CN113197857A

CN113197857A - Trametinib microemulsion and application thereof

Info

Publication number: CN113197857A
Application number: CN202110588745.4A
Authority: CN
Inventors: 徐月红; 王文秀
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2021-08-03

Abstract

The invention discloses a trametinib microemulsion and application thereof, wherein the microemulsion comprises trametinib, methyl salicylate, vitamin E, caprylic/capric glyceride, diethylene glycol monoethyl ether and polyoxyethylene castor oil EL. Compared with the trametinib aqueous suspension, the trametinib microemulsion has high retention amount; compared with oral trametinib suspension, the trametinib microemulsion has more obvious drug effect of inhibiting tumors, and shows that the trametinib microemulsion can effectively inhibit melanoma and has more obvious curative effect and advantage in the aspect of treating melanoma. In addition, the adopted instruments and equipment are simple and convenient, the preparation process is efficient, simple and controllable, and the method is suitable for industrial production.

Description

Trametinib microemulsion and application thereof

Technical Field

The invention belongs to the field of pharmaceutical preparations, and particularly relates to a trametinib microemulsion and application thereof.

Background

Melanoma is a skin cancer with high aggressiveness and high mortality, with 4% of the cases, but 79% of the cases. Melanoma cells become cancerous in the basal portion between the epidermis and dermis, and may migrate to other sites at an advanced stage. Ultraviolet radiation is the major cause of skin melanoma and can be inherited. During the development of melanoma, the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) signaling pathways are often mutated. Studies report that up to 90% of melanomas exhibit aberrant activation of the MAPK pathway. Whereas BRAFV600 mutations are found in 40% to 50% of melanomas. Wherein activated BRAF leads to downstream activation of mitogen-activated protein kinase (MEK) by inducing phosphorylation of serine residues. Activated MEK triggers serine/threonine kinase extracellular signal-regulated kinase (ERK). Phosphorylated ERK translocates to the nucleus and regulates gene expression of more than 50 substrates leading to the development of cancer.

Trametinib is a small-molecule MEK1/2 inhibitor, and 5 months 2013, the U.S. Food and Drug Administration (FDA) approves trametinib as a single drug for treating BRAF V600E/K mutant metastatic melanoma. Trametinib is a slightly soluble drug, the solubility of the trametinib is less than 0.1 mu g/mL, the commercially available preparation is an oral tablet, the recommended dose is 2mg per day, and the trametinib has the curative effect of causing tumor regression and disease stabilization of patients with V600E or V600K BRAF mutant melanoma. The topical treatment is a highly effective method for treating skin diseases such as skin melanoma by directly acting on affected parts, and topical administration via skin can shorten administration time, reduce systemic side effects, and can also be used as adjuvant method of chemotherapy or radiotherapy. However, the problems of trametinib being poorly soluble, and the lack of topical therapeutic formulations, have not been addressed.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides a microemulsion, which comprises the following components: 5.5-16.5% of oil phase, 9-27% of surfactant and 3-9% of cosurfactant.

In some embodiments of the invention, the oil phase is at least one of caprylic capric acid glyceride, methyl salicylate, vitamin E.

In some preferred embodiments of the invention, the oil phase is caprylic capric acid glyceride, methyl salicylate, and vitamin E.

In some embodiments of the present invention, the ratio of caprylic/capric glyceride, methyl salicylate, and vitamin E is 3.5-10.5: 1.5-4.5: 0.5 to 1.5.

In some embodiments of the invention, the ratio between caprylic capric acid glyceride, methyl salicylate, and vitamin E is 7:3: 1.

In some embodiments of the invention, the surfactant is at least one of caprylic capric acid polyethylene glycol glyceride, polyethylene glycol-15 hydroxystearate, polyoxyethylene castor oil EL.

In some preferred embodiments of the invention, the surfactant is polyoxyethylated castor oil EL.

In some embodiments of the invention, the co-surfactant is diethylene glycol monoethyl ether.

In some embodiments of the invention, the remainder of the microemulsion is water.

In some preferred embodiments of the invention, the microemulsion comprises the following components: 11% of oil phase, 18% of surfactant, 6% of cosurfactant and 65% of water.

In some preferred embodiments of the invention, the microemulsion comprises the following components: 3% of methyl salicylate, 1% of vitamin E, 7% of caprylic/capric glyceride, 18% of polyoxyethylene castor oil EL, 6% of diethylene glycol monoethyl ether and 65% of water.

The invention also provides the application of the microemulsion in preparing a carrier or a solvent of a slightly soluble medicament.

In some embodiments of the invention, the poorly soluble drug is tanshinone iia, trametinib, vemurafenib, or cryptotanshinone.

In some preferred embodiments of the invention, the poorly soluble drug is trametinib.

The invention also provides a trametinib external preparation, which comprises the microemulsion and trametinib.

In some embodiments of the invention, the ratio of trametinib is 0.0025-0.0075%.

In some preferred embodiments of the present invention, the trametinib is 0.005% by weight.

The invention also provides a preparation method of the external preparation of the tremetinib, which comprises the following steps:

s1: mixing the oil phase, the surfactant and the cosurfactant to form a solution A;

s2: and adding trametinib into the solution A and uniformly mixing.

The invention also provides application of the microemulsion or the external preparation in treating tumors.

In some preferred embodiments of the invention, the tumor is melanoma.

The invention has the beneficial effects that:

1. the microemulsion provided by the invention has a certain inhibition effect on melanoma tumor cells, can efficiently deliver insoluble drugs, and can increase the solubility and bioavailability of the insoluble drugs such as trametinib, thereby enhancing the drug effect.

2. The microemulsion is more conveniently smeared on a tumor part in an external administration mode, can directly target tumor tissues and cells, fully exerts the drug effect and reduces the toxic and side effects of the whole body.

3. The microemulsion can increase the solubility of the slightly soluble drug trametinib, and meanwhile, the microemulsion has smaller particle size, so that the residence of trametinib through the skin can be promoted, and the bioavailability is improved.

4. Compared with the trametinib aqueous suspension, the external trametinib microemulsion has high retention; compared with oral trametinib suspension, the trametinib suspension can avoid the first pass effect of the liver, has more obvious drug effect of inhibiting tumors, and provides a novel trametinib administration mode. The trametinib microemulsion can effectively inhibit melanoma, has more obvious curative effect and advantage in treating melanoma, and increases patient compliance. An external application method of trametinib for treating melanoma is provided. In addition, the adopted instruments and equipment are simple and convenient, the preparation process is efficient, simple and controllable, and the method is suitable for industrial production.

Drawings

Figure 1 shows the solubility of trametinib in different oil phases, surfactants, cosurfactants.

FIG. 2 is a pseudo-ternary phase diagram of a screening prescription. Wherein, the A picture takes polyoxyethylene castor oil EL (cremophor EL) as a surfactant, the B picture takes polyethylene glycol-15 hydroxystearate (SolutolHS15) as the surfactant, and the C picture takes caprylic capric acid polyethylene glycol glyceride (Labrasol) as the surfactant.

Fig. 3 is the skin retention. Wherein, A is the retention in vitro, B is the retention in vivo.

Figure 4 is a graph of inhibition of a375 cells by the trametinib microemulsion.

FIG. 5 shows the efficacy of different formulations on in situ melanoma. Wherein, A is the change of tumor volume in 0-12 days of administration; b is the tumor inhibition rate after 12 days of administration; panel C taken out the tumor mass 12 days after dosing; graph D shows the body weight change of nude mice after administration for 0-12 days; panel E is a photograph of the tumor 12 days after administration.

FIG. 6 is an evaluation of the inhibition effect of different prescriptions on distant tumors. Wherein Panel A is the change in distal tumor volume at 0-12 days of administration; panel B is distal tumor mass 12 days after dosing; panel C is a photograph of the distal tumor 12 days after administration; d picture is the photograph of the tumor in situ and the tumor far away 12 days after the administration; graph E shows tumor weights of the in situ and distal tumors 12 days after administration.

Note: p < 0.05, with statistical differences.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

Optional components are screened out by measuring saturation solubility in different oil phases, surfactants and cosurfactants, a microemulsion formula is screened out by a pseudo ternary phase diagram, and finally the effective gain effect of the trametinib microemulsion is further illustrated by an in vitro transdermal experiment, an in vitro and in vivo melanoma inhibition experiment and the like.

Example 1 determination of the saturated solubility of trametinib in different oil phases, surfactants, co-surfactants

The trametinib is added into different oil phases, surfactants and cosurfactants for solubility investigation. And determining the optional prescription components through the measurement of saturated solubility, and carrying out the next screening.

Experimental materials:

and (3) testing the sample: oleic Acid (OA), Ethyl Oleate (EO), isopropyl myristate (IPM), caprylic capric glyceride (ODO), vitamin E (Vit E), Methyl Salicylate (MS), caprylic capric macrogol glyceride (Labrasol), polyoxyethylene castor oil EL (cremophor EL), polyethylene glycol-15 hydroxystearate (SolutolHS15), Tween 80(Tween 80), polyethylene glycol 400(PEG 400), diethylene glycol monoethyl ether (Transcutol P), Ethanol (Ethanol), and 1, 2-Propanediol (PG).

The experimental method comprises the following steps: adding excessive trametinib into different oil phases, surfactants and cosurfactants, carrying out 40HZ ultrasonic treatment for 30min, carrying out constant temperature shaking table at 37 ℃ for 24h, centrifuging, taking supernatant, filtering, taking filtrate, diluting, and measuring saturated solubility.

The solubility of trametinib in different oil phases, surfactants and cosurfactants is shown in figure 1. Wherein, the oil phase has good solubility of caprylic capric glyceride and methyl salicylate, and is selected as oil phase component, vitamin E is used for keeping moisture, and is selected as one of oil phase components. Labrasol, HS15 and Cremophor EL in the surfactant have higher solubility, and are used as alternative surfactants for next screening. Transcutol P has the highest solubility in the cosurfactant, so that the Transcutol P is selected as the cosurfactant. The oil phase consists of caprylic capric acid glyceride, methyl salicylate and vitamin E, the cosurfactant is Transcutol P, and the surfactant is further screened.

EXAMPLE 2 screening of surfactants

The fixed oil phase is a mixture of caprylic capric glyceride, methyl salicylate and vitamin E, the cosurfactant is Transcutol P, different surfactants are added to prepare the microemulsion, and a pseudo-ternary phase diagram is drawn. And (4) determining the optimal surfactant by drawing a pseudo ternary phase diagram.

Experimental materials:

and (3) testing the sample: caprylic capric acid polyethylene glycol glyceride (Labrasol), polyoxyethylene castor oil EL (cremophor EL), polyethylene glycol-15 hydroxystearate (Solutol HS 15).

The experimental method comprises the following steps: preparing microemulsion with Labrasol, Cremophor EL and HS15 as surfactants by taking a mixture of caprylic capric glyceride, methyl salicylate and vitamin E as an oil phase and Transcutol P as a cosurfactant, and drawing a pseudo-ternary phase diagram according to the content of each component at a titration end point. The areas of the microemulsion regions in the pseudo-ternary phase diagram were compared.

The results are shown in FIG. 2, wherein A in FIG. 2 is polyoxyethylene castor oil EL (cremophor EL) as the surfactant, B in FIG. 2 is polyethylene glycol-15 hydroxystearate (Solutol HS15) as the surfactant, and C in FIG. 2 is caprylic capric acid polyethylene glycol glyceride (Labrasol) as the surfactant.

From the results of the pseudo ternary phase diagram, it can be seen that Cremophor EL as a surfactant forms the largest area of the microemulsion region. Therefore, Cremophor EL is selected as the surfactant of the microemulsion.

EXAMPLE 3 preparation of a microemulsion

The microemulsion of the embodiment comprises the following raw materials in percentage by mass:

the preparation method of the microemulsion comprises the following steps:

A. according to the formula ratio, at room temperature, methyl salicylate, vitamin E and caprylic capric glyceride are mixed to form a transparent and clear solution;

B. adding Transcutol P into the solution A according to the formula ratio;

C. adding Cremophor EL into the solution B according to the formula ratio, and forming a clear transparent solution by a magnetic stirrer;

D. and (3) slowly dripping water into the solution C at room temperature according to the formula ratio, and forming a uniform, stable, transparent and clear solution by using a magnetic stirrer to obtain the water-based transparent and clear solution.

Example 4 preparation of a trametinib microemulsion

The trametinib microemulsion in the embodiment comprises the following raw materials in percentage by mass:

the preparation method of the trametinib microemulsion comprises the following steps:

B. adding trametinib and Transcutol P into the solution A according to the formula ratio;

Example 5 test example

1. Microemulsion transdermal penetration test

The trametinib microemulsion prepared in example 4 and the water suspension of trametinib are subjected to in vitro and in vivo transdermal permeation experiment investigation. Compared with the transdermal penetration of an aqueous suspension, the higher the retention of the trametinib microemulsion is, the stronger the transdermal penetration of the medicine is promoted, and the higher the bioavailability is.

Experimental materials:

and (3) testing the sample: 0.5ml of the trametinib microemulsion of this example 4; trametinib: 0.005% in the form of clear transparent liquid;

comparison products: 0.5ml trametinib aqueous suspension, trametinib: 0.005% in suspension form and granular precipitate.

The experimental method comprises the following steps:

obtaining of skin: human skin is often difficult to obtain and SD rat abdominal skin is used to replace human skin in transdermal permeation studies. SD rats were obtained from the laboratory animal center of Zhongshan university, and after the SD rats had been depilated at their abdomens for 24 hours, the skin was removed, the adherent subcutaneous tissue was removed with a scalpel, and only the skin portion was left, and after washing in 0.9% physiological saline (m/v), the surface water was blotted with filter paper, wrapped with tin foil, and frozen in a freezer at-20 ℃ for use. Visual observation confirmed that only skin samples without any damage could be tested.

Transdermal experiment: ex vivo transdermal penetration experiments. Before use, the SD rat skin is naturally thawed, washed by normal saline, and the surface moisture is absorbed by filter paper to obtain the SD rat skin. The integrity of the skin was checked before the experiment to ensure no damage. In vitro percutaneous permeation experiment, Franz diffusion cell is adopted, the sheared intact skin is fixed between a supply cell and a receiving cell, and the effective transdermal area of the diffusion cell is 3.14cm²The volume of the receiving pool is 7.5mL, the temperature of the water bath of the diffusion instrument is adjusted to be 32 +/-2 ℃, and the rotating speed of the stirrer is 250 rpm. 0.5mL of the trametinib microemulsion prepared in example 4 and an aqueous suspension of trametinib with the same drug content are respectively fed into a feeding pool, a receiving solution is a 20% hydroxypropyl-beta cyclodextrin aqueous solution, and 1mL of the receiving solution is taken and a blank receiving solution with the same volume is supplemented in 1,2, 4, 6, 8, 12 and 24 hours. All the samples are filtered by a 0.22 mu m nano-pore filter membrane, and the content of the trametinib in the samples is measured.

After the transdermal experiment is ended for 24h, taking out the skin from the diffusion cell, wiping the surface of the skin for 3 times respectively by using water-methanol-water to remove residual medicines, shearing the skin, adding 2mL of methanol, carrying out ultrasonic treatment for 0.5h, centrifuging at 3000rpm for 5min, taking supernatant fluid, filtering by using a 0.22 mu m microporous filter membrane, taking subsequent filtrate, and measuring the content of the trametinib by using a high performance liquid chromatography to obtain the retention amount of the in-vitro skin. In a percutaneous permeation experiment, SD rat is subjected to abdominal depilation, and after 24h, the supply pool is fixed on abdominal skin, and the effective area is 3.14cm². 0.5mL of the trametinib microemulsion and the drug contained in the microemulsion are respectively administered to the supply tankThe same amount of trametinib aqueous suspension is subjected to dislocation and sacrifice of cervical vertebrae of rats 24h after a body transdermal experiment, the residual medicines are removed by wiping the surface of the skin for 3 times respectively in the sequence of water, methanol and water, the skin is cut off along the edge of a supply pool and collected in an EP (EP) tube. Shearing skin, adding 2mL of methanol, performing ultrasonic treatment for 0.5h, centrifuging at 3000rpm for 5min, collecting supernatant, filtering with 0.22 μm microporous membrane, collecting filtrate, and measuring content of trametinib by high performance liquid chromatography to obtain in vivo skin retention. The results of the ex vivo and in vivo experiments are shown in table 1 and fig. 3. Wherein the graph A in FIG. 3 is the retention in vitro and the graph B in FIG. 3 is the retention in vivo. Note: *: p is less than 0.05, compared with the water suspension of trametinib; trametinib was administered in an amount of 25 μ g in both formulations.

TABLE 1 skin Retention and penetration results

It can be seen from table 1 and fig. 3 that the trametinib microemulsion of example 3 significantly increases the skin retention of the drug, and has statistical differences compared with the water suspension group. The trametinib microemulsion has good retention promoting effect and is more beneficial to the exertion of drug effect. And because the drug loading of the trametinib is too low, the transdermal permeability is difficult to measure.

2. Evaluation of melanoma cell proliferation inhibiting effect of trametinib microemulsion through cell experiment

The advantages of the trametinib microemulsion in inhibiting melanoma in vitro are demonstrated by respectively inhibiting the proliferation of melanoma cells (A375) by the dimethyl sulfoxide solution of the trametinib and the trametinib microemulsion.

The experimental method comprises the following steps:

configuration of drug concentration: trametinib is prepared into mother liquor with the concentration of 100 mu g/mL by dimethyl sulfoxide, and then the trametinib microemulsion (the trametinib microemulsion in the embodiment 4), the blank microemulsion (the microemulsion in the embodiment 3) and the dimethyl sulfoxide mother liquor of the trametinib are diluted into medicine liquor with the concentration of 0.1 mu M by a DMEM liquid culture medium.

Culture of A375 cellsCulturing: a375 was cultured in a culture dish containing 10% fetal bovine serum and 1% streptomycin/penicillin in DMEM medium and placed at 37 ℃ and 5% CO₂In the cell culture box, the cells are subcultured every 1 to 2 days.

Drug anti-a 375 cell proliferation assay: when the cells are subcultured next time, 100 mu L of the cells with the cell density of 8 multiplied by 10 are precisely measured⁴adding/mL cell suspension into a 96-well plate, culturing for 12h, discarding the culture solution, respectively adding 100 mu L blank microemulsion, trametinib dimethyl sulfoxide solution and DMEM culture medium diluent of trametinib microemulsion, culturing for 24h in an incubator, discarding the liquid medicine, adding 120 mu L MTTT solution, continuously incubating for 4h, discarding the MTT solution, adding 150 mu L dimethyl sulfoxide solution into each well, and placing on a shaking table for more than 10min to completely dissolve the obtained bluish purple crystals. Finally, the absorbance value (OD) of each well was measured at 490nm using a microplate reader, and the viability of A375 cells was calculated. Wherein% cell viability is (sample a-a blank)/(control a-a blank) x 100%.

The experimental result is shown in fig. 4, and it can be seen that trametinib can significantly inhibit a375 cell proliferation at a smaller concentration, the blank microemulsion also has the effect of inhibiting a375 cell proliferation, and trametinib keeps the same or stronger inhibition effect on a375 cell after being loaded into the microemulsion.

3. Evaluation of the therapeutic efficacy of the trametinib microemulsions in example 4 from in vivo anti-melanoma studies

In order to investigate the anti-tumor effect of trametinib for external use on the trametinib microemulsion in example 4, an in vivo anti-melanoma experiment was performed. A375 was injected in situ to construct a melanoma model and in vivo pharmacodynamic evaluations were performed by giving tumor volume changes, mass and body weight changes of different prescriptions. The trametinib microemulsion in external application example 4, the blank microemulsion in external application example 3, the external trametinib aqueous suspension and the oral trametinib suspension are compared, so that the treatment effect of the trametinib microemulsion in example 4 is evaluated, and the advantage of inhibiting melanoma in vivo is proved.

Experimental materials:

experimental animals: BALB/c-nu/nu nude mice.

And (3) testing the sample: trametinib microemulsion, trametinib: 0.005% and is a clear and transparent liquid.

Comparison products: the blank microemulsion is a clear and transparent liquid.

Trametinib aqueous suspension, trametinib: 0.005% and the character is suspension.

Trametinib suspension containing 2.5% dimethyl sulfoxide, trametinib: 0.005% and the character is suspension.

In vivo anti-melanoma experimental method:

culture of a375 cells: after the cells are recovered, when the cells are transmitted to 3-6 generations, the cells are counted by using a blood cell counting plate according to the 2 multiplied by 10⁵Cell suspension was placed in EP tubes at a cell density of 100. mu.L.

Inoculation of a375 cells: the cell suspension in the EP tube was injected subcutaneously into the left and right dorsal skin of nude mice using a 1mL sterile insulin syringe (2X 10)⁵100 μ L), the day of injection was the first day of the molding protocol.

Administration to melanoma nude mice: after the model is successfully made, the tumor volume reaches 200-400 mm³At that time, administration is started. The blank microemulsion, the trametinib microemulsion and the trametinib aqueous suspension are externally applied in a smearing mode, the trametinib suspension containing 2.5% of dimethyl sulfoxide is applied in an oral intragastric administration mode, the administration is once a day and is continuously performed for 12 days, and the tumor volume and the body weight are measured every day. After 12 days the administration was completed, the animals were sacrificed by cervical dislocation and bilateral tumor tissues were taken for mass weighing and correlation analysis. Wherein, the tumor volume is measured by using a vernier caliper to respectively measure the major diameter and the minor diameter of the tumor part, and the tumor volume is calculated according to the following formula:

tumor volume (mm)³) Long diameter x wide diameter²/2。

The tumor inhibition rate is calculated to obtain the tumor volume of each group on the last day of tumor growth, and the tumor inhibition rate is obtained by substituting the tumor volume into the following formula:

tumor inhibition rate (%) - (1-tumor volume)_{Administration set}Tumor volume_{Control group})×100％。

1) The efficacy results of in vivo treatment of A375 in situ melanoma are shown in FIG. 5, wherein A in FIG. 5 is the change in tumor volume between 0 and 12 days of administration; FIG. 5, panel B, is the tumor inhibition rate after 12 days of administration; FIG. 5 is a graph C showing the body weight changes of nude mice after administration for 0-12 days; panel D of figure 5 is the mass taken from a tumor 12 days after administration; in FIG. 5, panel E is a photograph of the tumor 12 days after administration. Note: p < 0.05, indicating a statistical difference.

It can be seen from the graph a in fig. 5 that the model group shows a clear trend of continuous tumor growth after the melanoma is planted in situ by the A375, and the tumor volume of the blank microemulsion and water suspension treatment group has no significant difference from the model group, which indicates that the blank microemulsion and water suspension do not have a significant effect of inhibiting tumor growth. The tumor volumes of the external trametinib microemulsion and the oral trametinib suspension group are obviously smaller than that of the modeling group, which shows that the external trametinib microemulsion and the oral trametinib suspension can effectively inhibit tumor growth. In addition, after 12 days of administration, the tumor volume of the external trametinib microemulsion group is obviously lower than that of the oral group, which shows that the external trametinib microemulsion has stronger tumor growth inhibition effect compared with the oral trametinib suspension, and the local external drug effect is stronger under the condition of the same administration amount probably due to the liver first pass effect existing in oral administration. Similarly, it can be seen from the graph C in fig. 5 that the tumor mass of the external trametinib microemulsion group was the smallest after 12 days of administration with different prescriptions, which is statistically different from the manufactured group, the blank microemulsion group, the trametinib aqueous suspension group and the oral trametinib suspension group. As can be seen from panel B in fig. 5, trametinib administered topically had the highest tumor suppression rate. Meanwhile, as can be seen from the graph D in FIG. 5, the weight of the nude mice changes, and the weight of the mice slowly increases within 12 days after administration, which indicates that the safety of each prescription is good. It can also be seen from the E-plot in fig. 5 that the external trametinib microemulsion is significantly inhibited compared to the manufactured, blank, aqueous trametinib suspension, and oral trametinib suspension. In conclusion, it is demonstrated that the external trametinib microemulsion of example 4 has a significant advantage in inhibiting the growth of in situ melanoma.

2) The results of the evaluation of the inhibition effect of different prescriptions on the distal tumor are shown in fig. 6, in which a in fig. 6 is the change in the volume of the distal tumor after 0-12 days of administration, B in fig. 6 is the mass of the distal tumor after 12 days of administration, C in fig. 6 is a photograph of the distal tumor after 12 days of administration, D in fig. 6 is a photograph of the in situ tumor and the distal tumor after 12 days of administration, and E in fig. 6 is a photograph of the bilateral tumor after 12 days of administration.

As can be seen from Panel A of FIG. 6, the distal tumor volume and mass changes are consistent with the in situ tumor changes. The growth trend of the far-end tumor of the modeling group is continuous, and the external trametinib microemulsion has a remarkable inhibition trend on the volume of the untreated far-end tumor, which shows that the external trametinib microemulsion can inhibit the growth of the far-end tumor. Also, as can be seen from panel B in fig. 6, the distal tumor mass was significantly reduced compared to the modeled group after 12 days of dosing. As can be seen from the graph C in fig. 6, the distal tumors after 12 days of external trametinib administration were significantly inhibited compared to the manufactured model group, the blank microemulsion group, the trametinib aqueous suspension group, and the oral trametinib suspension group. As can be seen from the D-graph in fig. 6 and the E-graph in fig. 6, both the external trametinib microemulsion and the oral trametinib suspension group showed bilateral tumor growth inhibition effects, wherein the external trametinib microemulsion group showed stronger bilateral tumor inhibition effects. It is demonstrated that the external trametinib microemulsion of this example 4 has significant advantages in inhibiting the growth of distal melanoma.

In conclusion, in the research on in vivo anti-melanoma, the external trametinib microemulsion in the embodiment 4 has obvious advantages for inhibiting bilateral melanoma, and effectively treats melanoma in an external administration mode.

The present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.

Claims

1. A microemulsion comprising the following ingredients: 5.5-16.5% of oil phase, 9-27% of surfactant and 3-9% of cosurfactant.

2. The microemulsion according to claim 1, wherein the oil phase is at least one of caprylic capric glyceride, methyl salicylate, and vitamin E, preferably caprylic capric glyceride, methyl salicylate, and vitamin E.

3. The microemulsion according to claim 2, wherein the ratio of caprylic-capric glyceride, methyl salicylate and vitamin E is 3.5-10.5: 1.5-4.5: 0.5 to 1.5.

4. The microemulsion according to claim 1, wherein the surfactant is at least one of caprylic/capric polyethylene glycol glyceride, polyethylene glycol-15 hydroxystearate, polyoxyethylene castor oil EL, preferably polyoxyethylene castor oil EL.

5. The microemulsion of claim 1 wherein the co-surfactant is diethylene glycol monoethyl ether.

6. The microemulsion according to any one of claims 1 to 5, for use in the preparation of a carrier or a solvent for a poorly soluble drug.

7. The use according to claim 6, wherein the poorly soluble drug is trametinib.

8. A trametinib external preparation comprises the following components: a microemulsion and trametinib according to any one of claims 1-5, wherein the ratio of trametinib is 0.0025-0.0075%.

9. The external preparation according to claim 8 for use in treating melanoma.

10. A preparation method of the external preparation of trametinib comprises the following steps:

s1: mixing the oil phase, surfactant and co-surfactant as described in claim 8 to form solution a;

s2: and adding trametinib into the solution A and uniformly mixing.