MXPA01000431A - Treatment of restenosis - Google Patents

Abstract

Bisphosphonate (BP), pyrophosphate (PP) a complex of BP or PP, a polymer of BP or PP or a pharmaceutically acceptable salt or ester thereof, are used for the prevention or treatment of vascular restenosis.

Description

TREATMENT OF RESTENOSIS FIELD OF THE INVENTION The present invention concerns compositions capable of preventing, inhibiting or reducing restenosis (sometimes referred to in the art as "accelerated arteriosclerosis" and "post-angioplasty narrowing").

PREVIOUS TECHNIQUE The following references are considered pertinent in order to understand the background of the present invention. 1. Waller, B.F., Orr, C.M., VanTassel J., et al. Clin-Cardiol. 20 (2): 153-60, (1997). 2. Anderson, W. D., King, S. Br., Curr-Opin-Cardiol., 11 (6): 583-90, (1996). 3. Moorman, D.L., Kruyer, W.B., Jackson, W.G., Aviat-Space-Environ-Med.67 (10): 990-6, (1996) 4. Laurent S, Vanhoutte P, Cavero I, et al., Fundarn. Clin. Pharmacol., 10 (3): 243-57, (1996). 5. Walsh, K .; Perlman, Semin-Interv-Cardiol., 1 (3): 173-9, (1996). 6. Schwartz, R.S., Semin-Interv-Cardiol., 2 (2): 83-8, (1997). 7. Allaire, E .; Clowes, A.W., Ann. Thorac. Surg., 63: 582-591 (1997). 8. Hamon, M., Bauters, C, McFadden, E.P., et al., Eur. Heart J., 16: 33s-48s, (1995). 9. Gottsauner-Wolf, M., Moliterno, D.J., Lincoff, A.M., Topol, E.J., Clin. Cardiol., 19: 347-356, (1996). 10. Herrman, J.P.R., Hermans, W.R.M., Vos, J., Serruys, P.W., Drugs, 46: 18-52, (1993). 11. Leclerc, G., Voisine, P., Bouchard, M., Fleser, A., Martel, R. Elsevier Science, 722-724, (1995). 12. Topol, E., The NY Academy of Sciences, 225-277, (1997). 13. Fleixch, H., in: Bisphosphonates in bone disease (Bisphosphonates in bone diseases). Parthenon Publishing Group Inc., pp. 184-186 (1997). 14. Mónkkónen, J. Taskinen, M., Auriola, s., Urtti, J. Drug Target, 2: 299-308 (1994). 15. Kramsche, D.M., and Chan, C.T., Circ. Res., 42: 562-572, (1978). 16. Braunwald, E. Heart Disease in: A textbook of cardiovascular medicine (A textbook for cardiovascular medicine), 5th ed., W.B.

Saunders Company; Philadelphia (1997). 17. Gennaro Alfonso, R. Remington, in: The Science and Practice of Pharmacy, Mack Publishing, Easton PA, 19th ed., (1995). 18. Mónkkónen, J., and Heath, T.D., Calcif. Tissue Int., 53: 139-145 (1993). 19. M. Donbrow in: Microencapsulation and Nanoparticles in Medicine and Pharmacy, CRC Press, Boca Raton, FL, p.347.

The above references will be acknowledged in the text below by indicating their number (as shown in parentheses) of the previous list.

ANTEC EDENTS OF THE INVENTION Over the past decade, mechanical means to achieve revascularization of obstructive atherosclerotic vessels have been greatly improved. Percutaneous transluminal coronary angioplasty (PTCA) procedures include, but are not limited to, balloon dilation, excision atherectomy, endoluminal stent placement, rotabulation, and laser ablation. However, revascularization induces neointimal thrombosis and perplasia, which in turn causes restenosis in a substantial proportion of coronary arteries after successful wolf angioplasty and in saphenous vein coronary artery bypass graft and other coronary grafts. In addition, intimal hyperplasia causes restenosis in many superficial femoral angioplasties, carotid endarterectomies, and leads from the imelo-distal veins. The introduction of endovascular stents has helped reduce the incidence of restenosis, but this problem remains significant (1-9). Despite extensive research on the incidence, times, mechanisms and pharmacological interventions in humans and animal models, there is currently no therapy that consistently prevents coronary restenosis (1 0-1 2). Compositions and methods for the reduction or prevention of restenosis are still greatly desired today.

Bisphosphonates (BP) (formerly diphosphonates) are compounds characterized by two C-P bonds. If the two bonds are placed on the same carbon atom (P-C-P), they are called gem-bisphosphonates. BPs are analogs of endogenous inorganic pyrophosphate, which is involved in the regulation of bone formation and resorption. The term bisphosphonates is generally used for gem and non-geminal bisphosphonates. The BPs and pyrophosphates can form together, sometimes, polymer chains. BPs act on bone due to their affinity for bone minerals and are potent inhibitors of bone resorption and ectopic calcification. The PBs or pyrophosphates have been used mainly in a clinical manner as (a) clear antiesteol agents in patients with increased bone destruction, especially in Paget's disease, tumor bone disease and osteoporosis.; (b) skeletal markers for diagnostic purposes (linked to 99mTc); (c) calcification inhibitors in patients with ectopic calcification and ossification, and (d) antisharp agents added to the toothpaste (1 3).

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, a BP or pyrophosphate (collectively herein "active ingredient") is used for vascular treatment or prevention. The term bisphosphonate (BP), as used herein, denotes both gemic and non-gem bisphosphonates. The term "active ingredient" also encompasses in its overview, polymer chains of the BPs or pyrophosphate, particularly such chains consisting of up to 40 BP monomers. Preferred active ingredients are compounds of the following formula (I) OH OH O = I P - R - P I = F I i OH OH wherein R represents O or a group CR1 R2; RT is H, OH or a halogen group; and R2 is halogen; C 1 -C 1 linear or branched alkyl or C 2 -C 10 alkenyl optionally substituted by heteroaryl or heterocyclyl C 1 -C 0 alkylamyl or C 3 -C 3 cycloalkylamino, where the amino can be primary, secondary or tertiary; -NHY, where Y is hydrogen, cycloalkyl, aryl or C3-C8 heteroaryl; or R2 is -SZ, where Z is pyridinyl or chlorosubstituted phenyl. In this manner, the present invention provides the use of said active ingredient, a complex of said active ingredient or a pharmaceutically acceptable salt or ester thereof, for the preparation of a medicament for the prevention or treatment of vascular restenosis. The present invention also provides a method of treating restenosis, comprising administering to an individual in need, an effective amount of said active ingredient, a complex thereof or a pharmaceutically acceptable salt or ester thereof. The present invention still further provides a pharmaceutical composition for the prevention or treatment of restenosis, comprising, as an active ingredient, an effective amount of said active network ing, a pharmaceutically acceptable free acid, a complex or a salt thereof, optionally together with a pharmaceutically acceptable carrier or dioluent. A particularly preferred carrier is a liposome preparation. The term "effective amount" denotes an amount of the active ingredient that is effective to achieve the desired therapeutic result, namely, prevention or reduction of vascular restenosis. The effective amount may depend on a variety of factors, including: weight and gender of the individual treated; the type of medical procedure, for example, if the vascular restenosis to be inhibited is after balloon angioplasty, balloon angiotoplasty followed by deployment of a stent, etc.; the mode of administration of the active ingredient (ie, whether it is administered systemically or directly to the site); the type of carrier being used (for example, if it is a carrier that rapidly releases the active ingredient or a carrier that releases it for a period); the therapeutic regimen (for example, if the active ingredient is administered once a day, several times a day or once a certain time); clinical factors that influence the speed of development of restenosis, such as diabetes, smoking, hypercholesterolemia, kidney diseases, etc.; anatomical factors, such as, if there is severe pre-angioplasty stenosis, total occlusion, left anterior descending coronary artery location, saphenous vein graft lesion, long lesions, multi-lesion or multilayer PTCA; in the dosage form of the composition; etc. Moreover, the procedural variables may also have presence in the dosage, such as, greater residual stenosis following PTCA, severe dissection, intimal tearing, appropriate size of the balloon and the presence of thrombi. The technician, through routine experimentation, should not have any difficulties in determining the effective amount in each case. The invention is applicable for the prevention, reduction or treatment of vascular restenosis, and mainly, but not limited to, coronary restenosis after angioplasty. Vascular restenosis results from several angioplasty procedures including balloon angioplasty, intravascular stent implantation or other methods of percutaneous angioplasty (including angioplasty of coronary arteries, carotid arteries and other receptive vessels for angioplasty), as well as for resenosis resulting from vascular graft stenosis (eg, following bypass surgery) (1 6). In addition, the invention is also applicable for use in the prevention, reduction or treatment of vascular restenosis in peripheral arteries and veins. An exemplary application of the invention is to plan and treat in-stent restenosis. It is a widely acceptable medical procedure to deploy a stent within a blood vessel within the framework of an angioplastic procedure to support the walls of the blood vessel. However, restenosis very often occurs without involving the presence of the stent within the blood vessel. According to the invention, the active ing network noted above can be administered, either systemically or directly to the site, in order to prevent or inhibit such restenosis. Potentially, said active ingredient can be formed in a manner that allows its incorporation onto the stent, which will, in effect, produce the administration of said active ingredient directly at the site. The active ingredient can be formulated in that manner, for example, by including it within a coating of the stent. Examples of coating are polymer coatings, for example, made of polyurethane or a gel. The active ingredient used according to the invention can be formed in pharmaceutical compositions by any of the conventional techniques known in the art (see, for example, Alfonso, et al, 1995 (17)). The compositions can be prepared in various forms, such as capsules, tablets, aerosols, solutions, suspensions, as a coating of a medical device, such as, a stent (see above), etc. In addition, the pharmaceutical compositions of the invention can be formulated in a form suitable for topical administration with a carrier or in a delivery form that allows the penetration of the active ingredient through the skin into the body in order to act systemically. The preferred form of administration in each case will depend on the desired mode of delivery, which usually is the one that is most physiologically compatible according to the condition of the patient, other therapeutic treatments the patient receives, etc. According to a preferred embodiment of the invention, said active ingredient is formulated in a particulate form. This can be achieved by encapsulating or impregnating the active ingredient into particles, for example, polymer particles, lipid vesicles or liposomes. Additionally, such particles may be particles of polymerized active ingredient (see below). Particularly preferred are liposome preparations of said active ingredient. The liposomes can be prepared by any of the methods known in the art (with respect to liposome preparation methods, see Mónkkónen et al., 1 994 (14) and Mónkkónen et al (1 8)). Liposomes may be positively charged, they may be neutral or they may be negatively charged (currently, negatively charged liposomes are preferred), they may be simple or multilamellar. Sometimes, compositions comprising a combination of free (ie, non-encapsulated) active ingredient and said active ingredient encapsulated within the liposomes can also be used. By a preferred embodiment of the invention, the active protein is preferably selected from such compounds, which are capable of undergoing intracellular metabolism. A preferred active ingredient for this group is the compound clodronate (1 3), which has the following formula (I I): OH Cl OH O P = O (II) OH Cl OH Clodronate was previously described for use in the treatment of hypercalcemia that results from malignancy in the treatment of tumor-associated osteolysis (13), and as a macrophage inhibitor (14, 18).

Other preferred active ingredients of this group are Etidronate and Tiludronate, which have the following formulas (11) and (IV), respectively: OH CH3 OH I I I o = p - c - P = o (ni) I I i OH OH OH OH H OH O = P P = O (IV) OH OH Cl Additional BPs that have activities similar to those of clodronate are also preferred according to the invention. Such BPs can be selected based on their ability to mimic the biological activity of clodronate. This includes, for example: in vitro activity to inhibit the phagocytic activity of phagocytic cells, e.g., macrophages and fibroblasts; inhibition of secretion of I L-1 and / or I L-6 and / or TNF-α of macrophages; in vivo activity, for example, the ability of the BP tested to prevent or reduce restenosis in an experimental animal model, such as, for example, the rat or rabbit carotid catheter injury model described in Example 1 below, or model portion not of restenosis; etc. Another preferred group of active ingredients according to the invention are the ami no-BPs and any other nitrogen-containing BP, having the following general formula (V) OH OH OH O = P - C P = * O (V) OH X OH wherein x represents alkylamino of C TC ^ O cycloalk or C3-C8ylamino, where the amino can be primary, secondary or tertiary; or x represents NHY, where Y is hydrogen, cycloalkyl, aryl or heteroary lo of C3-C8. It is believed that the BPs belonging to this group are not metabolized and it has been shown that at relatively low concentrations they induce the secretion of interleukin I L-1 and cause, at relatively low concentrations, apoptosis in macrophages (1 8). The preferred BPs belonging to this group are, for example, Pamidronate and Alendronate, having the following formulas (VI) and (Vi l), respectively.

OH OH OH I I I O = P - C - P = O (VI) I I I OH (CH2) 2 OH. I NH2 OH OH OH I I I o = p - c - p = or rvii) I I I OH (CH2) 3 OH I NH2 Although gemological BPs are preferred BPs according to the invention, non-gemological BPs, monophosphonates of BPs generally referred to as phosphonates, can also be used as active reagents according to the invention. Another preferred active ingredient is pyrophosphate having the formula (VI I I): OH OH O = P - O - P = O (HIV) I I OH OH Preferably, the pyrophosphate is formed and adm ined into a liposome or a preparation of polymer particles.

The composition of the invention may comprise said active ingredient either in its free acid form, in complex with metal cations, such as calcium, magnesium or organic bases, or it may be in the form of salts or esters, or they may be polymerized to produce polymers of up to 40 monomers. The salts may be sodium, potassium, ammonium or calcium salts, or salts formed with any other suitable basic cation (eg, organic amino compounds). The salts or polymers may be in a particulate form in microns, having a diameter in the range of about 0.01-1.0 μm, preferably within a range of about 0. 1 -5 μm. The active ingredients in the compositions of the invention which are either in free acid form or salt form, may or may not have water of crystallization (hydrated or anhydrous). By a preferred embodiment, the active protein is encapsulated within a liposome prepared by any of the methods known in the art. Suitable liposomes according to the invention are preferably non-toxic iposomes, such as, for example, those prepared from phosphatidyl-choline phosphatidylglycerol and cholesterol, for example, as described later. In many cases, the use of the active encapsulated protein in a liposome results in enhanced uptake of the active ingredient by cells via endocytosis (14, 18) (such uptake may play a role in the therapeutic effect). The liposome diameter used in the examples below was between 0.5 and 300 nm. However, this is not limiting, but merely an example, and liposomes of other size ranges can also be used. In addition, the active ingredient can be encapsulated or embedded in inert polymeric particles, such as, for example, any of the microcapsules, nanocapsules, nanoparticles, nanospheres, microspheres, microparticles, etc. known in the art (1 9). The release of the active n ng of such particles can be a controlled release, which results, in some cases, in a prolonged and intensified effect and uptake of said active ingredient. The pharmaceutical carrier or diluent used in the composition of the invention can be any of the conventional solid or liquid carriers known in the art. A solid carrier, for example, can be lactose, sucrose, talc, gelatin, agar, etc. Where the carrier is a liquid carrier, this may be, for example, peanut oil, phospholipids, water, etc. Where the solid carrier is used for oral administration, the composition may be in the form of a tablet, in the form of a hard capsule (e.g., a gelatin capsule), in powder or pellet form. Where a liquid carrier is used, the preparation may be in the form of a syrup, emulsion, liposomes, soft or liquid sterile and sterile capsule, such as a liposome preparation, a liquid aqueous or non-aqueous suspension or a solution (1 7). The composition of the invention used for injection can be selected from emulsions, solvents, suspensions, colloidal solutions containing suitable additives, etc.

The compositions of the invention can be administered by any route, which effectively transports the active compound to the appropriate or desirable site of action. By a preferred embodiment of the invention, modes of administration are intravenous (i.v.) and intra-arterial (i.a.) (particularly suitable for in-line administration). Other modes of administration include intramuscular (i.m.) or subcutaneous (s.c.). Such administration can be infusions or bolus injections. The compositions may also be admired locally at the diseased site of the artery, for example, by means of a drainage / exudate balloon known in the art. Another mode of administration may be by pervasive delivery, coating the delivery system in a balloon or a stent, or by any other method of delivery systems of cardiovascular medicament known in the art. Combinations of any of the above routes of administration according to the invention may also be used. The dosage of the active ingredient to be used also depends on the specific activity of the active ingredient used, the mode of administration (eg, systemic administration or local delivery), the form of the active ingredient (eg, if it is in the form of a medicament, in a form of a polymer, if it is encapsulated in a particle, such as a liposome, etc.) and other factors as are known per se. According to a preferred embodiment of the invention, treatment of an individual with the active ingredient may be for the purpose of preventing restenosis before it occurs. For prevention, the active ingredient may be admired to the individual prior to the angioplasty procedure, during the procedure or after the procedure, as well as a combination of before, during or after the administration of the procedure. According to another embodiment of the invention, the active ingredient is administered to an individual suffering from restenosis for the purpose of reducing or treating restenosis. In such a case, the active ingredient may also be admired to the individual at different periods after the restenosis is discovered, either alone or in combination with other kinds of treatments. In addition, the active ingredient can be admired before any other condition that can produce accelerated atherosclerosis, as well as precisely after the process has been initiated to prevent further development of the condition.

BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1-3 are bar graphs of results demonstrating the effect of clodronate encapsulated in l iposomes on the reduction of restenosis in an experimental rat carotid catheter injury model, as compared to the effect of control liposomes, which do not contain clodronate in the same rats. In these figures: Fig. 1 shows the degree of average luminal ntimal formation and the neointimal proportion at average averaging in rats treated with liposomes containing Clodronate, as compared to rats treated with control liposomes; Fig. 2 shows the% stenosis in rats treated with liposomes containing Clodronate, as compared to% stenosis in rats treated with control liposomes; and Fig. 3 shows the degree of medial area as an indirect index of soft muscle cell viability and determined as the difference between the total arterial area and the original lumen area in rats treated with liposomes containing Clodronate, as compared to treated rats with control liposomes only.

EXAMPLES The invention will now be demonstrated by way of example, not limitation, with reference to the accompanying drawings: Example 1 Methods and materials Clodronate liposomes Stock solutions of clodronate were prepared by dissolving the drug in deionized water at a concentration of 0. 1 1 M, pH = 7.

Preparation of liposomes We accurately weighed 38.9 mg of distearoylphosphatidylglycerol (DSPG), 1 8.5 mg of distearoyl-phosphatidylcholine (DSPC) and 38.7 mg of cholesterol, and dissolved in 20 ml of chloroform: methanol (9: 1) in a Round bottom flask. The bottle was heated gently. The solvent was then evaporated in a rotoevaporator. Then 20 ml of hydrated diisopropyl ether was added and the bottle was placed in a water bath until the contents dissolved. Then 8 ml of the clodronate solution prepared as described was added and the solution was stirred at 55 ° C for a period of 45 ml. The organic phase was then evaporated on a rotoevaporator (55 ° C, 1 00 rpm). Similarly, other liposomes containing medicine can be prepared.

Purification of prepared liposomes A Sephadex gel was prepared by dissolving 2.6 g of Sephadex G-50 in 40 μl of water and stabilizing overnight. The column was rinsed with 1 00 ml of buffer (50 mM month + 50 mM HEPES + 75 mM NaCl, pH 7.2). The liposomes were applied to the column and the column was rinsed with the buffer. The liposome is seen as a band, which can be segmented in the column by its color. Approximately 20 drops of the column were collected in each tube.

Animals Animals were obtained and housed in the animal facilities of the Faculty of Medicine, the Hebrew University of Jerusalem, according to the standards of care and use of laboratory animals of the Hebrew University of Jerusalem. Male rats of strain Sabrá weighing 350-420 g were used. The animals were fed standard laboratory feed and running water ad libitum. All live experiments were done under general anesthesia achieved with 80 mg / kg of ketamine and 5 mg / kg of xylazine administered i. p.

Rat Carotid Catheter Injury Model The external carotid and distal left common arteries were exposed through a midline neck neck injury. The left common carotid artery stripped of the endothelium by the intraluminal passage of a 2F wolf catheter, introduced through the external carotid artery. The catheter was passed three times with the balloon sufficiently distended with saline solution to generate a slight resistance. The catheter was then removed and the external carotic artery was ligated: and the wound was closed with surgical staples. Seven rats served as the control group and 6 rats served as the treated group (randomly chosen). Posodomal li clodronate was injected i.v. to the "treated group" one day before the arterial injury (6 mg of clodronate per rat) and repeated on day 6. In the control group, similar injections were admitted but with "empty" liposomes (without clodronate) . All animals were sacrificed 14 days after the injury by an overdose of pentobarbital. The arteries were fixed with perfusion with 1 50 ml of 4% formaldehyde solution, pH 7.4 at 1 00 mm Hg. The right atrium was dissected and a 1 8G catheter connected to the perfusion system was inserted into the left ventricle. The arterial segments were dissected, cut, gently separated from the polymer, and fixed posteriorly for at least 48 h in the same fixation solution. The arterial segments were embedded in paraffin and cut into 8-10 separate sites 600 μm, and sections of 6 μm were mounted and stained with Verhoeff elastin stain for histological examination.

Morphometric analysis The slides were examined microscopically by a researcher blinded to the experimental group type. Six to eight sections on each slide were evaluated by morphometric analysis and the sectioned data were additionally used as representative of a complete slide for cross-group comparisons. The residual lumen, the area joined by the internal elastic lamina (original lumen) and the area circumscribed by the external elastic lamina ("total arterial area") were measured directly. The degree of neointimal thickening was expressed as the ratio between the area of the neointima and the original lumen (% stenosis), and as the ratio between the neointimal area to the area of the mean (N / M). The medial area, an indirect index of SMC viability, was determined as the difference between the total arterial area and the original lumen area.

RESULTS The surgical procedure and treatment did not cause mortality or apparent morbidity of the animals. As seen in Fig. 1, the degree of average neointimal formation and the neointimal to average mean (N / M) ratio following the treatment with clodronate encapsulated in liposomes was significantly reduced. The N / M ratio in rats treated with clodronate was 0.28 ± 0.23, as compared to 1.42 ± 0.26 in the control group (mean ± SD, p <0.01). Similarly, as seen in Fig. 2, a significant inhibition of% stenosis was achieved in the treated group: 9.8 ± 7.76 vs 4.53 ± 7.9, treated and control groups, respectively (mean ± SD, p <0.01). There were no apparent systemic side effects or effects on somatic growth as seen in Fig. 3. Conclusion: The treatment of rats with liposomes containing clodronate significantly reduces the restenosis seen as neointimal formation following lesion by wolf of the carotid artery.

Example 2 Materials and methods The anti-restenotic effects of liposomal clodronate injections were studied in models of atherosclerotic rabbit carotid artery and balloon-injured rat. The rats were treated by liposomes containing clodronate, empty liposomes (control) and clodronate in solution (additional control). The dose of clodronate injected was 1.5 and 1.5 mg / kg administered on the day before the procedure (-1) and / or on day 6 (+6) after injury. Rabbits (following 30 days of the atherosclerotic diet) were treated one day before balloon angioplasty by liposomal clodronate (10 mg / kg). The areas and volumes of lumen, neointimal, medial and vessel were measured in the groups of treated and control animals by means of digital planimetry of histological sections, at 14 and 30 days after lesion in the rat and rabbit models, respectively.

Results The results are shown in the following Table 1 As can be seen, no significant differences were found between treatments with empty liposomes and free clodronate in solution (see table), exhibiting a marked neointimal formation. The average neointimal formation rate, the ratio of neo intima to average averaging (N / M) and% stenosis following the treatment with liposomes loaded with clodronate was significantly reduced. The medial area was not affected by the various treatments, indicating no detrimental effect on quiescent cells. Furthermore, there were no apparent systemic side effects or effects on somatic and bone growth. Significantly more potent treatments, without any significant difference between them, were injections of 1 x 1 5 mg / kg (-1) and 2 x 1 5 mg / kg (-1 and +6). Similar findings were observed without adverse effects in the study of rabbits. Liposomal clodronate was significantly effective in reducing neointimal formation and% stenosis. Injection of silica particles also reduces intimal formation (Table 1). This effect could be attributed to the known inhibition effect of silica on macrophages. The results show that the treatment by liposomes containing clodronate significantly reduces the neointimal formation following balloon injury in both rat and rabbit models. There were no apparent local and systemic side effects or effects on somatic growth. It should be noted that although B Ps are known to affect bone, no effects on bone or calcium and phosphorus levels in bone and blood were observed, following treatment with the liposomal clodronate preparation.

Claims (24)

1. The use of an active ingredient that is particulate bisphosphonate (BP), a particulate complex or salt of BP, particulate polymer of BP, for the preparation of a pharmaceutical composition for the prevention or treatment of vascular restenosis.

2. The use according to claim 1, wherein the pharmaceutical composition is for intravenous (i.v.), intramuscular (i.m.) or subcutaneous (s.c.) administration.

3. The use according to claim 1, wherein said active ingredient has the general formula (I), which is in a particulate form: OH R? OH I! I O = P - c - P = O I I I OH R2 OH R1 is H, OH or halogen group; and R2 is halogen; linear or branched C1-C10 alkyl or C2-C10 alkenyl optionally substituted by heteroaryl or heterocyclyl C1-C10 alkylamino or C3-C8 cycloalkylamino, where the amino may be primary, secondary or tertiary; -NHY, where Y is hydrogen, cycloalkyl, aryl or C3-C8 heteroaryl; or R2 is -SZ, wherein Z is pyridinyl or chlorosubstituted phenyl; for the preparation of a pharmaceutical composition for the prevention or treatment of vascular restenosis.

4. The use according to claim 2, wherein said active ingredient is selected from the group consisting of clodronate, etidronate, tiludronate, pamidronate or alendronate.

5. The use according to any of claims 1 to 3, wherein said restenosis is arterial restenosis.

6. The use according to claims 1 to 5, wherein the particulate active ingredient is encapsulated within liposomes.

7. The use according to any of claims 1-5, wherein the particulate active ingredient is embedded in polymeric particles.

8. Use according to any of claims 1-7, to prepare a composition for parenteral administration.

9. The use according to any of claims 1-4, comprising preparing a particulate active ingredient for incorporation into a stent.

A method of treating restenosis, comprising administering to an individual in need an effective amount of an active ingredient selected from the group consisting of particulate bisphosphonate (BP), a particulate complex or salt of BP or a particulate polymer of BP.

11. A method according to claim 9, wherein the administration is intravenous (i.v.), intramuscular (i.m.) or subcutaneous. (s.c.) 12.

A method according to claim 9, comprising administering to the individual an active ingredient, having a compound having the following formula (I): OH K? OH I! I O = P - c - P = or I I I OH R2 OH R1 is H, OH or halogen group, and R2 is halogen, straight or branched C1-C10 alkyl or C2-C10 alkenyl optionally substituted by hetero-halo or heterocyclyl C1-C10 alkylamino or C3-C8 cycloalkylamine, where the amino be primary, secondary or tertiary, -NHY, where Y is hydrogen, cycloalkyl, aplo or heterocycle of C3-C8, or R2 is -SZ, where Z is pipdinyl or chlorosubstituted phenyl.

A method according to claim 12, wherein said active ingredient is clodronate, etidronate, tiludronate, pamidronate or alendronate, particulate, pyrophosphate.

A method according to any of claims 10-13, wherein said restenosis is coronary restenosis.

A method according to claim 10, comprising administering liposomes containing said active ingredient

16 A method according to any of claims 10 to 15, wherein the active ingredient is systemically administered

17 A pharmaceutical composition ica comprising as an active ingredient, particulate bisphosphonate (BP), particulate complex or salts of BP, a particulate polymer of BP together with a pharmaceutically acceptable carrier or diluent for the prevention or treatment of vascular restenosis

18. A pharmaceutical composition according to claim 17, for intravenous (i.v.), intramuscular (i.m.) or subcutaneous (s.c.) administration.

19. A pharmaceutical composition according to claim 17, wherein said active ingredient has the general formula (I): OH R? OH I I I o = P - c - p = o I I l OH R2 OH R1 is H, OH or halogen group; and R2 is halogen; linear or branched C 1 -C 10 alkyl or C 2 -C 10 alkenyl optionally substituted by heteroaryl or heterocyclyl C 1 -C 10 alkylamino or C 3 -C 8 cycloalkylamino, where the amino may be primary, secondary or tertiary; -NHY, where Y is hydrogen, cycloalkyl, aryl or C3-C8 heteroaryl; or R2 is -SZ, where Z is pyridinyl or chlorosubstituted phenyl.

20. A composition according to claim 19, wherein said active ingredient is clodronate, etidronate, tiludronate, pamidronate or alendronate.

21. A pharmaceutical composition according to any of claims 18-20, wherein said restenosis is coronary restenosis.

22. A pharmaceutical composition according to claim 19, wherein said particles are liposome particles encapsulating said active ingredient.

23. A pharmaceutical composition according to claim 22, wherein said active ingredient is embedded in a polymeric particle.

24. A pharmaceutical composition according to claim 14 to 24, wherein said active ingredient is insoluble particles having a size above 1 nM.