DESC:TECHNICAL FIELD
The present invention relates to the pharmaceutical composition of L-Arginine and Fenugreek extract for erectile dysfunction (ED) in Elderly Diabetic patients.

BACKGROUND AND PRIOR ART OF INVENTION
Erectile dysfunction (ED), a common condition among men, is defined as the inability to achieve or maintain an erection sufficient for a satisfactory sexual performance. Prevalence of ED increases with age.

The prevalence and risk factors for ED include cardiovascular disease (CVD) (hypertension, atherosclerosis, and hyper lipidemia), diabetes, depression, alcohol use, smoking, pelvic/perineal surgery or trauma, neurologic disease, obesity, pelvic radiation, and Peyronie’s disease. Hormone deficiency or hypogonadism, whether primary or secondary due to low levels of testosterone that will impact erectile function. ED may influence interpersonal relationships and impact a couple’s relationship in a negative fashion.

Patients with ED showed a significantly higher prevalence of cardiovascular disease (CVD) (18% vs.10%), Diabetes Mellitus (DM) (24% vs. 11%), and depression (11% vs. 5%) compared to patients without ED.

The ED more commonly affects men of increasing age with 10% of men 20–30 years old and as many as 70% of men older than 70 years being diagnosed with ED.

The etiology is related to ageing and vascular, neurogenic, psychological, and hormonal components. The pathogenesis has been linked to poor psychological status, arterial endothelial damage, and low testosterone.

With men ageing, there is generally a decrease in testosterone levels due to reduced gonadal function. Based on a gradual decline of systematic availability of testosterone in healthy men by 1% every year after the third decade of life, sub physiological values of 35–50% can be seen by the sixth decade of life. The ratio of collagen to elastic fibers in the corpora cavernosa also increases with aging. The association observed among age, testosterone deficiency, cavernosal fibrosis, and ED, suggests that this fibrotic process is a possible cause of ED in older men with decreasing levels of testosterone.

Patients with decreasing testosterone levels in the presence of insulin resistance, central obesity and hypercholesterolemia may have decreased sexual desire and fail to achieve adequate penile tumescence with sexual stimulation.

Erection is the neurovascular event that involves relaxation of arteries and trabecular smooth muscle in corpus cavernosum, thereby increasing arterial blood flow to penis. Nitric oxide and cGMP are acting as primary mediator and secondary messenger. Nitric oxide (NO) is produced from non-adrenergic, non-cholinergic nerve terminal of penis by neuronal NO synthase. This NO synthase activates the production of NO via endothelial NO synthase in endothelial cell of penis and bind to guanylate cyclase in vascular smooth muscle to generate cGMP (cyclic Guanosine monophosphate). This cGMP is secondary messenger in muscle cell causes relaxation and vasodilation, resulting in penis erection. This erection subsides when cGMP is degraded by phosphodiesterase type 5 enzyme.
Endocrine hormone- Testosterone plays a major role in erection function (EF). Testosterone modulates every component involved in EF, from pelvic ganglions to smooth muscle and the endothelial cells of the corpora cavernosa. It also regulates the timing of the erectile process as a function of sexual desire, coordinating penile erection with sex. Epidemiologic studies confirm the significant overlap of hypogonadism and ED.

The sequence of nerve stimulation precisely the afferent and efferent pathways. Testosterone deficiency decreases endothelial NOS activity by up-regulating reactive oxygen species production, and the decreased eNOS activity decreases cGMP levels in the penis. It also preserves smooth muscle contractility by regulating both contraction and relaxation. Thus, testosterone maintains the structure of the corpus cavernosum.
The pathogenesis and etiology reveals that ED is multifactorial and has been linked to arterial endothelial damage, and low testosterone.

Traditionally, PDE5 inhibitors are used as first line therapy for erectile dysfunction alone. This may be useful in NO centric ED. It may not have significant effect with hormonal based ED.

Testosterone replacement therapy or oral testosterone capsules are used to treat men with certain form of hypogonadism. This therapy may have significant side effect and potential risk of cardiovascular diseases including myocardial infarction, heart failure, stroke, depression and aggression etc.

The patent No PCT/IB2019/051894 discloses the invention related to compositions, process and preparation as formulation for the treatment of diabetes mellitus, brain associated disorders, joint pain, gastrointestinal disorder & erectile dysfunction.

US patent US09/865,189 discloses the use of proanthocyanidins as an active ingredient of a stimulator as a source of arginine and a source of nitric oxide in the treatment of erectile dysfunction. The active ingredient stimulates the endothelial NO-synthase enzyme, which acts as a catalyst for the synthesis of nitric oxide from its substrate L-arginine or its salts.

European Patent 1909782B1 discloses liquid oral compositions comprising arginine as a substance which improves nitric oxide (NO) availability, in combination with R-a-lipoic acid and their use for improvement of sexual function.

Maheshwari et al. discloses the effect of clinical study of 500 mg of daily fenugreek seed extract for 12 weeks for men aged 35–65 diagnosed with symptomatic hypogonadism. Subjects experienced a significant increase in free testosterone.

Meta analysis of “Assessment of combination Vs monotherapy for ED discloses that combination therapy provides better efficacy.

Prevalence of ED is high with diabetic patient, especially elderly diabetic patient. Treatment option of any one condition like impaired NO production or testosterone hormone synthesis may not provide better efficacy/ solution.

The present invention therefore provides composition of L-Arginine and Fenugreek extracts for improving the testosterone deficiency and impaired NO production for erectile dysfunction in Elderly Diabetic patients.

SUMMARY OF THE INVENTION
In line with the above objective, the present invention provides a Pharmaceutical composition of L-Arginine and Fenugreek extract for Erectile Dysfunction. More particularly, present invention provides a pharmaceutical composition of L arginine and Fenugreek formulation and its method of preparation for the treatment of Erectile dysfunction (ED) in the elderly diabetic patent.

L-arginine in the present invention acts as catalyst for NO synthesis and vasodilation in penis smooth muscle. This may be useful in treating ED with various disease conditions that are associated with impaired NO production, like erectile dysfunction and peripheral vascular disease.

The present composition further comprises Fenugreek extract which consists the saponins like protodioscin, flavanoids, alkaloids, fatty acids, glycosides, amino acids, and the like. Saponin (Protodioscin) plays a major role in the synthesis of testosterone. Thus, Fenugreek is useful in the ED with impaired testosterone synthesis and level.

The present invention of pharmaceutical composition of L arginine and Fenugreek extract provides better treatment for ED patient with testosterone deficiency and impaired NO production and vascular disease.
DETAILED DESCRIPTION OF INVENTION

The present invention will now be described in detail in connection with certain preferred and optional embodiments, so that various aspects therefore maybe fully understood and appreciated.

Throughout the description of this specification, the word “comprise” and variations of the word, such as “comprising” and “comprises,” means “including but not limited to,” and is not intended to exclude, for example, other additives, components, integers or steps.

Prevalence of Erectile Dysfunction increases with age. Erectile dysfunction (ED) a common condition among men, is defined as the inability to achieve or maintain an erection sufficient for a satisfactory sexual performance.

The penile erectile tissue, specifically the cavernous smooth musculature and the smooth muscles of the arteriolar and arterial walls, plays a key role in the erectile process. In the flaccid state, these smooth muscles are tonically contracted, allowing only a small amount of arterial flow for nutritional purposes. The blood partial pressure of oxygen (PO2) is about 35mmHg range.

Sexual stimulation triggers release of neurotransmitters from the cavernous nerve terminals. This results in relaxation of these smooth muscles and the following events:
• Dilatation of the arterioles and arteries by increased blood flow in both the diastolic and the systolic phases
• Trapping of the incoming blood by the expanding sinusoids
• Compression of the subtunical venular plexuses between the tunica albuginea and the peripheral sinusoids, reducing the venous outflow
• Stretching of the tunica to its capacity, which occludes the emissary veins between the inner circular and the outer longitudinal layers and further decreases the venous outflow to a minimum
• An increase in PO2 (to about 90 mmHg) and intracavernous pressure (around 100 mm Hg), which raises the penis from the dependent position to the erect state (the full-erection phase)
• A further pressure increase (to several hundred millimeters of mercury) with contraction of the ischiocavernosus muscles (rigid-erection phase)

Erection thus involves sinusoidal relaxation, arterial dilatation, and venous compression. The importance of smooth muscle relaxation has been demonstrated in animal and human studies.

Neurogenic NO is considered the most important factor for smooth muscle relaxation of penile vessels and corpus cavernosum (CC). The role of other mediators, released from nerves or endothelium, has not been definitely established.

Erectile dysfunction (ED), defined as the “inability to achieve or maintain an erection adequate for sexual satisfaction,” may have multiple causes and can be classified as psychogenic, vasculogenic or organic, neurologic, and endocrinologic. Many patients with ED respond well to the pharmacological treatments that are currently available, but there are still groups of patients in whom the response is unsatisfactory. The drugs used are able to substitute, partially or completely, the malfunctioning endogenous mechanisms that control penile erection.

Most drugs have a direct action on penile tissue facilitating penile smooth muscle relaxation, including oral phosphodiesterase inhibitors and intracavernosal injections of prostaglandin E1.

Phosphodiesterase-5 (PDE-5) inhibitors are the first-line drugs for the treatment of ED which is useful in the treatment of NO impaired ED, but not for testosterone impaired ED.

Testosterone can help to counter the signs and symptoms of male hypogonadism, such as decreased sexual desire, decreased energy, decreased facial and body hair, and loss of muscle mass and bone density.

Oral testosterone capsule to treat men with certain forms of hypogonadism (testosterone undecanoate) are available in the market. The side effects of oral medication show the possibility of potential increased risk of cardiovascular disease and adverse effects of abuse of anabolic androgenic steroids, including myocardial infarction, heart failure, stroke, liver injury, male infertility, and mood changes including depression, aggression, and hostility due to the high doses of testosterone oral dosage forms.

Testosterone treatment may be useful for the treatment of testosterone impaired ED, but not for NO impaired ED.

In an embodiment, the present invention relates to a novel pharmaceutical composition comprising L-Arginine and Fenugreek extract together with pharmaceutically acceptable excipients for the treatment of Erectile Dysfunction.

The amount of L-arginine in the present composition ranges between 50%w/w to 80%w/w.

The amounts of fenugreek extract in the present composition ranges between 10%w/w to 30%w/w.

Suitable pharmaceutically acceptable excipients according to the present invention include but are not limited to diluents, binders, disintegrants, glidants, lubricants,
surfactants, viscosity modifying agents, polymers, stabilizers, plasticizers, sweeteners, flavoring agents, anti-caking agents, opacifiers, buffering agents, coloring agents, carriers, fillers, anti-adherents, solvents, taste-masking agents, preservatives, antioxidants, coating agents or combinations thereof in suitable amounts.

L-arginine is a natural precursor of Nitic oxide which is used in the present invention to treat erectile dysfunction.

In an embodiment, the L-arginine used in the present composition may be generated from L-citrulline by argininosuccinate synthase as part of the urea cycle.

The essential mediator required for penile erection is nitric oxide (NO). NO binds to guanylate cyclase inside the cells of vascular smooth muscle generating the cyclic guanosine monophosphate that acts as a second messenger to exert relaxation and vasodilation determining the penile erection. L arginine is physiological substrate of NO Synthase which generates NO. Increased concentration of the substrate leads to a higher amount of NO and is considered as effective treatment for ED, especially for patients affected with mild to moderate ED.

Arginine is a natural origin of this amino acid. Its good bioavailability after oral absorption, and its excellent tolerance allowing long-course therapy has made arginine a widely used supplement by men seeking natural treatment and/or self-medication for ED.

Similarly, the other active component Fenugreek extract (Trigonella foenum-graecum Linn) consists of saponin compound Protodioscin. The level of Protodioscin may vary with grade and region where Fenugreek is harvested.

Protodioscin achieves this primarily through causing an increase in androgen receptor immunoreactivity, meaning it increases the concentration of androgen receptors in cells, causing the organism to become more sensitive to androgens like testosterone and DHT.

Protodioscin has been demonstrated to trigger release of nitric oxide in corpus cavernosum tissue, and also to produce statistically significant increase in the levels of the hormone’s testosterone, dihydrotestosterone and dehydroepiandrosterone.

Protodioscin, boosts testosterone levels via stimulation of the pituitary gland. This stimulation is thought to promote the production of Luteinizing Hormone (LH), which increases unbound free-testosterone levels.

Protodioscin treats impotence symptoms by stimulating increase in free testosterone via secretion of Luteinizing Hormone. This effectiveness is enhanced by its effectiveness at maintaining healthy blood pressure thus improving the flow of oxygenated blood to sexual organs, improving function.

Elderly diabetic patients are proven to low level of testosterone and impaired NO production due to Diabetic mellitus and its co-morbidity conditions like depression, obesity, CVD. Thus, this patent may need therapy which should works in two modes instead of either mode of NO production and testosterone secretion.

Thus, the present invention provides alternative approach and suitable solution to elderly diabetic patient with Erectile Dysfunction.

In an embodiment, the pharmaceutical composition of L Arginine and Fenugreek extract is provided as solid oral dosage form which include but not limited to tablets, capsule, granules, sachets, powder, suspension, etc.

In yet another embodiment the present invention relates to a process for preparation of the pharmaceutical composition comprising;
1. Preparation of L Arginine granules;
2. Preparation of Fenugreek extract granules; and
3. Mixing the L-Arginine granules and Fenugreek extract granules in a blender for suitable time;
4. Optionally compressing the mix to tablets and coating the tablets.

In a further embodiment the present invention is used for Erectile Dysfunction in elderly diabetic patients.
In another embodiment the present invention provides a method of treating Erectile Dysfunction in elderly diabetic patients comprising administering therapeutically effective amount of the pharmaceutical composition to the subject in need thereof.

Examples:
The following examples are set forth below to illustrate the compositions and methods according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative compositions and methods. These examples are not intended to exclude equivalents and variations of the present invention, which are apparent to one skilled in the art.
Example 1: L Arginine and Fenugreek extract tablet:
S. No. Ingredients Qty/Tab (mg)
1 L-Arginine 800.00
2 Microcrystalline Cellulose PH 112 14.00
3 Hydrogenated Castor Oil 10.00
4 Colloidal Silicon dioxide 16.00
5 Magnesium Stearate 16.00
6 Fenugreek Seed Extract 200.00
7 Microcrystalline Cellulose 49.50
8 Croscarmellose sodium 10.00
9 Povidone 4.50
10 Hypromellose 15 cps 28.000
12 Ethyl cellulose 24.000
13 Titanium Dioxide 10.000
14 Talc 6.320
15 Ferric oxide red 0.480
16 Propylene Glycol 9.200
17 Ethyl vanillin 2.000
18 Dichloromethane qs
19 Isopropyl alcohol qs

Procedure:
a) Preparation of L- Arginine granules:
1. Mill the L Arginine with suitable screen size and transfer to blender
2. Microcrystalline cellulose is added to above step and blended for suitable time.
3. Colloidal silicon dioxide and Hydrogenated Caster oil added to above step blended for suitable time
4. Magnesium stearate is added to above step and blended for suitable time.

b) Preparation of Fenugreek extract granules:
1. Binder solution is prepared using povidone and isopropyl alcohol
2. Fenugreek extract, microcrystalline cellulose and croscarmellose is added to granulator and binder added to the above dry mix. Once desired granules is formed, dried to achieve suitable granules.
C) Final granules: L Arginine granules and Fenugreek granules are mixed in blender for suitable time
d) Compression: Above granules are compressed using suitable machine by keeping all tableting parameter satisfactory.
e) Coating: Compressed tablets are coated using coating solution.

Example 2: L Arginine and Fenugreek extract sachet
S. No. Ingredients Qty/sachet (mg)
1 L-Arginine 2500
2 Microcrystalline Cellulose PH 112 42.00
3 Hydrogenated Castor Oil 30.00
4 Colloidal Silicon dioxide 82.00
5 Magnesium Stearate 28.00
6 Fenugreek Seed Extract 500.00
7 Microcrystalline Cellulose 262.5
8 Croscarmellose sodium 30.00
9 Povidone 13.50
10 Ethyl vanillin 12.000
11 Isopropyl alcohol qs
12 Purified water qs

Procedure:

a) Preparation of L Arginine granules:
1. Mill the L Arginine with suitable screen size and transfer to blender
2. Microcrystalline cellulose is added to above step and blended for suitable time.
3. Colloidal silicon dioxide and Hydrogenated Caster oil added to above step blended for suitable time
4. Magnesium stearate is added to above step and blended for suitable time.

b) Preparation of Fenugreek extract granules:
1. Binder solution is prepared using povidone and isopropyl alcohol
2. Fenugreek extract, microcrystalline cellulose and croscarmellose is added to granulator and binder added to the above dry mix. Once desired granules is formed, dried to achieve suitable granules
C) Final granules: L Arginine granules and Fenugreek granules are mixed in blender for suitable time along with ethyl vanillin.
,CLAIMS:1. A pharmaceutical composition comprising L-Arginine in the concentration
ranging from 10% to 80% w/w and Fenugreek seed extract in the concentration ranging from about 5% to 50% w/w along with pharmaceutically acceptable excipients.

2. The pharmaceutical composition as claimed in claim 1, wherein, the composition comprises
a) L- Arginine in an amount ranging from 300 mg to 3000 mg
b) Fenugreek extract in an amount ranging from 60 mg to 600 mg.

3. The pharmaceutical composition as claimed in claim 1, wherein, the composition is provided in the form of powders, pellets, granules, tablets, coated tablets, capsules and sachets.

4. The pharmaceutical composition as claimed in claim 1, wherein, Fenugreek extract further comprises an active ingredient selected from the group of steroidal saponin.

5. The pharmaceutical composition as claimed in claim 4, wherein the steroidal saponin is Protodioscin.

6. The pharmaceutical composition as claimed in claim 1, wherein the pharmaceutically acceptable excipients are selected from diluent, binder, flavouring agents glidant, lubricant, film former, plasticizer, opacifier, colourants or mixtures thereof.

7. The pharmaceutical composition as claimed in claim 1, wherein the diluent is selected from Microcrystalline cellulose. Lactose, starch, Dicalcium phosphate, Mannitol and mixtures thereof.

8. The pharmaceutical composition as claimed in claim 1, wherein the binders are selected from the group consisting of Povidone, sucrose, gelatin, Hydroxy propyl methyl cellulose (HPMC), HPC, Starch or mixtures thereof.

9. The pharmaceutical composition as claimed in claim 1, wherein the flavouring agent is Ethyl Vanillin.

10. The pharmaceutical composition as claimed in claim 1, wherein the film former is selected from Ethyl cellulose, Polyvinyl alcohol (PVA) or mixtures thereof.

11. The pharmaceutical composition as claimed in claim 1, wherein the coating system for coating the tablets is hydroalcoholic based or powder based.
12. A process for preparation of pharmaceutical composition comprising L-Arginine in the concentration ranging from 10% to 80% w/w and Fenugreek seed extract in the concentration ranging from about 5% to 50% w/w along with pharmaceutically acceptable excipients for Erectile Dysfunction in elderly diabetic patients comprising the following steps:
a) preparing Arginine granules by direct compression or wet granulation method.
b) preparing Fenugreek granules by direct compression or wet granulation
method.
c) Mixing the granules prepared I step a) and step b).
d) Filling the granule blend of step c) into a capsule or a sachet

13. A process for preparation of pharmaceutical composition comprising L-Arginine in the concentration ranging from 10% to 80% w/w and Fenugreek seed extract in the concentration ranging from about 5% to 50% w/w along with pharmaceutically acceptable excipients for Erectile Dysfunction in elderly diabetic patients comprising the following steps:
a) preparing Arginine granules by direct compression or wet granulation method
b) preparing Fenugreek granules by direct compression or wet granulation method
c) blending granules of step a) and step b) & compressing into tablets
d) Coating the compressed tablets of step c) by coating solution.
14. Use of the pharmaceutical composition as claimed in any of the preceding claims comprising L-Arginine and Fenugreek seed extract along with pharmaceutically acceptable excipients for Erectile Dysfunction in elderly diabetic patients.

15. The method of treating Erectile Dysfunction in elderly diabetic patients comprising administering to the subject in need thereof therapeutically effective amount of the pharmaceutical composition as claimed in any one of the claims 1 to 14.