USE

Abstract: The invention provides an alcoholic solution of a physiologically tolerable salicylic acid derivative and an acemannan for use in topical treatment of herpetic neuralgia. The invention also provides a method of treatment of herpetic neuralgia in a human subject which comprises applying an analgesically effective amount of such a solution to the affected area.

Description: Use This invention relates to the use of topically applied salicylic acid derivative compositions in the treatment of herpes zoster in humans, in particular to the use of such compositions which are in liquid form and which further contain aloe vera or acemannan, an active component thereof . The virus herpes zoster is a latent form of the virus responsible for chicken pox and causes the intractable and painful skin eruptions known as shingles which afflict many millions of the elderly in particular. Such painful occurrences are known as herpetic neuralgia, e.g. acute herpetic neuralgia and postherpetic neuralgia. Aspirin, acetyl salicylic acid (ASA) , is a very well known anti-inflammatory which is normally administered orally in tablet form. While liquid compositions containing ASA, in particular alkanolic solutions of ASA, have been proposed, e.g. for treatment of muscle and joint pain, rheumatism, etc, in recent years liquid ASA formulations have fallen out of favour since ASA is susceptible to hydrolysis producing the irritant salicylic acid. We have now found that topically applied alcoholic solutions of ASA and acemannan are surprisingly effective in combatting herpetic neuralgia, in particular providing a level of pain relief to the patient . Thus viewed from one aspect the invention provides an alcoholic solution of a physiologically tolerable salicylic acid derivative and an acemannan for use in topical treatment of herpetic neuralgia. Viewed from a further aspect the invention provides the use of a physiologically tolerable salicylic acid derivative, an alcohol and an acemannan for the manufacture of a topically applicable medicament for use in the treatment of herpetic neuralgia. Viewed from a still further aspect the invention provides a method of treatment of herpetic neuralgia in a human subject which method comprises applying to an affected area of the skin of said subject an analgesically effective amount of an alcoholic solution of a physiologically tolerable salicylic acid derivative and an acemannan. The salicylic acid derivative used according to the invention may be any physiologically tolerable derivative having analgesic properties. The salicylic acid derivative used in the present invention is preferably ASA, or a physiologically tolerable prodrug (e.g. glycolamide) or salt (e.g. a lysine salt) or ester form thereof or an analog thereof (e.g. a 4 or 5 substituted, for example a 4- and/or 5- nitro and/or methoxy acetyl salicylic acid) . The salicylic acid derivative, if used in salt form, will have as counterion a physiologically tolerable counterion, preferably an amino acid such as lysine. Other tolerable counterions include sodium and meglumine . Suitable prodrug forms of ASA include esters which hydrolyse more rapidly in vivo than the acetyl group, e.g. compounds of formula where R is -CH 2 -N -CH 2 SOCH 3 , -CH 2 S0 2 CH 3 , -CH 2 OOCCH 3 , -C^CONR^ , where R λ is _ 3 alkyl and R 2 is C^ alkyl , 2 -hydroxy-ethyl or -CH 2 CONH 2 , e.g. -CH 2 CON (CH 3 ) 2 , -CH 2 CON (C 2 H 5 ) 2 , -CH 2 CON (iPr) 2 , -CH 2 CON (CH 3 ) CH 2 CH 2 OH and CH 2 CON (CH 3 ) CH 2 CONH 2 . Acetyl salicylic acid is especially preferred. The topically applied compositions of the invention also contain acemannan, e.g. in the form of aloe vera. If aloe vera is used, it is preferably used in a pure gel state, although aloe vera in a slightly impure (e.g. at least 98% wt pure) may also be used. Acemannan as such may be used in place of aloe vera. The compositions of the invention may be in any topically applicable administration form which does not require rubbing of the affected skin, e.g. solutions, emulsions, dispersions, liposomal compositions, sprays, etc. Preferably, the compositions are in the form of solutions or liposome dispersions, particularly solutions . If desired, the compositions may contain transdermal uptake promoters, such as for example dimethylsulphoxide (DMSO) , dimethylformamide, dimethylacetamide, cycloalkanones, etc. (see US-A- 5164416 and EP-A-435436) . The compositions contain an alcohol solvent for the salicylic acid derivative, e.g. a Cχ_ 6 alkanol, preferably a propanol, especially isopropanol. The compositions of the invention preferably also contain a drying agent, e.g. an inorganic salt in anhydrous or partially hydrated form, so as to minimize the water content of the solvent phase . The drying agent is preferably a porous material which take up water into its pores or by surface adsorption. Alternatively, it may adsorb water by reaction or by hydration of an anhydrous or partially hydrated form of a crystalline substance with stable hydrated forms. Thus it may for example be a zeolite, e.g. a zeolite with a pore size of 4A or more, for example up to 10A (or where methanol is used as a solvent, a pore size of 3A) . Preferably a zeolite having a pore size of up to 6A, more preferably up to 5A, e.g. 3 to 4A, will be used. Such zeolites are available commercially, e.g. from Fluka. However calcined silica, alumina or silica-alumina or modified starches (e.g. the hydrolysed starch graft copolymers proposed for use in diapers or used in gardening as water retainers - see also GB-A-2009201 and EP-A-74179) , or anhydrous or partially hydrated salts, such as metal sulphates (e.g. magnesium sulphate or sodium sulphate) may alternatively be used. Water retainers, e.g. modified starches, developed in the 1980s by Henkel for diapers and sanitary pads (see the patent publications of Henkel) , and now used in gardening, are typified by "soil-moist", available from Sinclair, Linconshire, UK. The water-adsorbers used should preferably be substantially water free when incorporated into the compositions of the invention. Particle size is preferably 10 to 4000 μm, especially 50 to 2000 μm. The compositions of the invention further preferably contain a stabilizer, e.g. a polyol or polyalkylene oxide, for example glycerol, polyethyleneglycol, diethyleneglycol, triethyleneglycol, etc. Where the compositions are in the form of liposome suspensions, the lipids used as the liposomal membrane forming molecules are typically phospholipids or hydrogenated phospholipids such as natural or synthetic phosphatidylcholines (lecithins) (PC) , phosphatidylethanolamines (PE) , lysolecithins, lysophosphatidylethanolamines, phosphatidylserines (PS) , phosphatidylglycerols (PG) , phosphatidylinositol (PI) , sphingomyelins, cardiolipin, phosphatidic acids (PA) , fatty acids, gangliosides, glucolipids, glycolipids, mono-, di or triglycerides, ceramides or cerebrosides, e.g. liposome membrane forming compounds such as are described in WO-92/21017. The membrane forming lipids may also comprise polymerizable lipids, e.g. methacrylate lipids, thiol and disulphide lipids, dienoate lipids, styryl lipids and diacetylanic lipids as described by Johnston in Liposome Technology Vol. I, Gregoriades Ed., pages 123- 129 (1983) and Singh in Phospholipid Handbook, Cevc Ed., Dekker, pages 233-291 (1993) and references therein. The use of polymerizable lipids in the formation of the liposomes provides one route for increasing liposome stability. Liposomal compositions may be prepared by conventional means, e.g. sonication of a composition comprising the' salicylic acid derivative in solution in an alcohol, and the liposomal membrane forming material. After liposome formation, the continuous phase can if desired be replaced by a continuous phase essentially free of the salicylic acid derivative. The compositions of the invention will generally be applied directly to the affected skin site, e.g. by spraying or gentle swabbing. As the affected skin is often extremely tender, the compositions of the invention are especially preferably applied as sprayed solutions, e.g. from pump action or pressurized spray dispensers. Pressurized spray dispensers are especially preferable as access of moisture to the solution during storage before and after first use, and hence hydrolytic breakdown of the salicylic acid derivative, may be avoided. Compositions in this format are novel and form a further aspect of the invention. Viewed from this aspect the invention provides a pressurized spray dispenser containing: an essentially anhydrous alkanolic solution of a physiologically tolerable salicylic acid derivative; a propellant; and optionally but preferably an acemannan. In such dispensers, the propellant will be a compound or compound mixture, generally one which is in gaseous form at one atmosphere pressure at 21°C. Halocarbon propellants, e.g. CFCs, may be used but non- halocarbons are preferred. Typical suitable propellants include hydrocarbons such as propane and butane . Thus the compositions of the invention are generally low viscosity, easily sprayed liquids, which can be applied without discomfort to the patient. By "essentially anhydrous" it is meant that the water content of the alkanol solution is sufficiently low that hydrolysis of the salicylic acid derivative does not occur to a significant extent during storage, e.g. the water content is 2.0% wt or less, preferably 1.0% wt or less. Particularly preferably the compositions h'erein described are substantially free - from water. The compositions of the invention preferably contain 1 to 30% wt . salicylic acid derivative (preferably ASA) , especially 3 to 20% wt, more especially 4 to 8% wt, particularly 4.5 to 7.0% wt . Aloe vera is preferably present at 0.1 to 4% wt, especially 0.4 to 2% wt, particularly 0.7 to 1.5% wt . The stabilizer, if present, is preferably present at 0.5 to 20% wt, especially 2 to 10% wt, more especially 3 to 6% wt . Glycerol is preferably used in this regard. The alcohol solvent (preferably anhydrous isopropanol) is preferably in present at about 70 to 80% wt . These percentages are relative to the total weight of the composition excluding any drying agent. If a drying agent is used, this is preferably present at 1 to 20% wt, especially 5 to 15% wt relative to the total weight of the composition. The compositions of the invention are preferably administered in dosages of the salicylic acid derivative of 0.005 to 5 mg/cm 2 skin, especially 0.01 to 1.0 mg/cm 2 . The compositions of the invention may if desired contain further active ingredients, e.g. antiviral agents, NSAIDs, prostaglandin biosynthesis inhibitors, pain relievers (e.g. lidocaine or other -caine local anaesthetics) , antioxidants, pH modifying agents, skin treatment agents (e.g. α-hydroxy acids), antimicrobial agents, preservatives, aromas, etc. The compositions however will generally preferably be substantially free from Lowry Bronsted acid components, non-alcohol organic solvents (e.g. ethers, halocarbons, etc.) and ointment bases, e.g. containing no more than 2% wt, preferably no more than 0.5% wt in total of such components. In a preferred embodiment the compositions of the invention are substantially free from ethers and/or halogenated hydrocarbons . All documents referred to herein are hereby incorporated by reference . The invention will now be described further with reference to the following non-limiting Examples: EXAMPLE 1 Solution for administration from a pressurized spray dispenser Acetyl salicylic acid 5.7 parts by weight Isopropanol (anhydrous) 94.3 parts by weight EXAMPLE 2 Solution for application by spraying Isopropano1 (anhydrous) 74.8 parts by weight Glycerol 4.1 parts by weight Acetyl salicylic acid 5.1 parts by weight Aloe vera 0.85 parts by weight EXAMPLE 3 Solution for application by spraying Isopropanol (anhydrous) 81 parts by weight Glycerol 3 parts by weight Triethanolamine salicylate 15 parts by weight Aloe vera 1 part by weight EXAMPLE 4 Case 1 A solution according to the invention, including aloe vera was applied to a 61 year old male, with acute Herpes zoster in the T 3 dermatome, in a lot of pain. Before application, on a numeric rating scale (from 11- 0, where 11 is great pain) he rated the pain to 7, after application the following hour, he rated it to 4. He applied it almost every hour the following 24 hours. The skin-inflammation was greatly reduced, and the pain was reduced on the NR3 to 2-3. EXAMPLE 5 Case 2 A solution according to the invention, excluding aloe vera was applied to a 30 year old female, with acute Herpes simplex on lip. She enjoyed total relief after about 15 minutes of application. The inflammation was gone totally after 24 hours. She had used the spray approximately every 2 hours . EXAMPLE 6 Case 3 A solution according to the invention, excluding aloe vera was applied to a 37 old female, with acute Herpes simplex on a Labia majora, in pain. After 20 minutes she enjoyed full relief of pain, but she had to apply the spray every hour in 6 hours to get continuous pain relief. The inflammation was totally gone after 25 hours .

Claims: Claims : 1. An alcoholic solution of a physiologically tolerable salicylic acid derivative and an acemannan for use in topical treatment of herpetic neuralgia. 2. A solution as claimed in claim 1 wherein the salicylic acid derivative is selected from: acetyl salicylic acid, a physiologically tolerable prodrug of acetyl salicylic acid, a salt of acetyl salicylic acid with a physiologically tolerable counterion, an ester form of acetyl salicylic acid or an analogue thereof. 3. A solution as claimed in either of the preceding claims comprising aloe vera as said acemannan. 4. The use of a physiologically tolerable salicylic acid derivative, an alcohol and an acemannan for the manufacture of a topically applicable medicament for use in the treatment of herpetic neuralgia. 5. The use as claimed in claim 4 wherein said medicament is administered by spraying. 6. A method of treatment of herpetic neuralgia in a human subject, which method comprises applying to an affected area of the skin of said subject an analgesically effective amount of a solution as claimed in any of claims 1 to 3. 7. A method as claimed in claim 6 wherein the solution is administered by spraying. 8. A method as claimed in either of claims 6 or 7 wherein the solution is administered in dosages of the salicylic acid derivative of 0.005-5 mg/cm 2 skin. 9. A method as claimed in any of claims 6 to 8 wherein said derivative is acetyl salicylic acid. 10. A pressurized spray dispenser containing: an essentially anhydrous alkanolic solution of a physiologically tolerable salicylic acid derivative; a propellant; and optionally but preferably an acemannan. 11. A pressurized spray dispenser as claimed in claim 10 which contains an acemannan.

Inventors: KLAVENESS JO, STEENFELDT-FOSS HENRIK, THRANE PER STANLEY, KLAVENESS, JO, STEENFELDT-FOSS, HENRIK, THRANE, PER, STANLEY
Applicants: COCKBAIN JULIAN, KLAVENESS JO, NORWAY MEDICAL GROUP INT AS, STEENFELDT FOSS HENRIK, THRANE PER STANLEY, COCKBAIN, JULIAN, KLAVENESS, JO, NORWAY MEDICAL GROUP INT. AS, STEENFELDT-FOSS, HENRIK, THRANE, PER, STANLEY
Application year: 2001
Main classification: A61K9
IPC codes: A61K9, A61K31, A61K36, A61K47, A61P29