over time. This indicates that preparing diaminopyrimidine oxide into micelles can significantly improve the transdermal efficiency of the drug. The transdermal efficiency of the amphoteric surfactant group (formulation 1) was significantly higher than that of other surfactant groups. Figure 6 As shown, Formulas 2 and 3 have comparable transdermal efficiency to Formula 1, such as... Figure 7 The transdermal efficiency of formulations 5 and 9 is significantly lower than that of formulation 1.

[0101] Example 7

[0102] This embodiment provides the application of diaminopyrimidine oxide nanomicelles in the treatment of androgenetic alopecia. The specific experimental steps are as follows:

[0103] Several male SPF-grade C57BL / 6J mice were randomly divided into control group (Con), model group (MD), minoxidil group (MXD), diaminopyrimidine oxide group (AW), glycyrrhizic acid-amphoteric surfactant group (LG), and nanomicelle group (LG-AW). A mouse model of androgenetic alopecia was established by subcutaneous injection of testosterone for 28 days. The effect of micelles on improving androgenetic alopecia was evaluated by observing the hair growth on the back of the mice.

[0104] The prepared nanomicelles with a formulation of 0.1% GA + 3% AW + 1% LAD were administered topically to mice for 2 weeks. The hair growth status of the mice was scored. After the administration was completed, the back skin of the mice was taken and stained with HE to observe the number of hair follicles in the back skin and evaluate the promoting effect of the nanomicelles on the hair follicle growth of mice.

[0105] Hair length:

[0106] After anesthetizing the mice, four areas were randomly selected from the back of the mice. Hair was plucked with tweezers, and the length of the hair was measured with a ruler. The results are as follows: Figure 8 As shown, the results indicated that after testosterone modeling, the hair growth on the back of mice was slow and the hair was short. The hair length of mice in the blank group and the positive group was similar. At the same time, the hair of mice in each drug administration group increased significantly, showing a significant difference compared with the model group.

[0107] Hematoxylin-eosin staining (HE staining):

[0108] After the experiment, 2 mice from which hair was removed during modeling were harvested. 2 cm of dorsal skin was fixed with 4% (w / v) paraformaldehyde for 48 h, then treated with 80% (v / v) ethanol for 5 h, 90% (v / v) ethanol for 5 h, and 95% (v / v) ethanol overnight. The skin was then treated with anhydrous ethanol I, II, and III for 30 min each, xylene I, II, and III for 30 min each, paraffin I and II for 30 min each, and paraffin III for 1 h. After dehydration, paraffin infiltration, embedding, and sectioning, paraffin sections were obtained. The paraffin sections were stained with hematoxylin and eosin (HE) according to the steps in Table 3 and mounted with neutral resin. The results are shown below. Figure 9 As shown in Table 5. All percentage contents are volume concentrations.

[0109] Table 5

[0110]

[0111] The results showed that after subcutaneous injection of testosterone solution, hair follicle growth in the mouse model area was slow and the number was significantly reduced compared with the blank group; after coating AW with glycyrrhizic acid and LAD, the number of hair follicles on the back of the mice increased significantly; both diaminopyrimidine oxide alone and blank micelle solution formed by glycyrrhizic acid and LAD alone could promote hair growth, but the effect was not as obvious as LG-AW.

[0112] This invention provides a diaminopyrimidine oxide polymer micelle for androgenetic alopecia that is effective, safe, reliable, and process-stable. The stability of its formulation and process was verified by comparing parameters such as micelle size, polydispersity index (PDI), and zeta potential of micelles formed by co-encapsulating diaminopyrimidine oxide with different carriers and glycyrrhizic acid. Furthermore, its efficacy was validated in a C57BL / 6J mouse androgenetic alopecia (AGA) model. This provides a reference for the clinical or commercial development of anti-hair loss products.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A diaminopyrimidine oxide nanomicelle characterized in that, It consists of the following components by mass percentage: 1%~1.5% amphoteric surfactant, 0.1%~0.5% glycyrrhizic acid and ≤3% diaminopyrimidine oxide, with the balance being solvent; The amphoteric surfactant is cocamidopropyl betaine, disodium lauroyl amphiphilic diacetate, or sodium cocoyl hydroxyethanesulfonate.

2. The diaminopyrimidine oxide nanomicelles according to claim 1, characterized in that, It consists of the following components by mass percentage: 1% amphoteric surfactant, 0.1% glycyrrhizic acid and ≤3% diaminopyrimidine oxide, with the balance being solvent.

3. The diaminopyrimidine oxide nanomicelles according to claim 1 or 2, characterized in that, The particle size of the nanomicelles is 20~100 nm.

4. The method for preparing diaminopyrimidine oxide nanomicelles according to any one of claims 1 to 3, characterized in that, The amphoteric surfactant, glycyrrhizic acid, diaminopyrimidine oxide, and solvent were mixed according to the formulation to obtain diaminopyrimidine oxide nanomicelles.

5. The preparation method according to claim 4, characterized in that, Includes the following steps: A. Mix the amphoteric surfactant, glycyrrhizic acid and solvent according to the formula to obtain a nano micelle solution; B. The diaminopyrimidine oxide solution was subjected to rotary evaporation according to the formula, and then mixed with the nanomicelle solution to obtain diaminopyrimidine oxide nanomicelles.

6. The application of the diaminopyrimidine oxide nanomicelles according to any one of claims 1 to 3, or the diaminopyrimidine oxide nanomicelles prepared by the preparation method according to claim 4 or 5, in the preparation of anti-hair loss products.

Images