KR100338179B1 - Graft copolymer for ophthalmic drug delivery and process for preparing thereof - Google Patents

Abstract

The present invention relates to a graft polymer for delivery of an ophthalmic disease therapeutic drug into the eye, and a method for preparing the graft polymer. At the same time it has the effect of promoting the regeneration of the corneal epithelium and conjunctival tissue of the eye.

Description

Graft polymer for the delivery of drugs for the treatment of eye diseases, and a method for preparing the same

The present invention relates to a novel graft polymer for the delivery of a drug for treating eye diseases into the eye, and a method of preparing the same. More particularly, the drug has a long contact time with the eye due to its excellent mucosal contact. The present invention relates to a novel graft polymer and a method for producing the same.

Since 1970, in the development of the Ophthalmic Drug Delivery System for treating eye diseases such as anti-inflammatory drugs and glaucoma in the eye, research has been focused on increasing drug efficiency and controlling effective drug release.

First, a conventional method for improving drug efficiency includes adding a viscosity enhancer using a cellulose derivative, PVA, carbomer, etc. (VHL, Lee et al., J. Ocul. Pharmarcol. Ther. 2 , 67 (1986) ), But there was a problem of poor drug efficiency in humans. Next, a method of forming an in-situ gel (M. Zignani et al., Adv. Drug. Deliv. Rev. 16, 51 (1995)) has been proposed, which has an unclear vision and an uncomfortable touch. Induced. Next are methods of using corneal penetration enhancers (J. Liaw et al, "in Ophthalmic drug delivery systems" (Mitra, AK, ed.) Pp 369-381, Marcel Dekker, New York, NY (1993)). , It was toxic and irritant. In addition, methods using prodrugs (VHL, Lee et al., J. Ocul. Pharmarcol. Ther. 2 , 67 (1986)), methods using liposomes (K. Singh et al., Int. J) Pharm. 16 , 339 (1983) has been proposed, but prodrugs require extensive pharmacokinetic information, and liposomes have difficulty in sterilization and mass production.

Next, for the control of drug release, ie the sustained release of drug release, a method of inserting a polymer into the eye is usually used, for example using biodegradable polymers (JW Shell, Drug Deliv. Res. 6, 245 (1985). )), A water-soluble drug in a hydrophilic polymer (MF Saettone, Adv. Drug Deliv. Res. 16 , 95 (1995)), or a water-insoluble drug in a hydrophilic polymer (R. Bawa, "in Ophthalic Drug Delivery Systems""(Mitra, AK, ed.), Pp 223-259, Marcel Dekker, New York, NY (1993)), or inserting polymers using an osmotic system (MF Saettone," in BIopharmaceutics of Ocular Drug Delivery "(Edman , P., ed.), Pp 61-79, CRC press, Boca Raton, FC (1993)), or by inserting using polymer membrane diffusion (MF Saettone, Adv. Drug Deliv. Res. 16 , 95 (1995)). And nanoparticles (C. Le Bourlais et al. Prog. Retinal Eye Res., 17 , 33 (1998)), but these polymers are difficult to insert and There is a problem such as rejection of the living body, loss due to carelessness, in particular, nanoparticles were a problem because of the change in particle size and non-biodegradability.

In addition, in order to increase the contact time between the eye cornea and the drug, the drug is supported and used on a highly viscous hydrogel. For example, carboxymethyl cellulose (trade name Lacril) gel may be loaded with timolol. (K. Jarvinen et. Al, STPPharm. Sci., 2 , 105 (1992)), supporting timolol in polyvinyl alcohol (trade name: Liquifiln) gel, or polyacrylic acid (trade name: Lacrigel, Lubrithal, Gel-Larm) Betaxolol was supported on the gel (RN Weinerb et al., J. Parenthreral Sci. Tech., 46 , 51 (1992)), or methyl prednisone on hyaluronic acid (Hy-Drop) gel. ) Was proposed (K. Kyrronen et al., Int. J. Pharm., 80 , 161 (1992)). In addition, it has been proposed to maintain drug release sustained release by using poloxamer, which has a property of sol at room temperature and gel at body temperature (M. Vadnere et al, Int. J. Pharm). ., 22 , 207 (1984)) and also using cellulose acetophthalate, which is a sol at pH 4.4 but a gel at pH 7.4, which sustains sustained release of drug release (R. Gurny et al, The development and use of in situ). formed gels triggered by pH.In: Biopharmaceutics of Ocular Drug Delivery (P. Edman, ed.) pp 81-90.CRC press, Boca Raton, Florida), using a mixture of methylcellulose and carbopol at 25 ° C. and pH 4 To sol, but to gel at 37 ° C and pH 7.4 to control drug release (S. Kumar et al, J. Ocul. Pharmacol. 10 , 47 (1995)), to poloxamers that sol at room temperature and gel at body temperature. Contact time in eyes by introducing polyacrylic acid, a synthetic polymer with mucoadhesiveness It has been proposed to extend (G. Chen et al., Temrperature-induced gelation pluronic-g-poly (acrylic acid) graft copolymers for prolonged drug delivery to the eye, ACS symposium series 680, 441, 1997).

On the other hand, in Korea, more than 90% of the solution is currently in the eye for the treatment of conjunctivitis, glaucoma and uveitis. First, since the drug is in the liquid state, it must be frequently injected at high concentrations. Only penetrates into the cornea or tissue within the eye. Second, since the cornea of the eye is composed of hydrophobic epithelium, hydrophilic endothelial and internal epilepsy, considering the physicochemical properties of the drug, consider the rate of penetration into the cornea or the permeation route. There is a problem that the drug must be selected.

Accordingly, the present inventors have continued to study a novel polymer composition capable of efficiently delivering a drug into the eye due to a long contact time with the eye without giving any irritation to the eye and without disturbing the visual field. The graft polymer was synthesized.

That is, the object of the present invention is to control the release rate of the drug in the eye due to the long contact time with the eye, and has a good drug delivery effect by gelation at sol or body temperature at room temperature, and at the same time with the corneal epithelium of the eye It is to provide a novel graft polymer having an effect of promoting regeneration of conjunctival tissue.

Another object of the present invention is to provide a method for preparing the graft polymer.

1 is an NMR analysis graph of the graft polymer of the present invention.

2 is a graph showing the sol-gel transition temperature of the graft polymer of the present invention.

The present invention relates to a graft polymer having a repeating unit represented by the following Chemical Formula 1 and having a molecular weight of 10,000 to 1,000,000.

Provided that n and m are each an integer of 1 or more.

In addition, the present invention is graft polymerization of hyaluronic acid (HA) including a repeating unit of the formula (2) and ethylenediamine pluronic (ethylenediamine pluronic) containing a repeating unit of the formula (4) using a coupling agent It relates to a method for producing a graft polymer comprising a repeating unit of the formula (1) characterized in that the molecular weight is 10,000 ~ 15,000.

Provided that n, m, x and y are each an integer of 1 or greater.

In the present invention, the ethylenediamine pluronic compound of Formula 4 is preferably prepared from Pluronic F127 comprising a repeating unit of the formula (3).

Provided that x and y are integers of 1 or greater.

The graft polymer of the present invention is activated by introducing an amino group into Pluronic F127 (Poloxamer 407), a synthetic polymer that gels directly at room temperature in a sol or eye at room temperature. It is prepared by graft polymerization with hyaluronic acid, a biopolymer having adhesion to mucous membranes.

The hyaluronic acid used to prepare the graft polymer of the present invention is a linear mucopolysaccharide having a repeating unit represented by the following Chemical Formula 2 composed of N-acetyl-D-glucosamine and D-glucuronic acid. This hyaluronic acid is widely distributed in animal tissues and is present in high concentrations in the synovial fluid of the joints, the vitreous of the eyes, and the connective tissue of the cock crest.

Provided that n is an integer of 1 or more.

Pluronic F127 is a triblock copolymer composed of polyethylene oxide (PEO) -polypropylene oxide (PPO) -polyethylene oxide (PEO) of Formula 3, currently sold under the trade name Poloxamer 407. This has a property of gelling at sol state at room temperature but at body temperature.

Provided that x and y are integers of 1 or greater.

Hereinafter, a method for preparing the graft polymer of the present invention will be described in detail.

1. Synthesis of Ethylenediamine Pluronic (4)

The reaction of introducing and activating an amino group into the pluronic acid is shown in Scheme 1 below.

As shown in Scheme 1 above, Pluronic F127 is first dissolved in a suitable solvent (eg methylene chloride) and then 4-nitrophenyl chloroformate is added thereto in the presence of a neutralizing agent (eg triethylamine). React. At this time, the molar ratio of Pluronic F127: 4-nitrophenyl chloroformate: Triethylamine is 1: 1: 1 to 3: 4: 4, preferably 4: to attach the amino group to only one end of Pluronic F127. The ratio is 5: 5. The reaction is carried out at room temperature, and the reaction time is preferably 3 to 5 hours.

Subsequently, the reaction product is reacted with ethylenediamine to prepare a pluronic substituted with an amino group. In this case, the molar ratio between the reactants is 1: 2 to 1: 4, preferably 1: 3, and reacted at room temperature for 12 to 15 hours.

2. Synthesis of Graft Polymer (1) of the Present Invention by Graft Polymerization of Ethylenediamine Pluronic (4) and Hyaluronic Acid (2)

As shown in Scheme 2, the graft polymer of the present invention is prepared by reacting hyaluronic acid with EDC and then reacting it with pluronic substituted with an amino group as a dry product of Scheme 1. At this time, the pH is 4.5 to 4.9, preferably about 4.7, and the reaction time is about 2 to 4 days, preferably about 3 days.

Hereinafter, the present invention will be described by specific examples, but the present invention is not limited by the following examples.

<Example 1>

Synthesis of Ethylenediamine Pluronic (4)

3 g (about 2.381 x 10 ^-4 mol) of Pluronic F127 (poloxamer 407, X = 100, Y = 65, molecular weight about 12,600) was dissolved in 30 ml of methylene chloride as a solvent. And 42 μl (about 2.965 × 10 ⁻⁴ mol) of triethylamine as a neutralizer was added thereto. Finally, 0.06 g (about 2.9761x10 ^-4 mol) of 4-nitrophenyl chloromate was added. After reacting at room temperature for 4 hours, the mixture was precipitated in a poor solvent petroleum ether, filtered, and dried in a vacuum oven.

2.9 g (about 2.272 × 10 ⁻⁴ mol) of the dried product was dissolved in ²⁹ ml of methylene chloride, and 46 μl of ethylenediamine (about 6.816 × 10 ⁻⁴ mol) was added thereto to adjust the molar ratio of 1: 3. After reacting for about 12 hours at room temperature, precipitation, filtration, and drying were performed. Dialysis was performed for 3 days using a dialysis membrane with a cut-off of about 3,500 to remove the aromatic ring of salt and 4-nitrophenyl chloropromate. After dialysis, lyophilization yielded 1.753 g of pluronic amino acid substituted (yield 60%).

<Example 2>

Synthesis of Graft Polymer (1) of the Present Invention

First, 5.5 mg of hyaluronic acid was added to 5 ml of a pH 4.7 buffer solution (TEMED 10 mM, HCl 1M). Next, after 15 minutes of 5.3 mg of EDC (Mw; 191.7), 173.8 mg of the product of Example 1 was added thereto, and reacted at room temperature with pH 4.7 for 3 days. That is, the molar ratio of pluronic: hyaluronic acid: EDC was about 1: 1: 2.

After the reaction, the cut-off was dialyzed for 3 days using a dialysis membrane between 12,000 and 15,000 and lyophilized to obtain 122.7 mg of product (yield 68.4%). The NMR analysis of the product is shown in FIG.

Referring to Figure 1, the peak coming out of about 1.2 ppm is the proton peak of CH ₃ of the pluronic, the peak coming out of about 2.2 ppm can be seen as the proton peak of the N-acetylate of hyaluronic acid. The remaining 3.5-4 ppm peaks are indistinguishable from overlapping sugar peaks of hyaluronic acid and CH ₂ peaks of pluronics.

As a result of confirming the weight content ratio using the integral of the two peaks, about 6.42% is hyaluronic acid, and the molar ratio of pluronic to hyaluronic acid is 31.35%, which is 31.35% of the repeating units of hyaluronic acid. It can be seen that Pluronic grafts were made. The molecular weight of the polymer shows a wide distribution in hyaluronic acid at 50,000 or more, and also shows various distributions at 50,000 or more.

<Test Example 1>

Gelation Temperature of Graft Polymers of the Invention

Next, the gelation temperatures of the graft polymers of the present invention were measured at 18.0, 19.0 and 20.0 wt%, respectively, using the vertical method. The gelation temperature of the Pluronic F127 was measured in the same manner, and the results are shown in FIG. 2. As shown in FIG. 2, the gelation temperature of the graft polymer of the present invention was about 1 ° C compared to the Pluronic F127 alone. It can be seen that is raised. This is likely due to the influence of hydrophilic hyaluronic acid.

As described above, when the drug for treating eye diseases is injected into the graft polymer of the present invention and introduced into the eye, since the graft polymer of the present invention has a mucosal adhesion, the drug stays in the eye for a long time to control the drug release rate. It is possible to control the release of the drug because the gelation is made at the body temperature, and because the extracellular matrix is combined has the effect of promoting the regeneration of the corneal epithelium and conjunctival tissue of the eye.

Claims (3)

Graft polymer comprising a repeating unit of the formula (1) and a molecular weight of 10,000 ~ 1,000,000. Provided that n and m are each an integer of 1 or more. Including a repeating unit of the formula (1) characterized in that the graft polymerization of the polymer compound comprising a repeating unit of the formula (2) and the repeating unit of the formula (4) using a coupling agent and a molecular weight of 10,000 ~ 1,000,000 A method of making an in graft polymer. Provided that n, m, x and y are each an integer of 1 or greater. The method of claim 2, wherein the high molecular compound comprising a repeating unit of Formula 4 is prepared from a high molecular compound comprising a repeating unit of the following Formula 3. Provided that x and y are integers of 1 or greater.