WO2007046123A2

WO2007046123A2 - Composition containing vitamins k and d as well as taurine for the preventio and treatment of osteoporosis

Info

Publication number: WO2007046123A2
Application number: PCT/IT2006/000737
Authority: WO
Inventors: Enrico Boldrini; Giulia Falcone
Original assignee: Opocrin S.P.A.
Priority date: 2005-10-21
Filing date: 2006-10-16
Publication date: 2007-04-26
Also published as: WO2007046123A3; ITRM20050521A1

Abstract

Composition for oral administration based on vitamins K and D, particularly indicated for the prevention and therapy of menopausal osteopenia and as a co-adjuvant in the treatment of osteoporosis, in which an enhanced absorption of vitamins K1 and D3 is obtained by combining these active ingredients with taurine, which promotes enteric absorption. The invention also concerns the use of a combination of vitamin K, vitamin D and taurine for the prevention and treatment of osteopenia and osteoporosis, particularly indicated in subjects with pathologies or disorders characterised by a reduced hepatic absorption.

Description

COMPOSITION CONTAINING VITAMINS K AND D FOR THE PREVENTION AND TREATMENT OF OSTEOPOROSIS

DESCRIPTION

The present invention concerns a composition containing vitamins K and D for the prevention and treatment of osteoporosis. More specifically, the invention concerns a pharmaceutical preparation for oral administration that is particularly recommended for the prevention and therapy of menopausal osteopenia and as a co-adjuvant in the treatment of osteoporosis, in which an enhanced absorption of vitamins Ki and D₃ is obtained by combining these active ingredients with taurine, which promotes enteric absorption.

As is known, osteoporosis is an anomalous rarefaction of the bone mass occurring often as a result of other pathologies, but more frequently associated with the hormonal deficiencies found in women in the period after menopause. Throughout life, new bone tissue is constantly formed thanks to the osteoblasts and, at the same time, bone tissue is resorbed through the action of osteoclasts. While during childhood and early adulthood the rate of new bone production by osteoblasts is greater than the bone resorption rate, later on in life the bone resorption rate begins to overtake the new bone production rate. Although this phenomenon occurs in both sexes, it is more marked in women, in whom, in the period after menopause, it often leads to an anomalous decrease in bone mass, accompanying a deterioration of bone tissue microarchitecture and an increase in bone tissue porosity. This pathology, known as osteoporosis, leads to a weakening of the bone and an increased propensity to fracture.

In the early 1990s, hormone replacement therapy (HRP) was considered to be the preferred treatment for osteoporosis in post-menopause women, despite the increased risk of cardio-circulatory, neoplastic and hepatic pathologies that this therapy involves. Pharmacological research later made at least three important classes of drugs available to the clinician: bisphospho- nates, raloxifene and the parathyroid hormone. At first, in the mid-1990s, bis- phosphonates (such as alendronate, risedronate and ibandronate) were successfully introduced and resulted effective in limiting bone resorption and thus in preventing or slowing down the development of osteoporosis. These drugs are currently prescribed for the prevention and treatment of osteoporosis and osteopenia in general, even if their long-term effects have not been sufficiently evaluated.

Later on, in 1999, raloxifene came onto the market. This was the first selective estrogen receptor modulator (SERM), with an action similar to that of estrogens. Although the product is not as effective as estrogens themselves, it does reduce some of the typical risks of hormone replacement therapy. It must be noted that this kind of therapy can only be prescribed for women.

Only recently has the US Federal Drug Administration approved the use of a synthetic version of the parathyroid hormone, teriparatide - the first drug for osteoporosis that has an anabolic activity. The corresponding natural hormone is the primary regulator of calcium and phosphate in the bones. The use of teriparatide, necessarily by injection, is currently recommended only for patients with severe osteoporosis and who cannot be successfully treated by means of other therapies. As may be noted from the above, the compounds currently used for combating bone loss work through different action mechanisms. They tend to be active either by reducing bone resorption or by stimulating bone growth, or by enhancing bone mineralization. The drugs which decrease resorption reduce osteoclast activity while those with an anabolic activity stimulate os- teoblast activity.

To these new drugs must be added the use of vitamin K, which has been shown to play a significant role in bone metabolism. As already noted, the increase in bone mass and its subsequent mineralization improve bone conditions and reduce the risk of fracture, and the type of microarchitecture of the minerals achieved in the mineralization process is important for resistance to fracture. Vitamin K plays a key role as a regulator of bone microarchitecture, but it can also inhibit osteoclastic activity and stimulate osteoblastogene- SIS.

As is known, "vitamin K" is a general term referring to a group of naphthoquinone derivatives having a similar biological activity, which are necessary for the bioactivation of proteins involved in homeostasis. All the natural components of the group contain the 2-methyl-1 ,4-naphthoquinone nucleus with a lipophile lateral chain in position 3. Of these, the main ones are phylloquinone, or vitamin Ki, of plant origin, having the following structure:

and the menaquinones, or vitamin K₂ - a family of compounds of bacterial origin that have an isoprenyl chain of varying length in position 3, of which one member (menaquinone-7) has the following structure:

To these must be added the synthetic component known as menadione or vitamin K₃, which is the analogue of the above compunds without a lateral chain in position 3. Menadione is, in fact, a provitamin that can be converted in vivo into vitamin K₂. Other derivates of the aforesaid compounds have been identified in the literature in the vitamin K group, even if the pharmacologically most important compound is still phylloquinone or vitamin K-i.

Vitamin K was discovered in the early 1930s as a liposoluble factor necessary for blood coagulation homeostasis, and for a long time afterwards it was thought that the coagulation of the blood was the only physiological process regulated by this agent. It is mostly known for its role as a coenzyme for glutamate-carboxylase (or gamma-glutamyl-carboxylase) - the enzyme mediating the conversion of glutamate residues into gamma-glutamate (GIa). Be- sides the more widely known proteins containing GIa, which are the factors of the coagulation cascade, other Gla-proteins were subsequently identified, arriving at establishing that vitamin K-dependent γ-glutamate-carboxylase is widely found in nature and that the Gla-proteins play a key role not only in blood coagulation, but also in other important physiological processes includ- ing bone^* formation. It was in this field that the first Gla-containing protein not involved in blood coagulation was discovered - known as osteocalcin (or bone Gla-protein).

Osteocalcin, a protein that is exclusively synthesised by osteoblasts, contains three residues of γ-carboxyglutamic acid in the molecule that give it a strong affinity for the calcium ion. Through its GIa residues, this protein binds calcium leading to mineralization and defines bone microarchitecture. It has been found, actually, that osteocalcin represents a marker of bone formation and resorption, and that its concentration in the blood varies in some bone metabolic pathologies. Moreover, it has also been found that osteocalcin, like the other Gla-proteins, is a K-dependent protein and that its synthesis is regulated by vitamin D. As is known, vitamin D (here, too, consisting more specifically of a family of structurally similar compounds, the most important of which are ergo^'calciferol or vitamin D₂, and cholecalciferol or vitamin D₃, the latter being the form more generally used as a dietary supplement) is another lipo- soluble vitamin of great importance, known to mediate the bowel absorption of calcium and phosphate, and is widely used as a nutritional agent and antirachitic factor.

Since osteoblasts need vitamin K as a co-factor for the γ-glutamate- carboxylase enzyme carrying out the post-translational conversion of glutamic acid into γ-carboxyglutamic acid in the osteocalcin molecule, and since an under-carboxylated osteocalcin is associated with conditions of decreased bone quality and increased bone fragility, vitamin K supplementation improves bone turnover and safeguards against situations of post-menopausal osteopenia and osteoporosis. Moreover, since carboxylated osteocalcin, neces- sary for bone formation, is also vitamin D-dependent, an adequate supplementation aimed at safeguarding against an anomalous reduction of bone mineral density and, in particular, against osteoporosis, is obtained by combining vitamin K with vitamin D.

Indeed, epidemiological and prospective studies demonstrate that vitamin K not only increases bone mineral density but also reduces the risk of fracture. Moreover, various clinical trials have shown that vitamin K and vitamin D, if administered orally together, act in synergy to increase bone mineral density in osteoporosis.

The literature of the field already includes various proposals for dietary supplements and nutritional preparations for protecting bone tissues based on a vitamin K and vitamin D combination, possibly including other co-adjuvants as well. For example, international patent application No. WO 97/250549 (The Boots Company) discloses an oral composition for the treatment and prevention of osteoporosis, containing vitamin K, vitamin D and a compound of plant origin called diosgenin (whose biological function is not described, however), possibly combined with vitamin B₆ and/or vitamin A.

As a further example, international patent application No. WO 02/074308 (Roche Vitamins) discloses a composition for the prevention of osteoporosis, based on a combination of isoflavons and polyunsaturated fatty acid (PUFA) in which the third ingredient, that is preferably added to the preparation to improve its effectiveness, is vitamin D and/or vitamin K. This further confirms the fact that supplementation with these two vitamins is a measure of acknowledged validity in the treatment of osteoporosis.

The evaluation of the aetiology of osteoporosis in individuals may concern an examination of the hormonal aspects, the physical activity carried out, the kind of diet as well as the digestion and absorption of nutrients. The degree of nutrient absorption is particularly important because both vitamin K and vitamin D are substances soluble in lipids. Therefore, poor absorption of fats and their alteration in the small intestine can lead to a haematic deficiency of these vitamins, which are fundamental in bone metabolism to prevent os- teoporosis.

Indeed, chronic hepatic pathology is frequently associated with osteopenia ed osteoporosis, particularly in hepatic disorders associated with alcoholism and hepatic cholestasis. In this regard, it has been found that patients with alterations of the biliary flow are at risk of bone disorders, also due to the poor absorption of calcium, vitamin D and vitamin K. In particular, clinical studies have shown that in subjects with primary biliary cirrhosis show subnormal plasmatic levels of vitamin K, that are insufficient for protecting the bones (Kowdley K. V. et al., Plasma and vitamin Ki level is decreased in primary biliary cirrhosis, Am. J. Gastroenterol., 1997, 92:2059-61).

Moreover, recent studies showing that celiac disorder (a permanent intolerance to gluten) is not so rare since it affects one person out of every 250, underline the involvement of this intolerance in the aetiology of osteoporosis, due to the poor absorption of the necessary factors for bone tissue health, including vitamin K.

Even inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis, present a high incidence of osteopenia among patients, and in this case, too, the problem has been related to a deficiency or poor absorption of certain nutrients necessary for bone tissue, and particularly vitamins K and D (Dresner Pollak R. et al., Femoral neck osteopenia in patients with inflammatory bowel disease, Am. J. Gastroenterol., 1998, 93:1483-90; Duggan P. et al., Vitamin K status in patients with Crohn's disease and rela- tionship to bone turnover, Am. J. Gastroenterol., 2004, 99:2178-85).

In view of the foregoing, it is evident that the role of vitamin K and D supplementation for bone health is of great interest in patients with an altered biliary flow or altered lipid composition in the bowels due to deficiencies in micronutrient absorption. The present invention thus aims to provide a com- position for oral administration that is effective in the prevention and/or treatment of osteoporosis, where vitamins K and D are optimally absorbed and have an enhanced bioavailability with respect to conventional preparations based on these two vitamins. The sought composition would be, thus, particularly recommended also in cases of pathological deficiencies in absorption, such as the cases connected to the aforesaid hepatic, pancreatic and bowel disorders.

To this end, the studies leading to the present invention considered the possibility of combining the two liposoluble vitamins K and D with a co- adjuvant enabling an enhanced absorption following oral administration. This is in order to facilitate the conveyance of these factors, thereby increasing their bioavailability and achieving adequate levels in the action site, in particu- lar, in bone tissue. According to the present invention, it has been found that the amino acid known as taurine can optimally be used as the co-adjuvant, thus considerably enhancing the bioavailability of vitamin K and vitamin D when orally administered in combination with them.

As is known, taurine or 2-aminoethanesulfonic acid (NH2-CH2-CH2- SO₃H) is a non-essential amino acid widely found in nature. It is not used in protein synthesis but is found freely in the body in simple peptides. It is virtually absent in plants and is formed in animal tissues to varying extents depending on the species, but its physiological function is still not completely understood. Taurine has been shown to be essential in certain aspects of mammal development, particularly for cells of the cerebellum and of the retina, and in vitro studies have shown that low levels of this amino acid are associated with various pathologies including cardiomyopathy, retinal degeneration and stunted growth.

The hitherto most important known action of taurine is of a metabolic kind, for its capacity to combine with the biliary salts present in the milk of many animal species, including man (but only in very small amounts in cow milk). In the form of sodium salt, taurocholic acid is the largest component of the bile of carnivorous animals and it has been found that the emulsification of lipids by taurocholic acid is a mechanism facilitating the conveyance of lipid substances in the enterohepatic system.

There is also experimental evidence supporting the hypothesis that taurine has the function of mediating a protective action on the cell membrane leading to an increase in cell life, and that is why it has been considered a beneficial factor in regulating cell homeostasis in animals and in man. It is on the basis of the latter hypothesis that US patents 4629625 and 4751085 (Gerard E. Gaull) propose nutritional compositions for human use based on taurine and vitamins, to be used either for enriching food products, such as milk, or to be taken in the form of capsules or tablets as dietary supplements. It must be noted that the "vitamins" proposed for the described nutritional composition are mainly vitamins A, C and E₁ as well as iron, while many other factors (including vitamins K and D) are cited only as possible additional sec- ondary ingredients. No biological effect of the described nutraceutical composition, besides a generic benefit for nutrition and health, is mentioned in the two documents considered.

On the other hand, according to the present invention, it has been found that the capacity of taurine to convert lipids into a soluble aqueous state plays a key role in the absorption of liposoluble substances in the bowels, and particularly in the absorption of vitamin K and vitamin D. For this reason, the combination of vitamins K and D with taurine, proposed according to the present invention, enhances the effectiveness of the therapy and prophylaxis safeguarding bone tissues, enabling the successful treatment also of cases where, owing to particular pathological deficiencies, the two vitamins are not absorbed in a satisfactory way.

Therefore, the present invention specifically provides a composition for the prevention and treatment of osteopenia and osteoporosis containing, in combination, therapeutically effective amounts of vitamin K, vitamin D and taurine. As already noted, the preferred forms of vitamin K and vitamin D suitable for preparing the composition according to the present invention are, respectively, vitamin K₁ (phylloquinone) and vitamin D₃ (cholecalciferol), but the use of other biologically equivalent forms, derivatives or mixtures instead of the aforesaid ones is not to be ruled out. According to the preferred embodiments of the present invention, the proposed composition is formulated in a preparation suitable for oral administration, in particular in the form of tablets, pills, hard or soft capsules, granules to be dissolved in a liquid medium or drops for oral solutions.

More specifically, the proposed composition can comprise the follow- ing active ingredients in the following proportion ranges: vitamin Ki 0.07 - 1 mg (70 μg - 1 mg) vitamin D₃ 0.005 - 0.020 mg (5-20 μg = 200-800 Ul) taurine 100 - 1000 mg (100 mg - 1 g)

In a particularly preferred form, the composition corresponds to the following formulation: vitamin Ki 105 μg vitamin D₃ 7.5 μg taurine 150 mg

The active compositions according to the present invention can be incorporated in conventional pharmaceutical preparations, in solid or liquid dosage forms. These can contain additives normally used in pharmaceutical art such as sweeteners, flavours, colorants, covering agents and preservatives, inert diluents like calcium carbonate, sodium carbonate, lactose and talc, binders such as starch, gelatine and polyvinylpyrrolidone, suspension agents such as methylcellulose or hydroxyethylcellulose, imbibition agents like lecithin, polyoxyethylene stearate and polyoxymethylene sorbitan-monooleate, reducing agents such as ascorbic acid and its salts as well as other suitable pharmaceutical excipients. In particular, a composition in tablet form that is particularly suitable for the purposes of the present invention can contain as excipients, alongside the three aforesaid active ingredients, microcrystalline cellulose, magnesium stearate and colloidal silica. A suitable liquid composition can contain polysorbate 20 and 80, potassium sorbate, methyl p-hydroxy benzoate, citric acid and fructose; a granulate composition can contain, as excipients, maltodextrins and fructose; finally, a suitable composition for capsules can contain, as excipients, bibasic calcium phosphate, gelatine or hy- droxypropylmethylcellulose.

Depending on the pharmaceutical form and content of the active ingredients, the dosage may be of one unit, 1 to 4 times a day. For the aforesaid preferred formulation (vitamin K 105 μg, vitamin D 7.5 μg and taurine 150 mg), proposed in 400 mg tablets, a dosage of 1-2 tablets per day, on an empty stomach, is suggested.

Since the preparation aims to prevent a chronic disease such as os- teoporosis, the duration of the administrations must range from a minimum of 6 months to 5 years. To improve patient compliance, a break of 2-3 months every 12 months of treatment can be recommended.

According to another aspect thereof, the present invention concerns the use of a combination of vitamin K, vitamin D and taurine for the manufacture of a preparation for the prevention and treatment of osteopenia and osteoporosis. The preparation, which preferably contains vitamin Ki, vitamin D₃ and taurine, is specifically suitable for oral administration and preferably contains, as already noted, the following active ingredients in the following propor- tions: preferred vitamin Ki 0.07 - 1 mg 105 μg vitamin D₃ 0.005 - 0.020 mg 7.5 μg taurine 100 - 1000 mg 150 mg

It must be noted that, thanks to the synergistic combination with taurine, the use of the proposed preparation is particularly indicated for the prevention and treatment of osteopenia and osteoporosis in subjects with pathologies or disorders characterised by a reduced hepatic absorption. The specific features of the present invention, as well as its advantages and relative operating modalities, will be more evident with reference to the detailed description presented below merely for exemplificative purposes, together with the results of the experiments carried out on it, and the comparative data^' with respect to the prior art.

Biological trials - bioavailability

A study compared the absorption of vitamin Ki combined with vitamin D₃ with the absorption of the same combination in the presence of taurine.

The study was carried out on 5 women aged between 55 and 65 years in normal health conditions, by administering in a first phase a preparation (A) consisting of vitamin K (105 μg) and vitamin D₃ (7.5 μg) in a single administration. After 15 days the same subjects received preparation (B) consisting of vitamin K (105 μg) + vitamin D₃ (7.5 μg) + taurine (150 mg) still in a single administration.

In both stages of the trial, blood test sampling for determining vitamin K was carried out at time 0 and at various intervals up to 9 hours after oral administration. The vitamin K was measured by HPLC with fluorescence determination, using dihydro-vitamin K as an internal standard, according to a standardised method.

The results obtained are reported in Table 1 , which shows the vitamin K absorption in subjects supplemented with:

(A) : vitamin K (105 μg) + vitamin D₃ (7.5 μg)

(B) : vitamin K (105 μg) + vitamin D₃ (7.5 μg) + taurine (150 mg)

TABLE 1 Plasmatic levels of vitamin K

Group No. of Max. concn. ¹⁾ Max. t 2) AUC ³ ) subjects nmol/L h nmol/L h

(A) 5 2.7 ± 0.69 3.5 ± 0 56 3 .23 ± 0 89

(B) 5 3.29 ± 0.825 a) 4 9 + ₁ 0 ^a) 4 .38 ± 0 71

1) Peak vitamin K concentrations, m ± s.d..

2) Time corresponding to the maximum concentration observed.

3) Area under the absorption curve. a) Statistically significant differences of (B) Vs. (A) [P<0.009].

From the above data, it is evident that the supplementation of preparation (B) containing taurine appreciably enhances enteric absorption of vitamin K, enabling the obtaining of blood levels which can guarantee a greater contribution of vitamin K to the bones.

On the basis of the results shown, it may be deemed that the quantity of taurine used in the preparation according to the present invention promotes the bioavailability of liposoluble vitamin K. As already noted, this may be of great importance in all conditions of altered lipid absorption caused by hepatic and pancreatic bowel pathologies.

The present invention has been disclosed with reference to some of its specific forms of realisation, but it is understood that variations or modifica- tions thereof can be made by experts in the art without departing from the relative sphere of protection.

Claims

1. Composition for the prevention and treatment of osteopenia and osteoporosis containing, in combination, therapeutically effective amounts of vitamin K, vitamin D and taurine.

2. Composition according to claim 1 , wherein the said vitamin K is vitamin Ki.

3. Composition according to claims 1 or 2, wherein the said vitamin D is vitamin D₃.

4. Composition according to any one of claims 1-3, formulated in a preparation for oral administration.

5. Composition according to any one of claims 1-4, comprising the following active ingredients in the following proportions: vitamin Ki 0.07 - 1 mg vitamin D₃ 0.005 - 0.020 mg taurine 100 - 1000 mg

6. Composition according to claim 5, including the following active components in the following proportions: vitamin Ki 105 μg vitamin D₃ 7.5 μg taurine 150 mg

7. Use of a combination of vitamin K, vitamin D and taurine for the manufacture of a preparation for the prevention and treatment of osteopenia and osteoporosis.

8. Use according to claim 7, wherein the said vitamin K is vitamin K-|.

9. Use according to claims 7 or 8, wherein the said vitamin D is vitamin D₃.

10. Use according to any one of claims 7-9, wherein the said preparation is for oral administration.

11. Use according to any one of claims 7-10, wherein the said prepa- ration includes the following active ingredients in the following proportions: vitamin Ki 0.07 - 1 mg vitamin D₃ 0.005 - 0.020 mg taurine 100 - 1000 mg

12. Use according to claim 11 , wherein the said preparation includes the following active ingredients in the following proportions: vitamin Ki 105 μg vitamin D₃ 7.5 μg taurine 150 mg

13. Use according to any one of claims 7-12, wherein the said preparation is indicated for the prevention and treatment of osteopenia and osteopo- rosis in subjects with pathologies or disorders characterised by a reduced hepatic absorption.