New use of a PDE 5 inhibitor combination in promoting neurite outgrowth

Abstract

The present disclosure relates to the technical field of medicaments. Particularly, the present disclosure provides a pharmaceutical combination / composition comprising a phosphodiesterase type 5 (PDE5) inhibitor, arginine, and N-acetylcysteine and its applications in treating cardiovascular diseases and erectile dysfunction.

Description

NEW USE OF A PDE 5 INHIBITOR COMBINATION IN PROMOTING NEURITEOUTGROWTHFIELD

[0001] The present disclosure relates to the technical field of medicaments. Particularly, the present disclosure provides a pharmaceutical combination / composition comprising a phosphodiesterase type 5 (PDE5) inhibitor, arginine, and N-acetylcysteine and its applications in promoting neurite outgrowth and / or treating and / or preventing neurological disorders.BACKGROUND OF THE INVENTION

[0002] A phosphodiesterase type 5 inhibitor (PDE5 inhibitor) is a vasodilating drug that works by blocking the degradative action of cGMP-specific phosphodiesterase type 5 (PDE5) on cyclic GMP in the smooth muscle cells lining the blood vessels supplying various tissues. Part of the physiological process of vasodilatation involves the release of nitric oxide (NO) by vascular endothelial cells which then diffuses to nearby vascular smooth muscle cells. There, NO activates soluble guanylate cyclase, which converts guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP), the main effector of the system. PDE5 inhibitors prolong the action of cGMP by inhibiting its degradation by the enzyme PDE5, which is found throughout the body (Goldstein I, Lue TF, Padma-Nathan H, Rosen RC, Steers WD, Wicker PA (May 1998). "Oral sildenafd in the treatment of erectile dysfunction. Sildenafd Study Group", The New England Journal of Medicine. 338 (20): 1397-404). PDE5 inhibitors are contraindicated with alpha-blockers, soluble guanylate cyclase stimulators, or nitrate medications, which can cause blood pressure to be too low. The PDE5 inhibitor may cause headaches, stomachaches, diarrhea, flushing, dizziness, weakness, pruritus, erythema and the like after administration.SUMMARY OF THE INVENTION

[0003] The present disclosure relates to a PDE5 inhibitor or its pharmaceutically acceptable salt in combination with arginine and / or N-acetylcysteine (NAC), which surprisingly promote neurite outgrowth and treat and / or prevent neurological disorders.

[0004] In one aspect, the present disclosure relates to a method for promoting neurite outgrowth, comprising exposing the neuron to an effective amount of a pharmaceutical combination or composition comprising a phosphodiesterase type 5 (PDE5) inhibitor or a pharmaceutically acceptable salt thereof, arginine, and N-acetylcysteine, thereby promotingneurite outgrowth. Particularly, the pharmaceutical combination or composition can promote the outgrowth of axons and dendrites. Alternatively, the present disclosure relates to a pharmaceutical composition or combination disclosed herein for use in a method for promoting neurite outgrowth. Alternatively, the present invention discloses the use of a pharmaceutical composition or combination disclosed herein in preparation of a medicament for promoting neurite outgrowth.

[0005] In another aspect, the present disclosure relates to a method for treating and / or preventing a neurological disorder or injury via promotion of neurite outgrowth, the method comprising administering an effective amount of a pharmaceutical combination or composition comprising a phosphodiesterase type 5 (PDE5) inhibitor or a pharmaceutically acceptable salt thereof, arginine, and N-acetyl cysteine to a subject in need thereof. Alternatively, the present disclosure relates to a pharmaceutical composition or combination disclosed herein for use in a method for treating and / or preventing a neurological disorder or injury via promotion of neurite outgrowth. Alternatively, the present invention discloses the use of a pharmaceutical composition or combination disclosed herein in preparation of a medicament for treating and / or preventing a neurological disorder or injury via promotion of neurite outgrowth.

[0006] In one embodiment, the neurological disorder or injury via promotion of neurite outgrowth include, but is not limited to, epilepsy, Alzheimer disease and other dementias, cerebrovascular diseases including stroke, migraine and other headache disorders, multiple sclerosis, Parkinson's disease, neuroinfections, brain tumours, traumatic disorders of the nervous system due to head trauma, Huntington's disease, ALS, multiple sclerosis, ischemia associated with stroke, neural paropathy, motor neuron diseases, sciatic crush, peripheral neuropathy, neuropathy associated with diabetes, spinal cord injuries and facial nerve crushinjuries to the nervous system caused by physical, mechanical, or chemical trauma, memory loss, or psychiatric disorders, intracranial hemorrhage, spinal cord injury and neurological symptoms due to the infection or an immune response. .

[0007] In some other embodiments, the method of the invention can be used in the treatment of peripheral nerve damage caused by physical injury (associated with, e.g., bums, wounds, surgery, and accidents), ischemia, prolonged exposure to cold temperature (e.g., frost-bite), damage to the central nervous system due, for example, to stroke or intracranial hemorrhage (such as cerebral hemorrhage), dementia, Alzheimer's disease, Huntington's disease or Parkinson's disease.

[0008] In one embodiment, the PDE5 inhibitor in the present disclosure is selected from sildenafil, tadalafil, and vardenafil and or a pharmaceutically acceptable salt thereof.

[0009] In one embodiment, the amount of the PDE5 inhibitor in the pharmaceutical combination or composition as described herein ranges from about 0.1% (w / w) to about 50% (w / w). Certain embodiments of the amount of the PDE5 inhibitor include, but are not limited to, about 0.1% (w / w) to about 45% (w / w), about 0.1% (w / w) to about 40% (w / w), about 0.1% (w / w) to about 35% (w / w), about 0.1% (w / w) to about 30% (w / w), about 0.1% (w / w) to about 25% (w / w), about 0.1% (w / w) to about 20% (w / w), about 0.1% (w / w) to about 15% (w / w), about 0.1% (w / w) to about 10% (w / w), about 0.1% (w / w) to about 5% (w / w), about 0.1% (w / w) to about 2.5% (w / w), about 0.1% (w / w) to about 1% (w / w), about 0.5% (w / w) to about 50% (w / w), about 0.5% (w / w) to about 45% (w / w), about 0.5% (w / w) to about 40% (w / w), about 0.5% (w / w) to about 35% (w / w), about 0.5% (w / w) to about 30% (w / w), about 0.5% (w / w) to about 25% (w / w), about 0.5% (w / w) to about 20% (w / w), about 0.5% (w / w) to about 15% (w / w), about 0.5% (w / w) to about 10% (w / w), about 0.5% (w / w) to about 5% (w / w), about 0.5% (w / w) to about 2.5% (w / w), about 0.5% (w / w) to about 1% (w / w), about 1.0% (w / w) to about 50% (w / w), aboutl.0% (w / w) to about 45% (w / w), about 1.0% (w / w) to about 40% (w / w), about 1.0% (w / w) to about 35% (w / w), about 1.0% (w / w) to about 30% (w / w), about 1.0% (w / w) to about 25% (w / w), about 1.0% (w / w) to about 20% (w / w), about 1.0% (w / w) to about 15% (w / w), about 1.0% (w / w) to about 10% (w / w), about 1.0% (w / w) to about 5% (w / w), about 5% (w / w) to about 50% (w / w), about 5% (w / w) to about 45% (w / w), about 5% (w / w) to about 40% (w / w), about 5% (w / w) to about 35% (w / w), about 5% (w / w) to about 30% (w / w), about 5% (w / w) to about 25% (w / w), about 5% (w / w) to about 20% (w / w), about 5% (w / w) to about 15% (w / w), about 5% (w / w) to about 10% (w / w), about 10% (w / w) to about 50% (w / w), about 10% (w / w) to about 45% (w / w), about 10% (w / w) to about 40% (w / w), about 10% (w / w) to about 35% (w / w), about 10% (w / w) to about 30% (w / w), about 10% (w / w) to about 25% (w / w), about 10% (w / w) to about 20% (w / w), about 15% (w / w) to about 50% (w / w), about 15% (w / w) to about 45% (w / w), about 15% (w / w) to about 40% (w / w), about 15% (w / w) to about 35% (w / w), about 15% (w / w) to about 30% (w / w), about 15% (w / w) to about 25% (w / w), about 20% (w / w) to about 50% (w / w), about 20% (w / w) to about 45% (w / w), about 20% (w / w) to about 40% (w / w), about 20% (w / w) to about 35% (w / w), about 20% (w / w) to about 30% (w / w), about 20% (w / w) to about 25% (w / w), about 25% (w / w) to about 50% (w / w), about 25% (w / w) to about 45% (w / w), about 25% (w / w) to about 40% (w / w), about 25% (w / w) to about 35% (w / w), about 30% (w / w) to about 50% (w / w), about 30% (w / w) to about 45% (w / w), about 30% (w / w) to about 40% (w / w), about 35% (w / w) to about 50% (w / w), about 35% (w / w) to about 45% (w / w), about 40% (w / w) to about 50% (w / w) and about 40% (w / w) to about 45% (w / w).

[0010] In one embodiment, the amount of arginine in the pharmaceutical combination or composition as described herein ranges from about 4.0% (w / w) to about 80% (w / w). Certain embodiments of the amount of arginine include, but are not limited to, about 4.0% (w / w) to about 75% (w / w), about 4.0% (w / w) to about 70% (w / w), about 4.0% (w / w) to about 65% (w / w), about 4.0% (w / w) to about 60% (w / w), about 4.0% (w / w) to about 55% (w / w), about 4.0% (w / w) to about 50% (w / w), about 4.0% (w / w) to about 45% (w / w), about 4.0% (w / w) to about 40% (w / w), about 4.0% (w / w) to about 35% (w / w), about 4.0% (w / w) to about 30% (w / w), about 4.0% (w / w) to about 25% (w / w), about 4.0% (w / w) to about 20% (w / w), about 4.0% (w / w) to about 15% (w / w), about 4.0% (w / w) to about 10% (w / w), about 10.0% (w / w) to about 80% (w / w), about 10.0% (w / w) to about 75% (w / w), about 10.0% (w / w) to about 70% (w / w), about 10.0% (w / w) to about 65% (w / w), about 10.0% (w / w) to about 60% (w / w), about 10.0% (w / w) to about 55% (w / w), about 10.0% (w / w) to about 50% (w / w), about 10.0% (w / w) to about 45% (w / w), about 10.0% (w / w) to about 40% (w / w), about 10.0% (w / w) to about 35% (w / w), about 10.0% (w / w) to about 30% (w / w), about 10.0% (w / w) to about 25% (w / w), about 10.0% (w / w) to about 20% (w / w), about 10.0% (w / w) to about 15% (w / w), about 15.0% (w / w) to about 80% (w / w), about 15.0% (w / w) to about 75% (w / w), about 15.0% (w / w) to about 70% (w / w), about 15.0% (w / w) to about 65% (w / w), about 15.0% (w / w) to about 60% (w / w), about 15.0% (w / w) to about 55% (w / w), about 15.0% (w / w) to about 50% (w / w), about 15.0% (w / w) to about 45% (w / w), about 15.0% (w / w) to about 40% (w / w), about 15.0% (w / w) to about 35% (w / w), about 15.0% (w / w) to about 30% (w / w), about 15.0% (w / w) to about 25% (w / w), about 15.0% (w / w) to about 20% (w / w), about 20.0% (w / w) to about 80% (w / w), about 20.0% (w / w) to about 75% (w / w), about 20.0% (w / w) to about 70% (w / w), about 20.0% (w / w) to about 65% (w / w), about 20.0% (w / w) to about 60% (w / w), about 20.0% (w / w) to about 55% (w / w), about 20.0% (w / w) to about 50% (w / w), about 20.0% (w / w) to about 45% (w / w), about 20.0% (w / w) to about 40% (w / w), about 20.0% (w / w) to about 35% (w / w), about 20.0% (w / w) to about 30% (w / w), about 20.0% (w / w) to about 25% (w / w), about 25.0% (w / w) to about 80% (w / w), about 25.0% (w / w) to about 75% (w / w), about 25.0% (w / w) to about 70% (w / w), about 25.0% (w / w) to about 65% (w / w), about 25.0% (w / w) to about 60% (w / w), about 25.0% (w / w) to about 55% (w / w), about 25.0% (w / w) to about 50% (w / w), about 25.0% (w / w) to about 45% (w / w), about 25.0% (w / w) to about 40% (w / w), about 25.0% (w / w) to about 35% (w / w), about 25.0% (w / w) to about 30% (w / w), about 30.0% (w / w) to about 80% (w / w), about 30.0% (w / w) to about 75% (w / w), about 30.0% (w / w) to about 70% (w / w), about 30.0% (w / w) to about 65% (w / w), about 30.0% (w / w) to about 60% (w / w), about 30.0% (w / w) to about 55% (w / w), about 30.0% (w / w) to about 50% (w / w), about 30.0% (w / w) to about 45% (w / w), about 30.0% (w / w) to about 40%(w / w), about 30.0% (w / w) to about 35% (w / w), about 35.0% (w / w) to about 80% (w / w), about 35.0% (w / w) to about 75% (w / w), about 35.0% (w / w) to about 70% (w / w), about 35.0% (w / w) to about 65% (w / w), about 35.0% (w / w) to about 60% (w / w), about 35.0% (w / w) to about 55% (w / w), about 35.0% (w / w) to about 50% (w / w), about 35.0% (w / w) to about 45% (w / w), about 35.0% (w / w) to about 40% (w / w), about 40.0% (w / w) to about 80% (w / w), about 40.0% (w / w) to about 75% (w / w), about 40.0% (w / w) to about 70% (w / w), about 40.0% (w / w) to about 65% (w / w), about 40.0% (w / w) to about 60% (w / w), about 40.0% (w / w) to about 55% (w / w), about 40.0% (w / w) to about 50% (w / w), about 40.0% (w / w) to about 45% (w / w), about 45.0% (w / w) to about 80% (w / w), about 45.0% (w / w) to about 75% (w / w), about 45.0% (w / w) to about 70% (w / w), about 45.0% (w / w) to about 65% (w / w), about 45.0% (w / w) to about 60% (w / w), about 45.0% (w / w) to about 55% (w / w), about 45.0% (w / w) to about 50% (w / w), about 50.0% (w / w) to about 80% (w / w), about 50.0% (w / w) to about 75% (w / w), about 50.0% (w / w) to about 70% (w / w), about 50.0% (w / w) to about 65% (w / w), about 50.0% (w / w) to about 60% (w / w), about 50.0% (w / w) to about 55% (w / w), about 55.0% (w / w) to about 80% (w / w), about 55.0% (w / w) to about 75% (w / w), about 55.0% (w / w) to about 70% (w / w), about 55.0% (w / w) to about 65% (w / w), about 55.0% (w / w) to about 60% (w / w), about 60.0% (w / w) to about 80% (w / w), about 60.0% (w / w) to about 75% (w / w), about 60.0% (w / w) to about 70% (w / w), about 60.0% (w / w) to about 65% (w / w), about 65.0% (w / w) to about 80% (w / w), about 65.0% (w / w) to about 75% (w / w), about 65.0% (w / w) to about 70% (w / w), about 70.0% (w / w) to about 80% (w / w), about 70.0% (w / w) to about 75% (w / w), or about 75.0% (w / w) to about 80% (w / w).

[0011] In one embodiment, the amount of N-acetylcysteine in the pharmaceutical combination or composition as described herein ranges from about 4% (w / w) to about 80% (w / w). Certain embodiments of the amount of arginine include, but are not limited to, about 4.0% (w / w) to about 75% (w / w), about 4.0% (w / w) to about 70% (w / w), about 4.0% (w / w) to about 65% (w / w), about 4.0% (w / w) to about 60% (w / w), about 4.0% (w / w) to about 55% (w / w), about 4.0% (w / w) to about 50% (w / w), about 4.0% (w / w) to about 45% (w / w), about 4.0% (w / w) to about 40% (w / w), about 4.0% (w / w) to about 35% (w / w), about 4.0% (w / w) to about 30% (w / w), about 4.0% (w / w) to about 25% (w / w), about 4.0% (w / w) to about 20% (w / w), about 4.0% (w / w) to about 15% (w / w), about 4.0% (w / w) to about 10% (w / w), about 10.0% (w / w) to about 80% (w / w), about 10.0% (w / w) to about 75% (w / w), about 10.0% (w / w) to about 70% (w / w), about 10.0% (w / w) to about 65% (w / w), about 10.0% (w / w) to about 60% (w / w), about 10.0% (w / w) to about 55% (w / w), about 10.0% (w / w) to about 50% (w / w), about 10.0% (w / w) to about 45% (w / w), about 10.0% (w / w) to about 40% (w / w), about 10.0% (w / w) to about 35% (w / w), about 10.0% (w / w) to about 30% (w / w), about 10.0% (w / w) to about 25%(w / w), about 10.0% (w / w) to about 20% (w / w), about 10.0% (w / w) to about 15% (w / w), about 15.0% (w / w) to about 80% (w / w), about 15.0% (w / w) to about 75% (w / w), about 15.0% (w / w) to about 70% (w / w), about 15.0% (w / w) to about 65% (w / w), about 15.0% (w / w) to about 60% (w / w), about 15.0% (w / w) to about 55% (w / w), about 15.0% (w / w) to about 50% (w / w), about 15.0% (w / w) to about 45% (w / w), about 15.0% (w / w) to about 40% (w / w), about 15.0% (w / w) to about 35% (w / w), about 15.0% (w / w) to about 30% (w / w), about 15.0% (w / w) to about 25% (w / w), about 15.0% (w / w) to about 20% (w / w), about 20.0% (w / w) to about 80% (w / w), about 20.0% (w / w) to about 75% (w / w), about 20.0% (w / w) to about 70% (w / w), about 20.0% (w / w) to about 65% (w / w), about 20.0% (w / w) to about 60% (w / w), about 20.0% (w / w) to about 55% (w / w), about 20.0% (w / w) to about 50% (w / w), about 20.0% (w / w) to about 45% (w / w), about 20.0% (w / w) to about 40% (w / w), about 20.0% (w / w) to about 35% (w / w), about 20.0% (w / w) to about 30% (w / w), about 20.0% (w / w) to about 25% (w / w), about 25.0% (w / w) to about 80% (w / w), about 25.0% (w / w) to about 75% (w / w), about 25.0% (w / w) to about 70% (w / w), about 25.0% (w / w) to about 65% (w / w), about 25.0% (w / w) to about 60% (w / w), about 25.0% (w / w) to about 55% (w / w), about 25.0% (w / w) to about 50% (w / w), about 25.0% (w / w) to about 45% (w / w), about 25.0% (w / w) to about 40% (w / w), about 25.0% (w / w) to about 35% (w / w), about 25.0% (w / w) to about 30% (w / w), about 30.0% (w / w) to about 80% (w / w), about 30.0% (w / w) to about 75% (w / w), about 30.0% (w / w) to about 70% (w / w), about 30.0% (w / w) to about 65% (w / w), about 30.0% (w / w) to about 60% (w / w), about 30.0% (w / w) to about 55% (w / w), about 30.0% (w / w) to about 50% (w / w), about 30.0% (w / w) to about 45% (w / w), about 30.0% (w / w) to about 40% (w / w), about 30.0% (w / w) to about 35% (w / w), about 35.0% (w / w) to about 80% (w / w), about 35.0% (w / w) to about 75% (w / w), about 35.0% (w / w) to about 70% (w / w), about 35.0% (w / w) to about 65% (w / w), about 35.0% (w / w) to about 60% (w / w), about 35.0% (w / w) to about 55% (w / w), about 35.0% (w / w) to about 50% (w / w), about 35.0% (w / w) to about 45% (w / w), about 35.0% (w / w) to about 40% (w / w), about 40.0% (w / w) to about 80% (w / w), about 40.0% (w / w) to about 75% (w / w), about 40.0% (w / w) to about 70% (w / w), about 40.0% (w / w) to about 65% (w / w), about 40.0% (w / w) to about 60% (w / w), about 40.0% (w / w) to about 55% (w / w), about 40.0% (w / w) to about 50% (w / w), about 40.0% (w / w) to about 45% (w / w), about 45.0% (w / w) to about 80% (w / w), about 45.0% (w / w) to about 75% (w / w), about 45.0% (w / w) to about 70% (w / w), about 45.0% (w / w) to about 65% (w / w), about 45.0% (w / w) to about 60% (w / w), about 45.0% (w / w) to about 55% (w / w), about 45.0% (w / w) to about 50% (w / w), about 50.0% (w / w) to about 80% (w / w), about 50.0% (w / w) to about 75% (w / w), about 50.0% (w / w) to about 70% (w / w), about 50.0% (w / w) to about 65% (w / w), about 50.0% (w / w) to about 60% (w / w), about 50.0% (w / w) to about 55% (w / w), about 55.0% (w / w) to about 80% (w / w), about55.0% (w / w) to about 75% (w / w), about 55.0% (w / w) to about 70% (w / w), about 55.0% (w / w) to about 65% (w / w), about 55.0% (w / w) to about 60% (w / w), about 60.0% (w / w) to about 80% (w / w), about 60.0% (w / w) to about 75% (w / w), about 60.0% (w / w) to about 70% (w / w), about 60.0% (w / w) to about 65% (w / w), about 65.0% (w / w) to about 80% (w / w), about 65.0% (w / w) to about 75% (w / w), about 65.0% (w / w) to about 70% (w / w), about 70.0% (w / w) to about 80% (w / w), about 70.0% (w / w) to about 75% (w / w), or about 75.0% (w / w) to about 80% (w / w).

[0012] In one embodiment, the amounts of the PDE5 inhibitor, arginine and N- acetylcysteine range from about 0.1% (w / w) to about 50% (w / w), about 4.0% (w / w) to about 80% (w / w) and about 4% (w / w) to about 80% (w / w), respectively. Certain embodiments of the amount of the PDE5 inhibitor, arginine, and N-acetylcysteine are in the range as described herein.

[0013] In one embodiment, the amount of the PDE5 inhibitor in the pharmaceutical combination or composition as described herein ranges from about 0.5 mg to about 250 mg. Certain embodiments of the amount of the PDE5 inhibitor include, but are not limited to, about 0.5 mg to about 250 mg, about 0.5 mg to about 240 mg, about 0.5 mg to about 230 mg, about 0.5 mg to about 220 mg, 0.5 mg to about 210 mg, about 0.5 mg to about 200 mg, about 0.5 mg to about 190 mg, about 0.5 mg to about 180 mg, about 0.5 mg to about 170 mg, about 0.5 mg to about 160 mg, about 0.5 mg to about 150 mg, about 0.5 mg to about 140 mg, about 0.5 mg to about 130 mg, about 0.5 mg to about 120 mg, about 0.5 mg to about 110 mg, about 0.5 mg to about 100 mg, about 0.5 mg to about 90 mg, about 0.5 mg to about 80 mg, about 0.5 mg to about 70 mg, about 0.5 mg to about 60 mg, about 0.5 mg to about 50 mg, about 0.5 mg to about 40 mg, about 0.5 mg to about 30 mg, about 0.5 mg to about 20 mg, about 0.5 mg to about 10 mg, about 0.5 mg to about 5 mg, about 0.5 mg to about 1 mg, about 1 mg to about 250 mg, about 1 mg to about 240 mg, about 1 mg to about 230 mg, about 1 mg to about 220 mg, about 1 mg to about 210 mg, about 1 mg to about 200 mg, about 1 mg to about 190 mg, about 1 mg to about 180 mg, about 1 mg to about 170 mg, about 1 mg to about 160 mg, about 1 mg to about 150 mg, about 1 mg to about 140 mg, about 1 mg to about 130 mg, about 1 mg to about 120 mg, about 1 mg to about 110 mg, about 1 mg to about 100 mg, about 1 mg to about 90 mg, about 1 mg to about 80 mg, about 1 mg to about 70 mg, about 1 mg to about 60 mg, about 1 mg to about 50 mg, about 1 mg to about 40 mg, about 1 mg to about 30 mg, about 1 mg to about 20 mg, about 1 mg to about 10 mg, about 1 mg to about 5 mg, about 5 mg to about 250 mg, about 5 mg to about 240 mg, about 5 mg to about 230 mg, about 5 mg to about 220 mg, about 5 mg to about 210 mg, about 5 mg to about 200 mg, about 5 mg to about 190 mg, about 5 mg to about 180 mg, about 5 mg to about 170 mg, about 5 mg to about 160 mg, about 5 mg to about150 mg, about 5 mg to about 140 mg, about 5 mg to about 130 mg, about 5 mg to about 120 mg, about 5 mg to about 110 mg, about 5 mg to about 100 mg, about 5 mg to about 90 mg, about 5 mg to about 80 mg, about 5 mg to about 70 mg, about 5 mg to about 60 mg, about 5 mg to about 50 mg, about 5 mg to about 40 mg, about 5 mg to about 30 mg, about 5 mg to about 20 mg, about 5 mg to about 10 mg, about 10 mg to about 250 mg, about 10 mg to about 240 mg, about 10 mg to about 230 mg, about 10 mg to about 220 mg, about 10 mg to about 210 mg, about 10 mg to about 200 mg, about 10 mg to about 190 mg, about 10 mg to about 180 mg, about 10 mg to about 170 mg, about 10 mg to about 160 mg, about 10 mg to about 150 mg, about 10 mg to about 140 mg, about 10 mg to about 130 mg, about 10 mg to about 120 mg, about 10 mg to about 110 mg, about 10 mg to about 100 mg, about 10 mg to about 90 mg, about 10 mg to about 80 mg, about 10 mg to about 70 mg, about 10 mg to about 60 mg, about 10 mg to about 50 mg, about 10 mg to about 40 mg, about 10 mg to about 30 mg, about 10 mg to about 20 mg, about 20 mg to about 250 mg, about 20 mg to about 240 mg, about 20 mg to about 230 mg, about 20 mg to about 220 mg, about 20 mg to about 210 mg, about 20 mg to about 200 mg, about 20 mg to about 190 mg, about 20 mg to about 180 mg, about 20 mg to about 170 mg, about 20 mg to about 160 mg, about 20 mg to about 150 mg, about 20 mg to about 140 mg, about 20 mg to about 130 mg, about 20 mg to about 120 mg, about 20 mg to about 110 mg, about 20 mg to about 100 mg, about 20 mg to about 90 mg, about 20 mg to about 80 mg, about 20 mg to about 70 mg, about 20 mg to about 60 mg, about 20 mg to about 50 mg, about 20 mg to about 40 mg, about 20 mg to about 30 mg, about 30 mg to about 250 mg, 30 mg to about 240 mg, 30 mg to about 230 mg, 30 mg to about 220 mg, 30 mg to about 210 mg, about 30 mg to about 200 mg, about 30 mg to about 190 mg, about 30 mg to about 180 mg, about 30 mg to about 170 mg, about 30 mg to about 160 mg, about 30 mg to about 150 mg, about 30 mg to about 140 mg, about 30 mg to about 130 mg, about 30 mg to about 120 mg, about 30 mg to about 110 mg, about 30 mg to about 100 mg, about 30 mg to about 90 mg, about 30 mg to about 80 mg, about 30 mg to about 70 mg, about 30 mg to about 60 mg, about 30 mg to about 50 mg, about 30 mg to about 40 mg, about 40 mg to about 250 mg, about 40 mg to about 240 mg, about 40 mg to about 230 mg, about 40 mg to about 220 mg, about 40 mg to about 210 mg, about 40 mg to about 200 mg, about 40 mg to about 190 mg, about 40 mg to about 180 mg, about 40 mg to about 170 mg, about 40 mg to about 160 mg, about 40 mg to about 150 mg, about 40 mg to about 1 about 40 mg, about 40 mg to about 130 mg, about 40 mg to about 120 mg, about 40 mg to about 110 mg, about 40 mg to about 100 mg, about 40 mg to about 90 mg, about 40 mg to about 80 mg, about 40 mg to about 70 mg, about 40 mg to about 60 mg, about 40 mg to about 50 mg, about 50 mg to about 250 mg, about 50 mg to about 240 mg, about 50 mg to about 230mg, about 50 mg to about 220 mg, about 50 mg to about 210 mg, about 50 mg to about 200 mg, about 50 mg to about 190 mg, about 50 mg to about 180 mg, about 50 mg to about 170 mg, about 50 mg to about 160 mg, about 50 mg to about labout 50 mg, about 50 mg to about 140 mg, about 50 mg to about 130 mg, about 50 mg to about 120 mg, about 50 mg to about 110 mg, about 50 mg to about 100 mg, about 50 mg to about 90 mg, about 50 mg to about 80 mg, about 50 mg to about 70 mg, about 50 mg to about 60 mg, about 60 mg to about 250 mg, about 60 mg to about 240 mg, about 60 mg to about 230 mg, about 60 mg to about 220 mg, about 60 mg to about 210 mg, about 60 mg to about 200 mg, about 60 mg to about 190 mg, about 60 mg to about 180 mg, about 60 mg to about 170 mg, about 60 mg to about labout 60 mg, about 60 mg to about 150 mg, about 60 mg to about 140 mg, about 60 mg to about 130 mg, about 60 mg to about 120 mg, about 60 mg to about 110 mg, about 60 mg to about 100 mg, about 60 mg to about 90 mg, about 60 mg to about 80 mg, about 60 mg to about 70 mg, about 70 mg to about 250 mg, about 70 mg to about 240 mg, about 70 mg to about 230 mg, about 70 mg to about 220 mg, about 70 mg to about 210 mg, about 70 mg to about 200 mg, about 70 mg to about 190 mg, about 70 mg to about 180 mg, about 70 mg to about labout 70 mg, about 70 mg to about 160 mg, about 70 mg to about 150 mg, about 70 mg to about 140 mg, about 70 mg to about 130 mg, about 70 mg to about 120 mg, about 70 mg to about 110 mg, about 70 mg to about 100 mg, about 70 mg to about 90 mg, about 70 mg to about 80 mg, about 80 mg to about 250 mg, about 80 mg to about 240 mg, about 80 mg to about 230 mg, about 80 mg to about 220 mg, about 80 mg to about 210 mg, about 80 mg to about 200 mg, about 80 mg to about 190 mg, about 80 mg to about labout 80 mg, about 80 mg to about 170 mg, about 80 mg to about 160 mg, about 80 mg to about 150 mg, about 80 mg to about 140 mg, about 80 mg to about 130 mg, about 80 mg to about 120 mg, about 80 mg to about 110 mg, about 80 mg to about 100 mg, about 80 mg to about 90 mg, about 90 mg to about 250 mg, 90 mg to about 240 mg, 90 mg to about 230 mg, 90 mg to about 220 mg, 90 mg to about 210 mg, 90 mg to about 200 mg, 90 mg to about 190 mg, 90 mg to about 180 mg, about 90 mg to about 170 mg, about 90 mg to about 160 mg, about 90 mg to about 150 mg, about 90 mg to about 140 mg, about 90 mg to about 130 mg, about 90 mg to about 120 mg, about 90 mg to about 110 mg, about 90 mg to about 100 mg, about 100 mg to about 250 mg, about 100 mg to about 240 mg, about 100 mg to about 230 mg, about 100 mg to about 220 mg, about 100 mg to about 210 mg, about 100 mg to about 200 mg, about 100 mg to about 190 mg, about 100 mg to about 180 mg, about 100 mg to about 170 mg, about 100 mg to about 160 mg, about 100 mg to about 150 mg, about 100 mg to about 140 mg, about 100 mg to about 130 mg, about 100 mg to about 120 mg, about 100 mg to about 110 mg, about 110 mg to about 250 mg, about 110 mg to about 240 mg, about 110 mg to about 230 mg, about 110mg to about 220 mg, about 110 mg to about 210 mg, about 110 mg to about 200 mg, about 110 mg to about 190 mg, about 110 mg to about 180 mg, about 110 mg to about 170 mg, about 110 mg to about 160 mg, about 110 mg to about 150 mg, about 110 mg to about 140 mg, about 110 mg to about 130 mg, about 110 mg to about 120 mg, about 120 mg to about 250 mg, about 120 mg to about 240 mg, about 120 mg to about 230 mg, about 120 mg to about 220 mg, about 120 mg to about 210 mg, about 120 mg to about 200 mg, about 120 mg to about 190 mg, about 120 mg to about 180 mg, about 120 mg to about 170 mg, about 120 mg to about 160 mg, about 120 mg to about 150 mg, about 120 mg to about 140 mg, about 120 mg to about 130 mg, about 130 mg to about 250 mg, 130 mg to about 240 mg, about 130 mg to about 230 mg, about 130 mg to about 220 mg, about 130 mg to about 210 mg, about 130 mg to about 200 mg, about 130 mg to about 190 mg, about 130 mg to about 180 mg, about 130 mg to about 170 mg, about 130 mg to about 160 mg, about 130 mg to about 150 mg, about 130 mg to about 140 mg, about 130 mg to about 250 mg, about 130 mg to about 240 mg, about 130 mg to about 230 mg, about 130 mg to about 220 mg, about 130 mg to about 210 mg, about 130 mg to about 200 mg, about 130 mg to about 190 mg, about 130 mg to about 180 mg, about 130 mg to about 170 mg, about 130 mg to about 160 mg, about 130 mg to about 150 mg, about 130 mg to about 140 mg, about 140 mg to about 250 mg, about 140 mg to about 240 mg, about 140 mg to about 230 mg, about 140 mg to about 220 mg, about 140 mg to about 210 mg, about 140 mg to about 200 mg, about 140 mg to about 190 mg, about 140 mg to about 180 mg, about 140 mg to about 170 mg, about 140 mg to about 160 mg, about 140 mg to about 150 mg, about 150 mg to about 250 mg, about 150 mg to about 240 mg, about 150 mg to about 230 mg, about 150 mg to about 220 mg, about 150 mg to about 210 mg, about 150 mg to about 200 mg, about 150 mg to about 190 mg, about 150 mg to about 180 mg, about 150 mg to about 170 mg, about 150 mg to about 160 mg, about 200 mg to about 250 mg, about 200 mg to about 240 mg, about 200 mg to about 230 mg, about 200 mg to about 220 mg, about 200 mg to about 210 mg.

[0014] In one embodiment, the amount of arginine or N-acetyl cysteine in the pharmaceutical combination or composition as described herein ranges from about 25 mg to about 400 mg. Certain embodiments of the amount of the arginine or N-acetylcysteine include, but are not limited to, about 25 mg to about 400 mg, about 25 mg to about 390 mg, about 25 mg to about 380 mg, about 25 mg to about 370 mg, about 25 mg to about 360 mg, about 25 mg to about 350 mg, about 25 mg to about 340 mg, about 25 mg to about 330 mg, about 25 mg to about 320 mg, about 25 mg to about 310 mg, about 25 mg to about 300 mg, about 25 mg to about 290 mg, about 25 mg to about 280 mg, about 25 mg to about 270 mg, about 25 mg to about 260 mg, about 25 mg to about 250 mg, about 25 mg to about 240 mg, about 25 mg to about 230 mg,about 25 mg to about 220 mg, about 25 mg to about 210 mg, about 25 mg to about 200 mg, about 25 mg to about 190 mg, about 25 mg to about 180 mg, about 25 mg to about 170 mg, about 25 mg to about 160 mg, about 25 mg to about 150 mg, about 25 mg to about 140 mg, about 25 mg to about 130 mg, about 25 mg to about 120 mg, about 25 mg to about 110 mg, about 25 mg to about 100 mg, about 25 mg to about 90 mg, about 25 mg to about 80 mg, about 25 mg to about 70 mg, about 25 mg to about 60 mg, about 25 mg to about 50 mg, about 25 mg to about 40 mg, about 25 mg to about 30 mg, about 30 mg to about 400 mg, about 30 mg to about 390 mg, about 30 mg to about 380 mg, about 30 mg to about 370 mg, about 30 mg to about 360 mg, about 30 mg to about 350 mg, about 30 mg to about 340 mg, about 30 mg to about 330 mg, about 30 mg to about 320 mg, about 30 mg to about 310 mg, about 30 mg to about 300 mg, about 30 mg to about 290 mg, about 30 mg to about 280 mg, about 30 mg to about 270 mg, about 30 mg to about 260 mg, about 30 mg to about 300 mg, about 30 mg to about 240 mg, about 30 mg to about 230 mg, about 30 mg to about 220 mg, about 30 mg to about 210 mg, about 30 mg to about 200 mg, about 30 mg to about 190 mg, about 30 mg to about 180 mg, about 30 mg to about 170 mg, about 30 mg to about 160 mg, about 30 mg to about 150 mg, about 30 mg to about 140 mg, about 30 mg to about 130 mg, about 30 mg to about 120 mg, about 30 mg to about 110 mg, about 30 mg to about 100 mg, about 30 mg to about 90 mg, about 30 mg to about 80 mg, about 30 mg to about 70 mg, about 30 mg to about 60 mg, about 30 mg to about 50 mg, about 30 mg to about 40 mg, about 40 mg to about 400 mg, about 40 mg to about 390 mg, about 40 mg to about 380 mg, about 40 mg to about 370 mg, about 40 mg to about 360 mg, about 40 mg to about 350 mg, about 40 mg to about 340 mg, about 40 mg to about 330 mg, about 40 mg to about 320 mg, about 40 mg to about 310 mg, about 40 mg to about 300 mg, about 40 mg to about 290 mg, about 40 mg to about 280 mg, about 40 mg to about 270 mg, about 40 mg to about 260 mg, about 40 mg to about 400 mg, about 40 mg to about 240 mg, about 40 mg to about 230 mg, about 40 mg to about 220 mg, about 40 mg to about 210 mg, about 40 mg to about 200 mg, about 40 mg to about 190 mg, about 40 mg to about 180 mg, about 40 mg to about 170 mg, about 40 mg to about 160 mg, about 40 mg to about 150 mg, about 40 mg to about 140 mg, about 40 mg to about 130 mg, about 40 mg to about 120 mg, about 40 mg to about 110 mg, about 40 mg to about 100 mg, about 40 mg to about 90 mg, about 40 mg to about 80 mg, about 40 mg to about 70 mg, about 40 mg to about 60 mg, about 40 mg to about 50 mg, about 50 mg to about 400 mg, about 50 mg to about 390 mg, about 50 mg to about 380 mg, about 50 mg to about 370 mg, about 50 mg to about 360 mg, about 50 mg to about 350 mg, about 50 mg to about 340 mg, about 50 mg to about 330 mg, about 50 mg to about 320 mg, about 50 mg to about 310 mg, about 50 mg toabout 300 mg, about 50 mg to about 290 mg, about 50 mg to about 280 mg, about 50 mg to about 270 mg, about 50 mg to about 260 mg, about 50 mg to about 500 mg, about 50 mg to about 240 mg, about 50 mg to about 230 mg, about 50 mg to about 220 mg, about 50 mg to about 210 mg, about 50 mg to about 200 mg, about 50 mg to about 190 mg, about 50 mg to about 180 mg, about 50 mg to about 170 mg, about 50 mg to about 160 mg, about 50 mg to about 150 mg, about 50 mg to about 140 mg, about 50 mg to about 130 mg, about 50 mg to about 120 mg, about 50 mg to about 110 mg, about 50 mg to about 100 mg, about 50 mg to about 90 mg, about 50 mg to about 80 mg, about 50 mg to about 70 mg, about 50 mg to about60 mg, about 75 mg to about 400 mg, about 75 mg to about 390 mg, about 75 mg to about 380 mg, about 75 mg to about 370 mg, about 75 mg to about 360 mg, about 75 mg to about 350 mg, about 75 mg to about 340 mg, about 75 mg to about 330 mg, about 75 mg to about 320 mg. about 75 mg to about 310 mg, about 75 mg to about 300 mg, about 75 mg to about 290 mg. about 75 mg to about 280 mg, about 75 mg to about 270 mg, about 75 mg to about 260 mg. about 75 mg to about 750 mg, about 75 mg to about 240 mg, about 75 mg to about 230 mg. about 75 mg to about 220 mg, about 75 mg to about 210 mg, about 75 mg to about 200 mg. about 75 mg to about 190 mg, about 75 mg to about 180 mg, about 75 mg to about 170 mg. about 75 mg to about 160 mg, about 75 mg to about 150 mg, about 75 mg to about 140 mg. about 75 mg to about 130 mg, about 75 mg to about 120 mg, about 75 mg to about 110 mg. about 75 mg to about 100 mg, about 75 mg to about 90 mg, about 75 mg to about 80 mg, about100 mg to about 400 mg, about 100 mg to about 390 mg, about 100 mg to about 380 mg, about100 mg to about 370 mg, about 100 mg to about 360 mg, about 100 mg to about 350 mg, about100 mg to about 340 mg, about 100 mg to about 330 mg, about 100 mg to about 320 mg, about100 mg to about 310 mg, about 100 mg to about 300 mg, about 100 mg to about 290 mg, about100 mg to about 280 mg, about 100 mg to about 270 mg, about 100 mg to about 260 mg, about100 mg to about 1000 mg, about 100 mg to about 240 mg, about 100 mg to about 230 mg, about 100 mg to about 220 mg, about 100 mg to about 210 mg, about 100 mg to about 200 mg, about100 mg to about 190 mg, about 100 mg to about 180 mg, about 100 mg to about 170 mg, about100 mg to about 160 mg, about 100 mg to about 150 mg, about 100 mg to about 140 mg, about100 mg to about 130 mg, about 100 mg to about 120 mg, about 100 mg to about 110 mg, about125 mg to about 400 mg, about 125 mg to about 390 mg, about 125 mg to about 380 mg, about125 mg to about 370 mg, about 125 mg to about 360 mg, about 125 mg to about 350 mg, about125 mg to about 340 mg, about 125 mg to about 330 mg, about 125 mg to about 320 mg, about125 mg to about 310 mg, about 125 mg to about 300 mg, about 125 mg to about 290 mg, about125 mg to about 280 mg, about 125 mg to about 270 mg, about 125 mg to about 260 mg, aboutmg to about 1250 mg, about 125 mg to about 240 mg, about 125 mg to about 230 mg, about mg to about 220 mg, about 125 mg to about 210 mg, about 125 mg to about 200 mg, about mg to about 190 mg, about 125 mg to about 180 mg, about 125 mg to about 170 mg, about mg to about 160 mg, about 125 mg to about 150 mg, about 125 mg to about 140 mg, about mg to about 130 mg, about 150 mg to about 400 mg, about 150 mg to about 390 mg, about mg to about 380 mg, about 150 mg to about 370 mg, about 150 mg to about 360 mg, about mg to about 350 mg, about 150 mg to about 340 mg, about 150 mg to about 330 mg, about mg to about 320 mg, about 150 mg to about 310 mg, about 150 mg to about 300 mg, about mg to about 290 mg, about 150 mg to about 280 mg, about 150 mg to about 270 mg, about mg to about 260 mg, about 150 mg to about 250 mg, about 150 mg to about 240 mg, about mg to about 230 mg, about 150 mg to about 220 mg, about 150 mg to about 210 mg, about mg to about 200 mg, about 150 mg to about 190 mg, about 150 mg to about 180 mg, about mg to about 170 mg, about 150 mg to about 160 mg, about 175 mg to about 400 mg, about mg to about 390 mg, about 175 mg to about 380 mg, about 175 mg to about 370 mg, about mg to about 360 mg, about 175 mg to about 350 mg, about 175 mg to about 340 mg, about mg to about 330 mg, about 175 mg to about 320 mg, about 175 mg to about 310 mg, about mg to about 300 mg, about 175 mg to about 290 mg, about 175 mg to about 280 mg, about mg to about 270 mg, about 175 mg to about 260 mg, about 175 mg to about 250 mg, about mg to about 240 mg, about 175 mg to about 230 mg, about 175 mg to about 220 mg, about mg to about 210 mg, about 175 mg to about 200 mg, about 175 mg to about 190 mg, about mg to about 180 mg, about 200 mg to about 400 mg, about 200 mg to about 390 mg, about mg to about 380 mg, about 200 mg to about 370 mg, about 200 mg to about 360 mg, about mg to about 350 mg, about 200 mg to about 340 mg, about 200 mg to about 330 mg, about mg to about 320 mg, about 200 mg to about 310 mg, about 200 mg to about 300 mg, about mg to about 290 mg, about 200 mg to about 280 mg, about 200 mg to about 270 mg, about mg to about 260 mg, about 200 mg to about 2000 mg, about 200 mg to about 240 mg, about mg to about 230 mg, about 200 mg to about 220 mg, about 200 mg to about 210 mg, about mg to about 400 mg, about 225 mg to about 390 mg, about 225 mg to about 380 mg, about mg to about 370 mg, about 225 mg to about 360 mg, about 225 mg to about 350 mg, about mg to about 340 mg, about 225 mg to about 330 mg, about 225 mg to about 320 mg, about mg to about 310 mg, about 225 mg to about 300 mg, about 225 mg to about 290 mg, about mg to about 280 mg, about 225 mg to about 270 mg, about 225 mg to about 260 mg, about mg to about 250 mg, about 225 mg to about 240 mg, about 225 mg to about 230 mg, about mg to about 220 mg, about 225 mg to about 210 mg, about 225 mg to about 200 mg, about250 mg to about 400 mg, about 250 mg to about 390 mg, about 250 mg to about 380 mg, about 250 mg to about 370 mg, about 250 mg to about 360 mg, about 250 mg to about 350 mg, about 250 mg to about 340 mg, about 250 mg to about 330 mg, about 250 mg to about 320 mg, about 250 mg to about 310 mg, about 250 mg to about 300 mg, about 250 mg to about 290 mg, about 250 mg to about 280 mg, about 250 mg to about 270 mg, about 250 mg to about 260 mg, about 275 mg to about 400 mg, about 275 mg to about 390 mg, about 275 mg to about 380 mg, about 275 mg to about 370 mg, about 275 mg to about 360 mg, about 275 mg to about 350 mg, about 275 mg to about 340 mg, about 275 mg to about 330 mg, about 275 mg to about 320 mg, about 275 mg to about 310 mg, about 275 mg to about 300 mg, about 275 mg to about 290 mg, about 275 mg to about 280 mg, about 300 mg to about 400 mg, about 300 mg to about 390 mg, about 300 mg to about 380 mg, about 300 mg to about 370 mg, about 300 mg to about 360 mg, about 300 mg to about 350 mg, about 300 mg to about 340 mg, about 300 mg to about 330 mg, about 300 mg to about 320 mg, about 300 mg to about 310 mg, about 325 mg to about 400 mg, about 325 mg to about 390 mg, about 325 mg to about 380 mg, about 325 mg to about 370 mg, about 325 mg to about 360 mg, about 350 mg to about 350 mg, about 325 mg to about 340 mg, about 325 mg to about 330 mg, about 350 mg to about 400 mg, about 350 mg to about 390 mg, about 350 mg to about 380 mg, about 350 mg to about 370 mg, about 350 mg to about 360 mg, about 375 mg to about 400 mg, about 375 mg to about 390 mg, about 375 mg to about 380 mg.

[0015] In one embodiment , the pharmaceutical combination or composition as described herein comprises about 0.5 mg to about 250 mg of the PDE5 inhibitor, about 25 mg to about 400 mg of arginine and about 25 mg to about 400 mg of N-acetylcysteine. Certain embodiments of the pharmaceutical combination or composition as described herein have the amount of the PDE5 inhibitor, N-acetylcysteine, and arginine as disclosed herein.

[0016] In some embodiments, the amount of the PDE5 inhibitor in the pharmaceutical combination or composition as described herein is about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 mg, the amount of arginine is about 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, or 275 mg, and / or the amount of N- acetylcysteine is about 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, or 275 mg. In a certain embodiment, the amount of the PDE5 inhibitor is about 20 mg, the amount ofarginine is about 250 mg, and / or the amount of the N-acetylcysteine is about 250 mg. In a certain embodiment, the amount of the PDE5 inhibitor is about 20 mg, the amount of arginine is about 250 mg, and the amount of the N-acetylcysteine is about 250 mg.

[0017] In one embodiment, the daily dose of the pharmaceutical combination or composition is twice the dose of the PDE5 inhibitor, arginine, and / or N-acetyl cysteine as described herein. In one embodiment, the pharmaceutical combination or composition disclosed herein is administered twice a day, so that the daily dose of the pharmaceutical combination or composition is twice the dose of the PDE5 inhibitor, arginine, and / or N-acetyl cysteine as described herein.

[0018] In some embodiments, the daily dose of the PDE5 inhibitor in the pharmaceutical combination or composition disclosed herein is about 4 mg to about 100 mg. In some embodiments, the daily dose of arginine in the pharmaceutical combination or composition disclosed herein is about 20 mg to about 1000 mg. In some embodiments, the daily dose of N- acetylcysteine in the pharmaceutical combination or composition disclosed herein is about 20 mg to about 1000 mg. Certain embodiments of the pharmaceutical combination or composition disclosed herein have a daily dose of the PDE5 inhibitor being about 40 mg. Certain embodiments of the pharmaceutical combination or composition disclosed herein have a daily dose of arginine being about 500 mg. Certain embodiments of the pharmaceutical combination or composition disclosed herein have a daily dose of the N-acetylcysteine being about 500mg. Certain embodiments of the pharmaceutical combination or composition disclosed herein have a daily dose of the PDE5 inhibitor being about 40 mg, a daily dose of the arginine being about 500 mg, and / or the daily dose of the N-acetylcysteine being about 500 mg.

[0019] In one embodiment, the pharmaceutical combination or composition as described herein is in a liquid formulation, and the concentration of sildenafil disclosed herein is from about 1 to 1000 nM, the concentration of arginine is 1 to 1000 pM, and / or the concentration of N-acetylcysteine is 0.1 to 100 mM in the compound combination.

[0020] In one embodiment, the combination or composition disclosed herein is in the form of a solid or liquid formulation; in particular, a capsule or a tablet or a solution for injection or oral administration.

[0021] In one embodiment, the PDE5 inhibitor or a pharmaceutically acceptable salt thereof, arginine, and N-acetylcysteine disclosed herein is administered concomitantly, sequentially, or separately.

[0022] In one embodiment, the PDE5 inhibitor or a pharmaceutically acceptable salt thereof disclosed herein is administered concomitantly with N-acetylcysteine.

[0023] In a further embodiment, the PDE5 inhibitor is sildenafil or sildenafil citrate.

[0024] In one embodiment, the combination or composition disclosed herein result in synergistic effect compared with a PDE5 inhibitor or a pharmaceutically acceptable salt thereof, e.g., sildenafil or sildenafil citrate, alone.

[0025] In one embodiment, the combination or composition disclosed herein is for oral administration.

[0026] In one embodiment, the combination or composition disclosed herein is a unit dose formulation, comprising a fixed dose of 20 mg of a PDE5 inhibitor, 250 mg of arginine, and 250 mg of NAC. In a further embodiment, the PDE5 inhibitor is sildenafil. In a further embodiment, the combination or composition disclosed herein is a tablet or pill.

[0027] In one embodiment, the combination or composition disclosed herein is administered once or twice or three times a day; or once, twice, three times, four times, five times, six times, or seven times a week. In certain embodiment, the pharmaceutical combination or composition disclosed herein is administered twice a day.

[0028] In one embodiment, the agents (PDE5 inhibitor, arginine, and NAC) in the combination or composition disclosed herein are derivatives of said agents, including, but not limited to, a salt, pharmaceutically acceptable salt, solvate, hydrate, ester, tautomer, stereoisomer, enantiomer, or diastereomer thereof. Unless otherwise specified, the agents in the combination or composition disclosed herein cover the aforementioned derivatives.

[0029] In a further aspect, the present disclosure provides a fixed dose formulation comprising a PDE5 inhibitor, arginine and NAC in a ratio of about 2: about 25: about 25. In one embodiment, the formulation comprises a fixed dose of 20 mg of a PDE5 inhibitor, a fixed dose of 250 mg of arginine, and a fixed dose of 250 mg of NAC. In a further embodiment, the PDE5 inhibitor is sildenafil. In a further embodiment, the combination or composition disclosed herein is a tablet or pill.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1A to FIG. ID. Neurite Outgrowth with Treatment of SAN. FIG. 1A: After 24 hours of trauma injury, the blank group has no effect in the outgrowth of the neurite. In the groups of administration of S, A, N and SAN, the neurite regeneration in S only group was similar to the blank group (see FIG. IB), while the SAN group significantly increase the length and numbers of neurites (see FIG. 1C and FIG. ID). Comparing to the A+N group, the neurites in SAN group can regenerate up to 50% in number at 1 pg / ml (FIG. 1C) and 30% in length at 0.5 pg / ml (FIG. ID) .

[0031] FIG. 2. SAN Restores Memory Lose. The rats were subjected to brain injury surgery. After the surgery, the rates were administered with or without SAN for 28 days.

[0032] FIG. 3. The Neurite Regeneration. The treatment efficacy in the SAN group exhibits an advantageous effect in comparison with the sham group. The neurite in SAN group can regenerate up to 28%, which is 4.5 times higher than the 6% of the sham group

[0033] FIG. 4. SAN Restores Memory in Rats. The Morris water maze (MWM) task was used to assess memory function after brain injury. The TBI rats were trained for the MWM task at Week 4 post-injury and were tested at Week 5 post-injury. A total of 18 rats were randomly assigned into three groups: 1) Sham group (N=6); animals underwent the same operation procedure of inducing brain trauma except trauma induction; 2) Injury group (N=6): animals underwent traumatic brain injury surgery. 3) Injury + SAN group (N=6): Rats with TBI received oral gavage of SAN daily from Day 1 to Day 28 post-injury. The average time for the sham group to return to the floating board is 12 seconds, the trauma group is 30 seconds (* <0.05), and the group given SAN after trauma is 18 seconds (* <0.05), the SAN group obviously has the function of restoring memory.

[0034] FIG. 5A and FIG. 5B. Restoration of Neurites BDNF in Rats. FIG. 5A: Western analysis. The rats were euthanized via CO2 asphyxiation, and the brains were removed. Tissues were homogenized in TEE buffer with PMSF, and used Triton X-100 to lysis cell membrane. Lysates were centrifuged (13000 rpm at 4 °C) for 10 min, and the supernatants were collected. Protein concentrations were determined by BCA assay kit. Proteins were loaded 80 pg / well on a 12 % SDS-polyacrylamide gel and transferred to a PVDF membrane. Nonspecific reactivity was blocked for 1 h at room temperature and primary anti-BDNF and anti-alpha tubulin were incubated overnight at 4 °C. Then, the membranes were washed for 20 min for three times. Secondary antibodies conjugated with horseradish peroxidase (HRP) were used at 1 : 10000 dilution. Immunoreactive bands were detected using ECL system. The total intensity of bands were analyzed by ImageJ. FIG. 5B: Immunohistochemistry. Rats were perfused with PBS (pH 7.4), following by 4% PFA in PBS under Zoletil 50 (35 mg / kg) and Rompun (7.5 mg / kg) anesthesia. The brains were removed and fixed overnight in 4% PFA at 4°C. Then, the brains were embedded in OCT (optimal cutting temperature compound) and soaked in liquid nitrogen. Frozen sections were prepared at 10 pm thickness and fixed by 4% PFA. Heat-induced antigen retrieval using autoclave was applied. The sections were soaked in 2N HC1 for 30 min and placed into 0. IM borate buffer for 10 min. The sections were blocked 24 hr at 4°C. The sections were incubated with anti-BDNF 24 hr, then rinsed sections three times for 20 min. The sectionswere incubated with Alexa 488-conjugated goat anti-mouse IgG for 1 hr. The sections were mounted with DAPI-Fluoromount-G.FIG. 6A and FIG. 6B. SAN Restores CD68 Expression. FIG. 6A: Western analysis. The rats were euthanized via CO2 asphyxiation, and the brains were removed. Tissues were homogenized in TEE buffer with PMSF, and used Triton X-100 to lysis cell membrane. Lysates were centrifuged (13000 rpm at 4 °C) for 10 min, and the supernatants were collected. Protein concentrations were determined by BCA assay kit. Proteins were loaded 80 pg / well on a 12 % SDS-polyacrylamide gel and transferred to a PVDF membrane. Nonspecific reactivity was blocked for 1 h at room temperature and primary anti-CD68 and anti-alpha tubulin were incubated overnight at 4 °C. Then, the membranes were washed for 20 min for three times. Secondary antibodies conjugated with horseradish peroxidase (HRP) were used at 1 : 10000 dilution. Immunoreactive bands were detected using ECL system. The total intensity of bands were analyzed by ImageJ. FIG. 6B: Immunohistochemistry. Rats were perfused with PBS (pH 7.4), following by 4% PFA in PBS under Zoletil 50 (35 mg / kg) and Rompun (7.5 mg / kg) anesthesia. The brains were removed and fixed overnight in 4% PFA at 4°C. Then, the brains were embedded in OCT (optimal cutting temperature compound) and soaked in liquid nitrogen. Frozen sections were prepared at 10 pm thickness and fixed by 4% PFA. Heat-induced antigen retrieval using autoclave was applied. The sections were soaked in 2N HC1 for 30 min and placed into 0. IM borate buffer for 10 min. The sections were blocked 24 hr at 4°C. The sections were incubated with anti-CD68 for 24 hr, then rinsed sections three times for 20 min. The sections were incubated with Alexa 488-conjugated goat anti-mouse IgG for 1 hr. The sections were mounted with DAPI-Fluoromount-G.

[0035] FIG. 7. SAN Induces SOD-1 Expression. Western analysis. The rats were euthanized via CO2 asphyxiation, and the brains were removed. Tissues were homogenized in TEE buffer with PMSF, and used Triton X-100 to lysis cell membrane. Lysates were centrifuged (13000 rpm at 4 °C) for 10 min, and the supernatants were collected. Protein concentrations were determined by BCA assay kit. Proteins were loaded 80 pg / well on a 12 % SDS-polyacrylamide gel and transferred to a PVDF membrane. Nonspecific reactivity was blocked for 1 h at room temperature and primary anti-SOD-1 and anti-alpha tubulin were incubated overnight at 4 °C. Then, the membranes were washed for 20 min for three times. Secondary antibodies conjugated with horseradish peroxidase (HRP) were used at 1 : 10000 dilution. Immunoreactive bands were detected using ECL system. The total intensity of bands were analyzed by ImageJ.DETAILED DESCRIPTION OF THE INVENTION

[0036] As used herein, "treatment" refers to clinical intervention in an attempt to alter the natural course of the individual or cell being treated, and can be performed either for prophylaxis or during the course of clinical pathology. Desirable effects of treatment include preventing occurrence or recurrence of disease, alleviation of symptoms, diminishment of any direct or indirect pathological consequences of the disease, preventing or decreasing tissue / organ damage, decreasing the rate of disease occurrence, amelioration or palliation of the disease state, and remission or improved prognosis.

[0037] The term "pharmaceutical" or "pharmaceutically acceptable" when used herein as an adjective means substantially non-toxic and substantially non-deleterious to the recipient. By "pharmaceutical composition" it is further meant that the carrier, solvent, excipients and salt must be compatible with the active ingredient of the composition (e.g., a compound of the invention). It is understood by those of ordinary skill in this art that the terms “pharmaceutical formulation” and “pharmaceutical composition” are generally interchangeable, and they are so used for the purposes of this application.

[0038] An "individual" or a "subject" disclosed herein is a vertebrate. In certain embodiments, the vertebrate is a mammal. Mammals include, but are not limited to, farm animals (such as cows), sport animals, pets (such as cats, dogs, and horses), primates, mice and rats. In certain embodiments, the vertebrate is a human.

[0039] An "effective amount" disclosed herein refers to an amount which is effective, at certain dosages and for necessary periods of time, to achieve the desired therapeutic or prophylactic result. In one embodiment, the PDE5 inhibitor, arginine, and / or NAC in the combination or composition disclosed herein is in an effective amount.

[0040] A "therapeutically effective amount" of a substance / molecule of the present disclosure may vary according to factors such as the disease state, age, sex, and weight of the individual, and the ability of the substance / molecule, to elicit a desired response in the individual. A therapeutically effective amount is also one in which any toxic or detrimental effects of the substance / molecule are outweighed by the therapeutically beneficial effects. A “prophylactically effective amount” refers to an amount which is effective, at certain dosages and for necessary periods of time, to achieve the desired prophylactic result. Typically, but not necessarily, since a prophylactic dose is used in subjects prior to or at an earlier stage of disease, the prophylactically effective amount would be less than the therapeutically effective amount. In one embodiment, the PDE5 inhibitor, arginine, and / or NAC in the combination or composition disclosed herein is in a therapeutically effective amount.

[0041] Administration "in combination with" as disclosed herein includes simultaneous (concurrent) and consecutive administration in any order. As used herein, “combination therapy” or “in combination” includes the administration of a PDE5 inhibitor, arginine, and NAC as part of a specific treatment regimen intended to provide the beneficial effect from the co-action of these agents.

[0042] "Excipients" as used herein include pharmaceutically acceptable carriers or stabilizers that are nontoxic to the cell or mammal being exposed thereto at the dosages and concentrations employed. In one embodiment, a physiologically acceptable carrier is an aqueous pH buffered solution.

[0043] The term "about" as used herein indicates a variation of about ± 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 %.

[0044] The term "fixed dose" as used herein denotes that two or more different ingredients in a single composition are present in the composition in particular (fixed) ratios with each other.

[0045] Neurological diseases are associated with the death or injury' of neuronal cells. The loss of dopaminergic neurons in the substantia nigra is the etiological cause for Parkinson's disease. Although the molecular mechanism of neurodegeneration in Alzheimer's disease is yet to be established, it is clear that brain inflammation, and deposition of beta-amyloid protein and other such agents may inhibit the survival of neurons and mitigate the growth of neurites used for communication between neurons. In patients suffering from brain ischemia or spinal cord injuries, extensive neuronal cell death is observed. Currently, there are no satisfactory treatments for these diseases.

[0046] The present disclosure surprisingly found that the combination or composition of a PDE5 inhibitor (preferably sildenafil), arginine and N-acetylcysteine can promote neurite outgrowth, particularly compared with administration of the PDE5 inhibitor alone. Accordingly, the present disclosure provides methods or uses for promoting neurite outgrowth or treating and / or preventing a neurological disorder by administering a pharmaceutical combination comprising a PDE5 inhibitor (preferably sildenafil), arginine and N- acetylcysteine.

[0047] Several phosphodiesterase type 5 (PDE5) inhibitors or their pharmaceutically acceptable salts, such as sildenafil (SLID), tadalafil, and vardenafil, have been approved by the health authorities to treat erectile dysfunction. It has been found in previous experiments that the mechanism causing penile erection is nitric oxide (NO) diffusing into smooth muscle cells of the penis from vascular endothelial cells to activate guanylate cyclase (GC), therebyincreasing the generation of cyclic guanosine monophosphate (cGMP) and inhibiting the inflow of calcium ions, which will reduce the concentration of calcium ions in the cells and relax the smooth muscle of the cavernous body; the cavernous body is then congested and erected due to a large amount of blood. For example, sildenafil plays a role in inhibiting the hydrolysis of the cGMP, so that the cGMP can continuously act to achieve the effect of congestion and erection. According to the package insert of sildenafil, sildenafil has no direct relaxant effect on isolated human corpus cavemosum, but enhances the effect of nitric oxide (NO) by inhibiting phosphodiesterase type 5 (PDE5), which is responsible for degradation of cGMP in the corpus cavemosum. However, sildenafil also has multiple side effects. It may cause headaches, stomachaches, diarrhea, flushing, dizziness, weakness, pruritus, erythema and the like after administration. The side effects mostly occur within several minutes after sildenafil is taken. If Sildenafil is taken long term, serious hypertension may occur, and problems of transient loss of vision, coronary sclerosis and the like may be increased. These side effects are generally thought to be caused by vasodilatation; and rapid vasodilatation may cause vascular endothelial cells to bear pressure from high blood flow, which will cause vascular endothelial cells to release endogenous free radicals, thereby causing the vascular cells to be damaged by the free radicals.

[0048] Arginine is a medicine that can be used as an oral tablet or an oral capsule. In the erection process, L-arginine can be catalyzed to generate nitric oxide by endothelial nitric oxide synthase, and the nitric oxide may be quickly released to a space between cavernous tissues, so that the amount of divalent calcium ions in the cavernous artery smooth muscle cells is reduced to cause smooth muscle relaxation and increase blood flow.

[0049] N-acetyl cysteine (NAC) has an antioxidant effect and is capable of promoting the conversion of glutathione disulfide (GSSG) into glutathione (GSH) in the cells, and GSH is an indispensable element for synthesizing the most effective antioxidant enzyme in the body. In addition, it was reported that NAC has an inhibitory effect on inducible nitric oxide synthase (NOS) protein and NO production (Araki et al., N -acetylcysteine inhibits induction of nitric oxide synthase in 3T3-L1 adipocytes, J UOEH 29 (4):417-429 (2007); Bergamini et al., N- acetylcysteine inhibits in vivo nitric oxide production by inducible nitric oxide synthase, NITRIC OXIDE: Biology and Chemistry Vol. 5, No. 4, pp. 349-360 (2001); Rota et al., N- acetylcysteine negatively modulates nitric oxide production in endotoxin-treated rats through inhibition of NF-KB activation; Antioxidants & Redox Signaling, Vol.4, No.l (2004)). Therefore, NAC causes adverse effects in NO production, which is contrary to the effect brought by arginine.

[0050] However, the present disclosure unexpectedly found that the combination of a PDE5 inhibitor, NAC and arginine can promote neurite outgrowth or treat and / or prevent a neurological disorder.

[0051] In the pharmaceutical combination, examples of the amount or dose of the PDE5 inhibitor used herein include, but are not limited to, from about 1 mg to about 500 mg, from about 5 mg to about 490 mg, from about 5 mg to about 450 mg, from about 5 mg to about 400 mg, from about 5 mg to about 350 mg, from about 5 mg to about 300 mg, from about 5 mg to about 250 mg, from about 5 mg to about 200 mg, from about 5 mg to about 175 mg, from about 5 mg to about 150 mg, from about 5 mg to about 125 mg, from about 5 mg to about 100 mg, from about 5 mg to about 90 mg, from about 5 mg to about 80 mg, from about 5 mg to about 70 mg, from about 5 mg to about 60 mg, from about 5 mg to about 50 mg, from about 5 mg to about 40 mg, from about 5 mg to about 30 mg, from about 5 mg to about 20 mg, from about 5 mg to about 10 mg, from about 10 mg to about 480 mg, about 10 mg to about 470 mg, about 10 mg to about 460 mg, about 10 mg to about 450 mg, about 10 mg to about 440 mg, about 10 mg to about 430 mg, about 10 mg to about 420 mg, about 10 mg to about 410 mg, about 10 mg to about 400 mg, about 10 mg to about 390 mg, about 10 mg to about 380 mg, about 10 mg to about 370 mg, about 10 mg to about 360 mg, about 10 mg to about 350 mg, about 10 mg to about 340 mg, about 10 mg to about 330 mg, about 10 mg to about 320 mg, about 10 mg to about 310 mg, about 10 mg to about 300 mg, about 10 mg to about 290 mg, about 10 mg to about 280 mg, about 10 mg to about 270 mg, about 10 mg to about 260 mg, about 10 mg to about 250 mg, about 10 mg to about 240 mg, about 10 mg to about 230 mg, about 10 mg to about 220 mg, about 10 mg to about 210 mg, about 10 mg to about 200 mg, about 10 mg to about 190 mg, about 10 mg to about 180 mg, about 10 mg to about 170 mg, about 10 mg to about 160 mg, about 10 mg to about 150 mg, about 10 mg to about 140 mg, about 10 mg to about 130 mg, about 10 mg to about 120 mg, about 10 mg to about 110 mg, about 10 mg to about 100 mg, about 10 mg to about 90 mg, about 10 mg to about 80 mg, about 10 mg to about 70 mg, about 10 mg to about 60 mg, about 10 mg to about 50 mg, about 10 mg to about 40 mg, about 10 mg to about 30 mg, about 10 mg to about 20 mg, from about 20 mg to about 450 mg, from about 20 mg to about 400 mg, from about 20 mg to about 350 mg, from about 20 mg to about 300 mg, from about 20 mg to about 250 mg, from about 20 mg to about 200 mg, from about 20 mg to about 175 mg, from about 20 mg to about 150 mg, from about 20 mg to about 125 mg, from about 20 mg to about 100 mg, from about 20 mg to about 90 mg, from about 20 mg to about 80 mg, from about 20 mg to about 70 mg, from about 20 mg to about 60 mg, from about 20 mg to about 50 mg, from about 20 mg to about 40 mg, from about 20 mg to about 30mg, from about 50 mg to about 450 mg, from about 50 mg to about 400 mg, from about 50 mg to about 350 mg, from about 50 mg to about 300 mg, from about 50 mg to about 250 mg, from about 50 mg to about 200 mg, from about 50 mg to about 175 mg, from about 50 mg to about 150 mg, from about 50 mg to about 125 mg, from about 50 mg to about 100 mg, from about 50 mg to about 90 mg, from about 50 mg to about 80 mg, from about 50 mg to about 70 mg, from about 50 mg to about 60 mg, from about 100 mg to about 450 mg, from about 100 mg to about 400 mg, from about 100 mg to about 350 mg, from about 100 mg to about 300 mg, from about 100 mg to about 250 mg, from about 100 mg to about 200 mg, from about 100 mg to about 175 mg, from about 100 mg to about 150 mg, from about 100 mg to about 125 mg, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mg.

[0052] In the pharmaceutical combination, examples of the amount or dose of the arginine or N-acetyl cysteine used herein include, but are not limited to, from about 10 mg to about 2 g, from about 10 mg to about 1.9 g, from about 10 mg to about 1.8 g, from about 10 mg to about 1.7 g, from about 10 mg to about 1.6 g, from about 10 mg to about 1.5 g, from about 10 mg to about 1.4 g, from about 10 mg to about 1.3 g, from about 10 mg to about 1.2 g, from about 10 mg to about 1.1 g, from about 10 mg to about 1.0 g, from about 10 mg to about 900 mg, from about 10 mg to about 800 mg, from about 10 mg to about 700 mg, from about 10 mg to about 600 mg, from about 10 mg to about 500 mg, from about 10 mg to about 400 mg, from about 10 mg to about 300 mg, from about 10 mg to about 200 mg, from about 10 mg to about 100 mg, from about 10 mg to about 50 mg, from about 10 mg to about 25 mg, from about 100 mg to about 2 g, from about 100 mg to about 1.9 g, from about 100 mg to about 1.8 g, from about 100 mg to about 1.7 g, from about 100 mg to about 1.6 g, from about 100 mg to about 1.5 g, from about 100 mg to about 1.4 g, from about 100 mg to about 1.3 g, from about 100 mg to about 1.2 g, from about 100 mg to about 1.1 g, from about 100 mg to about 1.0 g, from about 100 mg to about 900 mg, from about 100 mg to about 800 mg, from about 100 mg to about 700 mg, from about 100 mg to about 600 mg, from about 100 mg to about 500 mg, from about 100 mg to about 400 mg, from about 100 mg to about 300 mg, from about 100 mg to about 200 mg, or about 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, or 1.0 g, or about 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, 150, 100, 50, 25, or 10 mg.

[0053] The combination or composition disclosed herein generally includes one or more pharmaceutically acceptable excipients, carriers or diluents. The particular carrier, diluent or excipient used will depend upon the means and purpose for which the active ingredient is being applied. In general, a tablet formulation includes materials such as diluents, binders, lubricants, disintegrants and mixtures thereof. Suitable diluents include various types of starch, lactose,mannitol, kaolin, calcium phosphate or sulfate, inorganic salts (e.g., sodium chloride), powdered sugar, and powdered cellulose derivatives. More specifically, examples of diluents or fillers include lactose, mannitol, xylitol, dextrose, sucrose, sorbitol, compressible sugar, microcrystalline cellulose, powdered cellulose, starch, pregelatinized starch, dextrates, dextran, dextrin, dextrose, maltodextrin, calcium carbonate, dibasic calcium phosphate, tribasic calcium phosphate, calcium sulfate, magnesium carbonate, magnesium oxide, poloxamers such as polyethylene oxide and hydroxypropyl methyl cellulose. If desired, a binder may be added. Suitable binders include substances such as celluloses (e.g., cellulose, methylcellulose, ethylcellulose, and hydroxymethylcellulose), polypropylpyrrolidone, polyvinylprrolidone, gelatin, gum arabic, polyethylene glycol, starch, sugars (e.g., lactose, sucrose, fructose, and glucose), natural and synthetic gums (e.g., acacia, alginates, and gum arabic) and waxes. A lubricant is typically used in a tablet formulation to prevent the tablet and punches from sticking in the die. Suitable lubricants include calcium stearate, glyceryl monostearate, glyceryl palmitostearate, hydrogenated vegetable oil, light mineral oil, magnesium stearate, mineral oil, polyethylene glycol, sodium benzoate, sodium lauryl sulfate, sodium stearyl fumarate, stearic acid, talc and zinc stearate. Disintegrants may also be added to the combination or composition to break up the dosage form and release the compound. Suitable disintegrants include sodium starch glycolate, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, croscarmellose sodium, polyvinylpyrrolidone, methyl cellulose, microcrystalline cellulose, powdered cellulose, lower alkyl-substituted hydroxypropyl cellulose, polacrilin potassium, starch, pregelatinized starch and sodium alginate.

[0054] The combination or composition of a PDE5 inhibitor in combination, arginine and NAC is useful in promoting neurite outgrowth or treating and / or preventing a neurological disorder. Surprisingly, a combination or composition of NAC and arginine can enhance the effect of a PDE5 inhibitor and simultaneously reduce adverse effects of the PDE5 inhibitor.

[0055] Neurological disorders are diseases of the central and peripheral nervous system. In other words, the brain, spinal cord, cranial nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular junction, and muscles. These disorders include epilepsy, Alzheimer disease and other dementias, cerebrovascular diseases including stroke, migraine and other headache disorders, multiple sclerosis, Parkinson's disease, neuroinfections, brain tumours, traumatic disorders of the nervous system due to head trauma, and neurological disorders as a result of malnutrition.

[0056] Many bacterial (i.e. Mycobacterial tuberculosis, Neisseria meningitides), viral (i.e. Human Immunodeficiency Virus (HIV), Enteroviruses, West Nile Virus, Zika), fungal (i.e.Cryptococcus, Aspergillus), and parasitic (i.e. malaria, Chagas) infections can affect the nervous system. Neurological symptoms may occur due to the infection itself, or due to an immune response.

[0057] The beneficial effect of the combination includes, but is not limited to, pharmacokinetic and / or pharmacodynamic co-action resulting from the combination of said agents. Administration of these agents in combination typically is carried out over a defined period of time (usually minutes, hours, days or weeks depending upon the combination selected). Combination therapy is intended to embrace administration of the indicated therapeutic agents in a concurrent, sequential or separate manner. For example, each therapeutic agent is administered at a different time, as well as administration of these therapeutic agents in a substantially simultaneous manner. Sequential, concurrent or separate administration of each therapeutic agent can be effected by any appropriate route, including, but not limited to, oral route, intravenous routes, intramuscular routes, and direct absorption through mucous membrane tissues.

[0058] Administration can be accomplished, for example, by administering to the subject a single oral dosage form having a fixed ratio of each agent or in multiple, single oral dosage forms for each of the therapeutic agents. In one embodiment of a fixed dose formulation, a PDE5 inhibitor, arginine and NAC are contained in a ratio of about 2: about 25: about 25. Particularly, the formulation comprises a fixed dose of 20 mg of a PDE5 inhibitor, a fixed dose of 250 mg of arginine, and a fixed dose of 250 mg of NAC. In a further embodiment, the PDE5 inhibitor is sildenafil. In a further embodiment, the composition, combination or formulation disclosed herein is a tablet or pill.

[0059] In another embodiment, the combinations and compositions of the present disclosure can be administered parenterally (e.g., by intramuscular, intrathecal, intravenous, and intraarterial routes), preferably intravenously. Typically, compounds and compositions of the invention for intravenous administration are solutions in sterile isotonic aqueous vehicles, such as water, saline, Ringer's solution, or dextrose solution. Where necessary, the compositions may also include a solubilizing agent. The combinations and compositions for intravenous administration may optionally include a local anesthetic such as lignocaine to ease pain at the site of the injection. For intravenous administration, the combinations and compositions of the present disclosure can be supplied as a sterile, dry lyophilized powder or water-free concentrate in a hermetically sealed container, such as an ampule or sachette, the container indicating the quantity of the active agent. Such a powder or concentrate is then diluted with an appropriate aqueous medium prior to intravenous administration. An ampule of sterile water, saline solution,or other appropriate aqueous medium can be provided with the powder or concentrate for dilution prior to administration. Or the combinations and compositions of the present disclosure can be supplied in pre-mixed form, ready for administration. Where the combinations and compositions of the present disclosure are to be administered by intravenous infusion, they can be dispensed, for example, with an infusion bottle containing sterile pharmaceutical-grade water, saline, or another suitable medium. Rectal administration can be effected through the use of suppositories formulated from conventional carriers such as cocoa butter, modified vegetable oils, and other fatty bases. Suppositories can be formulated by well-known methods using well- known formulations; for example, see Remington: The Science and Practice of Pharmacy, Alfonso R. Gennaro ed., Mack Publishing Co. Easton, Pa., 19th ed., 1995, pp. 1591-1597, incorporated herein by reference

[0060] A therapeutically effective dosage regimen for the treatment of a particular disorder or condition will depend on its nature and severity, and can be determined by standard clinical techniques according to the judgment of a medical practitioner. In addition, in vitro or in vivo assays can be used to help identify optimal dosages. Of course, the amount of a compound of the invention that constitutes a therapeutically effective dose also depends on the administration route.

[0061] The following examples are offered by way of illustration and are not intended to limit the scope of the invention.EXAMPLES

[0062] Experimental Methods

[0063] Preparation of Drug

[0064] Sildenafil (S), arginine (A), N-acetylcysteine (N), and S-nitroso-N-acetylpenicillamine (SNAP) were dissolved and diluted in phosphate buffered saline (PBS). In particular, the following solutions are prepared for cell culture: a solution containing 100 nM sildenafil (hereinafter called SILD or “S”); a mixed solution of 100 nM of sildenafil and 10 mM of N- acetylcysteine (hereinafter called “SN”); a mixed solution of 100 nM of sildenafil, 150 pM of arginine and 10 mM of N-acetylcysteine (hereinafter called “SAN”); a mixed solution of 100 nM of sildenafil and 100 pM S-nitroso-N-acetylpenicillamine (SNAP) (hereinafter called “SS”); and a mixed solution of 100 nM of sildenafil, 100 pM SNAP, and 10 mM of N- acetylcysteine (hereinafter called “SSN”). For animal model, SAN is a mixed solution of sildenafil (0.33 mg / kg) + Arginine (60 mg / kg) + N-acetylcysteine (60 mg / kg), sildenafil (3.3 mg / kg) + Arginine (60 mg / kg) + N-acetylcysteine (60 mg / kg) and sildenafil (33 mg / kg) + Arginine (60 mg / kg) + N-acetylcysteine (60 mg / kg). The solutions are stored at a temperatureof 4°C. For clinical trials and human tests, the combination of SAN comprising 20 mg of sildenafil, 250 mg of arginine, and 250 mg of NAC is used and applied to subjects.

[0065] Cell Culture

[0066] Primary cortical cells were isolated from embryonic 18 (El 8) Sprague-Dawley rats and plated on 24 well plates at a density of 2 x 105cells / well, 6 well plates at a density of 6 x 105cells / well or 35mm glass bottom Petri dishes at a density of 6 x 105cells / dish coated with 0.1 mg / mL poly-D-lysine (Sigma-Aldrich). Neurons were cultured in Neurobasal medium (Invitrogen) with B27 supplement (Invitrogen), GlutaMax Reagent (Invitrogen), and penicillin / streptomycin (P / S, Sigma-Aldrich) Cells were grown in a 5% CO2 atmosphere at 37°C.

[0067] Trauma Injury In Vitro Model

[0068] At DIV 16, cells were pretreated various concentrations of SAN (0, 0.01 pM of sildenafil plus 150 pM of arginine and 10 mM of N-acetyl cysteine, 0.1 pM of sildenafil plus 150 pM of arginine and 10 mM of N-acetyl cysteine, 0.5 pM of sildenafil plus 150 pM of arginine and 10 mM of N-acetyl cysteine, 1 pM of sildenafil plus 150 pM of arginine and 10 mM of N-acetyl cysteine) for 48 h. At DIV 17, a cell-free area was generated by gently scratching the cell monolayer with a sterile 200 pL Gil son-pipette tip. After ten minutes, cells were returned to recovery media with same concentrations of SAN described above for another 24 h. The neurite outgrowth was observed at 24 h using microscope after neurite were injured. The number and length of neurite outgrowth were measured by Imaged.

[0069] Fluorescent Image

[0070] After treatments with SAN, the fixed neurons were stain with mouse anti-MAP2 (1 :500, Abeam) following by secondary antibody. Cells nuclei stain by 300 nM 4', 6-diamidino- 2-phenylindole (DAPI) (Sigma-Aldrich). Stained neurons were observed at 200X magnification on an Olympus 1X51 Microscope.

[0071] Trauma Brain Injury Animals Model

[0072] Animals were deeply anesthetized using the intraperitoneal injection of a combination of Zoletil 50 (35 mg / kg) and Rompun (7.5 mg / kg). Once deep anesthesia was achieved, individual animals were fixed in a stereotaxic frame (World Precision Instruments, WPI). Using aseptic procedures a midline scalp incision was made, the skin and fascia were reflected to expose the skull. A hole was carefully drilled through the skull above the CAI region of the hippocampus using a WPI surgery drill. The syringe (25-gauge, SGE Analytical Science) was implanted into the hole using the following coordinates: AP -3.6 mm from Bregma; ML ± 1.5 mm from the midline; DV -4 mm from dura. After 10 min, the syringe was slowly removed, and the hole was filled with Gelfoam. Then the skin was pulled back over the skull and heldtogether by two staples. Animals divided randomly into eight groups: 1) Sham (n=6); animals underwent same operation procedure operation procedure of inducing brain trauma except trauma induction. 2) Injury (n=6); animals underwent traumatic brain injury surgery. 3) Injury + post-treat SAN (n=6); TBI animals that obtained oral gavage SAN after trauma daily until 28 days later.

[0073] Immunohi stochemi stry

[0074] Rats were perfused with PBS (pH 7.4), following by 4% PFA in PBS under Zoletil 50 (35 mg / kg) and Rompun (7.5 mg / kg) anesthesia. The brains were removed and fixed overnight in 4% PFA at 4°C. Then, the brains were embedded in OCT (optimal cutting temperature compound) and soaked in liquid nitrogen. Frozen sections were prepared at 10 pm thickness and fixed by 4% PFA. Heat-induced antigen retrieval using autoclave was applied. The sections were soaked in 2N HC1 for 30 min, and placed into 0. IM borate buffer for 10 min. The sections were blocked 24 hr at 4°C. The sections were incubated with following antibodies: anti-MAP-2 for 24 hr, then rinsed sections three times for 20 min. The sections were incubated with secondary antibody for 1 hr. The sections were mounted with DAPI-Fluoromount-G prior to microscopy usage.

[0075] Morris water maze task

[0076] The Morris water maze (MWM) was starting at day 4 after injury. The water maze was a black circle pool (160 cm in diameter, 45 cm in deep). The pool was divided into four equal space quadrants. The pool was filled to a depth of 27 cm with water (25 ± 2 °C). A circle platform (12 cm in diameter, 25 cm in deep) was submerged 2 cm below water surface and placed at a fixed position in quadrant III, 50.8 cm from the wall. The camera was mounted above of the center of the pool and analyzed by Ethovision XT v 10.0 software. The acquisition trial was carried out during 4 consecutive days. The rats received 4 consecutive training trials on each training days. A different starting location was used for each trial, which consisted of swimming following by remaining on the platform for at least 20 sec. If rats could not reach to the platform within 60 sec, it was guided it to platform. Time to reach the platform (latency to sec) and the path length were measured. After acquisition trial, the platform was removed from the pool. The rats were allowed to swim 60 sec. Frequency to platform, first time to platform (latency time) and swim path were measured.

[0077] Hematoxylin and eosin stain

[0078] Rats were perfused with PBS (pH 7.4), following by 4% PFA in PBS under Zoletil 50 (35 mg / kg) and Rompun (7.5 mg / kg) anesthesia. The brains were removed and fixed overnight in 4% PFA at 4 °C. Then, the brains were embedded in OCT (optimal cutting temperaturecompound) and soaked in liquid nitrogen. Frozen sections were prepared at 10 pm thickness and fixed by 4% PF A. The sections were soaked in Hematoxylin for 10 min, then rinsed sections with ddH2O for 1 min. The sections were stained with Eosin for 5 min, and used ethanol to dehydrate. The sections were soaked in xylene for 1 min twice, and mounted with Entellan.

[0079] Western analysis

[0080] The rats were euthanized via CO2 asphyxiation, and the brains were removed. Tissues were homogenized in TEE buffer with PMSF, and used Triton X-100 to lysis cell membrane. Lysates were centrifuged (13000 rpm at 4 °C) for 10 min, and the supernatants were collected. Protein concentrations were determined by BCA assay kit. Proteins were loaded 80 pg / well on a 12 % SDS-polyacrylamide gel and transferred to a PVDF membrane. Nonspecific reactivity was blocked for 1 h at room temperature and primary anti-BDNF, anti-CD68 and anti-alpha tubulin were incubated overnight at 4 °C. Then, the membranes were washed for 20 min for three times. Secondary antibodies conjugated with horseradish peroxidase (HRP) were used at 1 : 10000 dilution. Immunoreactive bands were detected using ECL system. The total intensity of bands were analyzed by ImageJ.

[0081] Immunohi stochemi stry

[0082] Rats were perfused with PBS (pH 7.4), following by 4% PFA in PBS under Zoletil 50 (35 mg / kg) and Rompun (7.5 mg / kg) anesthesia. The brains were removed and fixed overnight in 4% PFA at 4°C. Then, the brains were embedded in OCT (optimal cutting temperature compound) and soaked in liquid nitrogen. Frozen sections were prepared at 10 pm thickness and fixed by 4% PFA. Heat-induced antigen retrieval using autoclave was applied. The sections were soaked in 2N HC1 for 30 min, and placed into 0. IM borate buffer for 10 min. The sections were blocked 24 hr at 4°C. The sections were incubated with following antibodies: anti-BDNF, anti-CD68 for 24 hr, then rinsed sections three times for 20 min. The sections were incubated with Alexa 488-conjugated goat anti-mouse IgG for 1 hr. The sections were mounted with DAPI-Fluoromount-G before microscopy usage.

[0083] Experimental Results

[0084] Example 1. In Vitro Neurite Regeneration Assay

[0085] To test the neurite regeneration in vitro, the trauma injury assay were processed, which was used for testing cell migration and neurite outgrowth in previous reports (Loh SH, Francescut L, Lingor P, Bahr M, Nicotera P (2008), Cell Death Differ 15:283-298; Wu CL, Chou YH, Chan Tseng CY, Fir estein BL (2011) J Neurosci 31: 15468-15480g; YJ, Teng NY, Hsu HL, Chen L (2012) PLoS One 7:e34999). As shown in FIG. 1 A, after 24 hours of trauma injury, the blank group has no effect in the outgrowth of the neurite. In the groups ofadministration of S, A, N and SAN, the neurite regeneration in S only group was similar to the blank group (see FIG. IB), while the SAN group significantly increase the length and numbers of neurites (see FIG. 1C and FIG. ID). Comparing to the A+N group, the neurites in SAN group can regenerate up to 50% in number at 1 pg / ml (FIG. 1C) and 30% in length at 0.5 pg / ml (FIG. ID) .

[0086] Example 2. SAN Restores Memory Lose

[0087] The rats were subjected to brain injury surgery. After the surgery, the rates were administered with or without SAN for 28 days. As shown in FIG. 2, the treatment efficacy in the SAN group exhibits an advantageous effect in comparison with the sham group. The neurite in SAN group can regenerate up to 28%, which is 4.5 times higher than the 6% of the sham group (FIG. 3).

[0088] 28 days after the brain injury, we used the MWM water maze method to test the memory ability of the rats. It can be found that the speed of returning to the floating board was the fastest in the sham group, followed by the SAN group after trauma, and the slowest in the trauma group. As shown in FIG. 4, the average time for the sham group to return to the floating board is 12 seconds, the trauma group is 30 seconds (* <0.05), and the group given SAN after trauma is 18 seconds (* <0.05), the SAN group obviously has the function of restoring memory.

[0089] Example 3. Restoration of Neurites in Rats

[0090] In the process of repairing the nervous system, the nerve growth factor BDNF plays an important role, and the secretion of BDNF can help repair the nervous system. According to the protein expression of the whole brain tissue in FIG. 5 A, we can see that the expression of BDNF has no significant difference in all groups. However, in the post-treatment, the secretion of BDNF tended to increase gradually with the doses of SAN. In FIG. 5B, we used fluorescent to measure BDNF to analyze its expression location, we can find that BDNF will be evenly distributed in the whole brain, but for the injured brain, the secretion of BDNF will focus on the injured area, which may explain why there is no significant difference in the expression of BDNF in the whole brain alone.

[0091] In the process of nerve injury and repair, the quality of wound repair depends on the activity of astrocytic Astrocyte. We use the biological indicator of Astrocyte CD68 to determine its activity. According to the expression response of whole brain tissue protein CD68 in FIG. 6A, we found that compared with the blank group, CD68 in the trauma group, pre-treatment (0.33, 33 mg / kg), post-treatment (33 mg / kg) has a significant increase increased (T < 0.05); after SAN, both pre-treatment (0.33, 3.3 mg / kg) and post-treatment (0.33, 3.3 mg / kg) decreased significantly (* < 0.05); but only pre-treatment (3.3 mg / kg) and post-treatment (3.3 mg / kg) andsham groups were not significantly different (# > 0.05). In FIG. 6B, we used fluorescent markers to measure CD68 to analyze its expression location, and found that the secretion of CD68 in the uninjured brain was not high, but in the traumatized brain, CD68 was secreted in large quantities, and the location would also focus on the traumatized area piece.

[0092] With regard to the results of anti oxidation at wound area, we analyzed the anti -oxi dative protein SOD-1 in the brain to determine whether the administration of SAN can help the rat brain to carry out anti-oxidation against unnecessary oxidative stress. According to the protein expression of SOD-1 in the whole brain tissue of FIG. 7, it was found that the expression of SOD-1 was significantly improved in the middle and high doses of Pre-treatment and 3.3 mg / kg in the post-treatment group (* < 0.05 ).

[0093] The above description and illustration only represent a description of preferred embodiments of the present invention. Those skilled in the art can make modifications according to the general knowledge and the present invention herein, but these modifications should still be within the scope of the present invention herein for the spirit of the present invention.

Claims

CLAIMSWe claim:

1. A method for promoting neurite outgrowth, the method comprising exposing the neuron to an effective amount of a pharmaceutical combination comprising a phosphodiesterase type 5 (PDE5) inhibitor or a pharmaceutically acceptable salt thereof, arginine, and N- acetylcysteine.

2. A method for treating and / or preventing a neurological disorder or injury via promotion of neurite outgrowth, the method comprising administering an effective amount of a pharmaceutical combination comprising a phosphodiesterase type 5 (PDE5) inhibitor or a pharmaceutically acceptable salt thereof, arginine, and N-acetyl cysteine to a subject in need thereof.

3. The method of claim 2, wherein the neurological disorder or injury via promotion of neurite outgrowth is epilepsy, Alzheimer disease and other dementias, cerebrovascular diseases including stroke, migraine and other headache disorders, multiple sclerosis, Parkinson's disease, neuroinfections, brain tumours, traumatic disorders of the nervous system due to head trauma, Huntington's disease, ALS, multiple sclerosis, ischemia associated with stroke, neural paropathy, motor neuron diseases, sciatic crush, peripheral neuropathy, neuropathy associated with diabetes, spinal cord injuries and facial nerve crushinjuries to the nervous system caused by physical, mechanical, or chemical trauma, memory loss, or psychiatric disorders, intracranial hemorrhage, spinal cord injury or neurological symptoms due to the infection or an immune response.

4. The method of claim 2, wherein the neurological disorder or injury is central nervous system (CNS) disorder or injury is peripheral nerve damage caused by physical injury (associated with, e.g., bums, wounds, surgery, and accidents), ischemia, prolonged exposure to cold temperature (e.g., frost-bite), damage to the central nervous system due, for example, to stroke or intracranial hemorrhage (such as cerebral hemorrhage), dementia, Alzheimer's disease, Huntington's disease or Parkinson's disease.

5. The method of claim 3, wherein the neurological disorder or injury is stroke or intracranial hemorrhage.

6. The method of any preceding claims, wherein the PDE5 inhibitor is selected from sildenafil, tadalafil, and vardenafil.

7. The method of any preceding claims, whereinthe amounts of the PDE5 inhibitor, arginine and N-acetylcysteine range from about 0.1% (w / w) to about 50% (w / w), about 4.0% (w / w) to about 80% (w / w) and about 4% (w / w) to about 80% (w / w), respectively; or the pharmaceutical combination comprises about 0.5 mg to about 250 mg of the PDE5 inhibitor, about 25 mg to about 400 mg of arginine and about 25 mg to about 400 mg of N- acetylcysteine.

8. The method of any preceding claims, wherein the pharmaceutical combination is in the form of a solid or liquid formulation.

9. The method of any preceding claims, wherein the pharmaceutical combination is a capsule or a tablet.

10. The method of any preceding claims, wherein the PDE5 inhibitor or a pharmaceutically acceptable salt, arginine, and N-acetylcysteine is administered concomitantly, sequentially, or separately.

11. The method of any preceding claims, wherein the PDE5 inhibitor is sildenafil or sildenafil citrate.

12. The method of any preceding claims, wherein the pharmaceutical combination is administered twice a day.

13. The method of any preceding claims, wherein the pharmaceutical combination is a fixed dose formulation.

14. The method of claim 13, wherein the formulation comprises a fixed dose of 20 mg of a PDE5 inhibitor, a fixed dose of 250 mg of arginine, and a fixed dose of 250 mg of NAC.

15. The method of claim 14, wherein the PDE5 inhibitor is sildenafil.

16. The method of claim 15, wherein the formulation is a tablet or pill.

17. A fixed dose formulation comprising a PDE5 inhibitor, arginine and NAC in a ratio of about 2: about 25: about 25.

18. The fixed dose formulation of claim 17, wherein the PDE5 inhibitor is sildenafil.

19. The fixed dose formulation of claim 17, which is in the form of a tablet or pill.

Images