SK279253B6 - Highly water soluble, stable, crystalline salts of 2',3'- -dideoxyinoside and 2',3'dideoxy-2'-fluoroinosine, the method of their production and pharmaceutical components thereof - Google Patents

Abstract

Highly water soluble, stable, crystalline salts of 2',3'- -dideoxyinoside of common formula (II), wherein X represents an organic or inorganic cation and Y represents, in case of I compound, hydrogen and, in case of II compound, fluor. These salts can be gained, when a corresponding free substance is mixed, in an inert liquid system, with a corresponding base and newly formed salt is being crystallized. The gained salts are useful as antiviral agents. Furthermore, the pharmaceutical components contain ing these salts are described.

Description

Technical field

The invention relates to highly water soluble, stable and crystalline salts of 2 ', 3'-dideoxyinosine and 2', 3'-dideoxy-2'-fluorinosine with antiviral activity, including anti-retroviral activity. Mainly it concerns sodium salts.

BACKGROUND OF THE INVENTION

Infectious viral diseases are a serious health problem. In particular, progress in the treatment of infectious viral diseases requires the development of selective antiviral agents which are not intended to damage normal cell lines. At present, experiments are carried out with a number of antiviral agents which appear to have some selectivity. It is a nucleoside analogue, a better structural analogue of naturally occurring nucleosides. By structurally modifying the purine or pyrimidine base and / or the carbohydrate component, it is possible to obtain a synthetically modified derivative which, upon incorporation into the viral nucleic acid, interrupts further steps of the synthesis of the viral nucleic acid during its formation.

The efficacy of these antiviral agents depends on the selective conversion of the virus enzyme, but not the host enzyme, into the corresponding nucleotide analogs, which are then converted to triphosphates with subsequent incorporation into the viral nucleic acid. A major problem in this case is the emergence of certain viral strains whose enzymes only slightly induce phosphorylation of nucleoside analogues. In order to avoid this problem, it may be possible to use intact nucleotide analogs as antiviral agents for incorporation into the nucleic acids of the virus.

PCT patent application WO 87/01284 (Mitsuya and Broder) discloses the use of 2 ', 3'-dideoxyinosine for the treatment of AIDS.

Erik de Clercq describes in Potential Drugs for the Treatment of AIDS, Joumal of Antimicrobial Chemotherapy, 23, Section A, p. 35-46, 1989) the use of dideoxynucleoside analogues to inhibit the infectivity and cytopathic effect of human immunodeficiency virus (HIV).

In patent application EP 287 313 discloses ² ', 3'-dideoxy-2 ^l -fluorinozin, i.e. F-ddI, and its activity against HIV.

SUMMARY OF THE INVENTION

The present invention provides water-soluble, stable and crystalline salts of 2 ', 3'-didcoxyinosine, also of DDI of formula (I)

and 2 ', 3'-dideoxy-2'-fluorinosine, also F-DDI of formula (II)

ox

J <> N. 0.5 H ₂ O wherein X represents a cation, for example sodium, potassium or calcium.

The present invention also includes pharmaceutical compositions which contain as an active ingredient an antiviral effective amount of these salts together with a solid, liquid or gaseous, non-physiologically acceptable carrier.

These compositions can be used to treat warm-blooded individuals, for example humans.

The invention will now be described in more detail with reference to the accompanying drawings:

In the drawing no. 1 is an IR spectrum of the sodium salt of 2 ', 3'-dideoxyinosine, in FIG. 2 is a thermal analysis of TGA sodium salt of 2 ', 3'-dideoxyinosine; 3 is a DSC thermal analysis of 2 ', 3'-dideoxyinosine sodium salt; 4 is the NMR spectrum of the sodium salt of 2 ', 3'-dideoxyinosine, in FIG. Fig. 5 is an IR spectrum of the sodium salt of 2 ', 3'-dideoxy-2'-fluorinosine; 6 is a NMR spectrum of the sodium salt of 2 ', 3'-dideoxy-2'-fluorinosine; 7 is a DSC thermal analysis of 2 ', 3'-dideoxy-2'-fluorinosine sodium salt; FIG. 8 is a thermal analysis of TGA sodium salt of 2 ', 3'-dideoxy-2'-fluorinosine.

As mentioned hereinbefore, the invention relates in particular to cationically acceptable pharmaceutically acceptable cations, for example sodium, lithium, potassium, calcium and magnesium salts, but the salts may also contain caustic earth metal cations, ammonium or quaternary ammonium. The preferred salt is in particular the sodium salt.

Metal salts can be prepared by treating the organic derivative with an alkali metal hydroxide, the less soluble salt precipitates from the solution itself, and the more soluble salt remains in solution.

The compounds of the invention have the desired antiviral activity. Thus, for example, they are effective against Herpes simplex I, Herpes simplex II, cytomegalovirus, shingles virus, influenza virus, vaccinia virus, baby virus, rubella, varicella, cowpox, Epstein-Barr virus, measles, causing respiratory diseases in humans against papillomavirus and Sinbis virus; only part of the viruses for which said salts are effective have been listed, inter alia these salts are also effective against retroviruses, for example against human immunodeficiency virus, i. HIV.

As noted above, the compounds of the present invention are suitable active ingredients of pharmaceutical formulations in both medicine and veterinary medicine for the treatment and prophylaxis of diseases caused by retroviruses. Examples of medical indications for retroviruses are:

1. the treatment or prophylaxis of retrovirus infection in humans,

2. the treatment or prophylaxis of diseases caused by HIV, also referred to as HTLV III / LAV and / or AIDS, and further stages associated with infection by the virus, such as ARC, i.e. AIDS-associated complex as well as LAS, i. lymphatic adenopathy syndrome, as well as immunological system insufficiency and eneephalopathy caused by these retroviruses,

3. treatment or prophylaxis of HTLV I or HTLVII infections,

4. treatment or prophylaxis in the case of AIDS carriers where the disease is already communicable;

5. treatment and prophylaxis of diseases caused by hepatitis B virus

Examples of indications for use of these salts in veterinary medicine include the following:

1. Maedivisna ovine and caprine animals,

2. progressive pneumonia virus PPV in sheep and goats,

3. joint and enephalitis inflammation virus in ovine and caprine animals,

4. Zwoegerziekte virus in sheep,

5. Infectious anemia virus in horses

6. Leukemia virus infection in cats.

For use against viral diseases, the compounds of this invention may be formulated as pharmaceutical compositions. These may then contain one or more compounds of the invention and, in addition, carriers suitable for pharmaceutical use. Typical carriers and methods of making the compositions are set forth in A. R. Gennaro, Remington's Pharmaceutical Sciences, 17th edition, edited by Mack Publishing Co., 1985.

The compounds of this invention are administered systemically to warm-blooded individuals, e.g., humans, for oral, rectal or parenteral administration such as intramuscular, intravenous and subcutaneous administration, or nasal administration. Usually, in the case of oral administration, it is necessary to administer a higher amount of the compound to achieve the same effect as compared to the effect of parenteral administration. In accordance with clinical practice, it is desirable to administer the subject compounds in an amount that will produce the desired antiviral effect without causing undesirable side effects.

For therapeutic and prophylaxis purposes, the compounds of this invention are administered in the form of a pharmaceutical composition containing the active ingredient and the carrier as described herein. These pharmaceutical preparations contain less or more, for example 100 to 0.5%, of at least one compound of the invention in combination with a pharmaceutical carrier, which may be a single substance or a plurality of substances, may be solid, semi-solid or liquid diluents, fillers and excipients, of course, non-toxic, inert and pharmaceutically acceptable.

The pharmaceutical composition preferably takes the form of unit doses, i.e., physically discrete units, each containing a predetermined amount of active ingredient, which corresponds to a fraction or multiple of the dose calculated to produce the desired therapeutic effect. The composition may also contain other active ingredients.

Preferably, the pharmaceutical preparations contain 50 mg to 2 g of active ingredient per unit dose. They may be tablets, even those intended to be dissolved under the tongue, capsules, powders, granules, suspensions in water or oil, syrups, elixirs and aqueous solutions. Preferred oral dosage forms are tablets and capsules which may contain conventional excipients such as binding agents such as syrups, acacia gum, gelatin, sorbitol, tragacanth or polyvinylpyrrolidone, and fillers such as lactose, sugar, chicken starch, calcium phosphate. sorbitol or glycine, glidants such as magnesium stearate, talc, polyethylene glycol or silica, disintegrants such as starch, inorganic or organic buffers, and wetting agents such as sodium lauryl sulfuric acid.

Solutions or suspensions in a conventional vehicle may be used for parenteral administration. They are, for example, aqueous solutions for intravenous injection or suspensions in oil for intramuscular injection. Formulations of the desired clarity and stability for parenteral use may be obtained by dissolving 0.1 to 35% by weight of the active ingredient in water or a vehicle containing a polyhydric aliphatic alcohol such as glycerol, propylene glycol and polyethylene glycol, or mixtures thereof. . Polyethylene glycols are mixtures of non-volatile, usually liquid, water-soluble and organic-liquid polyethylene glycols having a molecular weight of 200 to 1,500.

The compounds undergo hydrolysis under acidic conditions. For optimal bioavailability, tablets, capsules and granules for oral administration should be enteric coated or contain a strong buffer against gastric juice, or both.

The salts of the compounds of the invention are stable, crystalline and have a high water solubility of greater than 300 mg / ml, making them ideal for the preparation of injectable solutions for low volume parenteral use. High alkalinity, i. The pH of 9.5 to 11 of these salts ensures their own buffering capacity against the action of stomach acid. Thus, smaller amounts of buffer can be used in oral formulations.

The salts of the present invention are reversibly immobilized in enol form and can thus be considered as intermediates for the synthesis of various potential biologically active derivatives, such as enol esters and enol ethers. These ester and ether groups may also have the role of protecting groups, thus allowing synthetic work on other moieties or functional groups of the molecule.

As regards the biological activity of the compounds, they have an antiviral activity, particularly suitable for use in the treatment of viral infections. In particular, viral diseases and mammalian infections, including retroviral infections.

The effective dose is in the range of 0.1-5 mg, preferably 1 to 4 mg / kg body weight. For clinical purposes, the compounds of the invention may be administered in a similar manner to the comparator azidovudine (AZT). For clinical purposes, the dosage should be carefully adjusted for each individual case and the doses will vary depending on usual factors such as the age, weight and general condition of the patient, the route of administration and the nature and severity of the disease being treated. The dose will usually be in the range of 150 mg to 5 g, preferably 50 to 1500 mg, of a compound of the invention once or three times a day for oral administration. In some cases, it may be possible to achieve a sufficient therapeutic effect even at lower doses, but at other times it may be necessary to give a higher dose compared to the above.

The compounds of the present invention will be described with reference to their preparation in the following examples, and are intended to illustrate the invention only, but are not intended to limit the invention in any way.

SK 279253-6

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Process for the production of 2 ', 3'-dideoxyinosine sodium monohydrate (DDI)

mol. DDI mass = 236.14 mol. NaOH weight = 40 g DDI / 236.14 = X / 40 = 169 mg NaOH / 40 and this means that 4.3 ml of 1 N sodium hydroxide solution is equivalent to 1 g DDI in a molar ratio of 1: 1.

1. 1 g of DDI is added to 4.51 ml of 1 H aqueous sodium hydroxide solution (1.05 mol equivalents) and the mixture is stirred at 10-25 ° C for 5 minutes. The solution obtained has a pH of 9.5 to 11.

2. If necessary, the solution may be clarified by passing through a 0.2 to 0.45 micron orifice filter such as Gelman HT-Tuffryn. Both steps are completed in 1.5 hours.

3. The DDI sodium salt solution is added to 50 to 75 ml of vigorously stirred isopropyl alcohol or acetone over 10 to 15 minutes to precipitate crystals, and the reaction mixture is stirred vigorously in a sealed vessel for 2 hours.

4. The crystals are sucked off and it is advisable not to dry the filter part too much, then smooth it so that it has neither cracks nor slits. But at the same time a large amount of air should not pass through this proportion.

5. Wash the filter portion using three 15 ml portions of isopropyl alcohol or acetone, then three portions of 20 ml each of acetone, again not passing too much air through the solid. Smoothing is then carried out to ensure that the surface is free of cracks.

6. The crystals are dried under high vacuum at 24-35 ° C for 24 hours. Yield: 1.0 to 1.1 g.

7. If desired, the otherwise highly preferred isopropyl alcohol can be replaced with acetone, the addition process can also be reversed and the solvent added to the stirred solution of DDI at half-hour intervals.

Instead of sodium hydroxide, potassium hydroxide and / or other strong inorganic or organic bases can be used to obtain the corresponding salt.

Chemical and physical properties of Na-DDl.HjO

1. Solubility in water above 300 mg / ml at pH 9,5 - 11;

2. stability of aqueous solution: 1 week at 50 ° C, loss of 5% week at 70 ° C, loss of 10%

3. solid state stability: 5 weeks at 70 ° C, loss 0

4. elemental analysis for C 1 (jH || NqOjNa.fbO, ie

C ₁₀ H ₁₃ N ₄ O ₄ Na calculated: 43.5% C, 4.7% H, 20.3% N,

Na (ash) 8.3

H2O KF for monohydrate 6.5% found: 43.18% C, 4.6% H, 20.16% N,

Na (ash) 8.26

H2O KF for monohydrate 6.57 mol% weight 276.26

5.IC spectrum, see FIG. 1

6. 2

7. DSC, see FIG. 3

8. X-ray diffraction - film:

Diffraction lines DDI Na-DDI H2O D I / Io D I / Io 14:57 100 8.75 60 8:39 80 7.82 80 7:46 20 6.21 30 6.60 10 5.81 20 6:00 20 5.28 10 5.5 20 5:00 10 5.14 20 4.65 40 4.79 30 4.22 50 4:46 30 3.89 100 3:54 90 3:49 20 3.21 40 3.25 20 3.4 40 3.9 10 2.92 50 2.77 10 2.61 20

9. NMR spectrum - see FIG. four

The following table shows the results obtained by high pressure liquid chromatography:

Table I

Column: IBM phenyl, 5 µm, 4.5 x 150 nm

Mobile phase: 98% 0.015 M ammonium dihydrogen phosphate solution in Milli-Q, pH 7.1, treated with ammonia,% acetonitrile

Flow rate: 0.1 mg / ml in water

Retention time: DDI 10 min., Hypoxanthine 3 min.

Example 2

Process for preparing 2 ', 3'-dideoxy-2'-fluorinosine sodium salt hemihydrate F-DDI

mol. F-DDI = 254.24 mol. NaOH mass = 40

436 mg of F-DDI / 254.24 = X / 40 = 68.6 mg of NaOH / 40 and this means that 1.72 ml of 1 N sodium hydroxide solution is equivalent to 436 mg of F-DDI in a molar ratio of 1: 1.

1. 426 mg of F-DDI is added to 1.8 ml of 1 N sodium hydroxide solution, resulting in a solution containing 256 mg / ml of NaFdd1, and the pH is stabilized at 9.9 over 2 minutes.

2. Add 2 ml of isopropyl alcohol, keeping the solution clean.

3. Isopropyl alcohol is added slowly and the solution becomes cloudy until 15 ml of isopropyl alcohol is added to form a thick precipitate of acicular crystals and the mixture is then allowed to stand for 10 minutes.

4. After addition of 15 ml of acetone, the mixture is allowed to stand again for 15 minutes.

5. The crystals are aspirated, washed with 15 ml of acetone and 20 ml of ether followed by drying under vacuum for 2 hours at 50 ° C in the presence of phosphorus pentoxide and 24 hours at 24 ° C. Yield: 430 mg of product.

From this substance, 21 mg is readily dissolved in 0.05 mg of water, then the solution contains 400 mg of product per ml, pH of the solution: 10.0.

Elemental analysis for C 10 H 10 N 2 O 2 Na 3 calculated: 42.0% C, 3.9% H, 19.6% N, 6.6% F,

8.0% NaH ₂ O KF for hemihydrate 3.23% found: 41.19% C, 3.73% H, 18.8% N, 6.13%

F, 8.11% NaH ₂ O KF for hemihydrate 3.23%

A pharmaceutical composition having an antiviral effect, comprising as active ingredient the salt of claim 1 in an antiviral effective amount and, in addition, a pharmaceutically acceptable carrier.

A process for the preparation of the highly water-soluble, stable and crystalline salts of the compounds of formula (I) and (II) according to claim 1, wherein X is an organic or inorganic cation and Y is hydrogen or fluorine, of formula 1 wherein X is hydrogen and Y is also hydrogen and a compound of formula (II) wherein X is hydrogen and Y is fluorine in an inert aqueous solvent by the appropriate base to form the corresponding cation, then the desired salt is crystallized from solution .

drawings

X-ray diffraction

D ΓΤδ 16:20 50 9:40 50 6.91 50 5.81 50 5:40 100

NMR spectrum, see FIG. 5

TGA see FIG. 8

DSC see FIG. 7

IR spectrum see fig. 6

Obviously, the invention has been illustrated by its preferred embodiments, but it is clear that many changes and modifications are possible and are within the scope of the invention.

Claims (2)

PATENT CLAIMS A water-soluble, stable, crystalline salt of 2 ', 3'-dideoxyinosine of formula I and its 2'-fluoro derivative of formula (II), (I) monothihydrate (II) hemihydrate wherein X represents an organic or inorganic cation and Y is hydrogen for compound I and fluorine for compound II. 2. A highly soluble, stable, crystalline salt of formula (I) or (II), wherein X is sodium.