CN101732345A - Cisplatin spinal tumor slow-release implant and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of pharmacy, and relates to controlled and sustained-release pharmaceutical preparations, in particular to a cisplatin sustained-release implant for treating spinal tumors, which uses polylactic acid-glycolic acid copolymer (PLGA) as a carrier and cisplatin as the main agent, and its Preparation. The weight ratio of cisplatin and PLGA is 1:99˜40:60. The cisplatin slow-release microspheres were prepared by the double emulsification-solvent evaporation method, and the microspheres were pressed into tablets to make cisplatin slow-release implants for interstitial chemotherapy after spinal tumors and other solid tumor operations. Tests have proved that the cumulative drug release rate of cisplatin sustained-release implants can reach 84% in vitro for 38 days, and the sustained-release time in vivo can be as long as 36 days, with high local drug concentration and remarkable tumor-inhibiting effect.

Description

Cisplatin spinal tumor slow-release implant and preparation method thereof

technical field

The invention belongs to the field of pharmacy, and relates to controlled and sustained-release pharmaceutical preparations, in particular to a cisplatin sustained-release implant for treating spinal tumors with polylactic acid-glycolic acid copolymer (PLGA) as a carrier and cisplatin as the main agent. Preparation.

Background technique

Spinal tumor is a relatively special disease among various tumors. With the development and progress of social economy, the incidence and diagnosis rate of spinal tumors are increasing year by year. However, due to the particularity of the anatomical structure of the spine, the complexity of adjacent structures, and the local invasion of spinal tumors, it is extremely difficult to completely and fully remove the tumor tissue, and recurrence or metastasis often occurs after surgery. Therefore, how to prolong the postoperative survival period and improve the quality of life of patients with spinal tumors is still a arduous task before us.

At present, the more active treatment plan for spinal tumors is a comprehensive treatment plan, that is, surgery + intravenous chemotherapy + radiotherapy + supportive therapy. Surgery supplemented by radiotherapy and intravenous chemotherapy can effectively improve the survival rate of patients with spinal tumors. Chemotherapy plays an increasingly important role in the comprehensive treatment of spinal tumors. Recent studies have proved that about 5% of malignant tumors can be completely cured by chemotherapy alone, and another 55% of tumor patients survived through chemotherapy in various ways. The period can be extended from 6 to 36 months.

Cisplatin (DDP) is a heavy metal complex that combines divalent platinum with 2 chlorine atoms and 2 ammonia molecules. It can not only inhibit protein synthesis, but also cross-link with DNA and damage DNA chains. It is a non-specific cell cycle Chemotherapy drugs. Although there are nearly 30 chemotherapeutic drugs currently in clinical use, cisplatin has become the drug of choice for single or combined chemotherapy for most tumors due to its broad-spectrum anti-tumor effect, no cross-drug resistance, and mild myelosuppression.

The curative effect of traditional systemic intravenous chemotherapy is often unsatisfactory: the inability of the drug to concentrate locally in the tumor, the short duration of action on the tumor, the large systemic side effects, the toxicity to normal tissue cells, and the instability of the drug in the body are all reasons for the reduced curative effect. The most ideal chemotherapeutic drug preparation should be targeted and long-acting. In order to improve the above problems, new drug release systems have become an important development direction in the field of pharmacy. In recent years, the study of polymer drug sustained release system has opened up a new way of tumor chemotherapy. Polyester polymers are the most widely studied and applied biodegradable polymers so far because of their good biocompatibility and tissue compatibility, and the diversification of their copolymer ratio and relative molecular weight is suitable for the adjustment of release rate. . Among them, polylactic acid-glycolic acid copolymer (PLGA), a copolymer made of glycolic acid and lactic acid, has become the material of choice for carriers such as microspheres, and has been approved by the FDA for use in pharmaceutical production. PLGA and drugs are made into microspheres, small pills, and tablets and implanted into the tumor cavity after surgery to exert a long-term local curative effect, making mesenchymal chemotherapy of spinal tumors possible.

Postoperative local slow-release drug interstitial chemotherapy for spinal tumors solves the shortcomings of traditional systemic intravenous chemotherapy drugs for spinal tumors, such as low concentration, short action time, and large side effects in the tumor area. Time, reduce systemic side effects.

Contents of the invention

The present invention is to provide a cisplatin sustained-release implant for treating spinal tumors, which uses polylactic acid-glycolic acid copolymer (PLGA) as a carrier, cisplatin as the main drug, and is implanted into the tumor cavity after spinal tumor resection. Play the role of long-term and efficient interstitial chemotherapy.

Another object of the present invention is to provide a preparation method of the spinal tumor cisplatin slow-release implant.

For realizing the above object, technical method of the present invention is as follows:

A cisplatin sustained-release implant for spinal tumors is composed of cisplatin and polylactic-co-glycolic acid (PLGA) in a weight ratio of 1:99-40:60. The cisplatin slow-release microspheres are prepared by double emulsification-solvent evaporation method, and the microspheres are pressed into tablets (shape is not limited) to make cisplatin slow-release implants, which are used in the interstitium of spinal tumors and other solid tumors after surgery chemotherapy.

The cisplatin slow-release implant was prepared by the double emulsification-solvent evaporation method: a certain amount of cisplatin was accurately weighed and dissolved in water as the inner water phase; a certain amount of PLGA was accurately weighed and dissolved in dichloromethane as the oil phase; Disperse the inner water phase into the oil phase under the conditions of dark, ice-water bath ultrasonic, ultrasonic emulsification to obtain W/O colostrum; quickly add this colostrum to the emulsifier; ultrasonic treatment until the formation of double emulsion (W/O/ W); then the gained double emulsion is added to the low-concentration emulsifier; dichloromethane is volatilized; the microspheres are collected by centrifugation and washed with distilled water to remove free drug; Making cisplatin slow-release microspheres; pressing the microspheres into tablets and sterilizing to make cisplatin slow-release implants.

The emulsifier described in the present invention is one of polyvinyl alcohol, methylcellulose and sodium cholate.

The in vitro release test shows that the cumulative drug release rate of the cisplatin sustained-release implant of the present invention after 38 days in vitro release can reach more than 84%. Animal experiments have shown that cisplatin slow-release implants can concentrate locally in the spine, which can significantly prolong the survival time of tumor-bearing rats.

The use method of the present invention: implant the cisplatin slow-release implant into the tumor cavity after spinal tumor resection of the patient at the later stage of spinal tumor operation, so as to exert a long-acting, local high-concentration tumor-inhibiting effect.

Description of drawings

Figure 1. In vitro release profile of cisplatin sustained-release implants

Figure 2. Drug release curve in rabbits

Figure 3. Tumor growth curve of tumor-bearing rats

Detailed ways

1. Preparation of cisplatin sustained-release implants

The preparation of the spinal tumor cisplatin slow-release implant of the present invention will be described in detail below in conjunction with the examples. It should be understood that the embodiments of the present invention are used to illustrate the present invention rather than limit the present invention.

Example 1

prescription:

Cisplatin: PLGA 30:70 (weight ratio)

The concentration of PLGA is 40% (50:50)

Oil phase solvent Dichloromethane

Emulsifier Polyvinyl Alcohol

Accurately weigh 300 mg of cisplatin, dissolve it in an appropriate amount of double-distilled water, and use it as the inner water phase. Accurately weigh 700 mg of PLGA, dissolve in an appropriate amount of dichloromethane, and use it as the oil phase. The oil phase is added to the inner water phase under the condition of avoiding light and ultrasonication in an ice-water bath to obtain colostrum. Quickly add this colostrum into the polyvinyl alcohol solution; ultrasonically treat until the double emulsion is formed; then add the resulting double milk into the low-concentration polyvinyl alcohol solution. Remove dichloromethane by volatilization; collect the microspheres by centrifugation, wash with distilled water 3 times; add double distilled water to make a suspension, and freeze-dry to obtain cisplatin slow-release microspheres; compress the microspheres and sterilize to make cisplatin Slow-release implants.

Example 2

prescription:

Cisplatin: PLGA 25:75 (weight ratio)

PLGA concentration is 15% (75:25)

Oil phase solvent Dichloromethane

Emulsifier Methylcellulose

Accurately weigh 250 mg of cisplatin, dissolve it in an appropriate amount of double-distilled water, and use it as the inner water phase. Accurately weigh 750 mg of PLGA, dissolve in an appropriate amount of dichloromethane, and use it as the oil phase. The oil phase is added to the inner water phase under the condition of avoiding light and ultrasonication in an ice-water bath to obtain colostrum. This colostrum is quickly added to the methylcellulose solution; sonicated until the double emulsion is formed; then the resulting double emulsion is added to the low-concentration methylcellulose. The subsequent preparation process was the same as in Example 1 to prepare a cisplatin sustained-release implant.

Example 3

prescription:

Cisplatin: PLGA 20:80 (weight ratio)

The concentration of PLGA is 30% (50:50)

Oil phase solvent Dichloromethane

Emulsifier Polyvinyl Alcohol

Accurately weigh 200 mg of cisplatin, dissolve it in an appropriate amount of double-distilled water, and use it as the inner water phase. Accurately weigh 800 mg of PLGA, dissolve in an appropriate amount of dichloromethane, and use it as the oil phase. The oil phase is added to the inner water phase under the condition of avoiding light and ultrasonication in an ice-water bath to obtain colostrum. The colostrum is quickly added to the polyvinyl alcohol solution; sonicated until the double emulsion is formed; then the resulting double emulsion is added to the low-concentration polyvinyl alcohol. The subsequent preparation process was the same as in Example 1 to prepare a cisplatin sustained-release implant.

Example 4

prescription:

Cisplatin: PLGA 10:90 (weight ratio)

PLGA concentration is 45% (25:75)

Oil phase solvent Dichloromethane

Emulsifier Methylcellulose

Accurately weigh 100 mg of cisplatin, dissolve it in an appropriate amount of double-distilled water, and use it as the inner water phase. Accurately weigh 900 mg of PLGA, dissolve it in an appropriate amount of dichloromethane, and use it as the oil phase. The oil phase is added to the inner water phase under the condition of avoiding light and ultrasonication in an ice-water bath to obtain colostrum. This colostrum is quickly added to the methylcellulose solution; sonicated until the double emulsion is formed; then the resulting double emulsion is added to the low concentration methylcellulose solution. The subsequent preparation process was the same as in Example 1 to prepare a cisplatin sustained-release implant.

Example 5

prescription:

Cisplatin: PLGA 15:85 (weight ratio)

PLGA concentration is 50% (75:25)

Oil phase solvent Dichloromethane

Emulsifier Polyvinyl Alcohol

Accurately weigh 150 mg of cisplatin, dissolve it in an appropriate amount of double-distilled water, and use it as the inner water phase. Accurately weigh 850 mg of PLGA, dissolve in an appropriate amount of dichloromethane, and use it as the oil phase. The oil phase is added to the inner water phase under the condition of avoiding light and ultrasonication in an ice-water bath to obtain colostrum. Quickly add this colostrum into the polyvinyl alcohol solution; ultrasonically treat until the double emulsion is formed; then add the resulting double milk into the low-concentration polyvinyl alcohol solution. The subsequent preparation process was the same as in Example 1 to prepare a cisplatin sustained-release implant.

Example 6

prescription:

Cisplatin: PLGA 30:70 (weight ratio)

PLGA concentration is 60% (50:50)

Oil phase solvent Dichloromethane

Emulsifier Sodium cholate

Accurately weigh 300 mg of cisplatin, dissolve it in an appropriate amount of double-distilled water, and use it as the inner water phase. Accurately weigh 700 mg of PLGA, dissolve in an appropriate amount of dichloromethane, and use it as the oil phase. The oil phase is added to the inner water phase under the condition of avoiding light and ultrasonication in an ice-water bath to obtain colostrum. Quickly add the colostrum into the sodium cholate solution; ultrasonically treat until the double emulsion is formed; then add the resulting double milk into the low-concentration sodium cholate solution. The subsequent preparation process was the same as in Example 1 to prepare a cisplatin sustained-release implant.

2. In vitro release of cisplatin sustained-release implants

To measure the drug-loading capacity of the cisplatin microspheres, a certain amount of cisplatin microspheres was accurately weighed, and pressed into tablets so that the drug content was 10 mg/tablet. Take 1 piece of cisplatin slow-release implant, place it in 5 mL of phosphate buffer (pH 7.4, 37° C.), and shake it on a constant temperature shaker at 100 rpm. Samples were taken at 6 hours, 1, 4, 7, 10, 15, 20, 26, 32, and 38 days to measure the drug concentration and calculate the cumulative release percentage of microspheres (n=6).

The results are shown in Fig. 1, the cumulative drug release rate of the cisplatin sustained-release implant of the present invention released in vitro for 38 days can reach more than 84%.

3. Drug release in animals

Experimental animals: 28 New Zealand rabbits, half male and half male, weighing 4-5 kg.

Experimental method: 28 New Zealand rabbits were randomly divided into 7 groups, 4 rabbits in each group. After anesthesia, the patient was fixed in the prone position, and the vertebral segment corresponding to the middle and lower border of the scapula (thoracic 8) was used as the surgical site. The back skin was incised longitudinally to expose about three spinal segments, part of the vertebral body was excised within the range that did not affect the stability of the spine, and 5 cisplatin sustained-release implants (with a drug content of 10 mg/tablet) were implanted into the vertebral column. The body and its nearby soft tissues are sutured. Animals were sacrificed at 7 time points of 1, 6, 12, 18, 24, 30, and 36 days after operation, and the operation site, its upper and lower spinal segments and surrounding soft tissues were taken to make a homogenate, and the content of cisplatin in it was determined. Calculate the cumulative release rate of the implant.

The results are shown in Figure 2, which shows that the cisplatin sustained-release implant of the present invention has obvious slow-release effect, can significantly increase the drug concentration of cisplatin in the spine and its nearby soft tissues, and the in vivo action time can reach 36 days.

4. Tumor growth experiment in tumor-bearing rats

Experimental animals: 80 Wistar rats, male or female, aged 4 weeks.

Model establishment and selection: Lewis lung cancer cells were cultured and passaged in the culture medium, and the culture medium was removed after the cells reached confluence, and diluted with buffer solution. An appropriate amount of the above solution was inoculated subcutaneously in the armpits of the forelimbs of 80 Wistar rats. One week later, tumors appeared under the armpits of the forelimbs of the rats. The tumor volume was measured, and 60 rats with the closest tumor volume were selected for the next experiment.

Experimental method: 6 rats were randomly selected from the above 60 rats and sacrificed, and the tumor tissues were dissected and weighed, and the average tumor weight was calculated. The remaining 54 rats were randomly divided into groups A, B and C, with 18 rats in each group. Group A: intravenous administration group; Group B: cisplatin sustained-release implant implantation group; Group C: blank group. The specific method is as follows:

Group A: The tumors under the armpits of the rats' forelimbs were surgically exposed, and then the incision was sutured, and 10 ml of cisplatin solution (containing 20 mg of cisplatin) was immediately injected through the tail vein. Three rats were randomly sacrificed on the 6th, 12th, 18th, 24th, 30th, and 36th day after operation, and the tumor tissues were dissected out and weighed.

Group B: The tumors under the axilla of the forelimbs of the rats were exposed by surgery, cisplatin slow-release implants (20 mg) were implanted into the tissues near the tumors, and the incisions were sutured. Three rats were randomly sacrificed on the 6th, 12th, 18th, 24th, 30th, and 36th day after operation, and the tumor tissues were dissected out and weighed.

Group C: Surgical exposure of tumors in the armpits of rat forelimbs, followed by suturing of the incisions. Three rats were randomly sacrificed on the 6th, 12th, 18th, 24th, 30th, and 36th day after operation, and the tumor tissues were dissected out and weighed.

The results are shown in Figure 3, which shows that the tumor-inhibiting effect of the cisplatin sustained-release implant is significantly better than that of the intravenous injection group and the blank group.

It has been proved by experiments that the present invention uses the biodegradable material polylactic acid-glycolic acid copolymer (PLGA) as the carrier, and the broad-spectrum chemotherapeutic drug cisplatin as the main drug, and the prepared cisplatin slow-release implant can be used in a relatively small dose. A high local therapeutic concentration is achieved with a long duration of drug release. It not only overcomes the disadvantages of large side effects of systemic intravenous chemotherapy, but also overcomes the short duration of local administration in the past, and is very suitable for local interstitial chemotherapy after spinal tumor surgery and other solid tumor surgery.

Claims (5)

1. cisplatin spinal tumor slow-release implant, it is characterized in that polylactic acid-glycolic guanidine-acetic acid copolymer (PLGA) is a carrier material, cisplatin is a principal agent, the weight ratio of cisplatin and polylactic acid-glycolic guanidine-acetic acid copolymer (PLGA) is 1: 99～40: 60, adopt emulsionization-solvent evaporation method to make the cisplatin sustained-release micro-spheres, with the microsphere tablet forming, make the cisplatin sustained-release implant, be used for tumor of spine and the postoperative chemotherapy of mesenchyma stroma of other entity tumors.

2. the optimum weight ratio according to cisplatin in the described cisplatin spinal tumor slow-release implant of claim 1 and polylactic acid-glycolic guanidine-acetic acid copolymer (PLGA) is 10: 90～30: 70.

3. the molecular proportion according to lactic acid in the described cisplatin spinal tumor slow-release implant carrier material of the claim 1 polylactic acid-glycolic guanidine-acetic acid copolymer (PLGA) and hydroxyacetic acid is 20: 80～80: 20.

4. preparing the employed emulsifying agent of cisplatin sustained-release micro-spheres according to the described employing of claim 1 emulsionization-solvent evaporation method can be a kind of in polyvinyl alcohol, methylcellulose, the sodium cholate.

5. do not limit according to the profile of the described cisplatin spinal tumor slow-release implant of claim 1, can be pressed into circle, rhombus, irregular shape etc.

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