CN115232048B - Ionic liquid and preparation method and application thereof - Google Patents

Abstract

The invention discloses an ionic liquid and its preparation method and application. The ionic liquid is prepared from vitamin A compounds and choline compounds. It has the characteristics of good solubility and high permeability. It can also significantly improve oral availability. It has significant advantages in preparation application and can be widely and effectively used in various applications. in preparations.

Description

An ionic liquid and its preparation method and application

Technical field

The invention belongs to the field of ionic liquids, and specifically relates to an ionic liquid and its preparation method and application.

Background technique

Vitamin A and its metabolites play important roles in the human body and are currently widely used to treat various diseases. For example, retinoic acid (molecular formula: C ₂₀ H ₂₈ O ₂ ), an intermediate product of vitamin A metabolism in the body, mainly affects bone growth and promotes epithelial cell proliferation, differentiation, keratolysis and other metabolic effects. Retinoic acid is mainly used to treat diseases such as acne vulgaris, psoriasis, ichthyosis, lichen planus, pityriasis rubra pilaris, keratosis pilaris, squamous cell carcinoma and melanoma. Oral retinoic acid can also be used to treat acute promyelocytic leukemia. Isotretinoin, the isomer of retinoic acid, can be taken orally to treat severe acne, especially for nodular cystic acne, and can also be used for diseases such as pityriasis rubra pilaris.

Vitamin A and its similar derivatives are fat-soluble and insoluble in water, so their dissolution in preparations and dissolution in the body are poor. Taking tretinoin and isotretinoin as examples, the commonly used clinical preparations are creams. Since tretinoin has extremely poor solubility, it is made by suspending tretinoin in a cream base. Due to the extremely poor solubility of retinoic acid, its release from the matrix is limited and its pharmacological effects are also hindered. In oral administration, retinoic acid or isotretinoin is directly made into ordinary tablets. Due to poor dissolution in the body, its bioavailability is extremely low and it cannot exert a good therapeutic effect. Currently, there are reports of using solid dispersion, inclusion technology, and nanoemulsion technology to improve the oral bioavailability of tretinoin. However, the shortcomings of these technologies limit the development of tretinoin preparations. Such as the aging performance of solid dispersions, the structural limitations of inclusion technology, and the safety issues of surfactants in nanoemulsions.

Contents of the invention

In order to improve the above technical problems, the present invention provides an ionic liquid, which is composed of anions ^A- and cations B ⁺ ;

According to an embodiment of the invention, the anion is selected from the following structures:

According to an embodiment of the present invention, the R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁ ', R ₂ ', R ₃ ', R ₄ ', R ₅ ', R ₆ ', R ₇ ', R ₈ ', R ₉ ', R ₁₀ ', R ₁₁ ', R ₁₂ ' the same or different from each other Independently selected from H, OH, halogen, C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy; preferably, independently selected from H, methyl, methoxy.

Preferably, the anion is selected from the following structures:

According to an embodiment of the present invention, the anion may be provided by a vitamin A compound; preferably, the vitamin A compound may be selected from the group consisting of tretinoin, isotretinoin, retinol and/or retinaldehyde.

According to an embodiment of the present invention, the cations are selected from quaternary ammonium ions; the cations are further preferably choline cations (choline compounds serve as cation donors).

According to an embodiment of the present invention, the cation is provided by a choline compound; preferably, the choline compound is selected from the group consisting of choline, glycerophosphorylcholine, betaine, choline chloride, choline hydroxide or Other physiologically acceptable salts of choline.

Preferably, the cation is selected from the following structures:

According to embodiments of the present invention, the other physiologically acceptable salts may be selected from inorganic acid salts, such as carbonates, bicarbonates, hydrobromic acid, phosphates, sulfates, perchlorates; and organic acids Salts such as acetate, oxalate, maleate, tartrate, citrate, succinate, malonate, adipate, alginate, ascorbate, aspartate, Benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentane propionate, digluconate, dodecanate Alkyl sulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, enanthate, hexanoate, hydroiodide , 2-Hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate Acid, niacinate, nitrate, oleate, oxalate, palmitate, pamoate, pectate, persulfate, 3-phenylpropionate, phosphate, picric acid Salt, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate, etc.

According to an embodiment of the present invention, the choline compound is preferably choline bicarbonate.

The molar ratio of cations and anions is (1.1-10):1, preferably (1.5-5):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7 :1.

In some embodiments, the ionic liquid is [A ^- ][B ⁺ ] _x , and x can be selected from 1-10, such as 1, 2, 3, 4, 5, 6, 7.

According to an embodiment of the present invention, the ionic liquid is obtained by reacting the vitamin A compound and the choline compound.

Preferably, the molar ratio of the choline compound and the vitamin A compound is (1.1-10):1, preferably (1.5-5):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1.

According to an exemplary embodiment of the present invention, the [A ^- ][B ⁺ ] _x has the following structure:

According to an embodiment of the invention, the ionic liquid is a viscous liquid.

The invention also provides a preparation method of the ionic liquid, which includes the following steps: obtaining the ionic liquid by reacting it with a retinoic acid compound and a choline compound.

According to an embodiment of the present invention, the preparation method of the ionic liquid includes the following steps: obtained by reacting the retinoic acid compound and the choline compound; preferably, the reaction can be a metathesis reaction or a melting reaction.

Preferably, the molar ratio of the choline compound and the retinoic acid compound is (1.1-10):1, preferably (1.5-5):1, for example, 2:1, 3:1, 4:1. ,5:1,6:1,7:1.

According to embodiments of the invention, the reaction may be carried out in a solvent. For example, the solvent is a solvent that can dissolve vitamin A substances and is volatile. For example, the solvent is selected from volatile organic solvents or a mixed solvent of the volatile organic solvent and water.

Preferably, the volatile organic solvent may be selected from one, two or three types of ethanol, methanol and acetone.

Preferably, in the mixed solvent of volatile organic solvent and water, the volume percentage of water does not exceed 50%.

According to an embodiment of the present invention, the reaction is carried out at 10-60°C, for example at 20-40°C, preferably at room temperature (25°C).

According to an embodiment of the present invention, the reaction time is 15-40h, such as 20-30h, exemplified by 24h, 25h, 35h.

According to an embodiment of the present invention, the preparation method further includes removing the solvent after the reaction is completed, for example, removing the volatile organic solvent. The solvent may be removed, for example, by means known in the art, such as by rotary evaporation.

According to an embodiment of the present invention, the preparation method further includes freeze-drying the reactant after removing the solvent.

The present invention also provides a composition containing the ionic liquid.

The present invention further provides the application of the ionic liquid or the composition in preparations, including but not limited to pharmaceutical preparations, cosmetics, care products, and beauty products.

According to embodiments of the present invention, the preparation can be applied topically through the skin, for example, selected from creams, patches, ointments, cream preparations, gels and sprays, etc., or can be administered orally (i.e., oral Preparation) administration, for example, selected from tablets, granules, capsules, oral liquid preparations, pills, suspensions, dropping pills, etc. The preparation further includes a physiologically acceptable carrier (for example, a biocompatible material), for example, optionally including surfactants, excipients, humectants, emulsification accelerators, suspending agents, for regulating penetration. Pressed salts or buffers, colorants, flavors, stabilizers, bactericides, preservatives or other conventional supplements.

According to an embodiment of the present invention, the administration route of the preparation includes but is not limited to gastrointestinal administration or parenteral administration; wherein the gastrointestinal administration can be oral administration; the parenteral administration Intestinal administration can be transdermal administration, etc.

Beneficial effects of the invention

The present invention combines retinoic acid compounds and choline substances to form ionic liquids with good safety, which can have the characteristics of good solubility and high permeability without adding additional transdermal auxiliaries, and can also significantly improve oral administration. Utilization. Therefore, the ionic liquid of the present invention has significant advantages in preparation application, overcomes the limitations of the prior art in the application field of retinoic acid compounds, and can be widely and effectively used in various preparations.

Description of drawings

Figure 1 shows the proton nuclear magnetic resonance spectra of retinoic acid ionic liquids with different molar ratios of raw materials: A represents 4:1[Ch][Tre], B represents 3:1[Ch][Tre], and C represents 2:1[Ch ][Tre].

Figure 2 shows the peak assignment of the hydrogen nuclear magnetic resonance spectrum of the retinoic acid ionic liquid [Ch][Tre] with a molar ratio of 2:1.

Figure 3 shows the FT-IR spectra of tretinoin ionic liquid [Ch][Tre] (molar ratio of 2:1), tretinoin (Tretinoin) and choline bicarbonate.

Figure 4 shows the NOSEY spectrum and related force analysis of retinoic acid ionic liquid.

Figure 5 shows the penetration amount of different transdermal agents in each layer of skin.

Figure 6 shows the plasma concentration-time curve after oral administration of tretinoin ionic liquid and tretinoin suspension.

Detailed ways

The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following examples are only illustrative and explain the present invention and should not be construed as limiting the scope of the present invention. All technologies implemented based on the above contents of the present invention are covered by the scope of protection intended by the present invention.

Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

The percentage content "%" in the following examples represents mass percentage content.

[Tre][Ch] or [Ch][Tre] represents the structure formed by the anion derived from retinoic acid and the choline cation. In this structure, the anion and cation parts can be in different proportions ([Tre] represents the anion part, [ Ch] represents the cationic part).

Example 1 Synthesis of retinoic acid ionic liquid

Dissolve retinoic acid and choline bicarbonate in ethanol solvent according to the molar ratio of 1:1, 1:2, 1:3, and 1:4 respectively, react at room temperature for 24 hours, remove the ethanol by rotary evaporation, and freeze-dry the product to obtain the product . The results show that the product prepared by retinoic acid and choline bicarbonate at a molar ratio of 1:1 is a solid, and the products obtained by other molar ratios are viscous liquids.

The NMR results (Figure 1 and Figure 2) prove that the structures prepared with raw material molar ratios of 1:2, 1:3 and 1:4 are retinoic acid ionic liquids ([Tre][Ch]).

1H-NMR(DMSO-d6): δ6.56(dd,1H,H-11,J＝15.2,12.0Hz),6.23(d,1H,H-8,J＝15.2Hz),6.15(d,1H ,H-12,J＝12.0Hz),6.11(d,2H,H-7/10,J＝12.0Hz),5.67(s,1H,H-14),3.83(t,J＝4.8Hz,2H ,H-3'),3.42(t,J＝4.8Hz,2H,H-2'),3.12(s,3CH ₃ -N),2.05(s,CH ₃ -9),1.99(t,J＝ 5.2Hz,2H,H-4),1.90(s,CH ₃ -13),1.67(s,CH ₃ -3),1.57(m,2H,H-5),1.43(m,2H,H-6 ),1.00(s,2CH ₃ -1).

1. In vitro characterization

(1)FT-IR

The FT-IR of choline bicarbonate, retinoic acid and ionic liquid (molar ratio of 1:2) were studied respectively, and the infrared spectra of the three substances were compared, indicating the existence of hydrogen bonding interactions in the ionic liquid (Figure 3). Compared with retinoic acid, a new absorption peak appears at 1657cm=1 in 2:1[Ch][Tre] ionic liquid, which is caused by the asymmetric stretching vibration of carboxylic acid. The broadening of the OH peak indicates a change in the intermolecular interaction force; the shift to a lower wave number (red shift) indicates the formation of intermolecular hydrogen bonding forces. Compared with choline bicarbonate, the electrons in the conjugated system are delocalized. The original single bonds also have the properties of some double bonds, while the electron density in the original double bonds or triple bonds is reduced, the bond length is increased, and the infrared The absorption undergoes a red shift, that is, the number of absorbed waves becomes smaller or the frequency of the absorbed waves decreases, so C=O (from 1674 to 1657cm ^-1 ). However, the introduction of the conjugated system delocalizes the fragment electrons of the acid, causing the choline fragment -OH electron cloud density to increase, and the infrared absorption to blue shift, that is, the absorbed wave number becomes larger.

(2)NOESY

¹ H- ¹ H NOESY spectrum (Figure 4) reveals the mutual proximity relationship between all protons in the molecule and between protons. When the distance between the two H is less than 5 Angstroms, the relevant horizontal and vertical coordinates are all hydrogen spectra, and the diagonal is itself. Proton signal related peaks, in addition to self-signal related peaks and impurity signals, [Tre][Ch] (molar ratio 1:2) belongs to 19 related peaks. As shown in the schematic diagram of the molecule, blue is within the ions, red is the interaction between ions in the system, and red has 11 related peaks. The asymmetric distribution of the NOESY signal for ionic liquids may be due to the fact that the measurement evaluates average interactions within the solvent rather than specific ions, which may mean that the relaxation is not symmetric.

2. Solubility and stability of retinoic acid ionic liquid

(1)Solubility

Use water to dilute [Tre][Ch] (molar ratio 1:2) retinoic acid ionic liquid to study its water solubility and hygroscopicity.

Experiments show that when the ionic liquid concentration is below 14%, the retinoic acid ionic liquid is destroyed and insoluble matter precipitates. When the concentration of tretinoin ionic liquid exceeds 14%, the tretinoin ionic liquid can be completely dissolved in water.

(2)Stability

The molar ratios of tretinoin and tretinoin ionic liquid ([Tre][Ch]() are respectively 1:2, 1:3, and 1:4, which can be recorded as 2:1[Ch][Tre], 3 :1[Ch][Tre], 4:1[Ch][Tre], or 2[Ch][Tre], 3[Ch][Tre], 4[Ch][Tre]) were placed under strong light ( 4500±500LX) for 15 days, and the stability of each sample was tested on 5, 10, and 15 days respectively.

Experimental results show that the stability of the three retinoic acid ionic liquids under light is not significantly different from that of retinoic acid itself, indicating that the formation of retinoic acid ionic liquids will not reduce the stability of retinoic acid.

Example 2 Transdermal agent and in vitro penetration experiment

With 20%-2[Ch][Tre], 40%-2[Ch][Tre], 60%-2[Ch][Tre], 80%-2[Ch][Tre], 100%-2[ Ch][Tre] retinoic acid ionic liquid is used as a transdermal agent, including 20%-2[Ch][Tre], 40%-2[Ch][Tre], 60%-2[Ch][Tre], 80%-2[Ch][Tre] retinoic acid ionic liquid is obtained by diluting it with water.

In vitro penetration test of transdermal agents:

The abdominal skin of 2-week-old domestic pigs was fixed in a standard Franz diffusion cell (FDC, effective diffusion area: 1.77cm ² , Shanghai Kaikai Technology Trading Co., Ltd., China), with the cuticle facing the supply cell. The receiving solution was 1% BSA in ultrasonic phosphate buffered saline (PBS, pH 7.4), stirred at 37°C (300 rpm). After equilibration, 200 mg of each formulation was placed in the supply reservoir and brought into contact with the skin. During the entire experiment, the equipment was covered with aluminum foil to protect it from light. After 6 h of administration, the skin was removed from the FDC, washed with ethanol and distilled water in sequence to remove residual formula, and wiped with a tampon. The skin was transversely sectioned into the stratum corneum (SC), epidermis (Epidermis) and dermis (Dermis) using a freezing microtome (Leica, Mainz, Germany), and each was treated with 650 μL MeOH/H ₂ O (1:1) and 100 μL Cnidoma monnieri. The skin was soaked overnight in a solvent composed of Osthole (Ost) solution (226 μLg/mL in MeOH) for quantitative analysis. Centrifuge at 10,000 g for 5 min, and measure the supernatant by HPLC.

HPLC test conditions are as follows:

Analytical HPLC is Agilent Technologies 1100 HPLC system (Agilent, Santa Clara, USA); chromatographic column: Agilent Eclipse XDB-C18 (5 μm, 4.6 mm × 150 mm); mobile phase: methanol-water-glacial acetic acid (361:39:1.3, v/v/v); elution flow rate: 1.0mL/min; detection wavelength: 350nm; injection volume: 20μL. Internal standard: osthole.

Calculate the transdermal transport amount of retinoic acid according to the following formula:

Q＝P _a /P _d

In the formula, Q is the percentage of transdermal absorption, P _a is the amount of drug in the receiving pool, and P _d is the amount of drug in the supply pool.

The penetration ability of each group of transdermal agents in the skin was studied through in vitro skin penetration experiments. Among them, 20%-2[Ch][Tre] can make retinoic acid penetrate through the skin, and vitamin A can be detected in the receiving pool. Acid; no retinoic acid was detected in the receiving pool in other groups. The amount of retinoic acid in each layer of the skin is shown in Figure 5: Transdermal agent 20%-2[Ch][Tre] group has no detectable retinoic acid. has the best permeability enhancement ability, followed by 40%-2[Ch][Tre], 60%-2[Ch][Tre], 80%-2[Ch][Tre] and 100%-2[Ch] [Tre]; It is worth noting that the difference between the 20%-2[Ch][Tre] group and other groups was significant in the epidermis and dermis (p<0.0001).

In addition, a commercially available cream (oil-in-water base, Divi) was used as the base, retinoic acid was added to make the mass content reach 20%, and it was suspended in the base. After the transdermal experiment, the retinoic acid in each layer of skin was The amounts were all below the limit of quantification (37ng/ml).

Example 3 Oral administration of retinoic acid ionic liquid

2[Ch][Tre]tretinoin ionic liquid was orally administered to rats once, with a single oral dose of 2 mg/kg, and at the same time, tretinoin suspension (40 mg tretinoin was added to 100 mL 0.5% CMC -Na solution, grind until uniformly dispersed, and obtain a tretinoin suspension) as a control orally administered to rats, with the same administration frequency and dosage as the tretinoin ionic liquid.

SD male rats were randomly divided into two groups of the same number. The rats were fasted overnight before the experiment and drank water freely. Each preparation was orally administered according to the above dosage at 10, 30, 50, and 70 days after administration. 0.5 mL of blood was taken from the orbit at 100, 130, 190, 250, 370, and 490 minutes, placed in a centrifuge tube treated with sodium heparin, and centrifuged at 4000 r/min for 15 minutes to separate the plasma. Precisely pipette 100 μL of blank plasma sample into a 1.5 mL EP tube, accurately add 20 μL of Acitren, Atr internal standard solution and vortex for 1 min to mix, then add 200 μL of acetonitrile, vortex for 5 min to mix thoroughly, and then vortex at 14000 rpm Centrifuge for 10 minutes to separate the supernatant, and finally take 30 μL of the supernatant and inject it via HPLC.

HPLC test conditions are as follows:

Analytical HPLC is Agilent Technologies 1260 HPLC system (Agilent, Santa Clara, USA); chromatographic column: InertSustain C18 (5 μm, 4.6 mm × 150 mm); mobile phase: methanol-2% glacial acetic acid (88/10, v/v); Elution flow rate: 1.0mL/min; detection wavelength: 350nm; column temperature: 25°C; injection volume: 30μL. Internal standard: acitretin.

As shown in Figure 6, the results show that after administration of tretinoin ionic liquid, the bioavailability of tretinoin is 3.61 times that of the suspension, and the peak concentration is 2.87 times that of the suspension. The oral bioavailability of tretinoin is greatly promoted through ionic liquid technology.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiment. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (9)

1. The preparation method of the ionic liquid is characterized by comprising the following steps of: is obtained by reacting tretinoin and choline compounds; the choline compound is selected from choline, choline chloride, choline carbonate or choline bicarbonate; the mol ratio of the choline compound to the tretinoin is (1.5-5) 1; the reaction is carried out in a volatile organic solvent or a mixed solvent of the volatile organic solvent and water; after the reaction was completed, the solvent was removed.

2. The ionic liquid of claim 1, wherein: the volatile organic solvent is selected from one, two or three of ethanol, methanol and acetone.

3. The ionic liquid of claim 1, wherein the reaction is carried out at a temperature of 10-60 ℃ for a time period of 15-40 hours.

4. An ionic liquid as claimed in any one of claims 1 to 3, wherein the choline-like compound is selected from choline carbonate or choline bicarbonate; the molar ratio of the choline compound to tretinoin is 2:1.

5. A composition comprising the ionic liquid of any one of claims 1 to 4.

6. Use of an ionic liquid according to any one of claims 1 to 4 or a composition according to claim 5 in a formulation.

7. The use according to claim 6, wherein the formulation is selected from the group consisting of pharmaceutical formulations, cosmetics, nursing products, cosmetology.

8. The use according to claim 7, wherein the formulation is administered topically through the skin or orally.

9. The use of claim 8, wherein the formulation further comprises a physiologically acceptable carrier.