Utilisation of dialkylfumarates

The present invention relates to the use of dialkyl fumarates for the manufacture of pharmaceutical compositions for use in transplant medicine or the therapy of autoimmune diseases and pharmaceutical preparations in the form of microtablets or micropellets containing dialkyl fumarates.

The present invention relates to the use of dialkyl fumarates for the manufacture of pharmaceutical compositions for use in transplant medicine or the therapy of autoimmune diseases and pharmaceutical preparations in the form of microtablets or micropellets containing dialkyl fumarates.

On the other hand, it therefore specifically addresses the use of dialkyl fumarates to prepare pharmaceutical preparations for the treatment, reduction or suppression of graft rejection reactions at the recipient, i.e. host-to-graft reactions or graft recipients, i.e., graft-to-graft recipients. host reactions. On the other hand, it deals with the use of dialkyl fumarates in the preparation of preparations for the treatment of autoimmune diseases such as polyarteritis, juvenile onset diabetes, Hashimoto's thyroiditis, Grave's disease, systemic Lupus erythematodes (SLE), Seagrass syndrome, pernicious anemia ( lupoid) hepatitis.

Both graft rejection and autoimmune diseases are based on medical ice unwanted reactions or dysregulation of the immune system. Cytokines such as interleukins or tumor necrosis factor α (TNF-α) are basic mediators that affect the immune system. Generally, both are treated by the administration of immunosuppressive agents such as cyclosporine.

In total, autoimmune diseases can be defined as a failure in the tolerance of endogenous substances or antigens. As a rule, this tolerance can only be maintained if the antigen continues to come in contact with immunological cells. When this tolerance is lost, antibodies are formed, i.e., a humoral immune response to endogenous tissue. The exact nature of the involvement of TNF-α is unknown.

Transplants are tissue or organ transplants, ie the transfer of tissues such as cornea, skin, bone (bone bites), vessels or fascia of organs such as kidney, heart, liver, lung, pancreas or intestines or of individual cells such as cell islands, α-cells and liver cells, the kidneys have the greatest significance as a transplanted organ.

According to the degree of kinship between the donor and recipient, we differentiate between auto-transplantation (transfer to another part of the body to the same individual), iso-transplantation (transfer to another, genetically identical individual) and allogeneic transplantation (transfer to another individual). of the same species).

Depending on the origin and transplant site, we further differentiate between homotopic transplant (transfer to the same site) and heterotopic transplant (transfer to a different site). The above transplants play an important role in modern medicine.

A major problem in transplant medicine is transplant rejection following transplantation of the tissue, organ or cell by immunological defense reactions of the recipient. Such graft rejections are also called host versus graft reactions. The immunological defense response of the organism to the heteroprotein often results in rejection or dissolution of the grafts.

In host-to-graft reactions, different steps can be separated. Depending on the degree of difference between the recipient and the donor, this reaction occurs at different rates, so we are talking about an acute, sub-acute or chronic reaction. The acute rejection process is followed by the irreversible loss of the graft (necrotization) as a result of arteritis or arteriolitis within 48 ice hours and cannot be affected by drug administration. The sub-acute rejection reaction appears as a rejection crisis from day 12 to month 4 with reversible functional disorders as a result of a graft vasculopathy. Finally, the loss of function of the transplant as a result of vascular changes such as obliterative arteriopathy, which lasts for weeks or years and is virtually unaffected by drugs, is referred to as a chronic rejection reaction.

Vice versa, rejection reactions of the graft to the recipient, the so-called graft-to-host reactions, can occur when immunocompetent tissue is transplanted, ie primarily in bone marrow transplantation. Again, the severity of the reaction is graded, and substantially similar complications result in host-to-transplant reactions namely arteriopathies and necrosis.

To avoid such rejection reactions, i.e. the host-to-graft reaction and the graft-to-host reaction, transplant medicine utilizes basic immune suppression, i.e., a weakening of the normal immune response. For this purpose, anti-lymphocyte sera are often used in combination with corticosteroids and so-called anti-meta bo litters, e.g. purine analogues such as 6-mercaptopuron and thioguanine which affect nucleic acid and protein synthesis and thus prevent cell division and proliferation. This leads to suppression of the production of antibodies and the cellular immune response. The immunosuppressive agents used for therapy are substances that suppress or impair the immune response in the body either specific or non-specific. Non-specific immunosuppressants are cytostatic agents such as, for example, alkylating agents or antimetabolites.

In addition, known active ingredients that cause at least partially specific immunosuppression, such as corticosteroids, antisera, antibodies FK-506, tacrolism, mycophenolatemophetil and primary cyclosporins such as cyclosporine A. As a result of using modern immunosuppressants, are the most important the representatives of these cyclosporins, especially ciclosporin A, were able to significantly improve the transplant results over the last few years. At present, the survival rate after one year is about 60% for io liver transplants, about 80% for heart transplants and over 90% for kidney transplants.

Autoimmune diseases in which the endogenous immune system attacks endogenous organs, tissues and cells are comparable to graft-to-host responses. These are also medically undesirable reactions of the immune system that can also be treated with immunosuppressants.

The danger of using immunosuppressants lies in weakening the body's defense against infectious diseases and the increased risk of malignant diseases. Therefore, it is an object of the invention to provide a pharmaceutical composition to be used in transplant medicine that can be used to treat, in particular, suppress, attenuate and / or alleviate host-to-graft reactions and graft-to-host reactions, but has not the disadvantages mentioned above.

It is another object of the invention to provide a pharmaceutical composition that can be used to treat autoimmune diseases, especially polyarthritis, juvenile onset diabetes, Hashimoto's thyroiditis, Grave's disease, systemic

Lupus erythematodes (SLE), Sjögren's syndrome, pernicious anemia and chronically active (= lupoid) hepatitis, without the disadvantages of immune suppression.

The object of the invention is achieved by using certain dialkyl fumarates to prepare pharmaceutical compositions for use in transplant medicine and for the therapy of autoimmune diseases and pharmaceutical preparations in the form of microtablets and micropellets containing these dialkyl fumarates. The individual objects of the invention are characterized in detail in the claims. The compositions of the invention do not contain any free fumaric acids per se.

Pharmaceuticals that, upon biological degradation after administration, are known to enter or are part of the citric acid cycle are gaining increasing therapeutic significance - especially when given at high doses - since they can alleviate or cure cryptogenetically-caused diseases.

For example, fumaric acid inhibits the growth of the Ehrlich ascites tumor in mice, reduces the toxic effects of mitomycin C and aflatoxin, and shows antipsorasic and antimicrobial activity. When administered parenterally, transdermally and especially orally, high doses of fumaric acid or its derivatives have been known so far as dihydroxylfumaric acid, fumaramide and fumaronitrile have such unacceptably severe adverse reactions and high toxicity that, in most cases, such therapy had to be previously stated.

Surprisingly, studies conducted by the applicant have shown that methyl hydrogen fumarate, a metabolite of the dimethyl fumarate, initially increases endotoxin-stimulated TNF-α secretion in human peripheral blood mononuclear cells (peripheral blood mononuclear cells = PBMC cells) and in isolated monocytes. In addition, the applicant was able to show that fumaric acid has an effect on in vitro and in vivo hemoglutination comparable to that of cyclosporine.

Surprisingly, it has now been found that dialkyl fumarates are advantageous in the preparation of pharmaceutical compositions for use in transplant medicine and for the therapy of autoimmune diseases. This is because compositions containing such dialkyl fumarates surprisingly allow a positive modulation of the immune system in host-to-graft reactions, graft-to-host reactions, and other autoimmune diseases.

European Patent Application 0 188 749 already discloses fumaric acid derivatives and pharmaceutical compositions containing them for the treatment of psoriasis.

Pharmaceutical compositions for the treatment of psoriasis containing a mixture of fumaric acid and other fumaric acid derivatives are known from DE-A-25 30 372. The content of free fumaric acid is mandatory for these drugs.

DE-A-26 21 214 discloses medicaments containing the fumaric acid monoethyl ester and its mineral salts as active ingredients for the treatment of psoriasis. The publication Hautarzt (Dermatologist) (1987) 279-285 discusses the use of fumaric acid monoethyl ester salts. Pharmaceutical preparations containing a mixture of fumaric acid monoalkyl ester salts and a fumaric acid diester for the treatment of psoriasis, psoriatic arteritis, neurodermatitis and enteritis regionalis Crohn are known from EP-0 312 697.

Specifically, the object of the invention is achieved using one or more dialkyl fumarates of the formula:

H COO-R ¹ c = c / \ r₂-ooc η wherein R 1 and R₂ which may be the same or different, independently representing a linear, branched or cyclic, saturated or unsaturated C₂o alkyl radical which may be optionally substituted with halogen (Cl, F, I, Br), hydroxy, C₄ alkoxy, nitro or cyano to prepare a pharmaceutical composition for use in transplant medicine or for the therapy of autoimmune diseases.

io Ci-₂₀ the alkyl radicals, preferably C₈ alkyl radicals, most preferably C₅ alkyl radicals, for example, are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, pentyl, cyclopentyl, 2-ethyl hexyl, hexyl, cyclohexyl, heptyl, cycloheptyl, octyl, vinyl, allyl , 2-hydroxyethyl, 2 or 3-hydroxypropyl, 2-methoxyethyl, methoxymethyl, or 2- or 3-methoxypropyl. Preferred is at least one of the radii Ri or R₂ CI₅ alkyl, especially methyl or ethyl. More preferred are R 1 and R 2₂the same or different Ci-₅ alkyl radicals such as methyl, ethyl, n-propyl or tbutyl, methyl and ethyl are particularly preferred. Most preferred are Ri and R₂ are identical and are methyl or ethyl. Particularly preferred are the dimethyl fumarate, methyl ethyl fumarate and diethyl fumarate.

The dialkyl fumarates to be used according to the invention are prepared by methods known in the art (see, for example, EP 0 312 697).

Preferably, the active ingredients are used to prepare oral preparations in the form of tablets, in scraps, pellets or granules, optionally in capsules or bags. Preparations in the form of micro-tablets or pellets, optionally filled in capsules or bags, are preferred and also an object of the invention. The oral preparations can be equipped with an enteric coating. Capsules can be soft or hard gelatin capsules.

The dialkyl fumarates used according to the invention can be used alone or as a mixture of many compounds, optionally in combination with the usual carriers and excipients. The amounts to be used are selected in such a way that the compositions obtained contain the active ingredient in an amount corresponding to 10 to 300 mg of fumaric acid.

Preferred preparations according to the invention contain a total amount of 10 to

300 mg of dimethyl fumarate and / or diethyl fumarate.

According to a preferred embodiment, the size or average diameter of the pellets or microtablets, respectively, is in the range of 300 to 2000 µm, especially in the range of 500 or 1000 µm.

In addition to graft-to-host reactions (see above), the following io autoimmune diseases to be treated can be named: polyarteritis, graft-host reactions, juvenile onset diabetes, Hashimoto's thyroiditis, Grave's disease, systemic Lupus erythematodes (SLE), Seagrass syndrome, pemic anemia and chronic active (lupoid) hepatitis. Autoimmune diseases in a wider sense also include psoriasis, psoriatic arteritis, neurodermatitis and enteritis regionalis ice Crohn.

In addition to the preparations for oral administration in the form of micropellets, microtablets, capsules (such as soft and hard gelatin capsules), granules and tablets listed above, suitable pharmaceutical preparations are preparations for cutaneous and transdermal administration in the form of ointments, plastics, lotions or showers preparations and for parenteral administration in the form of aqueous microdispersions, oil-in-water emulsions or oily solutions for rectal administration of suppositories or micro-enema. Pharmaceutical preparations in the form of microtablets or micropellets are preferred for the therapy of all of the autoimmune diseases mentioned above, including psoriasis, psoriatic arteritis, neurodermatitis and enteritis regionalis Crohn and are also an object of the invention.

According to the invention, a therapy with dialkyl fumarates can also be performed in combination with one or more preparations of the triple drug therapy commonly used in organ transplants or with cyclosporine alone. For this purpose, the administered compositions may contain a combination of the active ingredients respectively in the known dosages or amounts. Similarly, the combination therapy may consist of the parallel administration of separate preparations on the same or different routes. Optionally, the dosage of the active ingredient contained in addition to the dose of the fumaric acid derivative administered according to the invention may be advantageously reduced.

Another embodiment of the use of the invention is to alternate the drug therapy with immunosuppressive agents such as cyclosporin in sequence with an application of the above dialkyl fumarate. This means that an application of fumaric acid derivatives as defined above, over one or more weeks, may follow a cyclosporin therapy for one or more weeks. This allows the reduction of Ciclosporin A dosage resulting in a significant reduction in the proportion of side effects in long-term therapy.

In the preferred administration of dialkyl fumarates in the form of microtablets, gastrointestinal irritations and side effects, which are reduced already when conventional tablets are administered but are still being observed, are further reduced by the fumaric acid derivatives and salts.

It is believed that, when administered with conventional tablets, the ingredients in the ice tablets are released into the intestine at a concentration that is too high, causing local irritation of the intestinal mucous membrane. This local irritation results in a short-term release of very high TNF-α concentrations that may be responsible for the gastrointestinal side effects. In the case of the use of enteric coated microtablets in capsules, on the other hand, very low local concentrations of the active ingredients in the intestinal epithelial cells are obtained. The microtablets are incrementally released from the stomach and inserted into the small intestine by peristaltic movements to improve the distribution of the active ingredients.

This means that enteric-coated micro-tablets in the same dosage are already distributed in the stomach and brought to the intestine in portions, where the active ingredients are released in small doses. This avoids local irritation of the intestinal epithelial cells and the release of TNF-α. This is believed to result in the improved tolerance of microtablets in the gastrointestinal tract vis-a-vis conventional tablets.

In addition, resorption is improved because the dialkyl fumarates to be used according to the invention are not the active ingredient per se, but a so-called prodrug, which must be converted into the active ingredient in the body.

In order to illustrate the use of the invention, various examples of the preparation of preferred drugs are given below.

Produksionseksempler

In principle, the oral compositions of the invention in the form of tablets or micro-tablets can be prepared by classical tableting processes. Instead of such classic tabletting processes, other methods for the preparation of tablets can be used, such as direct tabletting and processes for preparing solid dispersions according to the melting method and spray drying method.

The tablets can be equipped with an enteric coating. The enteric coating can be applied in a classic coating pan or sprayed on or applied in a fluidized bed apparatus. The tablet can also be equipped with a film coating.

Example 1

Preparation of enteric coated microtablets in capsules containing 120.0 mg of dimethyl fumarate, equivalent to 96 mg of fumaric acid ice By taking the necessary precautions (breathing mask, gloves, protective clothing, etc.), 12,000 kg of dimethyl fumarate is crushed, mixed and homogenized and will be 800. Next, an excipient mixture of the following composition is prepared: 17.50 kg of starch derivative (STA-RX® 1500), 0.30 kg of microcrystalline cellulose (Avicel® PH 101), 0.75 kg of PVP (Kollidon® 120), 4, 00 kg of Primogel®,

0.25 kg of colloidal silicic acid (Aerosil®). The active ingredient is added to the entire powder mixture, mixed, homogenized by a sieve 200, prepared in the usual manner with a 2% aqueous solution of polyvinyl pyrrolidone (Kollidon® K25) to obtain a binder granulate and then mixed in the dry phase. with the outer phase. Said outer phase consists of 0.50 kg of Mg stearate and 1.50 kg of talc.

Then, the powder mixture is compressed in the usual way to obtain convex tablets having a total weight of 10.0 mg and a diameter of 2.0 mm.

An example of obtaining resistance to gastric acid is to dissolve a solution of

2,250 kg of hydroxypropyl methylcellulose phthalate (HPMCP, Pharmacoat® HP 50) in portions in a mixture of the following solvents: 13.00 l acetone, 13.50 l ethanol (94 wt / o denatured with 2% ketone) and 1.50 In demineralized water. As a plasticizer, castor oil (0.240 kg) is added to the finished solution and applied in portions to the tablet cores in the usual way.

After drying, a suspension of the following composition is applied as a film coating in the same apparatus: 0.340 kg of talc, 0.400 kg of titanium (IV) oxide Cronus RN 56, 0.324 kg of colored lacquer L-Rotlack 86837, 4,800 kg of Eudragit E 12.5% ​​and 0.120 kg of polyethylene glycol 6000, pH 11 XI in a solvent mixture of the following composition: 8.170 kg of 2-propanol,

0.200 kg of demineralized water and 0.600 kg of glycerol triacetate.

Subsequently, the enteric coated microtablets are filled into hard gelatin capsules having a net weight of 400 mg and sealed.

Example 2

Preparation of enteric coated microtablets in capsules containing 120.0 mg of dimethyl fumarate corresponding to 96 mg of fumaric acid.

12,000 kg of dimethyl fumarate is crushed and homogenized as above. Then an ice excipient composition is prepared as follows: 23.20 kg microcrystalline cellulose (Avicel® PH 200), 3.00 kg croscarmellose sodium (AC-Di-SOL-SD-711), 2.50 kg talc, 0.10 kg of anhydrous silica (Aerosil® 200) and 1.00 kg of Mg stearate. The active ingredient is then added to the entire powder mixture and mixed thoroughly. By direct tableting, the powder mixture is then pressed into convex tablets having a total weight of 10.0 mg and a diameter of 2.00 mm.

Then, a solution of 0.94 (kg?) Of Eudragit® L in isopropanol is prepared which also contains 0.07 kg of dibutyl phthalate. This solution is sprayed onto the tablet cores. Then, a dispersion of 17.32 kg of Eudragit® L D-55 and a mixture of 2.80 kg of microtalkum, 2.00 kg of Macrogol 6000 and 0.07 kg of dimeticone in water are prepared and sprayed onto the cores.

Then, the enteric coated tablets are filled into hard gelatin capsules having a net weight of 650 mg and sealed.

Example 3

Preparation of micropellets in capsules containing 50.0 mg of dimethyl fumarate corresponding to 40 mg of fumaric acid

5,000 kg of dimethyl fumarate are crushed and homogenized as above. In addition, 2 L of a 20% (m / v) polyvinyl pyrrolidone solution (Kollidon K-30) in ethanol is prepared.

7,250 kg of non-split pellets in a coating pan are sprayed with part of the Kollidon K30 solution until slightly moist. Then, the active ingredient is added portionwise until the pellets are dry. This wetting / drying procedure is continued until the entire active ingredient mixture has been added. Then the pellets are moved around until they are completely dry.

Then, the pellets are filled into hard gelatin capsules (126.5 mg pellets / capsule).

EXAMPLE 4 Preparation of enteric coated capsules containing 110.0 mg of dimethyl fumarate corresponding to 88 mg of fumaric acid.

11,000 kg of dimethyl fumarate is vigorously mixed in a mixture of 14.00 kg of starch, 5.65 kg of lactose, 2.00 kg of microcrystalline cellulose (Avicel®), 1.00 kg of polyvinyl pyrrolidone (Kollidon® 25) and 2.443 kg of Primogel® , and by taking the necessary precautions (breathing mask, gloves, protective clothing, etc.), homogenized using a strainer 800.

Using a 2% aqueous solution of polyvinyl pyrrolidone (Kollidon® K25), the entire powder mixture is processed into a binder granule in the usual manner and mixed with the outer phase when dry. Said outer phase consists of 0.350 kg of colloidal silicic acid (Aerosil®), 0.500 Mg of stearate and 1,500 kg of talc. The homogeneous mixture is filled into appropriate capsules in 400 mg portions which are then provided with an enteric coating consisting of hydroxypropyl methylcellulose stearate and castor oil which soften in the usual manner. Instead of using hard gelatin capsules, the product can also be filled into suitable enteric-coated capsules consisting of a mixture of cellulose acetate phthalate (HPMCP).

Compared to prior art substances such as cyclosporine, which can cause extensive and severe renal disorders or diseases of the lymphoproliferative system, a therapy with fumaric acid derivatives of the invention results in indications rarely listed in serious side effects.

Among other things, the immunosuppressive effect of cyclosporine is caused by the inhibition of Th-1 cell formation. As in vitro experiments by the applicant have shown, fumarates cause a shift in the Th1-type cytokine pattern to the Th2-type cytokine pattern.

In particular, in light of the long-term therapy and the obstacle always required in graft-to-host reactions and host-to-graft reactions or other autoimmune diseases, the unexpected effect of the use of the invention is of the greatest interest. In a combination therapy of cyclosporine with the fumaric acid derivatives, the toxic side effects of the previous compounds can be unexpectedly reduced to a significant degree. In addition, the use of the invention is also significant in the substitution of the corticosteroid therapy of autoimmune disease, which is known to be followed by serious side effects.