HK1047112A

HK1047112A - Diphosphate salt of a 4"-substituted-9-deoxo-9a-aza-9a-homoerythromycin derivative and its pharmaceutical composition

Info

Publication number: HK1047112A
Application number: HK02108632.5A
Authority: HK
Inventors: R‧J‧拉夫卡; C‧B‧拉甘; D‧J‧M‧艾伦
Original assignee: 辉瑞产品公司
Priority date: 1999-06-30
Filing date: 2000-06-13
Publication date: 2003-02-07

Description

4' -substituted-9-deoxo-9A-aza-9A-homoerythromycin derivative diphosphates and pharmaceutical compositions thereof

The present invention relates to a novel crystalline diphosphate salt of (2R, 3S, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R) -13- [ [2, 6-dideoxy-3-C-methyl-3-O-methyl-4-C- [ (propylamino) methyl ] -alpha-L-ribo-pyranosyl (hexopryanosyl) ] oxy ] -2-ethyl-3, 4, 10-trihydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11- [ [3, 4, 6-trideoxy-3-dimethylamino) -beta-D-xylo-pyranosyl ] oxy ] -1-oxa-6-azacyclopentadecan-15-one for use as an antibacterial and antiprotozoal agent in mammals (hereinafter referred to as "antimicrobial" and "antiprotozoal" agent As a diphosphate salt). The invention also relates to pharmaceutical compositions containing such diphosphate free base and methods of treating bacterial and protozoal infections in mammals by administering such diphosphate free base to a mammal in need of such treatment. When administered parenterally to a mammal, the free base of the diphosphate salt of the present invention has potent activity against various bacterial and protozoal infections.

Macrolide antibiotics are known to be useful in the treatment of a broad spectrum of bacterial and protozoal infections in mammals, fish and birds. Such antibiotics include various derivatives of erythromycin A, such as azithromycin, which is commercially available and described in U.S. Pat. Nos. 4,474,768 and 4,517,359, both of which are incorporated herein by reference in their entirety.

Summary of The Invention

The present invention relates to (2R, 3S, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R) -13- [ [2, 6-dideoxy-3-C-methyl-3-O-methyl-4-C- [ (propylamino) methyl ] methyl]-alpha-L-nuclear-hexopyranosyl]Oxygen gas]-2-ethyl-3, 4, 10-trihydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11- [ [3, 4, 6-trideoxy-3-dimethylamino) - β -D-xylo-hexopyranosyl]Oxygen gas]Two polymorphs of a diphosphate crystal of-1-oxa-6-azacyclopentadecan-15-one (hereinafter referred to as diphosphate) shown below:

wherein n is 0 to 8

In one embodiment of the invention, the diphosphate is a liquid crystal having a lath-like crystalline morphology and exhibiting longitudinal cleavage but no lateral cleavage. X-ray diffraction shows little or no disorder.

In another embodiment, the diphosphate salt is crystalline. Microscopic examination of this diphosphate salt revealed a plate-like or prismatic crystalline morphology, both of which are highly birefringent. This diphosphate salt is a crystal with good crystalline order and is characterized by the following X-ray diffraction pattern:

peak number	1	2	3	4	5	6	7	8	9	10
peak number	1	2	3	4	5	6	7	8	9	10	d interval	16.2	12.4	10.8	9.0	6.9	6.5	6.2	5.4	5.1	4.9

This crystalline diphosphate absorbs water gradually to about 13% at 87% relative humidity and rapidly to about 48% at about 90% relative humidity. Thermogravimetric analysis of this diphosphate revealed that three parts of water were lost at about 75 ℃, a fourth part at about 120 ℃, a fifth part at about 170 ℃ and a final three parts at about 200 ℃. The maximum number of water molecules necessary to stabilize the lattice is shown to be about eight. The diphosphate is dried in air at about 70 ℃ or in vacuo at 45 ℃ with removal of water leaving the pseudomorphic. The aqueous solubility of this crystalline diphosphate is about 280 mg/mL.

A process for preparing the diphosphate salt comprises dissolving the anhydrous free base in anhydrous ethanol under magnetic stirring at room temperature, adding a solution of phosphoric acid in anhydrous ethanol over a period of about 2 to 5 minutes to produce a precipitate, and then partially dissolving the resulting solid in a small amount of water. Stirring at room temperature for several hours yielded a crystalline product, which was collected by filtration and then washed with some small amount of ethanol-water of about 10/1 (v/v). After this diphosphate synthesis, it is converted back to a pharmaceutically acceptable free base by a process that includes dissolving in water, adding dichloromethane, increasing the pH to about 8.5 to 10, collecting and concentrating the organic phase, and crystallizing the amorphous free base from the hydrocarbon solvent.

A pharmaceutical composition having antibacterial and antiprotozoal activity in mammals comprises an effective amount of such a diphosphate free base and a pharmaceutically acceptable carrier in the treatment of bacterial and protozoal diseases. A method of treating bacterial and protozoal infections comprises administering to a mammal in need of such treatment an antibacterial amount of the free base diphosphate. An antibacterial amount of the free base is administered parenterally to a mammal.

Detailed Description

The present invention relates to (2R, 3S, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R) -13- [ [2, 6-dideoxy-3-C-methyl-3-O-methyl-4-C- [ (propylamino) methyl ] methyl]-alpha-L-nuclear-hexopyranosyl]Oxygen gas]-2-ethyl-3, 4, 10-trihydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11- [ [3, 4, 6-trideoxy-3-dimethylamino) - β -D-xylo-hexopyranosyl]Oxygen gas]Two polymorphs of crystalline diphosphate of (E) -1-oxa-6-azacyclopentadecan-15-one, shown below:

wherein n is 0 to 8

In another embodiment, the diphosphate salt is a hygroscopic salt crystal. Microscopic examination of this diphosphate salt revealed a plate-like or prismatic crystalline morphology, both of which are highly birefringent.This diphosphate salt is a crystal with good crystalline order and is characterized by the following X-ray diffraction pattern:

The present invention also relates to a process for preparing such a pharmaceutical composition of liquid crystals and crystalline diphosphate and the free base of crystalline diphosphate as shown in scheme 1 below:

scheme 1

Wherein n is 0 to 8

Differential scanning calorimetry of this crystalline diphosphate salt showed a single phenomenon (single event) at about 119 ℃, which is consistent with loss of water and dissolution of the salt in the released water. This phenomenon is followed by no crystallization.

Drying at VTI at 20-25 ℃ showed a weight loss of 10%; the dried salt gradually absorbed moisture to 15% at 85% RH (relative humidity) followed by rapid absorption of moisture to about 48% at 90% RH. At 90% RH, the compound deliquesced.

This diphosphate can also be studied by thermogravimetric analysis (TGA). The sample was rehydrated at 87% RH [ 13% moisture by Karl Fisher (KF) titration ], and four significant jumps were noted. Loss of 3 parts water at about 75 ℃; about 120 ℃ loses 4 parts of water, about 170 ℃ loses 5 parts of water, and about 200 ℃ loses 8 parts of water. The maximum number of water molecules necessary to stabilize the lattice is shown to be about eight. The reduction in water content in the hydrate did not cause a change in the X-ray diffraction data, indicating the formation of pseudoisomorphous hydrates.

The mobility of moisture within the crystal lattice is directly related to the relative humidity of the environment to which the diphosphate is exposed. For example, at about 87% relative humidity, the compound contains about 13% water; at 60% relative humidity, the compound contains about 8% water; and at 40% relative humidity, this diphosphate contains about 5% water (all calculated by KF).

Drying at 70 ℃ in air or 45 ℃ under vacuum removed all water leaving pseudoisomorphous. The salt rehydrates at about 87% relative humidity, yielding the octahydrate form.

The following examples illustrate the methods and compounds of the present invention. It is to be understood that the invention is not limited to these specific embodiments.

Example 1

Liquid crystals of this diphosphate

(2R, 3S, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R) -13- [ [2, 6-dideoxy-3-C-methyl-3-O-methyl-4-C- [ (propylamino) methyl ] methyl]-alpha-L-nuclear-hexopyranosyl]Oxygen gas]-2-ethyl-3, 4, 10-trihydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11- [ [3, 4, 6-trideoxy-3-dimethylamino) - β -D-xylo-hexopyranosyl]Oxygen gas]-1-oxa-6-azacyclopentadecan-15-one (7.5g, 97%, 9.0mmol) was dissolved in absolute ethanol (190mL) at room temperature. Then 15mL portions of absolute ethanolic phosphoric acid solution (7.15g of commercial H) were added₃PO₄Diluted to 100mL, 9.3mmol, 1.03 eq). A white precipitate formed immediately. After the suspension was stirred at room temperature for 1 hour, water (10mL) was added. The mixture was then stirred for 6 days, after which the solid was collected on a buchner funnel and washed twice with a small amount of absolute ethanol. The moist filter cake was dried under high vacuum at room temperature. The resulting solid exhibited birefringence under cross-polarized light, but did not exhibit an X-ray diffraction pattern.

KF analysis of such liquid crystals showed that they contained 5.5% water. Elemental analysis calculations and actual values are as follows:

calculated% Observation%

C 46.44 48.15

H 8.69 9.22

N 3.96 4.11

P 5.84 5.83

HPLC performance measurements were also performed. The diphosphate containing 5.5% water with the expected potency is 76.4%; the observed value was 76.9%.

The subsequent portions of air-dried only showed no X-ray pattern. A small amount of liquid crystal was placed in a test tube and dissolved (warmed) in 1-propanol (containing a small amount of water) and then placed outside the lid and slowly evaporated. The solid obtained in this experiment was used as seed for example 2.

Example 2

Crystalline octahydrate phosphate salt

This free base (10g, 98.8%, 12.3mmol) was dissolved in absolute ethanol (180mL) with magnetic stirring at room temperature. Phosphoric acid in absolute ethanol [18mL, 11.2mmol, 0.9 equiv. (7.15g H) was added within about 3 minutes₃PO₄Diluting to 100mL)]It causes the formation of a white, sticky precipitate. Water (10mL) was added and the mixture was stirred at room temperature overnight. The crystalline product was collected on a Buchner funnel and the solid was washed with three small portions of 10/1(v/v) ethanol-water. The recovered, air-dried solid weighed 2.09 g. X-ray analysis of the solid indicated the presence of a liquid crystalline form. 500mg of the liquid crystal sample was dissolved (warmed) in 2mL of 10: 1(v/v) ethanol-water. The resulting solution was cooled to room temperature and crystallized as a wet 1-propanol containing solid in a small scale experiment. The mixture was stirred at room temperature overnight. The resulting solid was collected on a Buchner funnel and washed with a small amount of 10: 1(v/v) ethanol-water, air dried to a weight of 370 mg. X-ray analysis showed this material to have good crystalline order and to show well defined powder patterns as shown below:

The liquid crystal and the crystal of this diphosphate are hygroscopic. When attempting in a hydrophilic solvent, the addition of 4% to 5% (v/v) water to the amorphous slurry caused the compound to crystallize as the octahydrate. Crystallization in ethanol/water indicates that metastable ethanol solvates may form.

Example 3

Purification of crystalline diphosphate octahydrate

1.18g of amorphous diphosphate octahydrate combined with 18.5mL of absolute ethanol and 1.05mL of water. The mixture was heated at reflux for 15 minutes to produce a cloudy solution. Heating was stopped and the stirred mixture was cooled to room temperature to promote crystallization. After 2 hours of granulation, the product was cooled, filtered and air dried at room temperature to yield pure octahydrate diphosphate salt.

Example 4

(2R, 33, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R) -13- [ [2, 6-dideoxy-3-C-methyl-3-O-methyl-4-C- [ (propylamino) methyl ] - α -L-ribo-hexopyranosyl ] oxy ] -2-ethyl-3, 4, 10-trihydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11- [ [3, 4, 6-trideoxy-3-dimethylamino) - β -D-xylo-hexopyranosyl ] oxy ] -1-oxa-6-azacyclopentadecan-15-one

This diphosphate (225g) was distributed between water (1200mL) and methylene chloride (500 mL). The pH of the aqueous phase was raised from 5.9 to 8.6 by the addition of solid potassium carbonate. The organic phase was collected, dried over anhydrous sodium sulfate and concentrated to a dry, amorphous foam (170 g).

Example 5

This amorphous free base (170g) was crystallized from heptane (700mL) to yield a clean, crystalline free base (115g), which was then formulated as a partial aqueous solvent suitable for parenteral use in livestock.

The above process and the resulting diphosphates have valuable and non-significant properties. This diphosphate formation allows the removal of a large amount of impurities in the resulting mother liquor. This results in a drug that forms very low levels of turbidity in a partially aqueous medium formulation when converted to the free base. This results in a pharmaceutically elegant solution suitable for parenteral use.

The active compounds may be administered by the routes previously described, either alone or in combination with a pharmaceutically acceptable carrier or diluent, and such administration may be carried out in one or more doses. More specifically, such active compounds may be administered in a wide variety of various dosage forms, i.e., they may be administered in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays, creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, aqueous suspensions, injections, elixirs, syrups, and the like, in combination with various pharmaceutically acceptable inert carriers. Such carriers include solid diluents or fillers, sterile aqueous media and various non-toxic organic solvents, and the like. Furthermore, oral pharmaceutical compositions may be suitably sweetened and/or flavored. Generally, the active compound content of these dosage forms is from about 5.0% to about 70% by weight.

For parenteral administration, an oil, partially aqueous carrier or solution of an aqueous carrier of the active composition may be employed. The oil may be selected from pharmaceutically acceptable oils; for example, sesame or peanut oil can be used. The non-aqueous component of the partially aqueous carrier may be selected from pharmaceutically acceptable ingredients; for example, propylene glycol or polyethylene glycol may be employed. The aqueous solution should be suitably buffered (pH preferably less than 8) if desired. Aqueous and partially aqueous solvents are suitable for intravenous purposes. Aqueous, partially aqueous and oily solutions are suitable for intra-articular, intramuscular and subcutaneous injection purposes. The preparation of all these solutions under sterile conditions can be readily accomplished by standard pharmaceutical techniques known to those skilled in the art.

Claims

1. The invention relates to (2R, 3S, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R) -13- [ [2, 6-dideoxy-3-C-methyl-3-O-methyl-4-C- [ (propylamino) methyl group]-alpha-L-nuclear-hexopyranosyl]Oxygen gas]-2-ethyl-3, 4, 10-trihydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11- [ [3, 4, 6-trideoxy-3-dimethylamino) - β -D-xylo-hexopyranosyl]Oxygen gas]-two polymorphs of the diphosphate salt of 1-oxa-6-azacyclopentadecan-15-one having the following formula:

wherein n is 0 to 8, polymorphs are selected from the group consisting of:

a. a smectic crystalline mesogenic phase of liquid crystals; and

b. crystal of diphosphate showing X-ray powder diffraction pattern Peak number 1 2 3 4 5 6 7 8 9 10 d interval 16.2 12.4 10.8 9.0 6.9 6.5 6.2 5.4 5.1 4.9

2. The diphosphate liquid crystal of claim 1 having a lath-like crystalline morphology and exhibiting longitudinal cleavage.

3. The diphosphate liquid crystal of claim 2, increasing in weight by about 15% at a relative humidity of about 87% with consequent loss of birefringence.

4. The diphosphate salt of claim 2 wherein the liquid crystal has about 5 to 6% water.

5. The diphosphate salt of claim 1, wherein the salt has about 48% C, about 9% H, about 4% N, about 6% P, and about 5.5% H₂O。

6. The diphosphate polymorph of claim 1, having a crystalline platy or prismatic crystalline shape with good crystalline order.

7. A diphosphate salt as claimed in claim 6, wherein the plate-like or prismatic crystalline shape is highly birefringent.

8. The crystalline diphosphate salt of claim 1, wherein the compound gradually absorbs about 13% of the water at a relative humidity of about 87%.

9. The diphosphate salt of claim 8, wherein the water is rapidly absorbed to about 48% at a relative humidity of about 90%.

10. A diphosphate salt according to claim 9, wherein the diphosphate salt becomes deliquescent at a relative humidity of about 90%.

11. The diphosphate salt of claim 1, wherein thermogravimetric analysis reveals that three parts of water are lost at about 75 ℃, a fourth part of water is lost at about 120 ℃, a fifth part of water is lost at about 170 ℃, and the last three parts of water are lost at about 200 ℃.

12. A diphosphate salt as claimed in claim 1, wherein the maximum number of water molecules necessary to stabilize the crystal lattice is eight.

13. The diphosphate salt of claim 1, wherein the water is removed by drying in air at about 70 ℃ or at 45 ℃ under vacuum, leaving pseudoisomorphous.

14. The diphosphate salt according to claim 1, wherein the aqueous solubility is about 280 mg/mL.

15. A method for preparing diphosphate comprises dissolving free alkali in absolute ethyl alcohol under magnetic stirring at room temperature; adding an anhydrous ethanol solution of phosphoric acid within about 2 to 3 minutes; dissolving the resulting solid in water; collecting the crystallized product at room temperature; washed with some small amount of about 10/1(v/v) ethanol-water.

16. A process for converting the diphosphate salt according to claim 15 to the free base without impurities, comprising dispersing the salt between dichloromethane and water; the pH was raised to about 8 to 10 and the organic phase was collected and evaporated.

17. A pharmaceutical composition having antibacterial and antiprotozoal activity in a mammal, comprising a free base of a diphosphate salt according to claim 1 in an amount effective to treat bacterial and protozoal diseases and a pharmaceutically acceptable carrier.

18. A method for the treatment of bacterial and protozoal infections comprising administering to livestock and swine in need of such treatment an antibacterially effective amount of the free base of a diphosphate according to claim 1.

19. The method of claim 18 wherein the antibacterially effective amount of the free base of the diphosphate is administered parenterally.