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`THIS IS TO CERTIFY THAT ANNEXED HERETO IS A TRUE COPY FROM
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`EREQLSJLMELSJ Sm CL“)va‘E’B
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`UNITED STATES DEPARTMENT OF COMMERCE
`United States Patent and Trademark Office
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`May 09, 2000
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`APPLICATION NUMBER: 60/123,244
`FILING DATE: March 08, 1999
`PCT APPLICATION NUMBER: PCT/US00/05 71 I
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`ARGENTUIVI EX1036
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`This is a request for filing a PROVISIONAL APPLICATION FOR PATENT under 37 CFR 1.53 (0).
`
`Given Name (first and middle [If any])
`Ellzabeth
`Joanne
`
`INVENTOR(S)
`Family Name or Surname
`
`Stoner
`Waldstreicher
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`Scotch Plains, New Jersey
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`CASE NUMBER
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`2°315PV
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`[:1 Additional inventors are being named on the_ separately numbered sheets attached hereto
`TITLE OF THE INVENTION (280 characters max)
`
`
`METHODS AND COMPOSITONS FOR TREATING ERECTILE DYSFUNCTION
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`
`CORRESPONDENCE ADDRESS
`
`
`Merck & 00., Inc.
`Patent Department - RY60-30
`P.O. Box 2000
`Rahway
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`[:l A check or money order is enclosed to cover the filing fees
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`13-2755
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`Respectfully submitted
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`TITLE OF THE INVENTION
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`METHODS AND COMPOSITIONS FOR TREATING ERECTILE
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`DYSFUNCTION
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`FIELD OF THE INVENTION
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`The present invention provides for novel methods for the
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`treatment of erectile dysfunction comprising a drug combination. More
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`particularly, the drug combination of the present invention comprises
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`an agonist of the melanocortin receptor with a cyclic—GMP-specific
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`phosphodiesterase inhibitor or an alpha-adrenergic receptor antagonist.
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`The present invention also provides for pharmaceutical compositions
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`comprising such drug combinations useful in the methods to treat
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`erectile dysfunction. MoreOVer, the present invention provides for a
`method of manufacture of a medicament useful in the treatment of
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`erectile dysfunction.
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`BACKGROUND OF THE INVENTION
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`Erectile dysfunction denotes the medical condition of
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`inability to achieve penile erection sufficient for successful sexual
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`intercourse. The term “impotence” is oftentimes employed to describe
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`this prevalent condition. Approximately 140 million men worldwide,
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`and, according to a National Institutes of Health study, about 30 million
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`American men suffer from impotency or erectile dysfunction. It has
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`been estimated that the latter number could rise to 47 million men by the
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`year 2000. Erectile dysfunction can arise from either organic or
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`psychogenic causes, with about 20% of such cases being purely
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`psychogenic in origin. Erectile dysfunction increases from 40% at age
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`40, to 67% at age 75, with over 75% occurring in men over the age of 50.
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`In spite of the frequent occurrence of this condition, only a small
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`number of patients have received treatment because existing treatment
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`alternatives, such as injection therapies, penile prosthesis implantation,
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`and vacuum pumps, have been uniformly disagreeable [for a discussion,
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`see “ABC of sexual health - erectile dysfunction,” ,B_rit_M§_d_J. 318: 387-
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`390 (1999)]. Only more recently have more viable treatment modalities
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`become available, in particular orally active agents, such as sildenafil
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`citrate, marketed by Pfizer under the brand name of Viagra®. Sildenafil
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`is a selective inhibitor of type V phosphodiesterase (PDE-V), a cyclic-
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`GMP-specific phosphodiesterase isozyme [see RB. Moreland e]:_a_l. ,
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`“Sildenafil: A Novel Inhibitor of Phosphodiesterase Type 5 in Human
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`Corpus Cavernosum Smooth Muscle Cells,” Life Sci, 62: 309-318 (1998)].
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`Prior to the introduction of Viagra on the market, less than 10% of
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`patients suffering from erectile dysfunction received treatment.
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`Sildenafil is also being evaluated in the clinic for the treatment of female
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`sexual dysfunction.
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`The regulatory approval of Viagra® for the oral treatment of
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`erectile dysfunction has invigorated efforts to discover even more
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`effective methods to treat erectile dysfunction. Several additional
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`selective PDE-V inhibitors are in clinical trials. UK—114542 is a sildenafil
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`backup from Pfizer with supposedly improved properties. 10-351 (ICOS
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`Corp.) is claimed to have greater selectivity for PDE-V over PDE-VI than
`sildenafil. Other PDE-V inhibitors include M-54033 and M-54O 18 from
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`Mochida Pharmaceutical Co. and 13-4010 from Eisai Co., Ltd.
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`Other pharmacological approaches to the treatment of
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`erectile dysfunction have been described [see, e.g., “Latest Findings on
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`the Diagnosis and Treatment of Erectile Dysfunction,” Drug News &
`
`Perspectives, 9: 572-5 75 (1996); “Oral Pharmacotherapy in Erectile
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`Dysfunction,” Current Opinion in Urology, 7: 349-353 (1997)]. Aproduct
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`under clinical development by Zonagen is an oral formulation of the
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`alpha-adrenaceptor antagonist phentolamine mesylate under the brand
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`name of Vasomax®. Vasomax® is also being evaluated for the
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`treatment of female sexual dysfunction.
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`Drugs to treat erectile dysfunction act either peripherally or
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`centrally. They are also classified according to whether they “initiate” a
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`sexual response or “facilitate” a sexual response to prior stimulation [for
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`a discussion, see “A Therapeutic Taxonomy of Treatments for Erectile
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`Dysfunction: An Evolutionary Imperative,” Int. J. Im otence Res, 9:
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`115-121 (1997)]. While sildenafil and phentolamine act peripherally and
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`are considered to be “enhancers” or “facilitators” of the sexual response
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`to erotic stimulation, sildenafil appears to be efficacious in both mild
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`organic and psychogenic erectile dysfunction. Sildenafil has an onset of
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`action of 30-60 minutes after an oral dose with the effect lasting about 4
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`hours, whereas phentolamine requires 5-30 minutes for onset with a
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`duration of 2 hours. Although sildenafil is effective in a majority of
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`patients, it takes a relatively long time for the compound to show the
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`desired effects. The faster-acting phentolamine appears to be less
`effective and to have a shorter duration of action than sildenafil. Oral
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`sildenafil is effective in about 70% of men who take it, whereas an
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`adequate response with phentolamine is observed in only 35-40% of
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`patients. Both compounds require erotic stimulation for efficacy. Since
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`sildenafil indirectly increases blood flow in the systemic circulation by
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`enhancing the smooth muscle relaxation effects of nitric oxide, it is
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`contraindicated for patients with unstable heart conditions or
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`cardiovascular disease, in particular patients taking nitrates, such as
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`nitroglycerin, to treat angina. Other adverse effects associated with the
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`clinical use of sildenafil include headache, flushing, dyspepsia, and
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`“abnormal vision,” the latter the result of inhibition of the type VI
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`phosphodiesterase isozyme (PDE—Vl), a cyclic—GMP-specific
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`phosphodiesterase that is concentrated in the retina. “Abnormal vision”
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`is defined as a mild and transient “bluish” tinge to vision, but also an
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`increased sensitivity to light or blurred vision. Moreover, since some
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`patients have developed a tolerance to prior phosphodiesterase
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`inhibitors, sildenafil may prove to have a similar outcome in some
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`percentage of patients when used over a long period of time.
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`Synthetic melanocortin receptor agonists (melanotropic
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`peptides) have been found to initiate erections in men with psychogenic
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`erectile dysfunction [See H. Wessells rial, “Synthetic Melanotropic
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`Peptide Initiates Erections in Men With Psychogenic Erectile
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`Dysfunction: Double-Blind, Placebo Controlled Crossover Study,” L
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`£191., 160: 389-393 (1998); Fifteenth American Peptide Symposium, June
`
`1449, 1997 (Nashville TN)1 Activation of melanocortin receptors of the
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`brain appears to cause normal stimulation of sexual arousal. In the
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`above study, the centrally acting a—melanocyte—stimulating hormone
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`analog, melanotan—II (MT-II), exhibited a 75% response rate, similar to
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`results obtained with apomorphine, when injected intramuscularly or
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`subcutaneously to males with psychogenic erectile dysfunction. MT-II
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`is a synthetic cyclic heptapeptide, Ac-Nle-c[Asp-His-DPhe-Arg—Trp-Lys]-
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`NH2, which contains the 4—10 melanocortin receptor binding region
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`common to oz-MSH and adrenocorticotropin, but with a lactam bridge.
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`5 MT-II (also referred to as PT-14) (Erectide®) is presently in clinical
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`development by Palatin Technologies, Inc. and TheraTech, Inc. as a
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`non-penile subcutaneous injection formulation. An oral transmucosal
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`delivery system for the drug is also being developed. It is considered to
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`be an “initiator” of the sexual response. The time to onset of erection
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`10 with this drug is relatively short (10-20 minutes) with a duration of
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`action approximately 2.5 hours. Adverse reactions observed with MT-II
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`include nausea, flushing, loss of appetite, stretching, and yawning.
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`Adverse effects associated with MT-Il may be the result of
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`the lack of selectivity of the compound for a particular melanocortin
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`15
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`receptor subtype. To date, five melanocortin receptor subtypes have been
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`cloned. Evidence has been presented suggesting that the erectogenic
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`properties of melanocortin agonists are mediated via binding to the MC-
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`4R subtype. Whereas MC-3R is expressed in the brain, gut, and
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`placenta, the MC—4R subtype is uniquely expressed in the brain, and
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`20
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`inactivation has been found to cause obesity.
`Because of the unresolved deficiencies of the various
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`pharmacological agents discussed above, there is a continuing need in
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`the medical arts for improved methods and compositions to treat
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`individuals suffering from psychogenic and/or organic erectile
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`25
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`dysfunction. Such methods should have wider applicability, enhanced
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`convenience and ease of compliance, short onset of action, reasonably
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`0
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`long duration of action, and minimal side effects with few
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`contraindications, as compared to agents now available.
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`It is therefore an object of the present invention to provide
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`30 methods of treating erectile dysfunction which comprise the
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`administration to a human subject in need thereof a centrally—acting
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`agent that ‘initiates” an erectogenic response in combination with
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`another centrally~acting agent or a peripherally-acting agent that
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`“facilitates” or “enhances” the response to erotic stimulation. The
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`human subject may be either male or female.
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`-4—
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`It is another object of the present invention to provide
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`pharmaceutical compositions comprising the combination that are
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`useful in the methods of the present invention.
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`It is still a further object of the present invention to provide a
`method of manufacture of a medicament useful in the treatment of
`
`erectile dysfunction.
`
`SUMMARY OF THE INVENTION
`
`10
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`15
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`The present invention provides for methods of treating
`
`erectile dysfunction in a human subject in need of such treatment
`
`comprising administration of a therapeutically effective amount of an
`
`agonist of the melanocortin receptor in combination with a
`
`therapeutically effective amount of a cyclic-GMP-specific
`
`phosphodiesterase inhibitor or an alpha-adrenergic receptor antagonist.
`
`Further, the present invention provides for pharmaceutical
`
`compositions useful in the methods of the present invention, as well as a
`method of manufacture of a medicament useful to treat erectile
`
`dysfunction.
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`DETAILED DESCRIPTION OF THE INVENTION
`
`The present invention is concerned with the combination of
`
`an agonist of the melanocortin receptor with a cyclic-GMP—specific
`phosphodiesterase inhibitor or an alpha-adrenergic receptor antagonist
`
`for the treatment of erectile dysfimction in a male or female human
`
`subject. This particular combination produces unexpectedly superior
`
`pharmacokinetic and pharmacodynamic results in the treatment of
`
`male or female erectile dysfunction. Thus, it is an object of the instant
`
`invention to describe the combination of the two drugs in the treatment of
`
`erectile dysfunction. In addition, it is an object of the instant invention to
`
`describe preferred embodiments within each category of compounds
`which are used as elements in the instant combination. It is a further
`
`object of this invention to describe compositions containing each of the
`
`compounds for use in the treatment of erectile dysfunction. It is a still
`
`further object of this invention to describe a method of manufacture of a
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`medicament containing the present drug combination which is useful
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`for the treatment of erectile dysfunction. Further objects will become
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`apparent from a reading of the following description.
`
`The instant combination for the treatment of erectile
`
`dysfimction contains as a first element an agonist of the melanocortin
`
`receptor. Representative agonists of the melanocortin receptor are
`
`disclosed in the following publications, which are incorporated by
`
`reference herein in their entirety:
`
`(1) M. E. Hadley gig” “Discovery and Development of Novel
`
`Melanogenic Drugs,” in Integration of Pharmaceutical Discoveg and
`
`Development: Case Studie , edited by Borchardt et al., Plenum Press,
`
`New York, 1998;
`
`(2) RT. Dorr, _et_al_., “Evaluation of Melanotan—II, A Superpotent Cyclic
`
`Melanotropic Peptide in a Pilot Phase-I Clinical Study,” Life Sci, 58:
`
`1777-1784 (1996); and
`
`(3) R.A.H. Adan, “Identification of Antagonists for Melanocortin M03,
`
`M04, and MC5 Receptors,” European J. Pharmacol., 269: 331-337 (1994).
`
`Compositions and methods for the treatment of psychogenic
`
`erectile dysfunction comprising melanotropic peptides are disclosed in
`
`US. Patent No. 5,576,290 and CA 2,158,425, which are incorporated by
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`reference herein in their entirety.
`
`In the instant combination for the treatment of erectile
`
`dysfunction, the first element of the combination is an agonist of the
`
`melanocortin receptor. In one embodiment of the combination of the
`
`present invention, the agonist of the melanocortin receptor is
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`melanotan-Il (MT—II).
`
`In another embodiment of the combination of the present
`
`invention, the agonist of the melanocortin receptor is selective for the
`
`MC-4R subtype. Selective MC-4R agonists have been described, and
`
`reference is made to the following disclosures, which are incorporated
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`30
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`by reference herein in their entirety:
`
`(1) C. Haskell-Luevano, et al., “Discovery of Prototype Peptidomimetic
`
`Agonists at the Human Melanocortin Receptors MClR and MC4R,”
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`J .Med. Chem., 40: 2133-2139 (1997); and
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`(2) H.B. Schioth, et 31., “Discovery of Novel Melanocortin—4 Receptor
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`35v
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`Selective MSH Analogues,” Brit. J. Pharmacol., 124: 75-82 (1998).
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`e
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`In the instant combination for the treatment of erectile
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`dysfunction, the second element of the combination is composed of either
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`a cyclic-GMP—specific phosphodiesterase inhibitor or an alpha-
`
`adrenergic receptor antagonist.
`
`In a further embodiment of the
`
`combination of the present invention, the second element of the
`
`combination is a cyclic—GMP-specific phosphodiesterase inhibitor
`
`selective for the type V phosphodiesterase isozyme (PDE-V).
`
`Representative PDE—V inhibitors are disclosed in the patent and
`
`scientific literature. The Pfizer pyrazolo[4,3-d]pyrimidin—7-one PDE-V
`
`inhibitors are disclosed in WO 94/28902; W0 96/16644; WO 96/16657; EP
`
`0,702,555; EP 0,463,?56; CA 2,163,446; and US. Patent No. 5,250,534; all of
`
`which are incorporated by reference herein in their entirety. Sildenafil
`
`is the generic name for 1—[4—ethoxy-(6,7-dihydro-1-methy1-7—oxo-3-propy1—
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`1H—pyrazolo[4,8-d]pyrimidin-5—yl)phenylsulfonyl]—4-methyl-piperazine.
`
`For a discussion of its efficacy in the treatment of male erectile
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`dysfunction, reference is made to I. Goldstein $11., N. Engl. J. Med,
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`338: 1397—1404 (1998) and M. Boolell gt_a_l_., “Sildenafil: an orally active type
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`5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of
`
`penile erectile dysfunction,” Int. J. Impotence Res, 8: 47-52 (1996).
`
`The 1008 Corp. tetracyclic PDE—V inhibitors are disclosed
`
`in WO 95/19978; WO 97/03675; and W0 97/1997 8; all of which are
`
`incorporated by reference herein in their entirety.
`
`IC—351 represents
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`(6R, 12aR)-2,3,6,7,12,12a-hexahydro-2—methyl—6—(3,4-
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`methylenedioxyphenyl)-pyrazino[2’,1’: 6,1]pyrido[3,4-b]indole-1,4-dione
`
`and is disclosed in WC 97/03675 for the treatment of impotence.
`
`The Mochida Pharmaceutical Co. pyridocarbazole series of
`
`PDE—V inhibitors, of which M-54018 and M—54033 are members, is
`
`disclosed in WO 97/45427, Which is incorporated by reference herein in
`
`its entirety. Other structural classes of PDE-V inhibitors are disclosed
`
`in WO 98/16224 (E. Merck GmbH), WO 99/02161 (Forssmann), WO
`
`98/07430 (Eisai), and JP 8225541 (Eisai), all of which are incorporated by
`
`reference herein in their entirety.
`
`In a class of this embodiment of the present invention, the
`
`combination for the treatment of erectile dysfunction comprises an
`
`agonist of the melanocortin receptor and a PDE-V inhibitor selected from
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`the group consisting of sildenafil citrate, IC-351, M—54018, and M-54033.
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`In a subclass of this class of the present invention, the agonist of the
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`melanocortin receptor is MT-II. In another subclass of this class of the
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`present invention, the combination of the present invention comprises a
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`selective agonist of the melanocortin-4 receptor and a PDE-V inhibitor
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`selected from the group consisting of sildenafil citrate, IC-351, M-54018,
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`and M—54033. An especially preferred combination is a selective agonist
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`of the melanocortin-4 receptor (MC—4R) and sildenafil citrate.
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`10
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`invention, the second element of the combination is an alpha-adrenergic
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`In another embodiment of the combination of the present
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`15
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`“i
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`receptor antagonist. In a class of this embodiment of the present
`
`invention, the alpha-adrenergic receptor antagonist is selective for the
`
`alpha—2 receptor subtype. In a subclass of this class of the present
`
`invention, the alpha—2 receptor antagonist is yohimbine or delquamine.
`
`The efficacy of yohimbine in the treatment of psychogenic erectile
`
`dysfunction is reported in Lancet, pp. 42-43 (1987). Delquamine is an
`
`alpha adrenoreceptor antagonist, with a greater affinity for the alpha-2
`receptor subtype [see A. Morales gal, “Oral and topical treatment of
`
`erectile dysfunction,” Urol. Clin. North Am., 22: 879-885 (1995)].
`
`In another subclass of this class of the present invention,
`
`the alpha—2 receptor antagonist is an arquuinolizine derivative disclosed
`
`in US. Patent Nos. 4,824,849 and 4,710,504, both of which are
`
`incorporated by reference herein in their entirety. In a subclass of this
`
`subclass of the present invention, the alpha-2 receptor antagonist is the
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`25
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`30
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`benzofuroquinolizine analog, MK—912, disclosed in US. Patent No.
`
`4,824,849. MK—912 represents 1’,3’-dimethylspiro(1,3,4,5’,6,6’,7,12b-
`
`octahydro-ZH-benzo[b]-furo[2,8-a]quinolizine)-2,4’—pyrimidin-2’~one and
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`is a potent, orally active agent with a pharmacologic profile consistent
`
`With alpha-2 antagonism [see D.J. Pettibone, 913A” “Pharmacological
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`profile of a new potent and specific alphaZ-adrenoceptor antagonist, L—
`
`657,743,” Naunyn—Schmiederberg’s Arch. Pharmacol., 336: 169—175
`
`(1987)]. The effect of the drug on penile erections in healthy male
`
`volunteers was observed by B.J. Gertz M. and reported in Qlin‘
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`Pharmacol. Then, 46: 566-575 (1989). An especially preferred
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`Page 10
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`Page 10
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`.,
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`combination is a selective agonist of the melanocortin-4 receptor (MC-4R)
`and MK—912.
`
`The instant combination of an agonist of the melanocortin
`
`receptor and a cyclic-GMP-specific phosphodiesterase inhibitor or an
`
`alpha-adrenergic receptor antagonist is useful in the therapeutic
`
`treatment of erectile dysfunction. Although the methods and
`compositions comprising drug combinations of the present invention are
`
`envisaged primarily for the treatment of male erectile dysfunction, they
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`may also be useful for the treatment of female sexual dysfunction,
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`including orgasmic dysfunction related to clitoral disturbances.
`
`The combination of an agonist of the melanocortin receptor
`
`and a cyclic-GMvapecific phosphodiesterase inhibitor or an alpha—
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`adrenergic receptor antagonist provides an unexpectedly superior effect
`
`in the treatment of erectile dysfunction. The combination provides for
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`effective treatment of either psychogenic or organic erectile dysfunction
`
`in a greater percentage of the affected population than either element of
`
`the combination separately. The combination provides for a shorter
`
`onset of action and longer duration of action than either element of the
`
`combination separately. The combination also has fewer side effects and
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`contraindications than either member of the combination separately.
`
`For use in medicine, the salts of the compounds of this
`
`invention refer to non-toxic "pharmaceutically acceptable salts." Other
`
`salts may, however, be useful in the preparation of the compounds
`
`according to the invention or of their pharmaceutically acceptable salts.
`
`Salts encompassed within the term "pharmaceutically acceptable salts"
`
`refer to non-toxic salts of the compounds of this invention which are
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`generally prepared by reacting the free base with a suitable organic or
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`inorganic acid. Representative salts include the following:
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`Acetate, Benzenesulfonate, Benzoate, Bicarbonate,
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`Bisulfate, Bitartrate, Borate, Bromide, Camsylate, Carbonate, Chloride,
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`Clavulanate, Citrate, Dihydrochloride, Edetate, Edisylate, Estolate,
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`Esylate, Fumarate, Gluceptate, Gluconate, Glutamate,
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`Glycollylarsanilate, Hexylresorcinate, Hydrabamine, Hydrobromide,
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`Hydrochloride, Hydroxynaphthoate, Iodide, Isothionate, Lactate,
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`Lactobionate, Laurate, Malate, Maleate, Mandelate, Mesylate,
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`10
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`15
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`20
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`25
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`3O
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`-9.
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`Methylbromide, Methylnitrate, Methylsulfate, Mucate, Napsylate,
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`Nitrate, N—methylglucamine ammonium salt, Oleate, Oxalate, Pamoate
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`(Embonate), Palmitate, Pantothenate, Phosphate/diphosphate,
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`Polygalacturonate, Salicylate, Stearate, Sulfate, Subacetate, Succinate,
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`Tannate, Tartrate, Teoclate, Tosylate, Triethiodide and Valerate.
`
`Furthermore, where the compounds of the inVention carry an acidic
`
`moiety, suitable pharmaceutically acceptable salts thereof may include
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`alkali metal salts, e.g., sodium or potassium salts; alkaline earth metal
`
`salts, e.g., calcium or magnesium salts; and salts formed with suitable
`
`10
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`organic ligands, e.g., quaternary ammonium salts.
`
` 15
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`iiniu
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`
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`.limii
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`2O
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`The compounds of the present invention may have chiral
`
`centers and occur as racemates, racemic mixtures and as individual
`
`diastereomers, or enantiomers with all isomeric forms being included
`
`in the present invention. Therefore, where a compound is chiral, the
`
`separate enantiomers, substantially free of the other, are included
`
`within the scope of the invention; further included are all mixtures of
`
`the two enantiomers. Also included within the scope of the invention are
`
`polymorphs and hydrates of the compounds of the instant invention.
`
`The present invention includes Within its scope prodrugs of
`the compounds of this invention.
`In general, such prodrugs will be
`
`functional derivatives of the compounds of this invention which are
`
`readily convertible in _vi_vg into the required compound. Thus, in the
`
`methods of treatment of the present invention, the term "administering"
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`25
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`30
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`shall encompass the treatment of erectile dysfunction with the
`
`compound specifically disclosed as an element of the combination or
`
`with a compound which may not be specifically disclosed, but which
`
`converts to the specified compound in M after administration to the
`
`patient. Conventional procedures for the selection and preparation of
`
`suitable prodrug derivatives are described, for example, in "Design of
`
`Prodrugs," ed. H. Bundgaard, Elsevier, 1985. Metabolites of these
`
`compounds include active species produced upon introduction of
`
`compounds of this invention into the biological milieu.
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`The term "therapeutically efiective amount" shall mean
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`that amount of a drug or pharmaceutical agent that will elicit the
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`biological or medical response of a tissue, system, animal or human that
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`is being sought by a researcher or clinician.
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`As used herein, the term "composition" is intended to
`
`encompass a product comprising the specified ingredients in the
`
`specified amounts, as well as any product which results, directly or
`
`indirectly, from combination of the specified ingredients in the specified
`amounts.
`
`In the combination of the present invention, the agonist of
`
`the melanocortin receptor may be administered separately or in
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`10
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`conjunction with the cyclic-GMP-specific phosphodiesterase inhibitor or
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`15
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`20
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`25
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`30
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`the alpha—adrenergic receptor antagonist. In addition, the
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`administration of one element of the combination of the present
`
`invention may be prior to, concurrent to, or subsequent to the
`administration of the other element of the combination.
`
`The elements of the combination of the present invention
`
`may be administered by oral, parenteral (e.g., intramuscular,
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`intraperitoneal, intravenous or subcutaneous injection, or implant),
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`buccal, nasal, vaginal, rectal, sublingual, or topical (e.g., ocular
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`eyedrop) routes of administration and may be formulated, alone or
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`together, in suitable dosage unit formulations containing conventional
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`non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles
`appropriate for each route of administration.
`v
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`The pharmaceutical compositions for the administration of
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`the compounds of this invention may conveniently be presented in
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`dosage unit form and may be prepared by any of the methods well known
`
`in the art of pharmacy. All methods include the step of bringing the
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`active ingredient into association With the carrier which constitutes one
`
`or more accessory ingredients.
`
`In general, the pharmaceutical
`
`compositions are prepared by uniformly and intimately bringing the
`
`active ingredient into association with a liquid carrier or a finely divided
`
`solid carrier or both, and then, if necessary, shaping the product into the
`
`desired formulation.
`
`In the pharmaceutical composition the active
`
`object compound is included in the combination in an amount sufficient
`
`to produce the desired pharmacologic effect upon the process or
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`35
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`condition of erectile dysfunction.
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`The pharmaceutical compositions containing the active
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`ingredient suitable for oral administration may be in the form of discrete
`
`units such as hard or soft capsules, tablets, troches or lozenges, each
`
`containing a predetermined amount of the active ingredient; in the form
`
`of a dispersible powder or granules; in the form of a solution or a
`suspension in an aqueous liquid or non-aqueous liquid; in the form of
`
`syrups or elixirs; or in the form of an oil—in—Water emulsion or a water-
`
`in-oil emulsion. Compositions intended for oral use may be prepared
`
`according to any method known to the art for the manufacture of
`
`pharmaceutical compositions and such compositions may contain one
`
`or more agents selected from the group consisting of sweetening agents,
`
`flavoring agents, coloring agents and preserving agents in order to
`
`provide a pharmaceutically elegant and palatable preparation.
`
`Solid dosage forms for oral administration include
`
`capsules, tablets, pills, powders and granules.
`
`In such solid dosage
`
`forms, the active compounds are admixed with at least one inert
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`pharmaceutically acceptable carrier such as sucrose, lactose, or starch.
`
`Such dosage forms can also comprise, as is normal practice, additional
`
`substances other than inert diluents, e.g., lubricating agents such as
`
`magnesium stearate. In the case of capsules, tablets and pills, the
`
`dosage forms may also comprise buffering agents.
`
`Tablets containing the active ingredient in admixture with
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`non-toxic pharmaceutically acceptable excipients may also be
`
`manufactured by known methods. The excipients used may be for
`
`example, (1) inert diluents such as calcium carbonate, lactose, calcium
`
`phosphate or sodium phOSphate; (2) granulating and disintegrating
`
`agents, such as corn starch or alginic acid; (3) binding agents such as
`
`starch, gelatin or acacia; and (4) lubricating agents such as magnesium
`
`stearate, stearic acid or talc. The tablets may be uncoated or they may be
`
`coated by known techniques to delay disintegration and absorption in the
`
`gastrointestinal tract and thereby provide a sustained action over a
`
`longer period. For example, a time delay material such as glyceryl
`
`monostearate or glyceryl distearate may be employed, They may also be
`
`coated by the techniques described in the US. Pat. Nos. 4,256,108;
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`4,160,452; and 4,265,874 to form osmotic therapeutic tablets for controlled
`release.
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`In some cases, formulations for oral use may be in the form
`
`of hard gelatin capsules wherein the active ingredient is mixed with an
`
`inert solid diluent, for example calcium carbonate, calcium phosphate
`
`or kaolin. They may also be in the form of soft gelatin capsules wherein
`
`the active ingredient is mixed with water or an oil medium, for example
`
`peanut oil, liquid paraffin, or olive oil.
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`10
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`15
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`Liquid dosage forms for oral administration include
`
`pharmaceutically acceptable emulsions, solutions, suspensions, syrups,
`
`and elixirs containing inert diluents commonly used in the art, such as
`
`water. Besides such inert diluents, compositions can also include
`
`adjuvants, such as wetting agents, emulsifying and suspending agents,
`
`and sweetening, flavoring, and perfuming agents.
`
`Aqueous suspensions normally contain the active materials
`
`in admixture with excipients suitable for the manufacture of aqueous
`
`suspensions. Such excipients may be
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`
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`20
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`25
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`30
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`1)
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`suspending agents such as sodium carboxymethyl-
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`cellulose, methylcellulose, hydroxypropylmethyl-
`
`cellulose, sodium alginate, polyvinyl-pyrrolidone,
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`gum tragacanth and gum acacia;
`
`(2)
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`dispersing or wetting agents which may be
`
`(a)
`
`a naturally—occurring phosphatide such as
`
`lecithin,
`
`(b)
`
`a condensation product of an alkylene oxide
`
`with a fatty acid, for example, polyoxyethylene
`
`stearate,
`
`(c)
`
`a condensation product of ethylene oxide with a
`
`long chain aliphatic alcohol, for example,
`
`heptadecaethyleneoxycetanol,
`
`(d)
`
`a condensation product of ethylene oxide with a
`
`partial ester derived from a fatty acid and a
`
`hexitol such as polyoxyethylene