CA1320727C

CA1320727C - Pharmaceutical compositions containing geminal diphosphonates

Info

Publication number: CA1320727C
Application number: CA000498177A
Authority: CA
Inventors: James John Benedict; Christopher Mark Perkins
Original assignee: Procter and Gamble Co
Current assignee: Warner Chilcott Co LLC
Priority date: 1984-12-21
Filing date: 1985-12-19
Publication date: 1993-07-27
Anticipated expiration: 2010-07-27
Also published as: JPH07285976A; JPH09202794A; JP2798666B2; AU587001B2; JPS61210033A; PH27078A; JP2568999B2; JP2702419B2; NZ214651A; AU5153485A

Abstract

PHARMACEUTICAL COMPOSITIONS CONTAINING
GEMINAL DIPHOSPHONATES
ABSTRACT
Pharmaceutical compositions, useful for treating abnormal calcium and phosphate metabolism, which contain geminal-diphosphonic acid compounds; and a method of treating diseases characterized by abnormal calcium and phosphate metabolism utilizing these pharmaceutical compositions.

Description

~35 1/~

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PHARMACEUTICAL COMPOSITIONS CONTAINING
CiEMlNAL DIPHOSPHONATES
James J. BenedTct Chris~opher M. Perkins , TECH~NiCAL FIELD
This invention relates to pharmaceutical compositions con-10 taining compounds which are useful in treating or preventingdiseases characterized by abnormal calcium and phosphate metab-olism, in particular those which are characterized by abnormal bone metabolism. This invention further relates to a method of treating or preventing diseases characterized by abnormal calcium and phosphate metabolism using pharmaceutical compositions of the present invention.
BACKGROUND OF THE INVENTION
A number of pathological conditions which can afflict warm-blooded animals involve abnormal calcium and phosphate metab-20- olism. Such conditions may be divided into two broad categories.
1. Conditions which are characterized by anomalous mohi-lization of calcium and phosphate leading to general or specific bone loss or excessively high calciurn and phosphate levels in the fluids of the body. Such conditior s are sometimes referred t~
25 herein as pathological hard tissue demineralizations.

2. Conditions which cause or result from deposition of calcium and phosphate anomalously in the body~ These conditions are sometimes referred to herein as pathological calcifications.
The first category includes osteoporosis, a condition in 30 which bone hard tissue is lost disproportionateiy to the devel-opment of new hard tissue. Marrow and bone spaces become larger, fibrous binding decreases, and compact bone becomes fragile. Osteoporosis can be subclassified as menopausal, senile, drug induced (e.g., adrenocorticoid, as can occur in steroid 35 therapy), disease induced te.g., arthritic and ~umor), etc., however, the manifes~ations are essentially the same. Another condition in the first category is Pagetls disease (osteitis de-~3~ 2~

formans). In this disease, dissolution of normal bone occurs which is then haphazardly replaced by soft, poorly mineralized tissue such that the bone becomes deformed from pressures of weight bearing, particularly in the tibia and ~emur. Hyperpara-thyroidism, hypercalcemia of malignancy, and os~eolytic bone metastases are conditions also inclu~ed in the first category.
The second category, involving conditions manifested by anomalous calcium and phosphate deposition, includes myositis ossificans progressiva, calcinosis universalis, and such afflictions as arthritis, neuri~is, bursitis, tendonitis and other inflammatory conditions which predispose involved tissue to deposition of calcium phosphates.
Polyphosphonic acids and their pharmaceutically-acceptable salts have been proposed for use in the treatment and prophyl-axis of such conditions. In particular diphosphonates, like ethane-1-hydroxy~ diphosphonic acid (EHDP), propane-3-amino-1-hydroxy-1,1-diphosphonic acid (APD), and dichloro-methane diphosphonic acid ~CI2MDP) have been the subject of considerable research efforts in this area. Paget's disease and heterotopic ossification are c urrently success~ully treated with EHDP. The diphosphonates tend to inhibit the resorption of bone tissue, which is beneficial to patients suf~ering from excessive bone loss. However, EHDP, APD and many other prior art diphosphonates have the propensity of inhibiting bone mineral-ization when administered at high dosage levels.
It is believed that mineralization inhibition is predominantly a mass related physico-chemical effect, whereas resorption inhibition results from a biological interaction with the cells. It is therefore desirable to develop more biologically potent diphosphonate com-pounds that can be administered at low dosage levels which cause little or no mineralization inhibition, thereby resulting in a wider margin of safety. Low dosage levels are also desirable to avoid the gastro-intestinal discomfort ~like diarrhea) sometimes associ-ated with oral administration of large quantities of ciiphospho-nateS~
It is therefore an object of this invention to provide high potency compositions for the treatment and prophylaxis of ab-1 3 ~

normal calcium and phosphate metabolism. It is a still further object of this invention to provide an improved method for treating diseases characterized by abnormal calcium and phosphate metabol ism .
BACKGRO_ND ART
U.S. Patent 3,683,080, issuecl August 8, 1972, to Francis, discloses compositions comprising polyphosphonates, in particular diphosphonates, and their use in inhibiting anomalous deposition and mobilization of calcium phosphate in animal tissue.
Japanese Patent 80-98,193, issued July 25, 1980, to Nissan Kygaku Kagyo K . K. discloses pyridyl ethane diphosphonic acid, S-(pyridyl)-thiomethane diphosphonic acid, and the derivatives with halogen or alkyl group substitution on the pyridyl ring.
These compouncls are used as post-emergence herbicides.
Japanese Pa~ent 80-98,105, issued July 25, 1980, to Nissan Chemical Industries, discloses N-t3-pyridyl)-aminomethane di-phosphonic acid, and the derivatives with halogen or alkyl group substitution on the pyridyl ring, for use as herbicides. Various N-(pyridyl)-aminomethane diphosphonates are also disclosed in West German Patent 2,831,578, issued February 1, 1979 to Fumio, for use as herbicides.
European Patent Application 100,718 ~Sanofi SA), published February 15, 1984, discioses various alkyl diphosphonates which are -substituted by a sulfide attached to a 5- or 6-membered nitrogen- or sulfur-containing heterocycle. These compounds are used as anti-inflammatory and anti-rheumatic drugs.
British Patent Application 2,004,888, published April 11, 1979, discloses N-(3-methyl-2-picolyl)-aminomethane and related compounds for use in herbicidal compositions.
W. Ploger et al., Z. Anorg. Allg. Chem., 389, 119 (1972), discloses the synthesis of N- (4-pyridyl)-aminomethane diphos-phonic acid. No properties or utility of the compound are dis-closed .
SUMMARY OF THE INVENTION
The present invention relates to pharmaceutical compositions comprising:
(a) from about 0. 001 mg P to about 600 mg P of a geminal ~32~7~,~

diphosphonic acid compound, or its pharmaceutically-acceptable salt or ester, in which the diphosphonic acid-containing carbon is Iinked directly, or via a chain of length from 1 to about 5 atoms, to a 6-membered aromatic ring containing one or more nitrogen 5 atoms with the parts of said compouncl being comprised as ~ollows:
- said ring may be unsubstituted or substituted with one or more substituents selected from the group consisting of substi-tuted and unsubstituted alkyl (saturated or unsaturated) having from 1 to about 6 carbon atoms, substituted and unsukstituted 10 aryl, substituted and unsubstituted benzyl, hydroxy, halogen, carbonyl, alkoxy, nitro, amido, amino, substituted amino, car-boxylate, and combinations thereof;
- said linking chain may be all carbon atoms, a nitrogen atom or nitrogen-containing chain, an oxygen atom or oxygen-contain-15 ing chain, or a selenium atom or selenium-containing chain, with said chain being unsubstituted or substituted on the nitrogen and/or carbon atoms, independently, with one or more substituted or unsubstituted alkyl (saturated or unsaturated) having from 1 to about 4 carbon atoms ,and said nitrogen atom also may be 20 substituted with an acyl group;
- said diphosphonate--containing carbon may be unsubstituted or substituted with substituted or unsubstituted alkyl ( saturated or unsaturated) having from 1 to about 6 carbon atoms, sub-stituted or unsubstituted aryl, substituted or unsubstituted ~5 benzyl, amino, substituted amino, amido, hydroxy, alkoxy, halo-gen or carboxylate, except where said diphosphonate-containing carbon is directly bonded to a nitrogen, selenium, or oxygen atom in the linking chain, then the substituents may be substituted or unsubstituted alkyl (saturated or unsaturated) having from 1 to 30 about ~ carbon atoms, substituted or unsubstituted aryl, or substituted or unsubstituted benzyl; and (b) a pharmaceutical carrier.
The invention further encompasses a method of treating diseases characterized by abnormal calcium and phosphate metabo-35 lism, comprising administering to a human or animal in need ofsuch treatment a safe and effective amount of a diphosphonic acid-containing composition of the present invention.

~ 3 2 ~ ~ 2 r~

DETAILED DESCRIPTION OF THE INVENTION
This invention relates to pharmaceutical compositions, pref-erably in unit dosa~e form, comprising a pharmaceutical carrier and a safe and effective amount of geminal diphosphonic acid 5 compounds, or their pharmaceutically-acceptable salts and esters, in which the diphosphonic acid-containing carbon is linked to a 6 membered aromatic ring containing one or more nitrogen atoms.
Preferred rings are pyridine, pyridazine, pyrimidine, and pyrazine. Most preferred are pyriMidine, and especially pyri-10 dine. The rings may be unsubstituted or substituted with one ormore substituents selected from the group consisting of substitut-ed and unsubstituted alkyl (saturated or unsaturated) having from 1 to about 6 carbon atoms, substituted and unsubstituted aryl (e.g., phenyl and naphthyl), substituted and unsubstituted 15 benzyl, hydroxy, halogen, carbonyl ~e.g., -CHO and -COCH3), alkoxy (e.g., methoxy and ethoxy), nitro, amido (e.g., -NHCOCH3)~ amino, substituted amino (e.g., dimethylamino, methylamino, and diethylamino), carboxylate (e.g., -OCOCH3), and combinations thereof. The rings may be fused with other 20 rings, e.g., benzene fused with pyridine (e.g., quinoline), and cyclohexane fused with pyridine (e.g., 5,6,7,8-tetrahydro-quinoline). Additional substituents could be substituted or unsubstituted sulfide, sulfoxide, sulfate, or suifone.
The linkage from the diphosphonic acid-containing carbon to 25 the ring may be direct through a single bond, or by a chain of length of from 1 to about 5 atoms. The chain may be all carbon atoms, a nitrogen atom or nitrogen-containing chain, an oxygen atom or oxygen-containing chain, or a selanium atom or selenium-containing chain. The carbon and nitrogen atoms in the chains 30 may, independently, be unsubstituted or substituted with one ~or one or two in the case of carbon atoms) substituted or unsub-stituted alkyl (saturated or unsaturated) having from 1 to about 4 carbon atoms (methyl and ethyl being preferredl. The nitrogen atoms in the chains may also be substituted with an acyl group 35 te.g., -COCH3). Unsubstituted carbon and nitrogen atoms in the chain are preferred. Also preferred are chains one atom in p~

length, i.e., -CH2-, -NH-, and -O-.
The carbon atom which has the phosphonate groups attached to it may be unsubstituted (i.e., 3 hydrogen atom~, or sub-stituted with amino, substituted amino, amido, hydroxy, alkoxy, halogen, carboxylate, substituted or unsubstituted alkyl (satu-rated or unsaturated) having from l to about 6 carbon atoms, substituted or unsubstituted aryl, or substituted or unsubstituted benzyl. For the compounds in which the phosphonate-containing carbon is linked to the ring via an oxygen, selenium, or nitrogen-containing chain, and that oxygen, selenium, or nitrogen atom is bonded directly to the phosphonate containing carbon, then the substituent on the phosphonate-containing carbon may be substituted or unsubstituted alkyl (saturated or unsaturated) having from l to about 6 carbon atoms, substituted or unsubstituted aryl, or substituted or unsubstituted benzyl.
Thus, diphosphonic acid compounds to be included in the pharmaceutical compositions of the present invention have the structure: -/R2 \ R2~ P~3H2 R3--Z _ -C--Q---C~C-PO H
R2 m R2 j7nRl wherein Q is oxygen, -NR4-, selenium, or a single bond, preferred being oxygen, -NR4-, or a single bond; m + n is an integer from 0 to about 5, with m + n = 0 or 1 pref~rred for Q
25 being oxygen, selenium, or -N R4-, and m ~ n = l or 2 preferred otherwise; Z is a ring selected from the group consisting of pyridine, pyrida~ine, pyrimidine, and pyrazine, with preferred being pyrimidine, and especially pyridine; Rl is hydrogen, sub-stituted or unsubstituted amino, amido, hydroxy, alkoxy, halo-30 gen, carboxylate, substituted or unsubstituted alkyl lsaturated orunsaturated) having from l to about 6 carbon atoms, substituted or unsubstituted aryl, or substituted or unsubstituted benzyl, except that when n = 0 and Q is oxygen, selenium, or -NR4-then Rl is hydrogen, substituted or unsubstituted alkyl (satu-35 rated or unsaturated) having from l to about 6 carbon atoms,substituted or unsubstituted aryl, or substituted or unsubstituted 132~ 127 benzyl, with R1 being hydrogen, chloro, amino, methyl, or hydroxy preferred; each R2 is, independently, hydrogen, or substituted or unsubstituted alkyl (saturated or unsaturated) having from 1 to about 4 carbon atoms, with R2 being hydrogen 5 preferred; R3 is one or more substituents selected from the group consisting of hydrogen, substituted or unsubstituted alkyl (satu-rated or unsaturated) having from 1 to about 6 carbon atoms, substituted and unsubstituted aryl, substituted and unsubstituted benzyl, hydroxy, halogen, carbonyl, alkoxy, nitro, amido, amino, 10 substituted amino, carboxylate, and combinations thereof, with preferred being hydrogen, methyl, amino, chloro, methoxy, nitro, hydroxy and combinations thereof; R4 is hydrogen, substituted or unsubstituted alkyl (saturated or unsaturated) having from 1 to about 4 carbon atoms, or acyl (i.e., the amide of the nitrogen), 15 with preferred being hydrogen, methyl, or ethyl; and pharma-ceutically-acceptable salts and esters of these compounds. Fi-nally, for any of the R1, R2, R3, or R4 substituents which are themselves substituted, the substitution on these substituents may be any one or more of the above substituents, preferred being 20 methyl, ethyl, amino, chloro, nitro, metho~y, hydroxy, acet-amido, and acetate.
More specifically, the diphosphonic acid compounds, and their pharmaceutically-acceptable salts and esters, to be included in the pharmaceutical compositions of the present invention are of 25 the structure:
/ R2 ~ l03H2 3 t R ~ R 3 2 / R2\ / 12\ ~3 2 t R2~ R4t R2~ R1 IR2\ 1 IR2~ 1 3~12 t ~1 t 27~ 1 132~

wherein m + n, Z, R1, R2, R3, and R4 are as described above.
Generally preferred diphosphonic acid compounds, and their pharmaceutically acceptable salts and esters, to be inçluded in the pharmaceutical compositions of the pnesent invention are of the S structure:

N~H~ C--PO3H2 or R3~ Ct Cl--PO3H~ ;

wherein for both structures above m + n = 1 or 2; R1 is hydro-15 gen, chloro, amino, or hydroxy; R3 is one or more substituents selected from the group consisting of hydrogen, methyl, amino, chloro, nitro, methoxy, hydroxy, and combinations thereof; or ~ tC~ )3H2 or R3~R4tH~ 3H2 r H ~3H2 R~_ Q--~C --C r P03H2 ; or R3~_ o ~c~ C _ PO3H2; or wherein for the four preceding structures n = 0 or 1; Rl is hydrogen, chloro, amino, or hydroxy when 132~ ~2~

n = 1, and R1 is hydrogen when n = 0; R3 is one or more substitu-ents setected from the group consisting olF hydrogen, methyl, amino, chloro, methoxy, nitro, hydroxy, and combinations there-of and R4 is hydrogen, methyl, or ethyl.
Specific examples of compounds which may be utilized in compositions o~ the present invention include;
N-(2-pyridyl)-aminomethane diphosphonic acid;
N-(2-~5-amino)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(5-chloro)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(5-nitro)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(3,5-dichloro)-pyridyl)-aminomethane diphosphonic acid;
N-(4-pyridyl)-N-ethyl-aminomethane diphosphonic acid;
N-(2-(3-picolyl))-aminomethane diphosphonic acid;
N-(2-(4-picolyl))-aminomethane diphosphonic acid;
N-(2-(5-picolyl))-aminomethane diphosphonic acid;
N-(2-(6-picolyl))-aminomethane diphosphonic acid;
N-(2-(3,4-lutidine))-aminomethane diphosphonic acid;
N-(2-14,6-lutidine))-aminomethane diphosphonic acid:
N-(2-pyrimidyl)-aminomethane diphosphonic acid;
N-(4-(2,6-dimethyl)-pyrimidyl)-aminomethane diphosphonic acid;
N-(2-(4,6-dihydroxy)-pyrimidyl)-aminomethane diphosphonic acid;
N-(2-(5-methoxy)-pyridyl)-aminomethane diphosphonic acid;
N-~2-pyridyl)-2-aminoethane-1,1-diphosphonic acid;
N-(2-(3-picolyl))-2-aminoethane-1,1-diphosphonic acid;
N-(3-pyridylj-2-amino-1-chloroethane-1,1-diphosphonic acid;
N-~2-(4-picolyl))-2-amino-1-hydroxy-ethane-1 ,I-diphosphonic acid;
(2-pyridyl)-methane diphosphonic acid;
(3-pyridyl)-aminomethane diphosphonic acid;
(2-pyridyl)-chloromethane diphosphonic acid;
(4-pyridylj-hydroxymethane diphosphonic acid;
2-(2-pyridyi)-ethane-1,1-diphosphonic acid;
2-(3-pyridyl)-ethane-1,1-diphosphonic acid;
2-(4-pyridyl)-ethane-1,1-diphosp~Dnic acid;
2-(2-pyridyl)-1-amino-ethane-1,1-diphosphonic acid;
2-(2-pyrimidyl)-1-hydroxy-ethane-1,1-diphosphonic acid;

132~727 2-(2-(3-picolyl))-1-chloro-ethane-1,1-diphosphonic acid 2-(2-(4-methoxy)-pyridyl)-ethane-1,1-diphosphonic acid;
1-(2-pyridyl)-propane-2,2-diphosphonic acid:
2-(2-pyridyl)-1-chloro-ethane-1,1-diphosphonic acid;
5 2-(2-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
2- ( 3-py ridy I ) -1 -hyd roxy-ethane- 1 ,1 -di phosphon ic ac id 2-(4-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
3-(3-pyridyl)-1-hydroxy-propane-1,1-diphosphonic acid;
0-(2-pyridyl)-2-oxa-ethane-1,1-diphosphonic acid;
10 0-(2-pyridyl)-oxamethane diphosphonic: acid;
0-(2-pyrimidyl)-oxamethane diphosphonic acid;
0-(2-(4-amino)-pyridyl)-oxamethane diphosphonic acid;
0-(2-pyrimidyl)-2-oxa-ethane-1,1-diphosphonic acid;
0-(2-(3-picolyl))-2-oxa-ethane-1,1-diphosphonic acid;
15 0-(2-(3-picolyl))-oxamethane-diphosphonic acid;
0-(2-pyridyl)-1-hydroxy-2-oxa-ethane-1,I-diphosphonic acid;
0-(4-pyridyl)-1-amino-2-oxa-ethane-1,1-diphosphonic acid; and pharmaceutically-acceptable salts and esters thereof.
Preferred compounds are 20 N-(2-(5-amino)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(5-chloro)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(3-picolyl))-aminomethane diphosphonic acid;
N-(2-(4-picolyl))-aminomethane diphosphonic acid;
N-(2-(5-picolyl))-aminomethane diphosphonic acid;
25 N-(2-(6-picolyl))-aminomethane diphosphonic acid N-(2-(3,4-iutidine~)-aminomethane diphosphonic acid;
N-(2-pyrimidyl)-aminomethane diphosphonic acid;
N-(2-pyridyl)-2-aminoethane-1,1-diphosphonic acid;
2-(2-pyridyl)-ethane-1,1-diphosphonic acid;
30 2-(3-pyridyl)-ethane-1,1-diphosphonic acid;
2-(4-pyridyl)-ethane-1,1-diphosphonic acid, 2-(2-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
2- ( 3-pyridyl ) -1 -hydroxy-ethane-1 ,1 -diphosphonic acid;
2-(4-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
35 0-t2-(3-picolyl)) oxamethane-diphosphonic acid; and pharmaceutically-acceptable salts and esters thereof.

The diphosphonate compounds to be included in the pharma-ceutical compositions of the present inventlon can be made using - the synthetic methods disclosed in Japanese Patent 80-g8,193 (July 25, 1980, to Nissan Kygaku Kagyo K.K.), Japanese Patent 5 80-98,105 (July 25, 1980, to ~lissan ChemTcal Industries), West German Patent 2,831,578 (February 1, 1979, to Fumio), and W.
Ploger et al., Z. A~. A~ Chem., 389, 119 (1972), The amlnoethane diphosphonie acid compounds, however, are best prepared as follows:
Synthesis of N-(2-(3-picolyl)?aminoethane DP
The above-named compound is prepared via a typical Michael reaction between tetraethyl vinyldiphosphonate and 2-amino-~-picoline. (See H.O. House, Modern Synthetic Reaction 2nd Ed. W.A. BenJamin Inc. p. 595-6~3.
To a solution of 1.62 g (15 mmol) of 2-amino-3-picoltne in tetrahydrofuran at 5C was added 4. 50 g ( 15 mmol ) tetraethyl vinyldiphosphonate. The reaction mixture was stlrred at room temperature for 16 hours. Evaporation of the solvent and chromatography (acetone/hexane, 4/1~ of the product on silica gel gave pure tetraethyi N-(2-(3-picolyl~)-2-aminoethane diphosphonate. P-31 NMR of the pure tetraethyl ester in CDCI3 shows a resonance at 22.1 ppm. The ester was hydrolyzed in refluxlng 6N HCI overnight. The product ~howed a P-31 NMR
signal in D2O at pH = 12 of 19.0 ppm.
N-(2-pyridyl)-2-aminoethane DP and N-(2-(5-picolyl))-2-aminoethane i)P were prepared in an identical manner.
Compounds having the general formula R3_ z ~ ~2~H3HP~3H2 ~wherein n is an ineeger of from 1 to about 5, preferably n = 1;
and Z, R2 and R3 are as described hereinbefore, with preferred Z being pyrimidine and especially pyridine, preferred R2 being hydrogen, and preferred R3 ~eing one or more substituents 132~7 selected from the group consisting of hydrogen, methyl, amino,chloro, nitro, methoxy, hydroxy, and combinations thereof) are best prepared as follows:
Synthesis of 2-(2-pyridyl)-1-hydroxy-ethane-1 ,1-diphosphonic 5 acid:
A 3-neck round-bottom flask fitted with a re~lux condenser and a magnetic stir bar is charged with 6.94 grams (0.04 mole) 2-pyridine acetic acid, 9.84 grams (0.14 mole1 phosphorus acid, and 150 ml of chlorobenzene. This reaction mixture is heated on a boiling water bath, and 16.5 grams (0.12 mole) phosphorus trichloride is added dropwise with stirring. This reaction mixture is heated for 2-1/2 hours during which time a viscous yellow oil forms. The reaction mixture is then cooled in an ice bath and the chlorobenzene solution is decanted off from the solidified product. The reaction flask containing this solidified product is charged with 150 ml of water and heated in a boiling water bath for several hours. The hot solution is then filtered through Celite 545R. 300 ml of methanol is added to the warm filtrate solution, and a precipitate develops. After cooling in ice for 1 hour, the precipitate is filtered off and then washed with methanol/water (1/1 volume/volume), methanol, and ether, and air dried. The product may be recrystallized from hot water. Yield is approximately 5.9 grams (52%~. The sample is characterized by P-31 and C-13 NMR.
By "pharmaceutically-acceptable salts and esters" as used herein is meant hydroly~able esters and salts of the diphos-phonate compounds whi~h have the same general pharmacological properties as the acid form from which they are derived, and which are acceptable from a toxicity viewpoint. Pharmaceuti-cally-acceptable salts include alkali metal ~sodium and potassium), alkaline earth metal (calcium and magnesium), non-toxic heavy metal ~stannous and indium), and ammonium and low molecular weight substituted ammonium (mono-, di- and triethanolamine) salts. Preferrecl compounds are the sodium, potassium, and ammonium saltsO
By "pharmaceutical carrier" as used herein is meant one or more compatible solid or liquid filler diluents or encapsulating ~32~7~,7 substances. By "compatible" as used herein is meant that the components of the composition are capable of being commingled without interacting in a manner which would substantially de-crease the pharmaceutical efficacy of the total cornposition under ordinary use situations.
Some examples of substances which can serve as pharma-ceutical carriers are sugars such as lactose, ~31ucose and sucrose:
starches such as corn starch and potato starch; cellulose and its derivatives, such as sodium carboxymethylcellulose, ethylcellulose, cellulose acetate; powdered tragacanth; malt; ~elatin, talc; stearic acid; magnesium stearate; calcium sulfate; vegetable oils, such as peanut oil, cottonseed oil, sesame oil, olive oil, corn oil and oil of theobroma; polyols such as propylene glycol, glycerin, sorbitol, mannitol, and polyethylene glycol; agar; alginic acid; pyrogen-free water; isotonic saline; and phosphate buffer solutions, as well as other non-toxic compatible substances used in pharma-ceutical formulations. Wetting ayents and lubricants such as sodium lauryl sulfate, as well as coloring agents, flavoring agents, lubricants, excipients, tableting agents, stabilizers, anti-oxidants and preservatives, can also be present. Other compatible pharmaceutical additives and actives (e.g., vitamin D
or vitamin D metabolites, and mineral supplements) may be included in the pharmaceutical compositions of the present invention .
The choice of a pharmaceutical carrier to be used in con-junction with the diphosphonates of the present composi~ions is basically determined by the way the diphosphonate is to be ad-ministered . I f the compound is to be injected, the preferred pharmaceutical carrier is sterile, physiological saline, the pH of which has been adjusted to about 7. ~1. However, the preferred mode of administering the diphosphonates of the present invention is oraliy, and the preferred unit dosage form is therefore tablets, capsules and the like, comprising from about 0.1 mg P to about 600 mg P of the diphosphonic acid compounds described herein.
Pharmaceutical carriers suitable for the preparation of unit dosage forms for oral administration are weli known in the art. Their ~ ~ 2 ~ P~

selection will depend on secondary considerations like taste, cost, shelf stability, which are not critical for the purposes of the present invention, and can be made without difficuity by a person skilled in the art. The pharma~:eutical carrier employed in con-junction with the diphosphonates of the present invention is used at a concentration sufficient to provide a practical size to dosage relationship. Preferably, the pharmaceutical carrier comprises from about 0. 01% to about 99. 99% by weight of the total composition .
EXAMPLE I
Capsules are prepared by conventional methods, comprised as follows:

ingredient Mg per capsule N-(2-(3-picolyl)) AMDP 100 (as mg P) Starch 55 . 60 Sodium lauryl sulfate 2 . 90 The above capsules administered orally twice daily for 6 months substantially reduce bone resorption in a patient weighing approximately 70 kilograms afflicted with osteoporosis. Similar results are obtained when the N-(2-(3-picolyl))-aminomethane diphosphonic acid, or its pharmaceutically-acceptable salt or ester, in the above-described capsules is replaced with N-(2-(5-amino)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(5-chloro)-pyridyl)-aminomethane diphosphonic acid N-(2-(4-picolyl))-aminomethane diphosphonic acid;
N-(2-(5-picolyl))-aminomethane diphosphonic acid;
N-(2-(6-picolyl))-aminomethane diphosphonic acid;
N-(2-(3,4-lutidine) )-aminomethane diphosphonic acid;
N-(2-pyrimidyl)-aminomethane diphosphonic acid;
N-(2-pyridyl)-2-aminoethane-1,1-diphosphonic acid;
2- ( 2-pyridyl )-ethane-l ,1 -diphosphonic acid;
2-(3-pyridyl)-ethane-1,1-diphosphonic acid;
2-(4-pyridyl)-ethane-1 ,1-diphosphonic acid;
2-(2-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
2-(3-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;

~ 3 2 ~

2- ( 4-py ridyl ) -1 -hydroxy-ethane-1 ,1 -diphosphonic acid;
0-(2-(3-picolyl) )-oxamethane-diphosphonic acid or the pharmaceuticalty-acceptable salts or esters thereof.
EXAMPLE N
Tablets are prepared by conventional methocls, formulated as fol I ows:
.Ingredient mg per tablet N-12-pyrimidyl) AMDP 25.00 Lactose 1~0 . 00 10 Starch 2 . 50 Magnesium stearate 1 . 00 The above tablets administered orally twice daily for 6 months substantially reduce bone resorption in a patient weighing approximately 70 kilograms afflicted with osteoporosis. Similar 15 results are obtained when the N-(2-pyrimidyl) AMDP, or its pharmaceutically-acceptable salt or ester, in the above-described tablets is replaced with N-(2-(5-amino)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(5-chloro)-pyridyl)-aminomethane diphosphonic acid 20 N-(2-13-picolyl~)-aminomethane diphosphonic acid N- ( 2- ~ 4-picolyl ) ) -aminomethane diphosphonic acid;
N-12-[S-picolyl))-aminomethane diphosphonic acid;
N-12-(6-picolyl))-aminomethane diphosphonic acid;
N-12-(3,4-lutidine))-aminomethane diphosphonic acid;
25 N-(2-pyridyl~-2-aminoethane-1,1-diphosphonic acid;
2-[2-pyridyl~-ethane-1,1-diphosphonic acid;
2-(3-pyridyl)-ethane-1,1-diphosphonic acid 2-(4-pyridyl~-ethane-1 ,l-diphosphonic acid;
2-12-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
30 2-13-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
2- ( 4-pyridyl ) -1 -hydroxy-ethane-1 ,1 -diphosphonic acid;
0-(2-(3-picolyl) )-oxamethane-diphosphonic acid; or the pharmaceutically-acceptable salts or esters thereof.

~.32~2 EXAMPLE l l i Injectable solutions are prepared ~y conventional methods using 1. 0 ml of either physiological saline or water solution and 3.5 mg o~ 2-(2-pyridyl)-ethane~ diphosphonic acid, adjusted to 5 pH = 7.4.
One injection, one time daily for 4 days results in appreci-able alleviation of hypercalcemia of malignancy in patients weigh-ing approximately 70 kilograms.
Similar results are obtained when the 2-(2-pyridyl)-ethane-1,1-10 diphosphonic acid in the above-described treatment is replaced with N-~2-(5-amino)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(5-chloro)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(3-picolyl))-aminomethane diphosphonic acid;
15 N-(2-(4-picolyl))-aminomethane diphosphonic acid;
N-(2-(5-picolyl))-aminomethane diphosphonic acid;
N-(2-(6-picolyl))-aminomethane diphosphonic acid;
N-(2-(3,4-lutidine))-aminomethane diphosphonic acid;
N-(2-pyrimidyl)-aminomethane diphosphonic acid, 20 N-(2-pyridyl)-2-aminoethane-1 ,1-diphosphonic acid;
2-(3-pyridyl)-ethane-1,1-diphosphonic acid;
2-(4-pyridyl)-ethane-1,1-diphosphonic acid;
2- ( 2-pyridyl ) -1 -hydroxy-ethane-1 ,1 -diphosphonic acid;
2-(3-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
25 2-(l~-pyridyl)-l-hydroxy-ethane-l~l-diphosphonic acid;
0-(2-(3-picolyi))-oxamethane-diphosphonic acid; or pharmaceutically-acceptable salts or esters thereof.
The compositions of the present invention are useful in the treatment of abnormal caicium and phosphate metabolism. Other 30 diphosphonis acids and their pharmaceutically-acceptable salts have been proposed for use in the treatment and prophylaxis of such conditions. In particular, ethane-1-hydroxy-1,1-diphos-phonic acid (EHDP), propane-3-amino-1-hydroxy-1,1-diphosphonic acid (APD), and dichloromethane diphosphonic acid (Cl2MDP) have 35 been the subject of considerable research efforts in this area.
However, the compositions of the prese~t invention are generally more biologically potent in inhibiting bone resorption than the art-disclosed diphosphonates. Thus, the compositions of ~32~2P~

the present invention may provide one or more of the following advantages over the art-disclosed diphosphonates of ( 1 ) being more potent in inhibiting bor~e resorption: (2) po$sessing less potential ~or inhibition of bone mineralization, since mineralization inhibition is believed to be predominantly a mass related physico-chemical effect; ~3) having ~enerally a wider margin of safety ( i . e ., wider dosing interval between the lowest effective antiresorptive dose and the lowest dose producing mineralization inhibition~ (4) allowing lower oral dosages to be administered, thereby avoiding the gastro-intestinal discomfort (like diarrhea) sometimes associated with higher dosages of diphosphonates; and (5) having potential for flexibility of dosing methods.
Another aspect of this invention is a method for treating or preventing diseases characterized by abnormal calcium and phos-phate metabolism, in particutar those which ara characterized by abnormal bone metabolism, in persons at risk to such disease, comprising the step of administering to persons in need of such treatment a safe and effective amount of a diphosphonic acid-containing composition of the present invention.
The preferred mode of administration is oral, but other modes of administration include, without limitation, transdermal, mucosal, sublingual, intramuscular, intravenous, intraperitoneal, and subcutaneous administration, as well as topical application.
By "abnormal calcium and phosphate metabolism" as used herein is meant (1 ) conditions which are characterized by anom-alous mobilization of calcium and phosphate leading to general or specific bone loss, or excessively hi~h calcium and phosphate levels in the fluids of the body; and (2) conditions which cause or result from deposition of calcium and phosphate anomalously in the body. The first category includes, but is not limited to~
osteoporosis, Pagets disease, hyperparathyroidism, hypercalcemia of malignancy, and osteolytic bone metastases. The second category includes, but is not limited to, myositis ossificans progressiva, calcinosis universalis, and such afflictions as arthritis, neuritis, bursitis, tendonitis and other inflammatory 13 ~ r~

conditions which predispose involved tissue to deposition of calcium phosphates.
By "person at risk", or "person in need of such treatment", as used herein is meant any human or lower animal which suffers S a significant risk of abnormal calcium and phosphate metabolism if left untreated, and any human or lower animal diagnosed as being afflicted with abnormal calcium and phosphate metabolism. For example, postmenopausal women; plersons undergoing certain steroid therapy; persons on certain anti-convulsant drugs; per-sons diagnosed as having Pagets disease, hyperparathyroidism, hypercalcemia of malignancy, or osteolytic bone metastases;
persons diagnosed as suffering from one or more of the various forms of osteoporosis; persons belonging to a population group known to have a significantly higher than average chance of developing osteoporosis, e.g., postmenopausal women, men over age 65, and persons being treated with drugs known to cause osteoporosis as a side effect; persons diagnosed as suffering from myositis ossificans progressiva or calcinosis universalis; and persons afflicted with arthritis, neuritis, bursitis, tendonitis and other inflammatory conditions which predispose involved tissue to diposition of calcium phosphate.
By "human or lower animal afflicted with or at risk to osteo-porosis" as used herein is meant a subject diagnosed as suffering from one or more of the various forms of osteoporosis, or a subjec~ belonging to a group known to have a significantly higher than average chance of developing osteoporosis, e.g., postmeno-pausal women, men over the age of 65, anà persons being treated with drugs known to cause osteoporosis as a side effect ( such as ad~enocorticoid ) .
By "safe and effective amount" as used herein is meant an amount of a compound or composition high enough to significantly positively modify the condition to be treated, but low enough to avoid serious side effects (at a reasonable benefit/risk ratio), within the scope of sound medical judgment. The sa~e and effec-tive amount of diphosphonates will vary with the particular con-dition being treated, the age and physical condition of the patient ~ 3 ~ 7 bein~3 treated, the severity of the condition, the duration of treatment, the nature of concurrent therapy, and the specific diphosphonate employed. However, single dosages can range from about 0. 001 mg P to about 3500 mg P, or from about 0.1 micro-grams P/kg of body weight to about 500 mg P/kg of body weight.
Preferred single ciosages are from about 0.1 mg P to about 600 mg P, or from about 0.01 to about 50 mg P/kg of body weight. Up to about four single dosages per day may be administered. Daily dosages greater than about 2000 rng P/kg are not requlred to produce the desired effect and may produce undesirable side effects. The hlgher dosages within this range are, of course, required in the case of oral administration because of limited absorption .
Schenk Model The compounds were evaluated for 'n vivo bone resorption inhibition and mineralization inhibition in an animal model system known in the field of bone metabolism as the Schenk Model. The general principles of this model system are disclosed in Shinoda et al., Calcif. Tissue Int., 35, 87-99 (1983); and in Schenk et al., Caicif. Tissue Res. 11, 196-214 (i973).

Materials and Methods Animals Preweaning 17-day-old 130 gms) male Sprague Dawley rats 25 (Charles River Breeding Laboratories~ were shipped with their mothers and placed in plastic cages with their mothers upon arrival. At 21 days of age, pups receiving Rat Chow and water ad libitum were randomly allocated into treatment groups com-prislng five animais per group, except for control animals re-30 ceiving saline vehicle which had 10 rats per group. On day 0and again on day 1 all animals were given a subcutaneous in-jection of Calcein (Sigma~ as a 196 soiution in 0.9~ NaCI solution to label the skeleton.
Dose Solutions and Dosing Procedure . . . _ .
All solutions were prepared for subcutaneous injection in 0.9~ normal saline and adjusted to pH 7.4 using NaOH and/or 132~72~

HCI. Dose solution calculation was made by considering the mass of powder (based on molecular weight, hydration) of the active material in mg/kg (body weight) that corresponds to mgP/kg.
Concentrations were based on dosing 0.2 ml/100 g body weightO
Initially, all compounds were administered at 0.1, 1.0 and 10.0 mg - Plkglday for 7 days. Compounds showing activity at 0.1 mg P/kglday were then tested at logarithmic decrements down to 0.001 mg Plkg/day. Adjustments in dosage based on changes in body weight were made on a daily basis.
Necropsy, Tissue Processing and Histomorphometry On day 8 after the start of dosing, all animals were sac-rificed by CO2 asphyxiation. Tibias were dissected free and placed in 70% ethyl alcohol. One tibia was dehydrated in graded ethanol solutions and embedded in methyl methacrylate using a rapid procedure described in Boyce et al., Lab. Investig., 48, 683-689 ( 1 983) .
IThe tibla was sectioned longitudlnally through the metaphyseal area ( LeitzR saw microtome at 150 ,~L ) . Specimens were stained on one surface with silver nitrate and mounted on 2û microscope slides for evaluation with a Quantlmet Image Analyzer (Cambridge Instruments, Inc.) using both incandescent and ultraviolet illumination. Metaphyseal trabecular bone content was measured in the region between the fluorescent label and the growth plat~: expressed as percent of total area (bone + mar-row). Epiphyseal growth plate wldth was obtained as the mean value of 10 equally-spaced measurements across the section.
Statistical evaluation of data was made using parametrlc and non-parametric analysis of varlance and Wilcoxons rank sum test to determine a statistically significant effect compared to control animals.
The Schenk model provided data for in vivo bone resorption inhibition by the compounds. The lowest effective [antiresorp-tive) dose ( LED ~ for representative compounds tested, as determined by the Schenk model, are provided in Table 1.

1~2~2~

TAB LE
Lowest Effective (Antiresorptive) Dose Schenk Diphosphonate Compound LED (mg P/kg~
EHDP 1. 0 Cl2MDP 1. 0 APD 0.1 N-(2-pyridyl) AMDP 0.01 N-(2-(5-chloro)-pyridyl) AMDP 0.01 N-(2-~3-picolyl~) AMDP 0.001 N-(2-(4-picolyl)) AMDP 0.001 N-(2-t5-picolyl)) AMDP 0.001 N-(2-~6-picolyl)) AMDP 0.001 N-(2-pyrimidyl) AMDP 0.001 N-(4-pyridyl~-N-ethyl AMDP 0.1 2-(2-pyridyl) EDP 0.01 2-(3-pyridyl) EDP 0.01 1-(2-pyridyl) propyl DP 10 EHDP = ethane-1-1hydroxy-1,1-DP
Ci2MDP = dichloromethane DP
APD = 3-aminopropane-1 hydroxy-1 ,l-DP
AMDP = aminomethane diphosphonic acid, where the ring is at-tached to the amine.
* = Compounds inciuded in pharmaceutical compositions of the 25 present invention.
EDP = ethane-1 ,1-c!iphosphonic acid, where the ring is attached at the 2 position of the ethane.
Propyl DP = propane-2,2-diphosphonic acid Diphosphonate compounds which have a bone mineralization 30 inhibiting effect cause widening of the epiphyseal growth plate, since matrix production continues but mineralization is impeded.
The widening of the epiphyseal growth plate as observed in the Schenk rrodel is, therefore, a measure of the mineralization in-hibiting effect of the diphosphonate compound tested.

132~7~

The lowest tested dosages producing a statistically signifi-cant widening of epiphyseal growth plate for compounds tested are given in Table ll.
TABLE I I
Mineralization Inhibition (Schenk Mode!l) - Lowest tested dosage producing a statistically significant widening of Diphosphonateepiphyseal growth plate 10 Compound (m~ P/Kgl C12MDP .. _ N-12-pyridyl) AMDP 0.1 15 N-(4-pyridyl)-N-ethyl AMDP 1) N-[2-(3-picolyl) ) AMDP -- 1 ) N-(2-(4-picolyl)) AMDP 0.1 N-(2-(5-picolyl)) AMDP 0.1 N-(2-(6-picolyl) ) AMDP -- 1 ) 20 N-(2-pyrimidyl) AMDP 1.0 N-(2-15-chloro)-pyridyl) AMDP__ 1 ) 2- ( 3-pyridyl ) ED P --2-(2-pyridyl ) EDP __ t ) - = No plate widening obserYed at highest dose tested lhighest 25 dose tested is 10 mg P/kg/day unless otherwise indicated~
1 ) = Highest dose evaluated is 1 mg P/kg/day lcompound lethally toxic at 10 mg P/kg/day) EHDP = ethane-1-hydroxy-1,1-DP
APD = 3-aminopropane-1-hydroxy-1,1-DP
30 C12MDP = Dichloromethane DP
AMDP = aminomethane diphosphonic acid, where the ring is at-t3~hed to the amine l--DP -- etharie-1,1-diphosphonic acid, where the ring is attached at the 2 position of the ethane 35 * = Compounds included in pharmaceutical compositions of the present invention 1 3 ~ 7 Thyroparathyroidectomized ~TPTX?_Rat Model The compounds were evaluated for 'n vlvo bone resorption inhibition potency by an animal model system known as the thyro-parathyroidectomized (TPTX) rat model. The general principles of this model system are dlsclosed in Russell et al., Calclf.
Tissue_ Research, 6, 183-196 (1970), and in Muhlbauer and .Fleisch, Mineral Electrolyte Metab., 5, 296-303 (1~81 ), The basic biochemlcal concept of the TPTX system is inhibltion of the parathyroid hormone (PTH) - induced rise in serum and ionized calcium levels by the respective bone active polyphosphonates.
Materials and Methods:
Materials Low calcium and low phosphorous diets used were prepared by TekladR Test Diets ( Harlan Industries, Madison, Wisconsin 53711; Order #TD82195) in a pellet form of approximately 0.18%
calcium and 0. 22~ phosphorous. The diets contained all the essential vitamins and mlnerals required for the rat, with the exception of calcium and phosphorous. The calcium and phos-phorous levels of the pellets were verified analytically ( Procter Gamble Co., Miami Valley Laboratories, Cincinnati, Ohio).
PTH was acquired as a powdered bovine extract (Sigma Chemical Co., P. O. Box 14508, St. Louis, Missouri, order #P-0892, Lot #72F-9650) at an activity of 138 USP units per mg.
PTH was prepared in 0.~% saline such that the final concentration was 100 U.S.P./ml. All solutions were filtered through a #4 Whatman Filter Papsr and refiltered through a 0.45 Jum Metricel R
fTlter .
Dose Solutions and Dosing Procedure All solutions of compounds ts be tested for bone resorption inhibition potency were prepared for subcutaneous injectlon in 0.996 normal saline and adjusted to pH 7. ll using NaOH and/or HCI. Dose solution calculation was made by considering the mass of powder (based on molecular weight, hydration) of the active material in mg/kg (body weight) that corresponds to mg P/kg.
Concentrations were based on dosing 0.2 mlllO0 grams of body ~' .

i32~2~

weight. Initially, all compounds were administered at 0.01, 0.1, and 1. 0 mg P/kg/day for 4 days. Where necessary the test was repeated, whereby the animals were administered with 0. 5 LED in order to refine the determination of l ED. Adjustments in dosage based on changes in body weight were made on a daily basis.
Animals In this study 50 male Wistar rats weighing approximately 150-1 6û grams were thyroparathyroidectomized surgically by the breeder (Charles River Breeding Laboratories). All rats were double housed on arrival in suspende~d cages with Purina Labora-tory Rodent ChowR and tap water _ libitum. After acclimation to the laboratory environment for 3-5 days, the rats were placed on a low calcium, low phosphorous (0.18~/0.22%) diet (TekladR) and given 2~ (W/V) calcium gluconate supplemented deionized water via water bottles.
Method On day four of low-calcium diet all rats were anesthetized with KetasetR (Ketamine Hydrochloride, 100 mg/ml, Bristol Myers), 0.10 ml/100 grams of body weight, weighed and then bled from the retro-orbital venous plexus for serum total calcium analysis using Flame Atomic Absorption ( FAA) . Ail rats weighing less than 180 grams were eliminated from the study. Animals were then randomized statistically such that the mean total serum calcium for each group was the same. Only rats deemed hypo calcemic (total serum calcium ~8.0 mg/dl) were placed in study groups comprising six animals per group.
Treatments with the various experimental compounds com-menced on day 6 and laste~ through day 9 of the study (at 1:00 P . M . each day) . Dose solutions were prepared to be given at a constant rate of 0.2 ml/100 grams o~ body weight subcutaneously in the ventral skin flap where the hind leg meets the torso. All rats were weighed and dosed daily. A 25 gauge 5/8" needle was used to administer drug, alternating dose sites daily. On day 8, animals were changed to deionized, distilled water via water bottles. On day 9 all rats were fasted in the afternoon at ap-proximately 4:00 P.M. On day 10 of study no treatment was 132~12~7 given. In the morning a 600 ,ul sample of whole ~lood was col-lected from each rat in Microtainer (B-D#5060) serum separater tubes for serum total calcium ( F~A) . Two 125 ~JI samples of heparinized whole blood were also collected to be used for ionized 5 calcium analysis. Immediately following blood collection all rats - were weighed and injected with bovine parathyroid hormone subcutaneously at a rate of 75 USP (filteredl per 100 grams of body weight. Blood sampling for total and ionized calcium was repeated three and one-half hours post-PTH injection.
10All pre- and post-PTH total and ionized calciums were stat-istically analyzed for significance compared to PTH alone t~ontrol) using Students t-test, analysis of variance, and their non-parametric equivalents. The post minus pre-change and ~ change were also determined on calcium levels and pre-drug vs post-drug 15 body weights.
The physiological effect of the PTH challenge is a rise in serum calcium level, with peak activity observed at three and one-half hours. Since the hormonal and dietary controls of calcium metabolism are minimized in the TPTX model, an observed 20 increase in serum calcium level is presumably the result of re-sorption of bone material. Since polyphosphonates tend to inhibit resorption of bone materials, the animals pretreated with poly-phosphonate showed a rise in serum calcium level after PTH
challenge which was less than that found in control animals which 25 had been treated with saline vehicle instead. The lowest dose at which the polyphosphonate is capable of inhibiting bone resorption, as evidenced by a decreased rise in serum calcium upon PTH challenge, is a measure of the bone resorption inhibi-tibn potency of the polyphosphonate. The LED values of the 30 bone resorption inhibition potency of representative compounds as determined by the TPTX rat model are presented in Table lll.

~ 32~ l%7 Lowest Effective ~Antiresorptive) Dose TPTX
Diphosphonate Compound LED (m~ Plkg~
5 EHDP 1.0 C~2MDP 1 . O
APD 0.1 N-l2-pyridyl) AMDP 0.01 N-[2-[5-amino)-pyridyl) AMDP 0.01 N-(2-(5-chloro)-pyridyl) AMDP 0.01 N-(2-(5-nitro)-pyridyl) AMDP 0.1 N-12-(5-carboxy)-pyridyl) AMDP N
N-(2-13,5-dichloro)-pyridyl) AMDP 1.0 N-14-pyridyl)-N-ethyl AMDP 0.1 N- 12-13-picolyl ) ) AMDP 0. 002 N- ( 2-1 4-picolyl ) ) AMDP 0.001 N- 12-15-picolyl ) ) AMD P 0 . 001 N-[2-[6-picolyl ) ) AMDP 0 . 01 N-[2-[3~4-lutidine)) AMDP 0.01 20 . N-[2-(4,6-lutidine) AMDP 0.01 1 ) N-~2-pyrimidyl) AMDP 0.01 N- ( 4-(2, 6-dimethyl ) -pyrimiiyl ) AMDP 1.0 N- ( 2- ( 4, 6-dihydroxy ) -pyrimidyl ) AMD P 0 . 01 1 ) N-(2-pyridyl ) AEDP 0. 01 N-(2-t3-picolyl) AEDP 10 2- ( 2-pyridyl ) EDP 0.01 2- ( 3-pyridy 1 ) EDP 0.01 2-(4-pyridyl) EDP 0.1 1-12-pyridyl) propyl DP 1.0 2-~2-pyridyl)-1-chloroethane DP 0.1 0-(2-pyridyi)-oxamethane DP 1.0 0-(2-(3-picolyl))-oxamethane DP 0.1 N = no activity at any of the dosage levels tested EHDP = ethane-l-hydroxy-l,l-DP
35 C12MDP = dichloromethane DP
APD = 3-aminopropane-1-hydroxy-1,1-DP

132~r~ %r -- 2~ -AMDP = aminomethane diphosphonic acid, where the ring i5 at-tached to the amine AEDP = 2-aminoethane-1 ,1-diphosphonic acid, where the ring is attached to the amine 5 EDP = ethane-1 ,1-diphosphonic acid, where the ring is attached at the 2 position of the ethane propyl DP = propane-2,2-diphosphonic acid * = Compounds included in pharmaceutical compositions of the present invention 0 1) = activity level questionable due to lack of dose response EXAMPLE IV
Patients weighing approximately 70 kilograms who are clin-ically diagnosed as sufferin~3 from hypercalcemia of malignancy are administered 0.7 mg P of 2-(2-pyridyl~-ethane-1,1-diphosphonic 15 acid, or its pharmaceutically-acceptable salt or ester, by a 2-1/2 hour intravenous infusion one time daily for 4 days. This treatment results in an appreciable alleviation of the hypercalcemia of malignancy.
Similar results are obtained when the 2-~2-pyridyl)-ethane-20 1,1-diphosphonic acid in the above-described treatment is re-placed with N-(2-(5-amino)-pyridyl)-aminomethane diphosphonic acid;
N-(2-l5-chloro)-pyridyl)-aminomethane diphosphonic acid;
N-(2-(3-picolyl))-aminomethane diphosphonic acid 25 N-(2-l4-picolyl))-aminomethane diphosphonic acid;
N-(2-(5-picolyl))-aminomethane diphosphonic acid;
N-12-(6-picolyl))-aminomethane diphosphonic acid;
N-~2-(3,4-lutidine~)-aminomethane diphosphonic acid;
,N-(2-pyrimidyl)-aminomethane diphosphonic acid;
30 N-(2-pyridyl)-2-aminoethane-1,1-~iphosphonic acid;
2-(3-pyridyl)-ethane-1,1-diphosphonic acid;
2- ( 4-pyridyl ) -ethane-1 ,1 -diphosphonic acid;
2-(2-pyridyl)-1-hydroxy-ethane-1,1-diphosphonic acid;
2- ( 3-pyridyl ) -1 -hydroxy-ethane-1 ,1 -diphosphonic acid;

~2~72~

2-(4-pyridyl)-1-hydroxy-ethane-1 ,1-diphosphonic acid;
O- ~ 2 - ( 3-picolyl ) ) -oxame~hane-diphosphon ic ac id; or pharmaceutically-acceptable salts or esters thereof.

WHAT IS CLAIMED IS:

Claims

1. A pharmaceutical composition comprising:
(a) a geminal diphosphonic acid compound, or a pharmaceutically-acceptable salt or ester thereof, at a level providing from 0.001 to 600 milligrams of phosphorus in said composition, in which the diphosphonic acid-containing carbon of said compound is linked directly or via a chain of length from 1 to 5 atoms, to a pyridine ring, wherein:
- said ring is unsubstituted, or substituted with one or more substituents selected from the group consisting of substituted and unsubstituted, saturated and unsaturated hydrocarbon chains having from 1 to 6 carbon atoms, substituted and unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, and combinations thereof, or substituted with from one to three substituents selected from the group consisting of substituted and unsubstituted phenyl, substituted and unsubstituted naphthyl, carbonyl, nitro, amido, carboxylate, and combinations thereof;
- said linking chain is selected from the group consisting of a carbon atom, a chain of carbon atoms, a nitrogen atom, a chain of nitrogen and carbon atoms, an oxygen atom, a chain of oxygen and carbon atoms, a selenium atom, and a chain of selenium and carbon atoms;
wherein said chain is unsubstituted, or substituted on a nitrogen or carbon atom, independently, with one or more substituted or unsubstituted, saturated or unsaturated hydrocarbon chains having from 1 to 4 carbon atoms, or substituted on a nitrogen atom with an acetyl group;
- said diphosphonate-containing carbon is unsubstituted, or substituted with a substituent selected from the group consisting of substituted and unsubstituted, saturated and unsaturated hydrocarbon chains having from 1 to 6 carbon atoms, substituted and unsubstituted phenyl, substituted and unsubstituted benzyl, amino, substituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, and carboxylate; except where said diphosphonate-containing carbon is directly bonded to a nitrogen, selenium or oxygen atom in said linking chain, then said substituent is selected from the group consisting of substituted and unsubstituted, saturated and unsaturated aliphatic hydrocarbon chains having from 1 to 6 carbon atoms, substituted and unsubstituted phenyl, and substituted and unsubstituted benzyl;
- said substituted substituents of said ring, of said linking chain and of said diphosphonate-containing carbon are independently substituted with methyl, ethyl, amino, chloro, nitro, methoxy, hydroxy, acetamido, or acetate; and (b) a pharmaceutical carrier.

2. A pharmaceutical composition according to Claim 1, wherein said diphosphonic acid compound is of the formula:

wherein Z is a pyridine ring; Q is oxygen, -NR4-, or a single bond; m + n is an integer of 0 to 5; R1 is hydrogen, substituted or unsubstituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, carboxylate, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstitutad phenyl, or substituted or unsubstituted benzyl, except that when n = 0 and Q is oxygen or nitrogen, then R1 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate; and R4 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 t 4 carbon atoms, or acutely; and wherein said substituted R1, R2, R3 and R4 groups are independently substituted with methyl, ethyl, amino, chloro, nitro, methoxy, hydroxy, acetamido or acetate.

3. A pharmaceutical composition according to Claim 2, wherein said diphosphonic acid compound is of the formula:

;

wherein Z is a pyridine ring; n is an integer from 0 to 5;
R1 is hydrogen, substituted or unsubstituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, carboxylate, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl, R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; and R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate.

4. A pharmaceutical composition according to Claim 2, wherein said diphosphonic acid compound is of the formula:

;

wherein Z is a pyridine ring; m + n is an integer from 0 to 5; R1 is hydrogen, substituted or unsubstituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, carboxylate, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl, except that when n = 0, then R1 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate; and R4 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms, or acetyl.

5. A pharmaceutical composition according to Claim 2, wherein said diphosphonic acid compound is of the formula:

;

wherein Z is a pyridine ring; m + n is an integer from 0 to 5; R1 is hydrogen, substituted or unsubstituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, carboxylate, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl, except that when n = 0, then R1 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; and R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate.

6. A pharmaceutical composition according to Claim 4, wherein m + n = 0.

7. A pharmaceutical composition according to Claim 5, wherein m + n = 0.

8. A pharmaceutical composition according to Claim 6, wherein said diphosphonic acid compound is of the formula:

wherein R1 is hydrogen; R3 is hydrogen, methyl, amino, chloro, methoxy, nitro, or hydroxy; and R4 is hydrogen, methyl, or ethyl.

9. A pharmaceutical composition according to Claim 7, wherein said diphosphonic acid compound is of the formula:

wherein R1 is hydrogen and R3 is hydrogen, methyl, amino, chloro, methoxy, nitro, or hydroxy.

10. A pharmaceutical composition comprising:
(a) a geminal diphosphonic acid compound or a pharmaceutically-acceptable salt or ester thereof, at a level providing from 0.001 to 600 milligrams of phosphorus in said composition, wherein said compound is of the formula:

wherein Z is a pyridine ring; n is 0 or 1; R1 is hydrogen, substituted or unsubstituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, carboxylate, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or a substituted or unsubstituted benzyl; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; and R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate; and wherein said substituted R1, R2 and R3 groups are independently substituted with methyl, ethyl, amino, chloro, nitro, methoxy, hydroxy, acetamido, or acetate;
and (b) a pharmaceutically-acceptable carrier.

11. A pharmaceutical composition according to Claim 10, wherein n = 1.

12. A pharmaceutical composition according to Claim 10, wherein said diphosphonic acid compound is of the formula:

wherein n = 0 or 1; R1 is hydrogen, chloro, amino, or hydroxy; and R3 is hydrogen, methyl, amino, chloro, methoxy, hydroxy, or nitro.

13. A pharmaceutical composition according to Claim 11, wherein said diphosphonic acid is selected from the group consisting of 2-(2-pyridyl)-ethane-1,1-diphosphonic acid; 2-(3-pyridyl)-ethane-1,1-diphosphonic acid; 2-(4-pyridyl)-ethane-1,1-diphosphonic acid; 2-(2-pyridyl)-hydroxyethane-1,1-diphosphonic acid; 2-(3-pyridyl)-hydroxyethane-1,1-diphosphonic acid; and 2-(4-pyridyl)-hydroxyethane-1,1-diphosphonic acid.

14. A pharmaceutical composition according to Claim 13, wherein said diphosphonic acid compound is 2-(2-pyridyl)-ethane-1,1-diphosphonic acid.

15. A pharmaceutical composition according to Claim 13, wherein said diphosphonic acid compound is 2-(3-pyridyl)-hydroxyethane diphosphonic acid.

16. Use of a composition as claimed in Claim 1 for treating diseases associated with abnormal calcium and phosphate metabolism.

17. Use of a composition as claimed in Claim 2 for treating diseases associated with abnormal calcium and phosphate metabolism.

18. Use of a composition as claimed in Claim 3 for treating diseases associated with abnormal calcium and phosphate metabolism.

19. Use of a composition as claimed in Claim 4 for treating diseases associated with abnormal calcium and phosphate metabolism.

20. Use of a composition as claimed in Claim 5 for treating diseases associated with abnormal calcium and phosphate metabolism.

21. Use of a composition as claimed in Claim 10 for treating diseases associated with abnormal calcium and phosphate metabolism.

22. Use of a composition as claimed in Claim 11 for treating diseases associated with abnormal calcium and phosphate metabolism.

23. Use of a composition as claimed in Claim 13 for treating diseases associated with abnormal calcium and phosphate metabolism.

24. Use of a composition as claimed in Claim 14 for treating diseases associated with abnormal calcium and phosphate metabolism.

25. Use of a composition as claimed in Claim 15 for treating diseases associated with abnormal calcium and phosphate metabolism.

26. Use of a composition as claimed in Claim 1 for treating osteoporosis in humans or lower animals.

27. A diphosphonic acid compound, or a pharmaceutically-acceptable salt or ester thereof, having the structure:

wherein Z is a pyridine ring; R1 is hydrogen substituted or unsubstituted amino, amido, hydroxy, C1-C6 alkoxy, halogen, carboxylate, a substituted or unsubstituted, a saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted phenyl, or substituted or unsubstituted benzyl; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate; and R4 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms, or acetyl; and wherein said substituted R1, R2, R3 and R4 groups are independently substituted with methyl, ethyl, amino, chloro, nitro, methoxy, hydroxy, acetamido or acetate.

28. A diphosphonic acid compound, or a pharmaceutically-acceptable salt or ester thereof, having the structure:

wherein Z is a pyridine ring; n is an integer of from 1 to 5; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; and R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate; and wherein said substituted R2 and R3 groups are independently substituted with methyl, ethyl, amino, chloro, nitro, methoxy, hydroxy, acetamido, or acetate.

29. A diphosphonic acid compound, or a pharmaceutically-acceptable salt or ester thereof, having the structure:

wherein Z is a pyridine ring; n is 0 or 1; R2 is hydrogen, or a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 4 carbon atoms; and R3 is hydrogen, a substituted or unsubstituted, saturated or unsaturated hydrocarbon chain having from 1 to 6 carbon atoms, substituted or unsubstituted benzyl, hydroxy, halogen, C1-C6 alkoxy, amino, substituted amino, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, carbonyl, nitro, amido, or carboxylate; and wherein said substituted R2 and R3 groups are independently substituted with methyl, ethyl, amino, chloro, nitro, methoxy, hydroxy, acetamido, or acetate.

30. A diphosphonic acid compound according to Claim 29, wherein n = 1.