surprisingly , the topical administration of a formulation comprising an effective amount of hyaluronic acid , or a pharmaceutically acceptable salt thereof , and polyvinylpyrrolidone provides an effective therapeutical or preventive treatment for mucositis and stomatitis of various origin and severity and , more generally , of the lesions of the oro - pharynx cavity and oesophagus , particularly those caused by dental devices and by radio - or chemotherapy and by surgery . without being bound by a particular mode of action , the favorable therapeutic results obtained by the use of the compositions of the present invention are believed to be due to both the interactions between hyaluronic acid , or a pharmaceutically acceptable salt thereof , and polyvinylpyrrolidone , and the capability of the formulation of adhering to the oral mucosa providing a protective coating for the exposed nerve endings , and thus , reduction of pain and promoting cicatrisation and healing of the lesions . furthermore , it is believed that the moisturizing effect of the compositions has beneficial effect as it protects mucous membranes from further irritating lesions . in one embodiment , the present invention involves a composition comprising from about 0 . 01 to about 5 percent by weight of hyaluronic acid , or a pharmaceutically acceptable salt thereof , having a molecular weight from about 1 . 6 to about 2 . 2 million daltons ; from about 0 . 04 to about 15 % by weight of a k60 to k100 polyvinylpyrrolidone ; and from about 86 to about 98 % water . in one embodiment , the viscosity of the composition is from about 50 to about 500 centipoise . in an alternative embodiment , the present invention involves a composition comprising from about 0 . 04 to about 5 percent by weight of hyaluronic acid , or a pharmaceutically acceptable salt thereof , having a molecular weight from about 1 . 6 to about 2 . 2 million daltons ; from about 0 . 08 to about 15 % by weight of a k60 to k100 polyvinylpyrrolidone ; and from about 86 to about 98 % water . in one embodiment , the viscosity of the composition is from about 50 to about 500 centipoise . the compositions of the present invention can be diluted with water , and accordingly , is useful for obtaining the above compositions . in an alternative embodiment , the composition can be diluted with physiological saline . these compositions can be used by themselves or in admixture with one or more medicaments , excipients and / or adjuvants , preferably forming a viscous and lubricating substance that remains adherent to the surface epithelium . these compositions are suitable for topical administration to epithelial surfaces such as , but not limited to , the oropharynx and oesophagus . a further aspect of the invention concerns the use of hyaluronic acid , or a pharmaceutically acceptable salt thereof , glycyrrhetinic acid , or a pharmaceutically acceptable salt thereof , and polyvinylpyrrolidone for treating or preventing inflammation in a patient . in one embodiment , the inflammation is of epithelial surfaces such as , but not limited to , the oral mucosa , particularly mucositis and stomatitis . preferably , the compositions of the present invention are administered by topical application . in a particular embodiment in which the composition is administered to the oral cavity , the patient , after gargling with the composition , and if desired , may refrain from eating or drinking for a certain time , ranging from minutes up to hours after gargling . alternatively , the patient , if desired , may eat or drink immediately after gargling . the compositions of the invention are preferably in the form of a slightly viscous aqueous liquid ( gel ) which provides a film - forming and coating effect on the epithelial surfaces such as , but not limited to the oral mucosa . as explained above , the present invention relates to a composition comprising from about 0 . 01 to about 5 percent by weight of hyaluronic acid , or a pharmaceutically acceptable salt thereof , having a molecular weight from about 1 . 6 and 2 . 2 million daltons ; from about 0 . 04 to about 15 % by weight of a k60 to k100 polyvinylpyrrolidone ; and from about 86 to about 98 % water . in one embodiment , the viscosity of the composition is from about 50 to about 500 centipoise . in an embodiment , the polyvinylpyrrolidone is from about k85 and k95 and is from about 3 and 10 % by weight of the composition . most preferably , the polyvinylpyrrolidone is from about 7 to about 10 % by weight of the composition . preferably , the hyaluronic acid , or the pharmaceutically acceptable salt thereof , is from about 1 . 8 to about 2 . 0 million daltons and from about 0 . 01 to about 2 % by weight . in one embodiment , the viscosity of the composition is from about 90 to about 1000 centipoise . preferably , the composition is in the form of a gel . most preferably , the hyaluronic acid , or the pharmaceutically acceptable salt thereof , is from about 1 . 8 to about 2 . 0 million daltons and from about 0 . 01 to about 2 % by weight of the composition , the viscosity of the composition is from about 90 to about 1000 centipoise and the composition is in the form of a gel . further , glycyrrhetinic acid , or a pharmaceutically acceptable salt thereof , can be present in weight percentages ranging from about 0 . 01 to about 3 % by weight of the composition . the viscosity of the compositions can be measured using routine methods . in particular , viscosity can be measured using a brookfield model dv1 + viscometer ( middleboro , mass .) at room temperature , preferably at about 22 °- 25 ° c ., or using a haake model vt02 viscometer ( karlsruhe , germany ) at room temperature , preferably at about 22 °- 25 ° c . in a particular embodiment of the present invention , the compositions are provided in a concentrated form for later dilution with water . the compositions comprise from about 0 . 04 to about 5 percent by weight of hyaluronic acid , or a pharmaceutically acceptable salt thereof , having a molecular weight from about 1 . 6 to about 2 . 2 million daltons ; from about 0 . 08 to about 15 % by weight of a k60 to k100 polyvinylpyrrolidone ; and from about 86 to about 98 % water . in one embodiment , the viscosity of the composition is from about 50 to about 500 centipoise . these compositions preferably comprise polyvinylpyrrolidone from about k85 to about k95 and from about 6 to about 12 % by weight of the composition , most preferably from about 8 to about 10 % by weight of the composition ; and comprise hyaluronic acid , or a pharmaceutically acceptable salt thereof , having a molecular weight from about 1 . 8 to about 2 . 0 million daltons and from about 0 . 04 to about 2 % by weight of the composition . preferably , hyaluronic acid , or the pharmaceutically acceptable salt thereof , is from about 1 . 8 to about 2 . 0 million daltons in molecular weight and from about 0 . 04 to about 2 % by weight of the composition . examples of pharmaceutically acceptable salts include , but are not limited to , sulfate , citrate , acetate , oxalate , chloride , bromide , iodide , nitrate , bisulfate , phosphate , acid phosphate , isonicotinate , lactate , salicylate , acid citrate , tartrate , oleate , tannate , pantothenate , bitartrate , ascorbate , succinate , maleate , gentisinate , fumarate , gluconate , glucaronate , saccharate , formate , benzoate , glutamate , methanesulfonate , ethanesulfonate , benzenesulfonate , p - toluenesulfonate , and pamoate ( i . e ., 1 , 1 ′- methylene - bis -( 2 - hydroxy - 3 - naphthoate )) salts . the term “ pharmaceutically acceptable salt ” also refers to a salt prepared from a compound having an acidic functional group , such as a carboxylic acid or sulfonic acid functional group , and a pharmaceutically acceptable inorganic or organic base . suitable bases include , but are not limited to , hydroxides of alkali metals such as sodium , potassium , and lithium ; hydroxides of alkaline earth metal such as calcium and magnesium ; hydroxides of other metals , such as aluminum and zinc ; ammonia , and organic amines , such as unsubstituted or hydroxy - substituted mono -, di -, or trialkylamines ; dicyclohexylamine ; tributyl amine ; pyridine ; n - methyl , n - ethylamine ; diethylamine ; triethylamine ; mono -, bis -, or tris -( 2 - hydroxy - lower alkyl amines ), such as mono -, bis -, or tris -( 2 - hydroxyethyl ) amine , 2 - hydroxy - tert - butyl amine , or tris -( hydroxymethyl ) methylamine , n , n ,- di - lower alkyl - n -( hydroxy lower alkyl )- amines , such as n , n ,- dimethyl - n -( 2 - hydroxyethyl ) amine , or tri -( 2 - hydroxyethyl ) amine ; n - methyl - d - glucamine ; and amino acids such as arginine , lysine , and the like . the compositions of the present inventions can comprise a pharmaceutically acceptable excipient , preferably for topical administration , such as one or more of the following : examples of said excipients comprise cellulose derivatives , acrylic or methacrylic acids polymers or copolymers , ethylene or propylene glycols , polyethoxylated hydrogenated castor oil , edta , sodium benzoate , sodium or potassium sorbate , dextrins , sodium saccharin , aspartame and other excipients conventionally used in the formulation of collutories or liquid oral forms . oral formulation can include standard carriers such as pharmaceutical grades of mannitol , lactose , starch , magnesium stearate , sodium saccharine , cellulose , magnesium carbonate , etc . additional examples of suitable excipients are described in “ remington &# 39 ; s pharmaceutical sciences ” by e . w . martin . the compositions of the present invention may further comprise one or more other active ingredients , such as an antibacterial , disinfectant , antifungal , analgesic , other anti - inflammatory , emollients , local anaesthetics and the like . suitable antimicrobials include , but are not limited to , quaternary ammonium salts such as benzalkonium chloride . the precise dose to be employed in the composition will depend on the route of administration , and the seriousness of the disease or disorder , and should be decided according to the judgment of the practitioner and each patient &# 39 ; s circumstances . in principle , however , for oral applications , a wash or gargle with 10 - 50 ml of solution , optionally diluted in water , for a time of about up to two or three minutes at least two but preferably three times or more daily , most preferably before meals , will be sufficient to provide an optimal therapeutic or preventive response . the treatment can be protracted until remission of symptoms , usually for at least 2 days , but preferably 5 - 10 days . more prolonged treatments are not contraindicated , considering the low , if any , toxicity of the components of the formulations of the invention . the present invention also provides a pharmaceutical pack or kit comprising one or more containers , e . g . a flexible packet , vial , ampoule , bottle and the like , filled with one or more of the ingredients of the compositions of the invention . optionally associated with such container ( s ) can be a notice in the form prescribed by a governmental agency regulating the manufacture , use or sale of pharmaceuticals or biological products , which notice reflects approval by the agency of manufacture , use or sale for human administration . in a preferred embodiment , the compositions of the present invention can be presented as single - or multi - dose forms in a flexible packet . preferably , the compositions of the present invention are packaged in the concentrated form in flexible packets with a dose of from about 10 to about 30 ml per packet that can be diluted with water to create about 40 - 60 ml of product for use by the patient . the following series of examples are presented by way of illustration and not by way of limitation on the scope of the invention . ingredient % by weight sodium hyaluronate 0 . 1 glycyrrhetinic acid 0 . 06 pvp ( k 60 to k 100 ) 9 . 0 maltodextrin 6 . 00 propylene glycol 2 . 94 potassium sorbate 0 . 3 sodium benzoate 0 . 3 hydroxyethyl cellulose 1 . 5 hydrogenated castor oil peg - 40 0 . 27 disodium edta 0 . 1 benzalkonium chloride 0 . 5 perfume ( glycyrrhiza comp . 2717 ) 0 . 16 sodium saccharin 0 . 1 depurated water 78 . 44 to prepare this composition , water was placed in a turboemulsifier , then a mixture of potassium sorbate , sodium benzoate and disodium edta was added , followed by hyaluronic acid and maltodextrin . the mixture was stirred after each addition until complete dissolution of the components . after that , pvp was slowly added under stirring and vacuum ( 30 mm hg ) until complete solvation . then sodium saccharin and hydroxyethylcellulose were subsequently added , the whole was subjected to vacuum and left under stirring until complete solvation . afterwards , hydrogenated castor oil 40 / oe and perfume , benzalkonium chloride , and a mixture of propylene glycol and glycyrrhetinic acid were added in that order , stirring after each addition until complete dissolution of the components . when the additions were completed , the mixture was stirred under vacuum for 30 minutes . for a concentrated version of the invention , 10 ml or 15 ml of the above composition were distributed in a packet or mono - dose vial , which can be diluted with 30 - 50 ml of water before use ; for the ready - to - use version , the composition disclosed above was diluted with depurated water to a concentration of 50 %, and 200 ml or 300 ml of the resulting composition were distributed in bottles . thirty patients , of age range from 30 to 60 years , were evaluated , 10 of them were aids patients 30 to 40 years of age who were also receiving anti - retroviral therapy . all patients in the study were affected with inflammatory pathologies of the oral cavity of various aetiology : patients were treated with the composition described in example 1 in 15 ml sachets ( packets ) diluted in water in a 1 : 4 ratio . the slightly viscous solution was retained in the mouth for 2 - 3 minutes during which it was gargled and swirled about to obtain homogeneous distribution on the whole surface of the oral mucosa . the solution was then discharged . the patients refrained from eating or drinking for various times after gargling ranging from immediately after gargling to more than 1 hour after gargling . the formulation was used three times a day 60 minutes before meal times for seven consecutive days . at the end of the treatment , the extent of inflammation and lesions , the decrease or disappearance of dysphagia for solid and semi - solid foods , and liquids , and the duration of the activity of the product were evaluated . after the first administration , more than 80 % of patients perceived within a few hours reduction of pain so as to permit food intake . the effect lasted three or four hours . healing of the lesions of the oral mucosa occurred after 3 - 4 days of treatment in about 60 % of treated cases . the percentage reached 90 % at the end of one week of treatment . in the remaining three cases only a pathological condition persisted , but with improved symptoms compared with the beginning of the treatment , providing a remarkable improvement of life quality and restoring a normal , differentiated diet . two patients with throat pain ( sore throat ) were unable to obtain relief with analgesics or other topical agents . patients were treated with the composition described in example 1 in 15 ml packets , the contents of which were diluted in water in a 1 : 4 ratio . the solution was retained in the mouth for about one minute during which time it was gargled to obtain good contact with the tissues of the throat . the solution was then discharged . within ten minutes , the patients experienced dramatic relief of their sore throat symptoms , which relief persisted for several hours . the present invention is not to be limited in scope by the specific embodiments described herein . indeed , various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying figures . such modifications are intended to fall within the scope of the appended claims . various publications are cited herein , the disclosures of which are incorporated by reference in their entireties .
the present invention relates to compounds containing as active ingredients hyaluronic acid and polyvinylpyrrolidone , for the treatment of inflammatory , ulcerative and painful conditions of moist epithelial surfaces such as mucositis , stomatitis , vestibulitis , aphthous ulcerations , and behcet &# 39 ; s syndrome .