KR20140038158A - Method for preparing plga with lactide and glycolide, and plga prepared therefrom - Google Patents

Abstract

The present invention relates to a production method of PLGA using lactide and glycolide, and PLGA produced by the method. According to the production method of the present invention, the PLGA of which weight-average molecular weight is 8,000-15,000 and the molecular weight distribution is 1.50-2.40 which is narrow is capable of being produced. The PLGA produced by the method remarkably reduces the deviation of the controlled release of drugs, and is capable of uniformly controlling the release of the drug when the PLGA is used in a drug delivery system. [Reference numerals] (AA) Coat a thermosetting resin on an LPM impregnated print sheet; (BB) Coat a UV-curable adhesive on one side of transparent PET film; (CC) Attach a thermosetting resin-coated side and a UV curable adhesive-coated side; (DD) Step of filtering a solution, in which the synthesized PLGA dissolves in methylene chloride by pressure reduction; (EE) Pass a heating apparatus and cure thermosetting resin; (FF) Step of filtering the deposit, obtaining the PLGA, and drying the same

Description

METHOD FOR PREPARING PLGA WITH LACTIDE AND GLYCOLIDE, AND PLGA PREPARED THEREFROM}

The present invention relates to a method for producing PLGA using lactide and glycolide, that is, a polylactide glycolide copolymer (poly (D, L-lactide-co-glycolide)), and a PLGA prepared by the method. . Specifically, it relates to a method for producing PLGA having a specific average molecular weight and molecular weight distribution (polydispersity), which can reduce the drug release control deviation in the drug delivery system.

In order to reduce the side effects of drugs and maximize the efficacy and effects, many researches have been conducted on the polymeric drug delivery system, which uses particles prepared with particles of nano and micro units by precipitating drugs together with polymers. It is becoming.

The drug delivery system is a technique for controlling the release rate of a drug by enclosing a drug such as a peptide into a hydrophobic polymer as a sustained release agent of the drug, and a polymer having biocompatibility and biodegradability is mainly used. In addition, as such a polymer, PLGA has a stable biocompatibility and biodegradation in the human body and is widely used. Examples thereof include a technique for sustained release and biodegradable nanoparticles using the polylactide glycolide copolymer disclosed in Korean Patent No. 10-0853309 and a method for producing the same.

PLGA is known to have a characteristic that determines the rate of degradation in the body depending on the ratio of the components of poly (lactic acid) (PLA) and poly (glycolic acid) (PGA), so that the drug is released as these carriers break down. The speed is adjustable.

Therefore, using these biocompatible and biodegradable polymers as a matrix for controlling drug release, drug release rates reduce dependence on the nature of the drug itself, and can be used for any program over days to months with a single dose or injection. Can have a controlled drug release behavior.

PLGA, which is currently commercialized as a support and drug delivery material for various injections, has a high production cost and a variation in the release control of the product due to its wide molecular weight distribution (polydispersity). Therefore, in order to reduce production costs and produce high quality drugs, research and development on a method for synthesizing and purifying high purity PLGA polymer is required.

Accordingly, the present inventors have completed the present invention as a result of intensively studying a method for producing PLGA having an average molecular weight and a molecular weight distribution (polydispersity) optimized for drug delivery systems in the formulation process field.

Korean Patent No. 10-0853309 (2008. 8. 20. Announcement, Sustained-Release and Biodegradable Nanoparticles of Polylactide Glycolide Copolymer Supported with Ciprofloxacin and Manufacturing Method Thereof)

An object of the present invention is to provide a method for producing PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.40.

It is still another object of the present invention to provide a PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.40, which is useful for controlling drug release in a drug delivery system.

In order to achieve this object, the present invention is a method for producing a PLGA having a weight average molecular weight of 8,000 ~ 15,000, molecular weight distribution of 1.50 ~ 2.40,

Stirring dissolving D, L-lactide and glycolide;

After the stirring dissolution, adding D, L-lactic acid as an initiator, and then adding and stirring a catalyst;

Standing after the stirring to obtain a synthesized PLGA;

Filtering the solution of the synthesized PLGA in methylene chloride under reduced pressure;

Injecting the filtrate obtained by the vacuum under reduced pressure to obtain a precipitate using a homogenizer; And

It comprises; filtering the precipitate to obtain a PLGA and dried.

In the method for preparing the PLGA, the step of stirring and dissolving the D, L- lactide and glycolide is carried out at a temperature of 110 ~ 150 ℃ in a vessel substituted with nitrogen.

In the method for producing the PLGA, the catalyst is preferably tin (II) 2 -ethylhexanoate.

According to still another aspect of the present invention, in the method for producing the PLGA, the D, L-lactide, glycolide, and D, L-lactic acid are each in a molar ratio of 1: 0.8 to 1.2: 0.01 to 0.06. It is preferable to be used

In the method for producing the PLGA, the D, L-lactic acid is preferably at least 90% purity.

According to another embodiment of the present invention, the amount of methylene chloride and methanol used is preferably methylene chloride: methanol 1: 1 to 25 by volume.

According to another aspect of the present invention, by the method for producing the PLGA, a PLGA having a weight average molecular weight of 8,000 to 15,000, a molecular weight distribution of 1.50 to 2.40, more preferably a weight average molecular weight of 8,000 to 15,000 And PLGA having a molecular weight distribution of 1.50 to 2.00.

Hereinafter, the present invention will be described in more detail.

In the present invention, as shown in the following [Scheme I], the monomers D, L- lactide and glycolide are each ring-opened when it reaches the melting point, in the presence of a catalyst, D, L- lactic acid in the presence of a catalyst The polymerization is initiated to synthesize a polylactide glycolide copolymer (poly (D, L-lactide-co-glycolide); PLGA).

[Reaction Scheme I]

According to the preparation method of the present invention, first, D, L-lactide and glycolide are stirred to dissolve. At this time, the container containing D, L-lactide and glycolide is filled with nitrogen gas and then sealed. Then, after adjusting the temperature to 110-150 ° C, more preferably 135-145 ° C, D, L-lactide and glycolide are dissolved while stirring. Here, the temperature control is preferably a method of controlling the temperature by putting a container in a heating mantle, or an oil bath.

Thereafter, D, L-lactic acid, which is an initiator, is reacted with the catalyst in the above vessel while being stirred, and then allowed to stand for 1 to 3 days from the time when the stirring stops due to the viscosity.

In the present invention, by using D, L-lactic acid as an initiator in the synthesis of PLGA, PLGA is controlled by controlling the weight average molecular weight of the synthesized PLGA to 8,000 to 15,000 and narrowly controlling the molecular weight distribution (polydispersity). When used in a delivery system, there is an effect that the rate of release of the drug can be constantly controlled.

D, L-lactic acid as the initiator has a specific ratio when compared to D, L-lactide and glycolide, that is, D, L-lactide: glycolide: D, L-lactic acid is 1: 0.8-1.2 It is preferable to use in a molar ratio of 0.01 to 0.06, and when the initiator is used in such a ratio, PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.40 can be obtained.

In the present invention, D, L-lactic acid as an initiator is preferably one having a purity of 90% or more, more preferably 95% or more.

As the catalyst, tin (II) 2 -ethylhexanoate is used. When injecting tin (II) 2 -ethylhexanoate into the container, the charged nitrogen does not leak and is slowly taken care not to touch the base wall. Drop it.

After stirring, the mixture is allowed to stand to obtain a synthesized PLGA, followed by purification and powdering of the PLGA.

Purifying and powdering PLGA, the step of filtering the solution of the synthesized PLGA in methylene chloride under reduced pressure; Injecting the resulting filtrate into methanol to obtain a precipitate using a homogenizer; And filtering these precipitates to obtain PLGA and then drying.

In the present invention, by using methylene chloride and methanol as cosolvents as a solvent for purifying the synthesized PLGA, PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.40 can be obtained.

In particular, it is preferable to use methylene colloid and methanol by volume ratio of 1: 1-25. If the amount of methanol is more than 25 times in volume ratio based on methylene chloride, there is a problem that the final product is obtained in the form of agglomerate rather than the powder form of PLGA.

In addition, more preferably, by using a volume ratio of 1:10 to 20, it is possible to obtain a high purity PLGA, when used in the drug delivery system, it has the effect of controlling the release rate of the drug constantly have.

When dissolving the synthesized PLGA in methylene chloride, it is preferable to completely dissolve the PLGA using ultrasonic waves. The solution thus obtained is filtered under reduced pressure using a membrane filter and a vacuum pump.

Then, when injecting the filtrate produced by vacuum filtration into methanol, it is preferable to inject slowly using a syringe while homogenizing using a homogenizer.

The precipitates are filtered through a filter and then dry-dried PLGA, the products remaining in the filter, at 30-60 ° C. for at least 12 hours to obtain PLGA in the form of a white powder.

According to the present invention, it is possible to provide a method for producing PLGA having a weight average molecular weight of 8,000 to 15,000 and a narrow molecular weight distribution of 1.50 to 2.40.

PLGA produced by the production method of the present invention has a weight average molecular weight of 8,000 ~ 15,000, the molecular weight distribution is narrow to 1.50 ~ 2.40, when used in the drug delivery system, significantly reduces the deviation in the controlled release of drugs, drug release There is a constant adjustable effect.

In addition, according to the manufacturing method of the present invention, it is possible to obtain a high purity and high yield PLGA, it is possible to produce at a low cost, there is an effect that can reduce the manufacturing cost of the drug.

1 is a flow chart showing a method for producing a PLGA of the present invention.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

1. Preparation of PLGA in accordance with the present invention

1-1. Synthesis of PLGA

≪ Example 1 >

3.1 g of D, L-lactide (manufactured by Daiwa Kasei) and 2.0 g of glycolide (manufactured by Daiwa Kasei) are placed in a glass container, replaced with nitrogen, and placed in an oil bath to dissolve at 130 ° C. Next, 36ul of D, L-lactic acid (purity: 95%, manufactured by Sigma Aldrich) and 5ul of tin (II) 2-ethylhexanoate (Tin (II) 2-ehtylhexanoate, manufactured by Sigma Aldrich) as an initiator were injected. Stirred to react. The mixture is allowed to stand for 2 days from the point when stirring stops.

<Example 2>

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Next, 18ul of D, L-lactic acid (purity 95%) as an initiator and 5ul of tin (II) 2-ethylhexanoate as a catalyst are injected and stirred. The mixture is allowed to stand for 2 days from the point when stirring stops.

&Lt; Example 3 >

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Next, 72ul of D, L-lactic acid (purity 95%) as an initiator and 5ul of tin (II) 2-ethylhexanoate as a catalyst are added and stirred to react. The mixture is allowed to stand for 2 days from the point when stirring stops.

<Example 4>

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Then, 36ul of D, L-lactic acid (purity: 90%, Fluka) as an initiator and 5ul of tin (II) 2-ethylhexanoate as a catalyst are injected and reacted with stirring. The mixture is allowed to stand for 2 days from the point when stirring stops.

&Lt; Example 5 >

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Then, 36ul of D, L-lactic acid (purity: 99%, manufactured by Sigma Aldrich) as an initiator, and 5ul of tin (II) 2-ethylhexanoate as a catalyst are reacted by stirring. The mixture is allowed to stand for 2 days from the point when stirring stops.

&Lt; Comparative Example 1 &

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Next, 5ul of tin (II) 2-ethylhexanoate is injected as a catalyst, followed by stirring. If the stirring stops due to the viscosity, it is allowed to stand for two days from the time when the stirring stops.

&Lt; Comparative Example 2 &

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Next, 50ul of tin (II) 2-ethylhexanoate is injected as a catalyst, followed by stirring. If the stirring stops due to the viscosity, it is allowed to stand for two days from the time when the stirring stops.

&Lt; Comparative Example 3 &

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Next, 36ul of glycolic acid (purity: 99%, manufactured by Sigma Aldrich) as an initiator, and 5ul of tin (II) 2-ethylhexanoate (manufactured by Sigma Aldrich) as a catalyst are added and stirred to react. The mixture is allowed to stand for 2 days from the point when stirring stops.

&Lt; Comparative Example 4 &

3.1 g of D, L-lactide and 2.0 g of glycolide are placed in a glass container, replaced with nitrogen, and placed in an oil bath to be stirred and dissolved at 130 ° C. Then, 36ul of benzyl alcohol (purity 99.8%, manufactured by Sigma Aldrich) as an initiator and 5ul of tin (II) 2-ethylhexanoate (manufactured by Sigma Aldrich) as a catalyst were added and stirred to react. The mixture is allowed to stand for 2 days from the point when stirring stops.

1-2. Synthesized PLGA Tablets and Powdered

12.4 g of D, L-lactide and 8.0 g of glycolide are placed in a glass container, replaced with nitrogen, and dissolved in an oil bath at 130 ° C. Then, 144ul of D, L-lactic acid (purity: 99%, manufactured by Sigma Aldrich) as an initiator, and 20ul of tin (II) 2-ethylhexanoate as a catalyst are reacted by stirring. Due to the viscosity, the mixture was allowed to stand for 2 days from the time when the stirring was stopped and allowed to react. This reaction product is then used for the purification and powdering process according to the examples below.

&Lt; Example 6 >

100 ml (Merck) of methylene chloride was added to the reaction product and completely dissolved by using a sonicator. Then, the membrane was filtered under reduced pressure using a membrane filter (5 μm), and the precipitate was slowly injected at 8000 rpm using a homomixer in methanol (100 ml) and filtered through a 20 μm filter. The filtered products are dry heat dried at 40 ° C. for at least 12 hours.

&Lt; Example 7 >

100 ml of methylene chloride is added to the reaction product and completely dissolved by using a sonicator. Then, the membrane was filtered under reduced pressure using a membrane filter (5 um), and the precipitate was slowly injected at 8000 rpm using a homomixer in methanol (200 ml) and filtered through a 20 um filter. The filtered products are dry heat dried at 40 ° C. for at least 12 hours.

&Lt; Example 8 >

100 ml of methylene chloride is added to the reaction product and completely dissolved by using a sonicator. Then, the membrane was filtered under reduced pressure using a membrane filter (5 μm), and the precipitate was slowly injected at 8000 rpm using a homomixer in methanol (1000 ml) and filtered through a 20 μm filter. The filtered products are dry heat dried at 40 ° C. for at least 12 hours.

&Lt; Example 9 >

100 ml of methylene chloride is added to the reaction product and completely dissolved by using a sonicator. Then, the membrane was filtered under reduced pressure using a membrane filter (5 μm), and the precipitate was slowly injected at 8000 rpm using a homomixer in methanol (2000 ml) and filtered through a 20 μm filter. The filtered products are dry heat dried at 40 ° C. for at least 12 hours.

&Lt; Comparative Example 5 &

At the end of the reaction, 100 ml of acetone (Duksan) was added and dissolved completely using a sonicator. Then, the membrane was filtered under reduced pressure using a membrane filter (5 μm), and the precipitate was slowly injected at 8000 rpm using a homomixer in an aqueous solution (1000 ml) and precipitated and filtered through a 20 μm filter. The filtered products were dried over 12 hours at 40 ℃

Joe.

&Lt; Comparative Example 6 >

At the end of the reaction, 100 ml of acetone is added and completely dissolved using a sonicator. Then, the membrane was filtered under reduced pressure using a membrane filter (5 μm), and the precipitate was slowly injected at 8000 rpm using a homomixer in an aqueous solution (2000 ml) and filtered through a 20 μm filter. The filtered products are dry heat dried at 40 ° C. for at least 12 hours.

2. Formulation Evaluation Test Method

2-1. Polymer composition check

To confirm the polymer composition synthesized above, about 3 mg of each compound was dissolved in 0.5 ml of chloroform (CDCl3) manufactured by Sigma Aldrich, and the mixing time was 0.1 seconds using NMR (nuclear magnetic resonance) (Noesy1D). The relaxation delay was repeated at 2.0 ° C. for 2.0 seconds, and the molar ratio was calculated by the following Equation 1.

[Equation 1]

Lactide molar ratio (%) = (2 X L) / (2 X L + G) X 100

Glycolide molar ratio (%) = G / (2 X L + G) X 100

(Multi-line signal strength near L = 5.2 ppm, G = 4.8 ppm multi-line signal strength)

As a result of the polymer composition analysis, PLGA synthesized in Examples 1 to 9 and Comparative Examples 1 to 6 was found that the composition ratio of lactide and glycolide is 50:50.

2-2. Extreme viscosity measurement

0.25 g of each compound is precisely weighed and dissolved in chloroform (Merck) to make exactly 25 ml. The sample solution is used as a test solution. The viscosity is measured using a capillary viscometer (CT-72, Dongjin) at 25 ° C. In addition, the intrinsic viscosity was calculated by the following formula.

[Equation 2]

Intrinsic Viscosity = (In (Viscosity Measurement of Test Solution / Viscosity Measurement of Public Test Solution) / Concentration of Sample (g / 100ml))

As a result of determining the intrinsic viscosity using the viscosity measurement value measured by the above evaluation method, the intrinsic viscosity of PLGA prepared in Examples 1 to 9 and Comparative Examples 1 to 6 was as follows.

division    Intrinsic viscosity (dl / g)        division  Intrinsic viscosity (dl / g) Example 1 0.21    Example 9 0.19 Example 2 0.17    Comparative Example 1 0.42 Example 3 0.16    Comparative Example 2 0.40 Example 4 0.21    Comparative Example 3 0.21 Example 5 0.20    Comparative Example 4 0.19 Example 6 0.20    Comparative Example 5 0.17 Example 7 0.21    Comparative Example 6  0.17 Example 8 0.20

2-3. Molecular weight measurement

In order to determine the average molecular weight and molecular weight distribution of each compound, 10 mg each was precisely weighed and placed in a 100 ml volumetric flask. It was then analyzed by RI detector at 100ul volume at 25 ° C using Gel Permeation Chromatography (GPC) (Agilent Technologies 1200 series).

PLGA synthesized according to the steps of Examples 1 to 6 and Comparative Examples 1 to 5 showed a weight average molecular weight and a molecular weight distribution as follows.

 Reaction condition (each molar ratio) Test result
D, L-Lactide
Glycolide
Initiator catalyst
(Tin (II) 2-ethylhexanoate)
Weight average
Molecular Weight
Molecular Weight
Distribution Example 1 1 eq 1 eq D, L-lactic acid 0.02eq
(95%) 0.0005eq 15,000 1.77 Example 2 1 eq 1 eq D, L-lactic acid 0.01eq
(95%) 0.0005eq 10,000 1.81 Example 3 1 eq 1 eq D, L-lactic acid 0.04eq
(95%) 0.0005eq 8,000 1.89 Example 4 1 eq 1 eq D, L-lactic acid 0.02eq
(90%) 0.0005eq 14,000 2.40 Example 5 1 eq 1 eq D, L-lactic acid 0.02eq
(99%) 0.0005eq 15,000 1.53 Comparative Example 1 1 eq 1 eq - 0.0005eq 63,000 2.95 Comparative Example 2 1 eq 1 eq - 0.005eq 57,000 3.12 Comparative Example 3 1 eq 1 eq Glycolic acid 0.02eq
(99%) 0.0005eq 15,000 2.83 Comparative Example 4 1 eq 1 eq Benzyl alcohol 0.02eq
(99.8%) 0.0005eq 18,000 3.01

As confirmed in Table 2, in Examples 1 to 5 according to the preparation method of the present invention, by using D, L-lactic acid as an initiator, no initiator was used (Comparative Examples 1 and 2) and As compared with the case where glycolic acid or benzyl alcohol (comparative example 3 or 4) is used as an initiator, the molecular weight distribution degree showed the narrow molecular weight distribution map in the range of 1.50-2.40.

PLGA synthesized according to Examples 6 to 9 and Comparative Examples 5 and 6 showed a weight average molecular weight and a molecular weight distribution as follows.

Reaction conditions Test result
division Cosolvent (volume ratio v / v)
yield Weight average
Molecular Weight Molecular Weight
Distribution
Appearance Methylene
Chloride Methanol Example 6 One One 63.3% 11,000 1.91 White powder Example 7 One 2 64.0% 12,000 1.85 White powder Example 8 One 10 68.0% 12,000 1.71 White powder Example 9 One 20 68.4% 11,000 1.99 White powder division Cosolvent (volume ratio v / v) yield Weight average
Molecular Weight Molecular Weight
Distribution Appearance Acetone D.I.Water Comparative Example 5 One 10 59.2% 12,000 2.61 White powder Comparative Example 6 One 20 59.8% 12,000 2.65 White powder

As confirmed in the test results of [Table 3], PLGA purified using methylene chloride and methanol as co-solvents according to Examples 6 to 9, which is a manufacturing method of the present invention, has a weight average molecular weight in the range of 8,000 to 15,000. And a narrow molecular weight distribution in the range of 1.50 to 2.40, which was a white powder.

On the other hand, as in Comparative Examples 5 and 6, PLGA obtained using acetone and water as a co-solvent showed a broader molecular weight distribution than Examples 6 to 9 of the present invention.

Therefore, referring to the test results of [Table 2] and [Table 3], according to the production method of the present invention, a PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.40 has a narrow distribution. You can see that you can.

Claims (8)

As a method for producing PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.40,
Stirring dissolving D, L-lactide and glycolide;
After the stirring dissolution, adding D, L-lactic acid as an initiator, and then adding and stirring a catalyst;
Standing after the stirring to obtain a synthesized PLGA;
Filtering the solution of the synthesized PLGA in methylene chloride under reduced pressure;
Injecting the filtrate obtained by the vacuum under reduced pressure to obtain a precipitate using a homogenizer; And
Filtering the precipitate to obtain PLGA and drying it;
PLGA manufacturing method comprising a. The method according to claim 1,
The step of stirring and dissolving the D, L- lactide and glycolide, in a vessel substituted with nitrogen, the production method of PLGA, characterized in that proceeds to a temperature of 110 ~ 150 ℃. The method according to claim 1,
The catalyst is a method for producing PLGA, characterized in that the tin (II) 2-ethylhexanoate. The method according to claim 1,
Said D, L-lactide, glycolide, and D, L-lactic acid are each used in the molar ratio of 1: 0.8-1.2: 0.01-0.06, The manufacturing method of PLGA. The method according to claim 1,
The D, L-lactic acid is a method of producing PLGA, characterized in that more than 90% purity. The method according to claim 1,
The use amount of the methylene chloride and methanol, the volume ratio, methylene chloride: methanol production method of PLGA, characterized in that 1: 1 to 25. The method according to claim 1,
The method for producing PLGA is a method for producing PLGA, characterized in that the PLGA having a weight average molecular weight of 8,000 to 15,000 and a molecular weight distribution of 1.50 to 2.00. PLGA manufactured by the manufacturing method in any one of Claims 1-6, The weight average molecular weight is 8,000-15,000, The molecular weight distribution is 1.50-2.40, The PLGA characterized by the above-mentioned.

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