More particularly, the present invention relates to therapeutic and prophylactic use of certain disulfide derivatives for treating or preventing allergic diseases.

Description of the Related Art Antihistamines and mast cell stabilizers are two types of drugs currently used topically to treat allergic diseases. Antihistamine drugs are used to interrupt the allergic effects that histamine causes after it has been released from a mast cell. Many topical antihistamine drugs are marketed.

For example, emedastine difumarate and levocabastine hydrochloride are available for ocular allergies (see Ophthalmic Drug Facts 1999, Facts and Comparisons, St. Louis, MO, pp. 59-80).

Mast cell stabilizers prevent mast cells from"degranulating"or releasing histamine and other components or"mediators"during an allergic reaction. Examples of ophthalmic drugs marketed as mast cell stabilizers include olopatadine (see U. S. Patent No. 5,641,805) and cromolyn sodium.

U. S. Patent No. 4,705,805 discloses certain disulfide derivatives that are useful as anti-thrombotic agents. The disulfide derivatives suppress blood platelet aggregation. The'705 patent does not disclose the use of disulfide derivatives in the topical treatment of allergic diseases of the eye or nose.

Summary of the Invention The present invention provides methods for preventing or treating allergic diseases of the eye, nose, skin, ear, gastrointestinal tract, airways or lung. The methods may also be used to treat manifestations of systemic mastocytosis. The methods of the present invention comprise topically or systemically administering to a patient a mast cell stabilizing disulfide derivative of the formula (l) wherein X is-C (=O)-N (-R')-R ; R and R1 are independently H; (un) substituted phenyl ; (un) substituted benzyl ; or Ci-Cs alkyl or alkenyl, optionally substituted with or terminated by OH, OR2, NR3R4 ; C4-C7 cycloalkyl, (un) substituted aryl, or (un) substituted 5-7 membered heterocyclic ring; where optional substituents are selected from the group consisting of C,-C6 alkyl or alkoxy ; halogen ; OH; CN; CF3 ; N02 ; and C02R2 ; R2 is Ci-C3 alkyl ; and R3 and R4 are independently H; benzyl ; C,-C8 alkyl or alkenyl ; C4-C7 cycloalkyl ; (un) substituted aryl ; or (un) substituted 5-7 membered heterocyclic ring; wherein optional substituents are selected from the group consisting of Ci-Ce alkyl or alkoxy ; halogen ; OH; CN; CF3 ; N02 ; and CO2R2.

The present invention is also directed toward topically or systemically administrable compositions for treating or preventing allergic diseases of the

eye, nose, skin, ear, gastrointestinal tract, airways or lung and treating or preventing manifestations of systemic mastocytosis, wherein the compositions comprise a disulfide derivative of formula (I).

Detailed Description of the Invention The disulfide derivatives of formula (I) are known or are commercially available from sources such as Aldrich Chemical Company (Sigma Aldrich Library of Rare Chemicals) in Milwaukee, Wisconsin and Maybridge Chemical Company Ltd. in the U. K or can be made using known techniques, such as those described in Domagala JM et al. Bioraanic and Medicinal Chemist volume 5 No. 3 pages 569-79 (1997), and US patent No. 4,705,805 (Yamotsu K. et al., 1987). The entire contents of both of these references are incorporated by reference.

Preferred compounds of formula (I) are those having the X substituents in the ortho position.

Most preferred are compounds wherein R and R1 independently = H; Cri-¬5 alkyl or alkenyl, optionally substituted with or terminated by OH, OR, NR3R4, C4-C7 cycloalkyl, (un) substituted aryl, or (un) substituted 5-7 membered heterocyclic ring, wherein optional substituents are selected from the group consisting of C,-C6 alkyl or alkoxy ; halogen ; OH; CN; CF3 ; NO2 ; and CO2R2.

Compounds of formula (I) may be administered topically (i. e., local, organ-specific delivery) or systemically by means of conventional topical or systemic formulations, such as solutions, suspensions or gels for the eye and ear; nasal sprays or mists for the nose; metered dose inhalers for the lung ; solutions, gels, creams or lotions for the skin; oral dosage forms including tablets or syrups for the gastrointestinal tract; and parenteral dosage forms including injectable formulations. The concentration of the compound of formula (I) in the formulations of the present invention will depend on the

selected route of administration and dosage form. The concentration of the compound of formula (I) in topically administrable formulations will generally be about 0.00001 to 5 wt. %. For systemically administrable dosage forms, the concentration of the compound of formula (I) will generally range from about 10 mg to 1000 mg.

The preferred formulation for topical ophthalmic administration is a solution intended to be administered as eye drops. For solutions intended for topical administration to the eye, the concentration of the compound of formula (I) is preferably 0.0001 to 0.2 wt. %, and most preferably from about 0.0001 to 0.01 wt. %. The topical compositions of the present invention are prepared according to conventional techniques and contain conventional excipients in addition to one or more compounds of formula (I). A general method of preparing eye drop compositions is described below : One or more compounds of formula (I) and a tonicity-adjusting agent are added to sterilized purified water and if desired or required, one or more excipients. The tonicity-adjusting agent is present in an amount sufficient to cause the final composition to have an ophthalmically acceptable osmolality (generally about 150-450 mOsm, preferably 250-350 mOsm).

Conventional excipients include preservatives, buffering agents, cheating agents or stabilizers, viscosity-enhancing agents and others. The chosen ingredients are mixed until homogeneous. After the solution is mixed, pH is adjusted (typically with NaOH or HCI) to be within a range suitable for topical ophthalmic use, preferably within the range of 4.5 to 8.

Many ophthalmically acceptable excipients are known, including, for example, sodium chloride, mannitol, glycerin or the like as a tonicity-adjusting agent; benzalkonium chloride, polyquaternium-1 or the like as a preservative; sodium hydrogenphosphate, sodium dihydrogenphosphate, boric acid or the like as a buffering agent; edetate disodium or the like as a cheating agent or stabilizer ; polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid,

polysaccharide or the like as a viscosity-enhancing agent; and sodium hydroxide, hydrochloric acid or the like as a pH controller.

If required or desired, other drugs can be combined with the disulfide derivatives of formula (I), including, but not limited to, antihistaminic agents, anti-inflammatory agents (steroidal and non-steroidal), and decongestants.

Suitable antihistaminic agents include emedastine, mapinastine, epinastine, levocabastine, loratadine, desloratadine, ketotifen, azelastine, cetirazine, and fexofenadine. The preferred antihistaminic agent for ophthalmic use is emedastine, which is generally included in topically administrable compositions at a concentration of 0.001-0.1 wt. %, preferably 0.05 wt. %.

Suitable anti-inflammatory agents includemometasone, fluticasone, dexamethasone, prednisolone, hydrocortisone, rimexolone and loteprednol.

Suitable decongestants include oxymetazoline, naphazoline, tetrahydrozoline, xylometazoline, propylhexedrine, ethylnorepinephrine, pseudoephedrine, and phenylpropanolamine.

According to the present invention, the disulfide derivatives of formula (I) are useful for preventing and treating ophthalmic allergic disorders, including allergic conjunctivitis, vernal conjunctivitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis; nasal allergic disorders, including allergic rhinitis and sinusitis; otic allergic disorders, including eustachian tube itching; allergic disorders of the upper and lower airways, including intrinsic and extrinsic asthma; allergic disorders of the skin, including dermatitis, eczema and urticaria; allergic disorders of the gastrointestinal tract, including systemic anaphylaxis resulting from ingestion of allergen and iatrogenic anaphylaxis caused by contrast agents used during diagnostic imaging procedures; and manifestations of systemic mastocytosis including hypotension.

The following examples are intended to be illustrative but not limiting.

Example 1: Topical Ophthalmic Solution Formulation Ingredient Concentration (wt. %) Compound of formula (I) 0.0001 to 0.2 Dibasic Sodium Phosphate (Anhydrous) 0.5 Sodium Chloride 0.65 Benzalkonium Chloride 0.01 NaOH/HCl q.s. pH 6 - 8 Purified Water q. s. 100 Example 2: Topical Ophthalmic Gel Formulation Ingredient Concentration (wt. %) Compound of formula (I) 0.0001 to 0.2 Carbopol 974 P 0.8 Edetate Disodium 0.01 Polysorbate 80 0.05 Benzalkonium Chloride 0.01 NaOH/HCl q.s. pH 6 - 8 Water for Injection q. s. 100 Example 3: Synthesis of 2,2-dithio-bis (N-3-morpholinopropyl-benzamide) (II) 2,2-Dithiodibenzoic acid chloride (1.5g, 4.37mmol) was dissolved in 10 ml of dioxane and cooled to 10 °C. To this solution, 4- (3-aminopropyl) morpholine (1.3moi, 8.74 mmol) was added slowly under nitrogen. The resulting mixture was stirred at 10 °C for 1hr and then at 70 °C for 2 hr. After cooling, the solids were filtered off. The filtrate was placed at room temperature.

Yellowish solids precipitated and were filtered. The crude product was recrystallized with ethanol/ethyl ether (1: 3), giving 0.80g of white product (II).

1H NMR (CDCI3) 8 8.04-7.18 (m, 8H), 3.73-3.54 (m, 12H), 2.60-2.39 (m, 12H), 1.87-1.80 (m, 4H). 13C NMR (CDC13) 8 167.63 (C=O), 137.32 (C), 134.23 (C), 131.07 (CH), 127.25 (CH), 127.17 (CH), 125.92 (CH), 66.91 (CH2), 58.49 (CH2), 53.74 (CH2), 40.35 (CH2), 24.21 (CH2). Analysis calculated for C28H3804N4S2 requires: C, 60.19; H, 6.85; N, 10.03 %.

Found: C, 60.15; H, 6.82; N, 9.96 %. CI N O O NH- S H -2/\- ci dioxan/ N 0 /N /O

(II) Example 4: Mast Cell Activity Preparation of cell suspension Methods detailing preparation of mono-dispersed HCTMC and mediator release studies with these cells have been described (US Patent No.

5,360,720 and Miller et al, Ocular Immunology and Inflammation, 4 (1) : 39-49 (1996)). Briefly, human conjunctival tissue mast cells were isolated from post-mortem tissue donors obtained within 8 hours of death by various eye banks and transported in Dexsol0 corneal preservation medium, or equivalent. Tissues were enzymatically digested by repeated exposure (30 min. at 37°C) to collagenase and hyaluronidase (2 X with 200 U each/gram tissue, then 2-4 X with 2000 U each/gram tissue) in Tyrode's buffer containing 0.1% gelatin. (Tyrode's buffer (in mM): 137 NaCI, 2.7 KCI, 0.35 NaH2PO4, 1.8 Cal2, 0.98 MgCI2, 11.9 NaHCO3, and 5.5 glucose). Each digestion mixture was filtered over NitexO cloth (100 um mesh, Tetko, Briarcliff Manor, NY) and washed with an equal volume of buffer. Filtrates were centrifuged at 825 x g (7 min). Pellets were resuspended in buffer then combined for enrichment over a 1.058 g/L Percoll0 cushion. The enriched pellet was washed, resuspended in supplemented RPMI 1640 medium and incubated at 37°C to equilibrate.

Histamine release studies Cells were harvested from the culture plate and counted for viability (trypan blue exclusion) and mast cell number (toluidine blue 0). Mast cells (5000/ tube; 1 mL final volume) were challenged (37°C) for 15 min with goat-anti- human IgE (10 ug/mL) following treatment (15 minutes; 37°C) with test drug or Tyrode's buffer. Total and non-specific release controls were exposed to 0.1% Triton X-100 and goat IgG (10 pg/mL), respectively. The reaction was terminated by centrifugation (500 x g, 4°C, 10 min). Supernatants were stored at-20°C until analyzed for histamine content by RIA (Beckman Coulter, Chicago, IL).

Preparation of test drug solutions All test drugs were made to solution immediately prior to use. Each was dissolved in DMSO at 10mM or greater concentration and then diluted in Tyrode's buffer containing 0.1 % gelatin over the concentration for evaluation.

Data Analysis Inhibition of histamine release was determined by direct comparison of with anti-IgE challenged mast cells using Dunnett's t-test (Dunnett,"A multiple comparison procedure for comparing treatments with a control", J. Amer. Stat. Assoc. (1955), 50: 1096-1121). An IC50 value (the concentration at which the test compound inhibits histamine release at a level of 50% compared to the positive control) was determined by 4-parameter logistic fitting using the Levenburg-Marquardt algorithm or by linear regression. The results are reported in Table 1.

Table 1 COMPOUND T x MOLSTRUCTURE IC50 (nM) NO. N O W-N \/ /o S-S N 39 0 N" zon 199 S-S N o N 78 S-S o \ s 199 39 N 388 r, [105] 0 p 21 388 N 231 s-r 121 | S S | °/3 | 5 X | 409 | 3 S-S SIP 121 9 128 N 128 39 o S9 39 0 69 N 1700 p CH3/ S 95 /409 S-S '0 po 149 N 66 [282] Table 1 (cont'd) H, C OH CH, ! 107 HO N 219 5 jN o 229 S, s 71 /71 <ry cl 402. 6 S-S N [3121 0, 0 metadisplacement

The data shown in Table 1 indicate that the compounds of formula (I) potently inhibit histamine release from human conjunctival mast cells in an in vitro model of allergic conjunctivitis.

Example 5: Topical Ophthalmic Solution Formulation ingredient Concentration (wt. %) Compound of formula (I) 0.0001 to 0.2 Emedastine 0.001 to 0.1 Dibasic Sodium Phosphate (Anhydrous) 0.5 Sodium Chloride 0.65 Benzalkonium Chloride 0.01 NaOH/HCI q. s. pH 6-8 Purified Water q. s. 100 The invention has been described by reference to certain preferred embodiments; however, it should be understood that it may be embodied in other specific forms or variations thereof without departing from its spirit or essential characteristics. The embodiments described above are therefore considered to be illustrative in all respects and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description.