Prodrugs of dithiol mucolytic agents

1. A compound represented by formula Ia or Ib:

wherein

R 1 and R 2 are each, independently, hydrogen, lower alkyl, halogen or triflouromethyl;

R 3 and R 4 are each, independently, hydrogen, lower alkyl, hydroxyl-lower alkyl, phenyl, (phenyl)-lower alkyl, (halophenyl)-lower alkyl, ((lower-alkyl)phenyl)-lower-alkyl, ((lower-alkoxy)phenyl)-lower-alkyl, (naphthyl)-lower-alkyl, or (pyridyl)-lower-alkyl;

each R 5 is, independently, hydrogen, halogen, trifluoromethyl, lower alkyl, unsubstituted or substituted phenyl, lower alkyl-thio, phenyl-lower alkyl-thio, lower alkyl-sulfonyl, phenyl-lower alkyl-sulfonyl, OH, —(CH 2 ) m —OR 8 , —O—(CH 2 ) m —OR 8 , —(CH 2 ) n —NR 7 R 10 , —(CH 2 ) n —NR 7 R 7 , —O—(CH 2 ) m —NR 7 R 10 , —O—(CH 2 ) m —NR 7 R 7 , —(CH 2 ) n (CHOR 8 )(CHOR 8 ) n —CH 2 OR 8 , —O—(CH 2 ) m (CHOR 8 )(CHOR 8 ) n —CH 2 OR 8 , —(CH 2 CH 2 O) m —R 8 , —O—(CH 2 CH 2 O) m —R 8 , —(CH 2 CH 2 O) m —CH 2 CH 2 NR 7 R 10 , —O—(CH 2 CH 2 O) m —CH 2 CH 2 NR 7 R 10 , —(CH 2 ) n —C(═O)NR 7 R 10 , —O—(CH 2 ) m —C(═O)NR 7 R 10 , —(CH 2 ) n —(Z) g —R 7 , —O—(CH 2 ) m —(Z) g —R 7 , —(CH 2 ) n —NR 10 —CH 2 (CHOR 8 )(CHOR 8 ) n —CH 2 OR 8 , —O—(CH 2 ) m —NR 10 —CH 2 (CHOR 8 )(CHOR 8 ) n —CH 2 OR 8 , —(CH 2 ) n —CO 2 R 7 , —O—(CH 2 ) m —CO 2 R 7 , —OSO 3 H, —O-glucuronide, —O-glucose,

-Link-(CH 2 ) m -CAP, -Link-(CH 2 ) n (CHOR 8 )(CHOR 8 ) n -CAP, -Link-(CH 2 CH 2 O) m —CH 2 -CAP, -Link-(CH 2 CH 2 O) m —CH 2 CH 2 -CAP, -Link-(CH 2 ) m —(Z) g -CAP, -Link-(CH 2 ) n (Z) g —(CH 2 ) m -CAP, -Link-(CH 2 ) n —NR 13 —CH 2 (CHOR 8 )(CHOR 8 ) n -CAP, -Link-(CH 2 ) n —(CHOR 8 ) m CH 2 —NR 13 —(Z) g -CAP, -Link-(CH 2 ) n NR 13 —(CH 2 ) m (CHOR 8 ) n CH 2 NR 13 —(Z) g -CAP, -Link-(CH 2 ) m —(Z) g —(CH 2 ) m -CAP, -Link-NH—C(═O)—NH—(CH 2 ) m -CAP, -Link-(CH 2 ) m —C(═O)NR 13 —(CH 2 ) m -CAP, -Link-(CH 2 ) n —(Z) g —(CH 2 ) m —(Z) g -CAP, or -Link-Z g —(CH 2 ) m -Het-(CH 2 ) m -CAP, with the proviso that at least one R 5 group contains at least one basic nitrogen;

each R 7 is, independently, phenyl, substituted phenyl, lower alkyl phenyl or —CH 2 (CHOR 8 ) m —CH 2 OR 8 ;

each R 8 is, independently, hydrogen, lower alkyl, lower alkyl phenyl, —C(═O)—R 1 , glucuronide, 2-tetrahydropyranyl, or

each R 9 is, independently, —CO 2 R 7 , —CON(R 7 ) 2 , —SO 2 CH 3 , —C(═O)R 7 , —CO 2 R 13 , —CON(R 13 ) 2 , —SO 2 CH 2 R 13 , or —C(═O)R 13 ;

each R 10 is, independently, —H, —SO 2 CH 3 , —CO 2 R 7 , —C(═O)NR 7 R 9 , —C(═O)R 7 , or —CH 2 —(CHOH) n —CH 2 OH;

each Z is, independently, —(CHOH)—, —C(═O)—, —(CHNR 7 R 10 )—, —(C═NR 10 )—, —NR 10 —, —(CH 2 ) n —, —(CHNR 13 R 13 )—, —(C═NR 13 )—, or —NR 13 —;

each R 11 is, independently, hydrogen, lower alkyl, phenyl lower alkyl or substituted phenyl lower alkyl;

each R 12 is, independently, —SO 2 CH 3 , —CO 2 R 7 , —C(═O)NR 7 R 9 , —C(═O)R 7 , —CH 2 (CHOH) n —CH 2 OH, —CO 2 R 13 , —C(═O)NR 13 R 13 , or —C(═O)R 13 ;

each R 13 is, independently, hydrogen, lower alkyl, phenyl, substituted phenyl or —CH 2 (CHOR 8 ) m —CH 2 OR 8 , —SO 2 CH 3 , —CO 2 R 7 , —C(═O)NR 7 R 9 , —C(═O)R 7 , —CH 2 —(CHOH) n —CH 2 OH, —(CH 2 ) m —NR 7 R 10 , —(CH 2 ) m —NR 7 R 7 , —(CH 2 ) m —NR 11 R 11 , —(CH 2 ) m —(NR 11 R 11 R 11 ) + , —(CH 2 ) m —(CHOR 8 ) m —(CH 2 ) m NR 11 R 11 , —(CH 2 ) m —(CHOR 8 ) m —(CH 2 ) m NR 7 R 10 , —(CH 2 ) m —NR 10 R 10 , —(CH 2 ) m —(CHOR 8 ) m —(CH 2 ) m —(NR 11 R 11 R 11 ) + , or —(CH 2 ) m —(CHOR 8 ) m —(CH 2 ) m NR 7 R 7 ;

each R 14 is, independently, —C(═O)—R 7 , —C(═O)-lower alkyl, or an amino acyl of the natural configuration;

each g is, independently, an integer from 1 to 6;

each m is, independently, an integer from 1 to 7;

each n is, independently, an integer from 0 to 7;

each -Het- is, independently, —N(R 7 )—, —N(R 10 )—, —S—, —SO—, —SO 2 —; —O—, —SO 2 NH—, —NHSO 2 —, —NR 7 CO—, —CONR 7 —, —N(R 13 )—, —SO 2 NR 13 —, —NR 13 CO—, or —CONR 13 —;

each Link is, independently, —O—, —(CH 2 ) n —, —O(CH 2 ) m —, —NR 13 —C(═O)—NR 13 —, —NR 13 —C(═O)—(CH 2 ) m —, —C(═O)NR 13 —(CH 2 ) m − , —(CH 2 ) n —(Z) g —(CH 2 ) n —, —S—, —SO—, —SO 2 —, —SO 2 NR 7 —, —SO 2 NR 10 —, or -Het-;

each CAP is, independently

with the proviso that when any —CHO 8 — or —CH 2 OR 8 groups are located 1,2- or 1,3- with respect to each other, the R 8 groups may, optionally, be taken together to form a cyclic mono- or di-substituted 1,3-dioxane or 1,3-dioxolane;

or racemates, enantiomers, diastereomers, tautomers, polymorphs, pseudopolymorphs or pharmaceutically acceptable salts thereof.

2. A method of liquefying mucus from mucosal surfaces, comprising:

administering an effective amount of the compound of claim 1 to a mucosal surface of a subject in need thereof.

3. A method of treating chronic bronchitis, treating bronchiectasis, treating cystic fibrosis, treating chronic obstructive pulmonary disease, treating asthma, treating sinusitis, treating vaginal dryness, treating dry eye, promoting ocular hydration, promoting corneal hydration, promoting mucus clearance in mucosal surfaces, treating Sjogren's disease, treating distal intestinal obstruction syndrome, treating dry skin, treating esophagitis, treating dry mouth, treating nasal dehydration, treating ventilator-induced pneumonia, treating asthma, treating primary ciliary dyskinesia, treating otitis media, inducing sputum for diagnostic purposes, treating cystinosis, treating emphysema, treating pneumonia, treating constipation, treating chronic diverticulitis, and/or treating rhinosinusitis, comprising:

administering an effective amount of the compound of claim 1 to a subject in need thereof.

4. A method of treating an eye disease characterized by the presence of ocular discharge comprising administering to a subject in need thereof an effective amount of the compound of claim 1 , wherein the eye disease is one or more conditions selected from the group consisting of blepharitis, allergies, conjunctivitis, corneal ulcer, trachoma, congenital herpes simplex, corneal abrasions, ectropion, eyelid disorders, gonococcal conjunctivitis, herpetic keratitis, ophthalmitis, Sjogren's Syndrome and Stevens-Johnson Syndrome.

5. A method of treating a disease ameliorated by increased mucociliary clearance and mucosal hydration comprising administering to a subject in need of increased mucociliary clearance and mucosal hydration an effective amount of an osmolyte and the compound of claim 1 , wherein the disease is one or more conditions selected from the group consisting of chronic bronchitis, bronchiectasis, cystic fibrosis, asthma, sinusitis, vaginal dryness, dry eye, Sjogren's disease, distal intestinal obstruction syndrome, dry skin, esophagitis, dry mouth (xerostomia), nasal dehydration, asthma, primary ciliary dyskinesia, otitis media, chronic obstructive pulmonary disease, emphysema, pneumonia, diverticulitis, rhinosinusitis and airborne infections.

6. The method of claim 5 , wherein the compound is administered preceding administration of the osmolyte.

7. The method of claim 5 , wherein the compound is administered concurrent with administration of the osmolyte.

8. The method of claim 5 , wherein the compound is administered following administration of the osmolyte.

9. The method of claim 5 , wherein the osmolyte is hypertonic saline or mannitol.

10. The method of claim 5 , wherein the osmolyte is sodium chloride which is delivered as a micronized particle of respirable size.

11. The method of claim 5 , wherein the effective amount of an osmolyte and the compound is administered by aerosolization using a device capable of delivering the formulation to the nasal passages or pulmonary airway wherein the aerosol is a respirable size.

12. A composition, comprising:

(a) the compound of claim 1 and (b) an osmotically active compound.

13. A method of inducing sputum, comprising administering to a subject in need of increased mucociliary clearance and mucosal hydration an effective amount of an osmolyte and the compound of claim 1 .

14. A method of therapeutic treatment against diseases or conditions caused by pathogens, comprising administering to a subject in need of increased mucociliary clearance and mucosal hydration an effective amount of the compound of claim 1 .

15. The method of claim 14 , wherein the pathogen is anthrax or plague.

16. A method for mitigating, and/or treating deterministic health effects to the respiratory tract and/or other bodily organs caused by respirable aerosols containing radionuclides in a human in need thereof, said method comprising administering to said human an effective amount of the compound of claim 1 or a pharmaceutically acceptable salt thereof.

17. A pharmaceutical composition, comprising the compound of claim 1 , and a pharmaceutically acceptable carrier.

18. A method for improving mucus penetration of therapeutic agents comprising administering an effective amount of the compound of claim 1 and a second therapeutic agent to a subject in need thereof.

19. The method of claim 18 , wherein the second therapeutic agents is an osmolyte, a sodium channel blocker, a secretogogue, a bronchodilator, an anti-infective, an anti-inflammatory, or a gene carrier.

20. A method for decreasing mucosal inflammation comprising administering an effective amount of the compound of claim 1 to a subject in need thereof.

21. A method for decreasing mucosal oxygen free radicals comprising administering an effective amount of the compound of claim 1 to a subject in need thereof.

22. The compound of claim 1 , which is represented by the formula:

23. The compound of claim 1 , which is an acid addition salt of an inorganic acid or an organic acid selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, oxalic acid, tartaric acid, succinic acid, maleic acid, furmaric acid, gluconic acid, citric acid, malic acid, ascorbic acid, benzoic acid, tannic acid, palmitic acid, alginic acid, polyglutamic acid, naphthalensulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonic acid, polygalacturonic acid, malonic acid, sulfosalicylic acid, glycolic acid, 2-hydroxy-3-naphthoate, pamoate, salicylic acid, stearic acid, phthalic acid, mandelic acid and lactic acid.

24. A composition containing a pharmaceutically acceptable carrier, hypertonic saline and a compound represented by the formula:

or a pharmaceutically acceptable salt thereof.