Levonorgestrel subcutaneous implant for treating adenomyosis

Abstract

The invention relates to the technical field of drug delivery, in particular to a levonorgestrel subcutaneous implant for treating adenomyosis. The levonorgestrel subcutaneous implant for treating adenomyosis comprises levonorgestrel and a carrier with effective therapeutic dose, and does not contain estrogen; a base material of the carrier is a pharmaceutically acceptable polymeric material, and systematic levonorgestrel exposure achieved after the carrier is released from a subcutaneous implant is equivalent to levonorgestrel exposure achieved after oral administration with the dosage of 150-200 micrograms per day. The levonorgestrel subcutaneous implant provided by the invention has a remarkable beneficial effect in the aspect of treating adenomyosis, is relatively low in adverse reaction rate and has a long-term stable curative effect, and compared with an oral administration mode, the subcutaneous implant reduces the frequency and inconvenience of taking medicine and improves the treatment compliance of a patient; in addition, the long-term release period and the stable drug release rate ensure the consistency and predictability of treatment, and are helpful to control the illness state and reduce the risk of illness state relapse.

Description

Technical Field

[0001] The present application relates to the technical field of drug delivery, and in particular to a levonorgestrel subcutaneous implant for treating adenomyosis. Background Art

[0002] Adenomyosis is a chronic disease that has long plagued many patients, characterized by abnormal invasion of the glands and stroma of the endometrium into the myometrium. The main clinical manifestations of this disease include abnormally heavy menstrual flow, prolonged menstrual period, and gradually worsening dysmenorrhea symptoms, which usually begin a week before the menstrual period and last until the end of the menstrual period.

[0003] During gynecological examinations, it can be found that the patient's uterus is uniformly enlarged or partially bulged, with a hard texture and tenderness. This change in the uterus may make it difficult for the patient to conceive, and even if she does become pregnant, she may easily miscarry. Currently, the general treatment for adenomyosis is mainly long-term drug therapy. For patients who do not have fertility needs, a total hysterectomy may be considered.

[0004] According to statistics, about 15% of women of childbearing age will suffer from adenomyosis. Clinically, the levonorgestrel-releasing intrauterine system is widely used as a conservative treatment with good results. However, for patients with adenomyosis with a large uterine cavity, the use of this system has the problem of a high rate of ring removal. On the other hand, the treatment method of oral progestin faces challenges such as a high recurrence rate. Therefore, there is currently no ideal treatment method that can completely solve the problem of adenomyosis. Summary of the invention

[0005] In order to solve the above problems, the present application provides a levonorgestrel subcutaneous implant for treating adenomyosis.

[0006] The present application provides a levonorgestrel subcutaneous implant for treating adenomyosis, which adopts the following technical scheme: a levonorgestrel subcutaneous implant for treating adenomyosis, which comprises an effective therapeutic amount of levonorgestrel and a carrier, and does not contain estrogen; the substrate of the carrier is a pharmaceutically acceptable polymer material, and the systemic levonorgestrel exposure achieved after release from the subcutaneous implant is equivalent to the levonorgestrel exposure after oral administration at a dose of 150-200 μg per day.

[0007] Furthermore, the levonorgestrel subcutaneous implant needs to be implanted within one week before the onset of menstruation when in use.

[0008] Furthermore, the levonorgestrel subcutaneous implant has a long-term release period lasting 45-48 weeks.

[0009] Furthermore, the drug release rate of the levonorgestrel subcutaneous implant can remain stable 12-36 hours after implantation.

[0010] In summary, this application has the following beneficial effects: 1. The levonorgestrel subcutaneous implant in the present application has a long-term and stable therapeutic effect. Compared with oral administration, the subcutaneous implant reduces the frequency and inconvenience of taking medicine and improves the patient's treatment compliance; in addition, the long-term release period and stable drug release rate ensure the consistency and predictability of treatment, which helps to control the disease and reduce the risk of recurrence.

[0011] 2. The levonorgestrel subcutaneous implant in the present application has significant beneficial effects in the treatment of adenomyosis and has a low adverse reaction rate. DETAILED DESCRIPTION

[0012] In order to explain the present application in more detail, the specific implementation methods of the present application will be given below in conjunction with the examples, which are only for the purpose of explanation and description and should not be construed as limiting the scope of the present application. When describing these specific implementation methods, no detailed description of known experimental methods, instruments, reagents and materials is provided to reduce unnecessary content in the present application.

[0013] The levonorgestrel used in the present invention can be obtained through commercial channels or synthesized by chemical methods known in the art.

[0014] The polymer material suitable for the carrier used for the subcutaneous implant in the present application can be any material suitable for subcutaneous implants that can be used in the current pharmaceutical preparation industry, has good biocompatibility and is harmless to body tissues. In the present application, it is methyl vinyl silicone rubber. The size and shape of the tube sleeve made of the polymer material can be changed according to specific application requirements. Example

[0015] (I) Preparation of levonorgestrel subcutaneous implant: Levonorgestrel was purchased from Wuhan Zenuo Biopharmaceutical Technology Co., Ltd. The carrier was a silicone tube rod. The preparation method thereof was referred to the preparation method of levonorgestrel subcutaneous implant in the existing public literature, which will not be repeated here. The silicone tube rod was 30 mm in length, 1.44 mm in outer diameter, and 0.52 mm in inner diameter. There were two in total, each containing 75±0.5 mg of levonorgestrel.

[0016] (II) In vitro drug release test of levonorgestrel subcutaneous implant 1. Drug release: Weigh 50 ml of distilled water in a 250 ml wide-mouth bottle, place two implants in a constant temperature water bath at 37°C, suspend and completely immerse them in distilled water, and oscillate back and forth at 90 rpm in a constant temperature shaker at 37±1°C. Change the distilled water every 24 hours. 2. Quantitative standard curve: Using 1:750 alkyldimethylbenzylamine chloride aqueous solution as solvent, prepare methylnorhenothrone standard solutions with concentrations of 0.5, 1.0, 2.0, 3.0, and 4.0 μg / ml, respectively, and test the extinction value A at a wavelength of 240 nm. The extinction value A and the concentration C (μg / ml) show a good linear relationship. The regression equation of the standard curve is: A=0.04794C-0.001217, and the correlation coefficient is 0.9999; 3. Quantitative analysis of drug components in distilled water The content of norethisterone was measured at 240 nm using an ultraviolet spectrophotometer. The daily release amount was calculated using a 1:750 alkyldimethylbenzylamine chloride aqueous solution as a reference solution according to the regression equation: Release amount = C × 50 (μg) Table 1: In vitro release rate of levonorgestrel subcutaneous implant As can be seen from the above table, the in vitro release rate of the levonorgestrel subcutaneous implant fluctuates, and has different performances in different release stages. The drug release rate is relatively large on the first day, and then the drug release amount remains stable on the 2nd and 3rd days, and increases slowly, and reaches the maximum value on the 14th day. Thereafter, in the period of about 15-43 days, the drug release amount decreases slightly, but maintains release at a stable release rate. In the period of about 44-60 days, the drug release amount slowly decreases and is basically in a stable release state.

[0017] (III) Blood concentration test of levonorgestrel subcutaneous implant in rats A total of 20 normal female Wister rats weighing 180-210g were prepared and randomly divided into a blank group and an experimental group. The experimental group was divided into group I and group II, with 7 rats in each group. One 30mm implant was subcutaneously implanted on one side of the dorsal spine of the rats in group I and two 30mm implants were subcutaneously implanted on one side of the dorsal spine of the rats in group II. One day after implantation and on days 3, 5, 7, 10, 12, 15, 30, 45, 60, 100, 120, 150 and 180, 2.5ml of blood was collected from the rat eye sockets, and the serum was separated after centrifugation. The concentration of levonorgestrel in plasma was determined by LC-MS-MS. The control group consisted of 6 rats, each of which was implanted with 2 30mm implants without the original drug in sequence. The testing method was the same as that of the experimental group.

[0018] Table 2: Mean blood drug concentration and time control in group II Time (day) Concentration (μg / ml) Time (day) Concentration (μg / ml) 1 0.56 30 1.30 3 0.69 45 1.25 5 1.54 60 1.21 7 1.31 100 1.23 10 1.24 120 1.27 12 1.26 150 1.20 15 1.23 180 1.22 Table 3: Mean blood drug concentration and time control in Group I As can be seen from the above table, the blood concentration of levonorgestrel subcutaneous implant reaches its peak 3 days after implantation in the body, and the time of peak blood concentration is the same for different dosages, and as the dosage increases, the blood peak also increases, but after 3 days the blood concentration gradually decreases and tends to be stable, with no significant difference.

[0019] (IV) Therapeutic effect of levonorgestrel subcutaneous implant on adenomyosis in mice SNH mice weighing 20-40 g were prepared, and an animal model of adenomyosis was established by surgical method. The size of the uterus was measured. The volume of the uterus was calculated as the volume of the ellipsoid, that is, V = Π (width / 2) × (depth / 2) × height. After calculating its volume (V1), the mice were divided into experimental and control groups, with 20 mice in each group. The experimental groups included group I and group II. For the mice in experimental groups I and II, For mice, one or two 30 mm long levonorgestrel subcutaneous implants were implanted under their skin, respectively. For mice in the control group, two 30 mm long subcutaneous implants without raw materials were implanted under their skin. After 3-4 months of implantation, 3-4 mice were randomly selected from each group and killed by breaking the neck every 30 days. The uterine volume (V2) was measured, and the inhibitory effect of the levonorgestrel subcutaneous implant on adenomyosis was calculated based on the change in uterine volume before and after administration. The inhibitory effect calculation formula is: [(1-V2 / V1)×100%].

[0020] Table 4: The therapeutic effect of levonorgestrel subcutaneous implant on adenomyosis in mice According to the experimental data in the above table, we can observe that in the adenomyosis mouse model, when one or more levonorgestrel subcutaneous implants are implanted subcutaneously, the uterine volume is significantly reduced. This effect is attributed to the fact that levonorgestrel can directly act on the endometrium and exert its effect in the uterine cavity, reducing the estrogen level in the uterine cavity through the direct and indirect effects of progesterone. This process causes the ectopic lesions to atrophy and degenerate, and the hypertrophic smooth muscle fibers to atrophy, ultimately reducing the volume of the uterus.

[0021] (V) The therapeutic effect of levonorgestrel subcutaneous implant on adenomyosis in patients 1. Treatment target Seventeen patients with adenomyosis who visited the Department of Obstetrics and Gynecology of Chongming Hospital Affiliated to Shanghai Health Medical College from October 2023 to July 2024 were selected. Based on preoperative examination, uterine enlargement (exceeding the size of 9 weeks of pregnancy); combined uterine fibroids; pelvic endometriomas; suspected endometrial lesions; contraindications to the use of progesterone; and 5 patients with a history of other treatment within 3 months were excluded. The age range of the treated patients was 30-45 years old, and dysmenorrhea often lasted for 4-10 years.

[0022] 2. Treatment Methods 2.1 Preoperative examination The patient needs to empty her bladder and undergo vaginal color Doppler ultrasound examination within the first week of menstruation and on the fourth day after the menstruation stops flowing to measure the position and size of the uterus; peripheral venous blood is drawn to test blood CA125 levels.

[0023] 2.2 Subcutaneous implantation Local anesthesia was administered on the inner side of the patient's upper arm, and a 2 mm surgical incision was made at the anesthesia site. Two implants with an effective drug load of 75 mg and a length of 30 mm were pushed subcutaneously through the small incision. A Band-Aid was applied externally and the procedure was completed after gauze bandage.

[0024] 2.3 Follow-up observation Patients were followed up at 3, 6, 9, and 12 months after implantation of the levonorgestrel subdermal implant. The follow-up included: 1) Menstrual pattern: Evaluate according to the table below.

[0025] Table 5: Definition of menstrual pattern Bleeding Mode Bleeding Bleeding Vaginal discharge contains blood and requires at least 1 sanitary napkin or tampon per day Spotting Vaginal discharge contains blood and requires no more than 1 sanitary napkin or tampon per day No bleeding Neither bleeding nor spotting was reported Bleeding and spotting episodes Bleeding or spotting is recorded for 1 day or for several consecutive days, with no bleeding for several days in between amenorrhea No bleeding or spotting within the 90-day reference period Occasional bleeding Excluding amenorrhea, bleeding within the 90-day reference period, spotting less than 3 times Normal frequency Within the 90-day reference period, 3-5 bleeding episodes and spotting occur Frequent bleeding Bleeding or spotting more than 5 times within the 90-day reference period Prolonged bleeding Continuous bleeding for more than 14 days within the 90-day reference period, spotting (continuous) Table 6: Changes in menstrual patterns before and after levonorgestrel implantation (n=12) Time Node amenorrhea Occasional bleeding Normal frequency Frequent bleeding Prolonged bleeding Before skin burial 2 cases 1 case 4 cases 3 cases 2 cases 3 months after skin implantation 2 cases 2 cases 4 cases 3 cases 1 case 6 months after skin implantation 3 cases 2 cases 4 cases 2 cases 1 case 9 months after skin implantation 3 cases 2 cases 5 cases 2 cases 0 cases 12 months after implantation 2 cases 2 cases 6 cases 1 case 1 case 2) Changes in uterine volume Table 7: Uterine size before and after levonorgestrel implantation (n=12) Time Node <![CDATA[Uterine volume (cm 3 )]]> Before skin burial 204.45±43.16 3 months after skin implantation 142.97±30.41 6 months after skin implantation 128.74±12.13 9 months after skin implantation 115.61±10.79 12 months after implantation 112.82±11.40 3) Serum CA125 level Table 8: Serum CA125 levels before and after levonorgestrel implantation (n=12) Time Node Serum CA125 (KU / L) Before skin burial 147.28±71.04 3 months after skin implantation 78.55±30.31 6 months after skin implantation 33.67±12.18 9 months after skin implantation 28.91±9.28 12 months after implantation 25.73±10.04 4) Dysmenorrhea severity: scored according to the visual analogue scale (VAS).

[0026] Table 9: VAS score table before and after levonorgestrel implantation (n=12) Time Node Dysmenorrhea VAS score (points) Before skin burial 8.12±1.59 3 months after skin implantation 1.66±0.74 6 months after skin implantation 1.52±0.76 9 months after skin implantation 1.51±0.62 12 months after implantation 1.49±0.51 The P values ​​of all the above data were less than 0.05, indicating that the differences were statistically significant compared with the data before implantation.

[0027] 5) Adverse reactions Among the 12 patients mentioned above, 2 patients showed weight gain; 1 patient showed acne; 2 patients showed breast pain; and no redness or swelling at the implant site or numbness in the upper arm occurred.

[0028] Comparative Example The difference between the comparative example and the embodiment of the present application is that the LNG-IUS implantation method is adopted, and the LNG-IUS comes from MIRENA.

[0029] Six eligible subjects were selected. The patients were required to empty their bladders, undergo vaginal color Doppler ultrasound examinations within the first week of menstruation and on the fourth day after menstruation to measure the position and size of the uterus; draw peripheral venous blood to test blood CA125 levels; perform bimanual examination to determine the size and position of the uterus; place the uterus according to the operating instructions after routine disinfection; and cut the tail thread 1.5 cm away from the cervical opening.

[0030] Patients were followed up at 3, 6, 9, and 12 months after LNG-IUS implantation. The follow-up included: 1) Menstrual pattern; 2) Changes in uterine volume; 3) serum CA125 level; 4) Dysmenorrhea severity: scored according to the visual analogue scale (VAS); Table 10: Changes in menstrual patterns before and after levonorgestrel implantation (n=6) Time Node amenorrhea Occasional bleeding Normal frequency Frequent bleeding Prolonged bleeding Before implantation 2 cases 0 cases 1 case 3 cases 0 cases 3 months after implantation 1 case 1 case 2 cases 2 cases 0 cases 6 months after implantation 1 case 1 case 1 case 2 cases 1 case 9 months after implantation 1 case 2 cases 1 case 2 cases 0 cases 12 months after implantation 2 cases 3 cases 0 cases 1 case 0 cases Table 11: Uterine volume, serum CA125 level, and dysmenorrhea VAS score before and after LNG-IUS implantation (n=6) Time Node <![CDATA[Uterine volume (cm 3 )]]> Serum CA125 (KU / L) Dysmenorrhea VAS score (points) Before implantation 203.19±40.37 139.20±64.26 8.09±1.47 3 months after implantation 190.62±38.94 121.96±45.84 2.45±0.83 6 months after implantation 179.57±35.38 70.19±30.21 1.37±0.79 9 months after implantation 172.24±36.12 49.47±20.06 1.28±0.71 12 months after implantation 160.23±33.18 31.65±12.34 1.33±1.02 5) Adverse reactions Among the 6 patients mentioned above, 3 patients showed weight gain; 2 patients showed acne; 3 patients showed breast pain; and no implant shedding occurred after implantation.

[0031] In summary, the levonorgestrel subcutaneous implant and LNG-IUS are both progestin drugs. Judging from the test results, the therapeutic effect of the levonorgestrel subcutaneous implant is more stable than that of the LNG-IUS, the incidence of adverse reactions is also lower, and the onset of action is faster. The levonorgestrel subcutaneous implant of the present application has excellent effects as a long-acting preparation for the treatment of adenomyosis.

[0032] The above are all modifications without creative contribution or solutions that obviously constitute technical inspiration that can be made to the present embodiment as needed by technical personnel in this field after reading this specification, but they should be protected by patent law as long as they are within the scope of the claims of this application.

Claims

1. A levonorgestrel subcutaneous implant for treating adenomyosis, comprising an effective therapeutic amount of levonorgestrel and a carrier, and does not contain estrogen; the substrate of the carrier is a pharmaceutically acceptable polymer material, and the systemic levonorgestrel exposure achieved after release from the subcutaneous implant is equivalent to the levonorgestrel exposure after oral administration at a dose of 150-200 μg per day.

2. The levonorgestrel subcutaneous implant for treating adenomyosis according to claim 1, characterized in that: When used, it must be implanted within one week before menstruation.

3. The levonorgestrel subcutaneous implant for treating adenomyosis according to claim 1, characterized in that: The implant has a long-term release period lasting 45-48 weeks.

4. The levonorgestrel subcutaneous implant for treating adenomyosis according to claim 1, characterized in that: The drug release rate can remain stable 12-36 hours after implantation.

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