Biodegradable polymer microparticle containing steroid drug and preparation method therefor

Abstract

Biodegradable polymer microparticles bearing a steroid drug and a preparation method therefor. In the method, a steroid drug and a biodegradable polyester-based polymer are dissolved in an organic solvent and sprayed into a low-temperature hydrocarbon solution to form frozen microparticles that are then immersed in a low-temperature, aqueous salt solution to deprive the microparticles of the organic solvent, thereby preparing biodegradable polymer microparticles bearing a steroid drug. The steroid drug or steroid sex hormone drug-bearing biodegradable polymer microparticles were found to have excellent biocompatibility, biodegradability, porosity, and mechanical strength and to release the steroid drug or steroid sex hormone drug for a long period of time.

Claims

1. A method for preparing biodegradable polymeric microparticles bearing a steroid drug, the method comprising the steps of: (a) dissolving a mixture of a steroid drug and a biodegradable polyester-based polymer in dimethylsulfoxide (DMSO) to prepare a solution containing the steroid drug and the biodegradable polyester-based polymer; (b) spraying the solution containing the steroid drug and the biodegradable polyester-based polymer into a C5-10 hydrocarbon solution maintained at a temperature of −10 to −5° C. to form microparticles; (c) adding the microparticles to an aqueous salt solution to dissolve and eliminate the DMSO; and (d) desalting the DMSO eliminated microparticles, wherein the mixture of the steroid drug and the biodegradable polyester-based polymer in step (a) comprises the steroid drug and the biodegradable polyester-based polymer at a weight ratio of 1:99 to 3:7 and is dissolved in an amount of 1-25% (w/v) in DMSO, based on the total volume of the solution, wherein the C5-10 hydrocarbon solution in step (b) is at least one selected from the group consisting of pentane, hexane, heptane, octane, nonane, decane, and petroleum ether, wherein the aqueous salt solution in step (c) is a 5-30% (w/v) solution of NaCl or CaCl.sub.2) in water, wherein the biodegradable polyester-based polymer is poly(D,L-lactic-co-glycolic acid)(PLGA), and wherein the biodegradable polymeric microparticles bearing a steroid drug are spherical porous microparticles having a diameter of 10-100 μm, and steadily release the steroid drug over at least one month.

2. The method of claim 1, wherein the biodegradable polyester-based polymer has a weight average molecular weight of 10,000 to 250,000.

3. The method of claim 1, wherein the steroid drug is at least one selected from the group consisting of deflazacort, desonide, desoximetasone, dexamethasone, diflorasone, diflucortolone, difluprednate, loteprednol etabonate, rimexolone, mazipredone, medrysone, methylprednisolone, meprednisone, mometasone furoate, beclomethasone, betamethasone, budesonide, algestone, alclometasone, amcinonide, enoxolone, corticosterone, cortisone, cortivazol, chloroprednisone, clobetasol, clobetasone, clocortolone, cloprednol, tixocortol, triamcinolone, triamcinolone acetonide, triamcinolone benetonide, triamcinolone hexacetonide, paramethasone, pregnenolone acetate, prednicarbate, prednisolone, prednisolone 25-diethylaminoacetate, prednisolone sodium phosphate, prednisone, prednival, prednylidene, fluazacort, flucloronide, flumethasone, flunisolide, fluocinolone acetonide, fluocinonide, fluocortin butyl, fluocortolone, fluorometholone, fluperolone acetate, fluprednidene acetate, fluprednisolone, flurandrenolide, fluticasone propionate, formocortal, halcinonide, halobetasol propionate, halometasone, halopredone acetate, hydrocortamate, hydrocortisone, and a sex hormone.

4. The method of claim 3, wherein the sex hormone is at least one selected from the group consisting of progesterone, testosterone, estrogen, androgen, estradiol, levonorgestrel, gestodene, desogestrel, dienogest, cyproterone acetate, and ethynyl estradiol.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows sizes of the steroid drug-bearing biodegradable polymer microparticles prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×200; polymer solution 4.2% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(2) FIG. 2 shows appearances of the steroid drug-bearing biodegradable polymer microparticles prepared according to the preparation method of the present disclosure, as observed by electron microscopy (×5,000; polymer solution 4.2% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(3) FIG. 3 shows the surface of the steroid drug-bearing biodegradable polymer microparticles prepared according to the preparation method of the present disclosure, as observed by electron microscopy (×10,000; polymer solution 4.2% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(4) FIG. 4 shows the inner structure of the steroid drug-bearing biodegradable polymer microparticles prepared according to the preparation method of the present disclosure, as observed by electron microscopy (×500; polymer solution 4.2% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(5) FIG. 5 shows sizes of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×1,000; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5 l/min).

(6) FIG. 6 shows appearances of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×3,000; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(7) FIG. 7 shows the surface of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×8,000; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(8) FIG. 8 shows the inner structure of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×300; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(9) FIG. 9 shows sizes of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×1,000; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(10) FIG. 10 shows appearances of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×2,000; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(11) FIG. 11 shows the surface of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×3,000; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(12) FIG. 12 shows the inner structure of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PLGA 50:50) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×1,500; polymer solution 12.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(13) FIG. 13 shows sizes of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×1,000; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(14) FIG. 14 shows appearances of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×2,500; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(15) FIG. 15 shows the surface of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×5,000; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(16) FIG. 16 shows the inner structure of the sex hormone drug-bearing biodegradable polymer microparticles (progesterone, testosterone, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×2,500; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(17) FIG. 17 shows sizes of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×1,000; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(18) FIG. 18 shows appearances of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×3,000; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(19) FIG. 19 shows the surface of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×4,000; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(20) FIG. 20 shows the inner structure of the sex hormone drug-bearing biodegradable polymer microparticles (ethynyl estradiol, PDLLA) prepared according to the preparation method of the present disclosure, as measured by electron microscopy (×700; polymer solution 9.0% (w/v); polymer solution spray rate: 1.0 g/min; air spray rate: 5l/min).

(21) FIG. 21 shows HPLC chromatograms indicating whether the sex hormone drug-bearing biodegradable polymer microparticles prepared in Example 4 (ethynyl estradiol, PLGA 50:50) release the same as the pure drug (ethynyl estradiol).

(22) FIG. 22 show the drug release behavior of the sex hormone drug-bearing biodegradable polymer microparticles prepared in Example 4 (ethynyl estradiol, PLGA 50:50) over time, as monitored by HPLC.

MODE FOR CARRYING OUT THE INVENTION

(23) Hereinafter, the present invention will be described in detail with reference to examples. These examples are only for illustrating the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

Example 1: Preparation of Steroid Drug-Bearing Biodegradable Polymer Microparticles

(24) Use was made of the anti-inflammatory drug triamcinolone as a steroid drug, poly(lactic-co-glycolic acid) (PLGA) as a biodegradable polyester-based polymer, and DMSO (dimethyl sulfoxide) as an organic solvent.

(25) In 500 ml of DMSO, 1 g of triamcinolone and 20 g of PLGA having a weight average molecular weight of 110,000 and a ratio of 75:25 of lactic acid:glycolic acid were dissolved to give a 4.2% (w/v) solution of the drug/biodegradable polymer mixture. The drug/biodegradable polymer mixture solution was sprayed at a rate of 1.0 g/min, together with air at a rate of 5.0 l/min, into n-hexane chilled to −5° C. The sprayed drug/biodegradable polymer mixture solution was frozen into spheres in the chilled n-hexane to form microparticles.

(26) The frozen microparticles thus obtained were left for 72 hours in 1,000 ml of a 25% (w/v) aqueous NaCl solution chilled to −20° C. to remove the DMSO, followed by filtration to obtain DMSO-free microparticles having the drug and the biodegradable polymer mixed therein.

(27) The microparticles were washed with 5,000 ml of distilled water and filtered to remove residual DMSO and NaCl, followed by lyophilization to prepare biodegradable polymer microparticles bearing a steroid drug.

Example 2: Physical Characterization of Steroid Drug-Bearing Biodegradable Polymer Microparticles

(28) For physical characterization, the steroid drug-bearing biodegradable polymer microparticles prepared in Example 1 were examined for size, morphology, surface, and inner states by electron microscopy, and the results are given in FIG. 1.

(29) In addition, the production yield of the steroid drug-bearing biodegradable polymer microparticles was calculating by measuring the amount of finally obtained microparticles relative to that of the polymer fed, and the results are given in Table 1, below.

(30) TABLE-US-00001 TABLE 1 Spraying Condition Drug-mixed Spray Spray Micro- polymer solution solution air particle size Yield (%, w/v) (g/min) (g/min) (μm) (%) 4.2 1.0 5 ≤100 62

(31) As can be seen in FIG. 1 and Table 1, the steroid drug-bearing biodegradable polymer microparticles prepared in Example 1 were measured to have a size of 100 μm or less.

(32) In addition, FIG. 2 shows appearances of the steroid drug-bearing biodegradable polymer microparticles prepared in Example 1. As can be seen in FIG. 2, the microparticles were spherical. The electron microscopic image of the surface in FIG. 3 indicates that the prepared microparticles are porous. Furthermore, the microparticles were observed to be hollow as seen in the microparticle inside image of FIG. 4.

(33) The data thus obtained demonstrate that the steroid drug-bearing biodegradable polymer microparticles prepared using the preparation method of the present disclosure have sizes suitable to be administered through a syringe into the body and are economically beneficial in terms of yield.

Examples 3-6: Preparation of Sex Hormone Drug-Bearing Biodegradable Polymer Microparticles

(34) In the case where the steroid drug is a sex hormone, biodegradable polymer microparticles bearing sex hormones were prepared by using progesterone (Tokyo Chemical industry, CAS. NO. 57-83-0/C.sub.21H.sub.30O.sub.2), testosterone (Tokyo Chemical industry, CAS. NO. 57-85-2/C.sub.22H.sub.32O.sub.3), and ethynyl estradiol (Tokyo Chemical industry, CAS. NO. 57-63-6/C.sub.20H.sub.24O.sub.2) as sex hormones and poly(D,L-lactic-co-glycolic acid) (PLGA) and poly-D,L-lactide (PDLLA) as biodegradable polymers.

(35) The sex hormone drugs and biodegradable polymers listed in Table 2, below, were mixed with DMSO (dimethyl sulfoxide) to give drug/biodegradable polymer mixture solutions. Each of the drug/biodegradable polymer mixture solutions was sprayed at a rate of 1.0 g/min, together with air at a spray rate of 5.0l/min, into n-hexane chilled to −5° C. The drug/biodegradable polymer mixture solutions were frozen into spheres in the chilled n-hexane to form frozen microparticles.

(36) After being harvested, the frozen microparticles were left for 72 hours in 1,000 ml of a 25% (w/v) aqueous NaCl solution chilled to −20° C. to deprive the microparticles of the DMSO ingredient, followed by filtration to obtain DMSO-removed microparticles in which the drugs and the biodegradable polymer were mixed. The microparticles were washed with 5,000 ml of distilled water and filtered to remove residual DMSO and NaCl. Thereafter, lyophilization afforded biodegradable polymer microparticles bearing sex hormone drugs according to the present disclosure.

(37) TABLE-US-00002 TABLE 2 Sex Hormone Drug Biodegradable Polymer Exam- Content Content DMSO ple # Kind (g) Kind (g) (ml) 3 Progesterone 1.4 PLGA with weight 20 183 Testosterone 0.6 average molecular weight of 72,000 4 Ethynyl 0.6 PLGA with weight 21.4 183 estradiol average molecular weight of 33,000 5 Progesterone 1.4 PDLLA with weight 20 244 Testosterone 0.6 average molecular weight of 103,000 6 Ethynyl 0.6 PDLLA with weight 21.4 244 estradiol average molecular weight of 103,000

Experimental Example 1: Physical Characterization of Sex Hormone Drug-Bearing Biodegradable Polymer Microparticles

(38) For physical characterization, the sex hormone drug-bearing biodegradable polymer microparticles prepared in Examples 3-6 were examined for size, morphology, surface, and inner states by electron microscopy, and the results are given in FIGS. 5-20.

(39) In addition, production yields of the sex hormone drug-bearing biodegradable polymer microparticles were calculating by measuring the amounts of finally obtained microparticles relative to those of the polymers fed. Before the calculation, the finally obtained microparticles were filtered via a sieve (CISA, 100 μm sieve). The results are given in Table 3, below.

(40) TABLE-US-00003 TABLE 3 Spraying Condition Drug-mixed polymer Spray Spray Micro- solution solution air particle size Yield Example # (%, w/v) (g/min) (l/min) (μm) (%) 3 12.0 1.0 5.0 ≤100 64.3 4 12.0 1.0 5.0 ≤100 64.7 5 9.0 1.0 5.0 ≤100 63.4 6 9.0 1.0 5.0 ≤100 63.1

(41) As can be seen in FIGS. 5, 9, 13, and 17 and Table 3, the sex hormone drug-bearing biodegradable polymer microparticles prepared in Examples 3-6 were measured to have a size of 100 μm or less.

(42) In addition, FIGS. 6, 10, 14, and 18 show appearances of the sex hormone drug-bearing biodegradable polymer microparticles prepared in Examples 3-6. As can be seen in the figures, the microparticles were spherical. The electron microscopic images of the surfaces in FIGS. 7, 11, 15, and 19 indicate that the prepared microparticles are porous. Furthermore, the microparticles were observed to be hollow as seen in the microparticle inside image of FIGS. 8, 12, 16, and 20.

(43) The data thus obtained demonstrate that the sex hormone drug-bearing biodegradable polymer microparticles prepared using the preparation method of the present disclosure have sizes suitable to be administered through a syringe into the body and are economically beneficial in terms of yield.

Experimental Example 2: Identification of Sex Hormone Drug Borne by in Biodegradable Polymer Microparticles and Drug Release from Microparticles

(44) Of the sex hormone drug-bearing biodegradable polymer microparticles prepared in Examples 3-6, the microparticles of Example 4 (ethynyl estradiol and PLGA 50:50) were examined to see whether the drug (ethynyl estradiol) borne by the microparticles was the same as the pure drug (ethynyl estradiol).

(45) In 10 ml of physiological saline, 0.1 g of the pure drug (ethynyl estradiol) or 0.1 g of the PLGA microparticles prepared in Example 4 was dissolved. The solutions were shaken for 10 min on a shaker roller and incubated for 12 hours in a 37° C. incubator, followed by characterization of the drug through HPLC (HP 1260, liquid chromatography/ACN 80:Water 20/1.0 ml (min)/20 μl/25° C./275 nm). The results are depicted in FIG. 21. As seen in FIG. 21, the drug (ethynyl estradiol) was identified to be the same as the drug (ethynyl estradiol) bore in the PLGA microparticles of Example 4.

(46) The sex hormone drug-bearing polymer microparticles prepared in Example 4 (ethynyl estradiol and PLGA 50:50) were measured for drug release behavior over time. In this regard, a solution of 1 g of the PLGA microparticles in 10 ml of physiological saline was placed on a shaker roller and agitated at a speed of 50 rpm to extract the drug at a rate of 1 ml per hour. The entire solvent was exchanged with a fresh one every hour for accurate drug release. Temporal drug release behavior was monitored using HPLC (HP 1260, liquid chromatography/ACN 80:Water 20/1.0 ml (min)/20 μl/25° C./275 nm)). The results are depicted in FIG. 22. As seen in FIG. 22, the microparticles were found to release the drug at constant rates, without a burst of release at the initial stage.

(47) As described hitherto, the microparticles are prepared from a solution of a polymer and a drug in DMSO during which the polymer and the drug are bound to each other, whereby the drug can be released at constant rates depending on the content of the drug and the degradation rate of the polymer. Compared to conventional approaches in which polymeric particles are mixed with a drug, together with an adhesive, to adsorb the drug onto the surface of the particles or polymeric particles are immersed in a drug solution to allow the drug to permeate into the particles, the present disclosure can steadily release the drug depending on polymer degradation speed and drug content.