GB2414184A - Liquid bandage composition - Google Patents

Abstract

The composition is suitable for the treatment of burns and wounds and scars and comprises a silicone wax (silicone polymer having alkyl substituents as side chains) and a silicone polymer (a polydimethylsiloxane). The wax may comprise 2-15% of the composition, and the polymer 50-99.5%. The composition may also include a low molecular weight silicone. Additional components include humectants (such as long chain alcohols), fatty acids or antibacterial compounds.

Description

Liquid bandies for buril and wound treatment The present inve,lioi relates

to liquid l:'anclapc compositions that may be used for the treatment of wouncis, par ticrla ly burns and scalds and methods for producing such compositions.

Burns are wounds that are c lassil'ied to clifl-'erent degrees according to the depth of wounded tissue (epiclermis ancl cierri.s) involvccl. In general first degree burns produce redness (erythema) of the outer epidernal skin srrfaec. Seeoncl ele,gree burns are generally classified as either superficial or deep dcr',al. 'Idle former involve ill Cry to the upper third of the dermis and tend to produce blistering while to latter involve in jury creep into the dermal layer damaging a high proportion of epidernal ceils. Althougl blister fernalion is rare in deep second degree burns, dense scarring may result it' Bloc wound is not excised and skin grafted. Full thickness or third degree burns produce elann.nge to tle entire epidermis and dermis and destruction of nerve endings leaving a wound tluat will not re- epitllelialize anal areas not closed by wound contraction will require skin grai'ting.

Treatment ol' bums involves nanageinent of the wound to decrease the potential for further local damage and sy.stenie disruption caused by the breach of the skin barrier function.

Traditionally this has involved application ol ciry elressings to the wound site prior to any attempt to cleanse anti bring about cIcbriciement of the wound. This procedure attempts to artificially restore the skin bar r ier lIuction to the WOUntl site by regulating fluid and heat loss, as both give rise to hcreasecl IcvCls ol pain] and trauma, anal prevention of bacterial invasion. In many cases both the application anal rcmov.-l ol'clry dre Sings from the burn wound site causes the patient some degree ol'pain dud trauma. Thus a clresshg that may be applied to a burn wound site in the form of a licluicl bandage that is last drying and will rapidly restore an artificial skin barrier function to the wnucl would be h IghlY desirable for the treatment of burns. It is the purpose of the present application to clescriLc lIrnulations that may be applied to a burn or wound as a liquid bancl.De that will swiftly ciry t<, act to rcgukate moisture loss as well as forming a barrier to microbial hv.ision of the wruncl and limit formation of scar tissue by controlling the environnct of the w-'uncl dui hag tle healhg process. The formulations of the invention may also be user to treat and alleviate nurture scars by bringing about a cosmetic improvement in the appeniancc ol the scar over a period ol'Lime and deliver a variety of additives to improve and protect to coalition ol'Lle slain.

In the early 198()s silicone elastomers were identil'ied as having beneficial effects when applied to keloid sears imcduch;, ibe both the extent arid r edness of the scar tissue. Courtney and McNeill published a mnber ol'slrdies on the efl'icacy of applying silicone elastomers to a range of existing sears, both old arid newly lorncd, belt were unable to identify any key feature of the silicone that gave rise to the el'l-'eet. Allhogh the neehanism of action of the silicone polymer to reduce searing r entrains unclear, n Abet ol'c'mmercial products for scar treatment based upon silicone gel elstoners hi sheet corns leave bee, developed.

Another approach to trcatig scar tissue with silicones was put forward by Kushner in US patent 5,741,509 which describes a silieoe l'luid is blended with fumed silica to produce a spreadable composition h.-vh;, the consistency ol' a.sti l'l' cream or grease that may be applied to wounds. Comrnereial products based upon this approach have been marketed in Europe and the USA, while they are adequate to ameliorate existing scours they suffer from the drawback of containing silica. However lunged silica has been demonstrated to cause local tissue reaction following intraperitoneal anal sub-cutaneous application (W. Kloterkotter Arch. Hyg. 149, 7-8, 1965). In addition sob-cutancrus in jections Cal various silica particles has been demonstrated to give rise to granuloma (l l..l. L.oblicl 8: K. Werkle, Beilr. Silikose-Porsch. 73, 37 1961), thus parenteral application to olden wound tissue find its use hi products to neat wounds involving a breach of the epidermis (sucl as by ns) is not encouracd.

A recent UK patent application by Hardy, GB 2 384 708A, teaches the use of compositions of silicones hi conbhntion with water Or treatments of scars. While the compositions described in this application are claimed to be last drying giving a tack free finish, their suitability for use with bursts is clucstionablc due to the presence of water within the composition. Not only does the presence of water within the composition limit the time of drying due to the relatively slow evaporation rate of waler but the aqueous component also serves to provide a merlin for microbial invasion and proliferation. In addition the requirement for a composition drying to a tack free finish nay be advantageous for cosmetic scar treatment product, but is not necessary lor a composition to be applied to a wound such as a burn.

Mooney et al in Ups. patents.S,8 14,():31 and 6,2.1,872 suggest the use of silicone waxes as flow control agents witlh occlusive wound dressings that are held in place by a porous covering material hi con junction \vith a support naterhl and an adhesive coated backing material. Adhesive backed circssh=s are generally more clilficult to apply to the contours of the body than liquid banciaOcs and removal and re-application may give rise to trauma. A composition that is compi isecl only ol silicone components or materials that are of a similar hydrophobic nature that r; piclly horns an occlusive, protective gel layer that will then form a film to prevent growth of microbial organisms would be preferable for the treatment of wounds and burns.

Accordingly the prc.scnt hvenlion.scelis to provide a spreadable liquid bandage composition that is suilallc liter use fin open wounds ancl is particularly tailored to meeting the requirements of treating horns. Such a composition will comprise of a component or components that will serve to r cstorc cpiclermal luncticii, by acting as a barrier to bacterial invasion and reduce transcliclcrnal water loss. lie c-nprsition should be fast drying to yield a thin coherent film or gel layer act Toss tle area t, which it is applied that rapidly acts to restore epidermal function. In acllition tlc nnajor coni>nent.s 'I talc composition should have a beneficial effect on the lornation ol scar tissue clurhO wound healing and reducing the extent of scarring after healing has taken place. Thus the licluicl bandage composition of the invention will be comprised predominately ol.silicone.s clue to lair scar reduction properties referred to above.

The major comlocnts ol tI,c licluicl banclaOc crnposition of the invention are comprised of silicone (polycldnclhylsiloxane) p'lymcrs together with silicone waxes (silicone polymers having long allays srbslitrels as side chains), present within the final composition in sufficient concentration lo produce a I:asl drying perl-ornace, such that upon application the liquid bandage remains ill contact with the wood or burls site and rapidly forms a gel or film layer over it. In additir to bigly molecular weight silicone polymers or silicone waxes should serve to reduce moisture loss h-on and act lo prevent microbial invasion of the site to which the composition is applied. AIIlorgh both silicone polymers and silicone waxes are hydrophobic in nature and will reduce moisture loss and not support microbial growth, it may be necessary to supplement their action by adclilio call other non- silicone constituents in order to provide a composition that is aclcquate for to lrcatme,l ol wounds and burns. These additives to the liquid bandage composition m,ry include lyciropilol.ic organic compounds to act as moisture transport modifiers and one or more anti-bactcr-ial ageists The use ol silicone waxes within the composition often necessitates mixing at high tenpcr-atrre, as these materials may not melt at temperatures below 70 -()"C Cerlai' additives, particularly those that exhibit anti-microbial properties, may be volatile or insufficiently tlcrmally stable to withstand mixing at high temperature and may be tlcrelorc i',lrcducccl kilo the lillal composition as components of a second part of the formulations Blat is nixecl alter cooling lo ambient temperature. When a second part of the liquid Conclave copo.silio' is necessary lo incorporate non-silicone additives it is preferably comprised Elf one or Snore low nolecuhr weight silicone compounds that will evaporate rapidly to allow talc colosition to lordly a gel fir fihn layer over the site of application.

The silicone polymers that may be used as a con.stiluent of the liquid dressings for burn treatment of the invention arc Vigil polyclinethylsilox;nc polymers (dimethicone) having the general formula shown Ludlow. CH3

-di-o- ]11 dH3 Materials of this type treat arc of suitable purify for woundcare applications are available from Dow Corning Corp'rati'n unclcr the talc name ()7-')120 silicone fluid in a kinematic viscosity range loom 2() celtistc)tCs to 12,5()() cCntiSl(-cs. The kinematic viscosity of the silicone fluid being dcpcnclent upon n; the number ol Ihncthylsiloxane units in the polymer chain. An alternative supply of nutcrials of this type is available from NuSil Corporation under the trade name Mcd-361 silicone Ihicl.

The silicone waxes that may be used as a conslitucut of the liquid dressings for burn treatment of the invention are silicones modiliel by ran inclusion of alkyl groups to yield an alkyl methicone having a iorunla shown belo\v.

CH3 CHi I I-li I $i o-<i-o-yi-o- ]x CH3 CH3 R represents an allays lyclrocarbon chairs tiLIt nuly be linear or branched and is randomly distributed along the polyncr chain An example ol such a wax that is suitable for use for woundcare applications is ST-wax 3() available Iron1 Dow Corning Corporation, having alkyl chain groups (R) that vary between 3() lo 45 car bon atoins. Such waxes are solid at room temperature and must gcerally be lroccssed at tenpcr.ilures above their melting point, typically 70-80 C or higher.

At least a portion 'I tics licluicl bandage compo;itios of the invention will therefor be mixed at elevated temperature lc portion nixecl fit elevated temperature will usually consist of liquid silicone (polydimetliylsiloxaue) pclyners togetlcr witl1 silicone waxes and comprise at least 70% by weight of talc Lionel]iquicl band.igc lormul; ition. The content of silicone waxes within the final liquid ba'cl.ugc formulation lrclcrably constitutes 0.5% by weight to 20% by weight, more preferably.()f%, by weight to 15'%, by weiglt. The content of liquid silicone (polydimethylsiloxane) polyucrs witlin the final litluicl bandage formulation preferably constitutes 50% by weiglt to')').S'%o by weirdly, Marc Tolerably 55% by weight to 98% by is eight. The kinematic viscosity of any liquid silicone ( polydimelhylsiloxane) polymer within the final liquid bandage fornlation pret'erahly lies in Else range 10 to 15,000 centistokes, more preferably 20 to 12,500 cc'listokcs.

The low molecrhi welt silicone con ponds dial act as a liquid carrier for various additives to be incorporated at anbicnl temperatures arc linear siloxane liquids such as hexamethyl disiloxane or >ctnellyl fri.siloxanc or mixnrcs thereof. The structures of hexamethyl disiloxane ancl octanctlyl lrisilexanc are shown below.

CH3 CH3 CH3- hi o pi Cold l-lcxamethyl clilsil.tne CH3 CH3 CH3 CH3 CHIN CH3- hi o (-) hi CH3 Oct.netlyl trisiloxane CH3 H3 CHIN These materials ol sritablc purity for sli'care applications are commercially available from Dow Conning Corpora align under lee Lraclc lunge (?7-9180 silicone fluid. Hexamethyl disiloxane (Q7-9180 silicone llcicl 0.65 centiSlokes) lugs a rapid rate of evaporation similar to that of acetone and oclanclhyl trisiloxane (Q7-9 I SO silicone fluid, 1.0 centiStokes) has a rate of evaporation similar to that ol'isolropanol. Thus both materials and mixtures thereof in any proportion are suitable l'cmsc as the liquid car i icr elenenl l'or incorporation of additives to the liquid bandage composite lo act as a burn drcsshg. 'I'hese low molecular weight silicone compounds preferably constitute () lo 13()% by weight withh1 the final liquid bandage formulation, more preferably 5.()'Yo by weight to 25% by weight.

Additives tint nay act as noi.sture lansporl nndil'iers are typically long chain alkyl alcohols, having an alkyl chain length ol'twelvc carbon atoms or greater for instance, 1- dodecanol, l-tetradeca',ol (nyristyl alC01101), 1-hexadccanol (cetyl alcohol) and 1-octadecanol (stearyl alcohol). Unsaturatecl alcohols such as oleyl alcohol may also be used. Alternatively alkyl esters of long chain carboxylic acicis havhg a chum length of twelve carbon atoms or greater (whether saluratccl fir unsaluratcd) Nay he used such as methyl laurate, isopropyl myristate, methyl linoleate' ctlyl linolenate and hexalccyl hexadeconate (cetyl palmitate).

Preferably used are long Cohn carboxylic acicis have g a chain length of twelve carbon atoms of greater (whether saturatccl or uns;luralecl) may he used l'or instance tetradecanoic (myrstic) acid, hexadecanoic (palmilic) as id, ;'ctaciccanoic (stcaric) acid, 9-octadecenoic (oleic) acid, 9,12 etadeeadienoie (linoleic) acid, 3.6,9,-ocladec.lrienoic (alpha linolenie) acid and 6,9,12- oetadeeatrienoie (gamma linolc,ic) acid. Any 'l the alcove materials may be used alone or in combination and it is particularly advanlageoui to apply combinations of long chain carboxylic acids to the liquid ballad c cc-uposilion in flee lore, ol lout seed oils that have high contents of such earboxylie acids E:xanlles ol such seed oils with high carboxylic acid contents are as follows. Albaraka seed oil (palni(ic acid 12- 15 oleit acid 20-25%, linoleic acid 50-58%), Black currant seed oil (lill> leic acid 4()-46% alpha lilircnic acid 13-14%, gamma linolenic acid 11-17%) Borage seed oil (,leic acid I S-20 Y,, iill>lcic acid 32-36%, gamma linolenic acid 17- 20%), Evening primrose oil (-,leic acid 5-12'Y.,, iinolcic acid 66-76%, gamma linolenic acid 8- 11 %) and Sea Buekthor n seed oi I (oleie acid l ')-22 Y,71 i oleie acid 33-36%, alpha linloenic acid 24-30%). Seed oils of the type described above are cunereially available from Euro Ingredients and are reported tic love.7,dded be'elits such as being antiallergenic, having antiinflammatory elfeets, to support restoration ol skin lissome and aid wound healing.

Additives that are l-,rel'crrecl lo enlancc to antimicrobial properties of the liquid bandage composition are cssctial oils that are letdown lo love anti-bacterial properties or materials containing silver Tlerc ar e many exanpics ol' essential oils known to exhibit anti- microbial effects such as laveicler, lea tree oil, lemo,grass oil, bay oil and oregano oil; because of their volatile nature it is prcl'crrecl to mix them into the i-'ormulation at ambient temperature in conjunction with a low molecular weight silicone materials of' the type described above. Silver containing materials suitable l'or use wili, the litlricl baclagc compositions of the invention are silver sulphadiazine, silver zeolitcs (e g Alpla.Sa available Prom Milliken Chemical) and phosphate glasses contahig silver such as Cor,>laes iron Cliltech technologies. These materials may be adversely ai'i'cctel lay heat leading to cliscoloci ation by formation of silver oxide. For this reason it is also prel'errecl to mix them into the l'ornulation at ambient temperature in conjunction with a low noleclar weight silicone materials of the type described above An advantage of Bloc licluicl b.uclage conpositiois of the invention is that in bulk, the compositions are opaque, beige_ white in colour lit rank lcmperature, but when spread upon the skin form a clear gel layer ''l'lc opacity of the liqicl b;nclage composition is particularly advantageous when a silver containhg anti-uicrobial agent is a constituent as these materials tend to be light sensitive anal may cicgracle to pocluce cliscolouration by formation of silver oxide.

Another advantage ol'ccrtain liquid banlage compositions of the invention is that highly viscous compositions (those loving a viscosity oL'50,()()() centipoise or greater) are found to exhibit thixotropy This Quakes composition easy to aclninisler by spreading easily across the skin despite being highly viscous and may be suitably supplied to a wound or burn from a tube.

Compositions of lower viscosity arc easily slre;d across the skin but are found to maintain their position after administration (i.e. they -lo not rrin ol I the skin), thus they may not only be suitably applied itom a lUI.)C inlet also) from an act O.SOI spay dispenser. The absolute viscosity of the liquid bandage formtl.rtio, lrclc'-ably lies in the ravine 100 to 250,()00 centipoise, more preferably 50() to 10(),()0() cetipoisc, most 1:rcler.lly 1()()0 to 50,000 centipoise.

The liquid landau iotNntialion.s ol tile inVcUtictt may also incorporate additives to protect or improve the cL'ldilion ol lhC skin dc'lcHdhi on the intended use of the formulation.

Examples of such adLlitivcs hclude: 1. Pharmacer.tlica I s 2. Attti-inllammatoty agents 3. Ultra violet light;llls>rllets (Slat protection lactots) 4. Emollients 5. vitartlins 6. Herbal extracts The invention will he lut-thCt illustrated lay Bloc Allowing, non-limiting examples of liquid bandage compositions tiuLt mly set-ye as wound or hLtrn dressings.

Example 1.

A 250-ml round lion split rc.sin leash was assembled in a heating mantle with a glass anchor stirring rod attaclcl to a nechattical stirtct- ancl a thermometer to monitor temperature.

The heating mastic was ail justccl lo give a lcmlcratutc ol'85 + 5 C within the flask and 2 grams of Dow Corning ST-wax 3() was initoclucecl tie flee l'I;sk with 98 grams of Dow Corning fluid Q7-9120 (12,500 centistcles') 'l'le hgt-edients were slirt-ed at 85 + 5 C for 90 minutes during which time the wax lead ncilel within the silicone livid to produce a clear solution. The temperature of the solution was then alkwccl to cool raclually over a period of 1-2 hours to a temperature of 35-40-C, tiut-ing which time to solution changed from clear to a white viscous gel-like fluid. Tl1c cotticuls t,1 11ie 1'1ask were tr.ulsicrtctl to a [SO-ml glass screw top bottle and allowed to stand overni,ll to reacimunbient temperature. ''flue absolute viscosity of the material was measured at ambient tenpetalute ushg a 13rcoLficid digital viscometer, model DV-E, equipped with a T-C.spinclle ole'-ating at a Ace ot' 1() revoluliotis per minute (rpm) and found to be 28,100 centipoise (nl'a-s). When applied to skhn tile composition was found to form a gel layer over the applied atctt within 3 tnitintes 1 application and dried to form a wax-like file, within 1 hour. The ability <I'tle conposition tt' i>t-n it lat-ricr Lo moisture loss was assessed by a hater vapour permcabillty (Payne cup) test Thc l'aync cup consists of aluminium rimmed cylindrical reservoir for w rIcr over to mouth ol which a membrane may be clamped to control the rate of evaporation ol waler Thc test was carried out by pre- warming 2 Payne cups containing 20 + 2 grams 1 svatcr in an oven sct al 34 + I "C for 2 hours and then clamping a microporous polyurethane memlrane (avaihallc loons Scapa Medical) over the mouth of 1 cup, weighing the cup as a.sscnbiccl and replacing it Pill in the oven The second cup is treated in an identical manner coccal Cleat a known wci:.lt (approximately 0.2 grams) of the silicone composition is spread ovei the rougher (micr-,porous) side of the membrane corresponding to the area covering the cup? s r escrvohAiler lee l'ayne CUpS have remained upright in the oven for 2 hours they were re-weiglcd and the Uprigll nioi.sturc vapour transport rate through both the treated and untreated menlri'cs was calculatecl in grams per square metre per 24 hours. The Payne cups were then invcrlccl anal replacccl ill the oven lor a further 2 hours after which time they were re-weighecl alibi tllc i'verlecl moisture valor transport rate through both the treated and untreated membranes was calculated in g! aIns per stlUarC metre per 24 hours. When tested in this manner the microporous polyureLlnuc nembrare was found to have upright and inverted moisture vapour transport ralex ol 3,879 awful.S,775 grams per square metre per 24 hours respectively. Applications oi ().2()1 grams of flee silicone liquid bandage composition to the microporous polyurelha'c ncnlrae was f()ulll to reduce these moisture vapour transport rates to 1, 297 and 1,0)7 grams pi r square metro lJcr 24 luur.s respectively. Thus the reduction in moisture vapour transport rate bloc lo the silicon liq'il bandage composition was 12,845 gram.

per square metre per 24 hours per gram of Talcs ial (upright determination) or 24,574 grams per square metre per 24 hours Per gram ol material (ivcrlccl determination).

Summary: Example l

Ingredient 1 Ingrc(lic',' (tic llroollield | Reduction in Reduction in (% by weight) by Nveiglt) viscosity ('1(: upright inverted spirally, 1() MVTR MVTR.

1n) (glm2124 (glm2124 _ _ _ hours/g) hours/g) S-T wax 3() Q7-912() 12,5()() 2S,1 ()() 12,845 24, 574 | (2%) centislole ()O) Cecil ipoi.sc

Example 2.

Using identical ppar;tus and mixing conlilions to those described in Example 1 a silicone liquid banciagc criprsilio consisli'g 'l l(.) ;. rtuns of Dow Corning ST-wax 30 and 13U Jams of Dow Corning flail Q7-') 12(1(12,50() ccnti.stolcs) was prepared. The material produced was again white, having the consistency 1' a stiff' cream. The Brookfield viscosity of the material was determhccl ill;i identical manner to that described in Example 1, except that a speed of 2 rpm was enpl'yccl clue to talc hi<'her viscosity ol' the composition which was found to be 235,000 centipoise (nil'a-s). When applied to skin, the composition was found to form a gel layer over the applied area vitliu 2-3 minutes find tli it'cl lo form a wax-like film within 1 hour of application. The cl'l'cct ol'lis coupositic-,n >u Inoisturc vapour transport rate was assessed in an identical manner to that tlescriDc-l in cxanple 1. Application of 0.231 grams of the silicone liquid bandage composition t1 tile nlicroporous pOIyUrL'thanC membrane was found to reduce the upright and inverted moisture vapour transport rates lo 1,()22 and 1,185 grams per square metre per 24 hours respectively. 'Idles the recluclic- in noi.stue vapour transport rate due to the, silicone liquid bandage conp,sition was 12.(i5 grams per square metre per 24 hours per gram of material (upright detcrniniion) or 19,87() grants Car scare metre per 24 hours per gram of material (inverted delermiuati<).

Summary: Exalnllc 2

Ingredient 1 anal evident 2 lil ookf ield Reduction in Reduction in (% by weight) (% by \vci<,ht) viscosity ('l'C upright inverted spindle, 2 r pin) MVTR MVTR (glm2124 (glm2124 hours/g) hours/g) S-T wax 3() Q7-') 12() 23.S ()()() 12, 365 19,870 (7.1%) 12 5()() centipoise cenlistol;c l (92 9'Y;) _

Example 3.

Using identical apparatus and mixing conclilions to those described in Example 1, a silicone liquid bandage ccnprsition consislhg, -'l 1().8 grams of Dow Corning ST-wax 30, 12.5 grams of Dow Corning l'ltitl Q7-912() (20 centist'kes), 29.7 grams of Dow Corning fluid Q7- 9120 (100 centistokc.s) anal 5().4,n-an.s of Dow (Corning, fluid Q7-9120 (12,500 centistokes) was prepared. The material prodrcccl was again while, leaving the consistency of a cream. The Brookfield viscosity of talc naterial was detcrniccl hi an identical manner to that described in Example 1, except that a sheen ol 2 r pin was enjoyed which was found to be 87,000 centipoise (mPa-s). When a speed >l l() rl was cnployecl II]C viscosity reading was found to reduce steadily with thee jnLIICatjI1 that else material Was cxlibiting thixotropy. This is a beneficial q property for a material to lie.lplied as a litluicl b.uclage to have as it indicates that the material will be easy to spreatl,-cross flee surface ol skill yet form a coherent gel on standing. This proved to be the case wisest this conpositio, was.'lplictl to skin, forming a gel layer over the applied area within 2-3 intei and drictl to form it wax-like film within 1 hour of application.

The effect of this conposili,i Ott moisture velour transport rate was assessed in an identical manner to that dc.scribetl ill cxanple I. Applications of ().22 grams of the silicone liquid bandage composition to the nicroporus polyurcthae nenlr.ue was found to reduce the upright and inverted moisture vapour Resort rates to 7(() .lti 1.()')7 grams per scluarc metre per 24 hours respectively. Thus the reflection hi noistrre v.lour transport rate due to the silicone liquid bandage composition w as 11.174 gn-am.s per square nctrc per 24 hours per gram of material (upright determination) fir 21.2(1 grams per sells arc score per 24 hours per gram of material (inverted determination).

Summary: Exalnp_e 2,

Ingredient Ingledicl1t | lnhlcdicllt Int,lic(licnt Brookfield | Reduction Reduction in | 1 (% by 2 (% by ( % lay 4 ( c,: lay viscosity in upright inverted weight) weight) l weight) \veihlt) (l C MVTR MVTR spindle, 2 (glm2124 (glm2/24 I rpm) hours/) hour.c/ó Q7-912(), -()-7--'jl2(.), 1 (37-'jl2(-), ;- I, t, t4,74 21 Z6l-hi (10.4%) 20 100 12,5()() centipoise l centistokc c enti.stoke centiitrkc I (12tYo) 1 (S,7 (4X.Ý>)

Example 4.

Using identical apparatus and nixhg c'nditi<>n.s to those described in Example l a silicone liquid bandage condition con. isting <'l l 2.) grams of Dow Corning ST-wax 30 22.5 grams of Dow Corning fluid (,27-)120 (20 cntistoLcs) 20.1 grams of Dow Corning fluid Q7- 9120 (350 centistokes) atoll 5() grams ol Dow C'rning fluid Q7-9120 (12, 500 centistokes) was prepared. The material Raced was agah white lua\iing the consistency of a stiff cream. The Brookfield viscosity of the n. itcrial was deternhccl in an identical manner to that described in Example 1 except that i speccl ol 2 rent w;is enjoyed which was found to be 193 000 centipoise (mPa-s). When a speed ol l() rpm was cnploycd the viscosity reading was found to reduce steadily with tin]L' i'tiicating that The material was exhibiting thixotropy thereby onveying the benefits rcl'errcl to in example S. When this composition was applied to skin, a gel layer over the applied area formed within 2-S minutes and dried to form a wax-like film within 1 hour ol'application. rl'lc cl'l-'ect ol' this composition on moisture vapour transport ram was assessed in an identical n.ncr to that described ifs example 1. Application of 0.217 grams of the silicone liquid ba:l;.,c composition tr, Alec nicroporous polyurethane membrane was found to reduce the uprigll find i,vertecl moisture v;pu transport rates to 611 and 1,110 grams per square metre per 24 Indoors c.speclively. 'Isles the reduction in moisture vapour transport rate due to the silicone liquid bandage composite \v.s I SO(j() grams per square metre per 24 hours' per gram of material (upri,<,it dclcrnination) or 21,497 grams per square metre per 24 hours per gram of material (inverted dcterminalion).

Summary: Examplc!

Ingredient Ingredient lnreditnt lngtdic''t lirooktield 1 Reduction 1 Reduction in 1(% by 2 (% by -] (% lay 1 ('NO lay viscosity in upright inverted weight) weight) vei',ht) \vei-,ht) (TC MVTR MVTR 1 rekindle, 2 (glm2124 (glm2124 r pm) hours/g) hours/g) S-T wax 30 Q7-9 1 2O, (?7-')120, Q7-') 1 ?(), 193,000 15,060 21,497 (12.2o) 20 3.() 10.()() 1 centipoise centistokc c enlistoke cenlistolc _ 2. 3 '%0 ( I ') . l c/G) ( 4 7)

Example 5.

The liquid bandage conposition prcprecl as described in Example 2 was modified by- addition of octametIlyl trisiloxrne and isopropyl nyri.state. Accordingly, 25.5 grams of the composition mixed as descrilcd in l:ixample 2 wits ackled to 5.5 grams of octamethyl trisiloxane (Dow Corning silicone llricl Q7-918(), 1.() cctistokes) and 4.7 grams of isopropyl myristate (Lexol IPM-NF, loom the latex Chemical (npany) the ingredients were mixedby rapid stirring at ambient temperatrrc. A white material leaving the consistency of a low viscosity cream resulted. The Broollicll viscosity ol Alec n.terial was determined in an identical manner to that descriLcd in Example I except that a spcccl ill SO rpm was employed which was found to be 3,800 centipoise (mPa-.; ). \Vlcn a speed ol I ()() rind was employed the viscosity was found tot- -- be 3,600 centipoise (mPa-s), ilic lhixotropic cilct relerretl to in example 3 was therefore much reduced. When this composition wax applickl lo slabs, a gel layer over the applied area formed Within 2-3 minutes and dried lo form a wax-lilc liLll within 30 minutes of application. The effect of this composition ion moisture vaporer transport rate was assessed in an identical manner to that described in cxamlle L, except that a leak.samplc of porous polyurethane material coated with a known wcill of the liquid bandage cmpo.sition was prepared and placed in a Payne cup without water. 'I'lc weight loss ol tlis culls clue to the evaporation of the volatile Q7- 9180 component of the condition was cleternincd and c.scd to correct the weight loss used for the calculation of the moistui c vaporer transport r ate. Application of 0.213 grams of the silicone liquid bandage composition l<' the microporos lolyructhane membrane was found to reduce the upright moisture vapc'n- tr;n.s'ort ratc.s to 847 mun.s Car square metre per 24 hours respectively.

Thus the reduction in upright nuisture vapor transport rate due to the silicone liquid bandage composition was 13,357 gaps per sqarc nctrc 1'cr 24 hours per gram of material. This represents an increase over talc I igrrc ol 1 2,3(i.grani per square metre per 24 hours per gram of material found for the col\sitio ol exan'le 2 (IrOIn which the composition of this examplq was derived), indicating At;dlition ol isopropyl nyristate was ellective in acting as a moisture transport moclifier.

Summary: Examp!L.5

-

Ingredient Ingredient I Ingredicut l'grcclicat Brookfield Reduction!, 1(% by 2 (% by 1 3 (% by l (% by viscosity in upright weight) weight) weight) \veigl, t) (TC MVTR spindle, 50 (glm2124 rum) hours/g) S- Twax30 Q7-')12(). Q7-)18(), i exoi 1 3,800 1 13,357 (49%) 12,50() 1 I centistoke NO centipoise cenli.stol;c | ( I 6 8(YO) ( 14 4'%) _ (63 9%) 1 1- __

Example 6.

The liquid banci.ngc conlosition prelarcri as cle.scribed in Example 3 was modified 0,; addition of hexamethyl trisil'xae anti a silver co'tainhg phosphate glass. Accordingly, 31.2 grams of the conposith, Nixed as descrilecl hi 1,xample 3 was added to 4.6 grams of hexamethyl trisiloxane (D'w Corning silicone i hid Q7-) 180, 0.65 centistokes) and 1. 7 grams of Corglaes SRP powder (lron (iiltech Technologies Lhiteci) the ingredients were mixed by rapid stirring at ambient tempcr;tire A white editorial h,ivhg the consistency of a low viscosity 1Z Ream resulted. The BrooLlicld viscosity of tlic natcrirl was, determined in an identical manner to that described in Example 1, except that a speed ol SO rpm was employed which was found to be 2,500 centipoise (mPa-s). \Vlcn a speed ol l I) r paid was employed the viscosity was found to be 2,300 centipoise (mPa-i). Alec tlixctropic cilecl rcicrrccl to in example 3 was therefore much reduced. When tlli.s comp>sitio was applied ti' skill a gel layer over the applied area formed within 2-3 minutes and.1ricd to corns a wx- likc Milan within 20 minutes of application. The material was stored hi a costar Miss screw sol:' l:>lilc atoll its appearance monitored over a period of 28 days at ambient tc,'peratrc for.sig.s <>l any photosensitive degradation leading to the development of black or ray discokuration wit else material; none was observed. The effect of this composition on n'isirrc vapour transport rate was assessed in an identical manner to that described in example l, except tint a blank.s;plc 'l poxus polyurethane material coated with a known weight ol the liquid bandage conpositio' was prepared and placed in a Payne cup without water. The weight loss of Allis cup due to Alec evaporation of the volatile Q7-9180 component of tle conposilio was cletermi,cc! atoll used to correct the weight loss used for the calculation ol the noistrrc v;lour transport rain. Application of 0.232 grams of the silicone liquid bandage conpositio l<' Alec nicroporous lolyur; Tulane membrane was found to reduce th upright moisture vap-r mascot ratc.s to 4()7 grains per square metro per 24 hours respectively.

Thus the reduction in lops icily noisturc vapid- tra.sport rate due to the silicone liquid bandage composition was 14,162;:rans Ace square mcin; Car 24 hours per gram of material.

Summary: Exanplc 6

ingredient lugredicut 1 1'-cdicnt lngcdic'l 1'cdiL: Ingrcdicut BrookH'cid I Reduction I 1 2:) 4 | 6 viscosity in upright (% by (% by ( BY., lay ( % by I ( a/. I,y (% by ( 1 C MVTR;' weight) weight) we idly) w eight) I vigil) weight) spindle, 50 (g/m2124 L-L; S-T wax Q7-9 12(), Q7-) 12(), Q7-9 120 ( )7-')18( ), Corglaes 2,500 1 4, 1 62 (8.7%) 2() i ()() 12,50() ().(5 SRP centipoise centistoke cclisrokc cctistokc cc,listol;c powder (10. 1 %) 1 (1 I): ) (4() ( / ) 1 9.9'Y, ) (4 5%)

Example 7. i

The liquid banclao composition prcpard as described in Example 4 was modified by addition of hexametlyl trisiloxac, oclamellyl lrisiloxane and lavender oil. Accordingly, 25.S grams of the compositions nixed as described hi l:,xample 4 was added to 1.4 grams or hexamethyl trisiloxane (I)ov C'orning.siliconc Ihicl Q7-9180, 0.65 centistokes), 2.4 grams of octamethyl trisiloxane (low G-,r'ing silicone Ihicl Q7-9180, 1.() centistokes) and 1.9 grams of lavender oil (l'rom Aromatics Limited), the i,,reclicts were mixed by rapid stirring at ambient temperature. A white Aerial luvhg the cr'sisieucy ol'a low viscosity cream resulted. The Brookfield viscosity ot' tlc material was de(ernhcci hi an identical manner to that described in Example 1, except that a speccl ol'50 rpu was ended which was found to be 2,400 centipoise (mPa-s). When a speed of I ()() r pin was employccl the viscosity was found to be 2,100 centipoise (mPa-s), the thixotropic ell'cct referred to in exanllc.3 was therefore much reduced. The effete of this composition on noistrr e vaporer transitory rate divas assessed in an identical manner to that described in example 1, excclt lest a blank Ale c-' f porous polyurethane material coated with a known weight ol' the liclici banclae conlositi, was prepared and placed in a Payne cup without water. The weight loss of this cup clue to the evaporation of the volatile Q7-9180 components ot' the ton \VOS determhctl alicl used to correct the weight loss used for the calculation of the moiLihrc val)tutr ttat-tspott ralC. Alplicatio'-t of 0. 21., grams of the silicone liquid bandage col-ttpoL;itir' to tle utict- opotoui lolyru-ctltane metnbrane was found to reduce the upright moistcite Val70Ut IrdI]sllott: tfites tO 5()8 r.ti Cot square metro per 24 hours respectively.

Thus the reduction in Ul.7ti,'ltI tttiStUtC vast itatslott rate due to the silicone liquid bandage composition was 14,6()6 grCtIl]S pal sClLIale nletre 1lcr 24 Itout.s per gram of material.

Summary: Exanp! 7

Ingredient Ingrcdicut I n, rot ice I ngrclic lit _ _ _ t grcdicnt | Ingredient Brookficid Reduction I 1 2 3 4 6 7 viscosity in upright (% by (% by (TO by (% by ('a by (% hy (% by (TC MVTR weight) weight) weiglt) w ciglU) weigl' U weight) weight) spindle, 50 (gim2124 W _. _ I S- T wax Q7-912() Q7-) 17() Q7-912() Q7-)18() ()7-9180 I avender 2 400 14 606 2() 35() 1 12 5()() () (i5 1 oil centipoise (10.0%) centistoke ccntistolic centisloke cctistolic ccntistokc (G 1%) ( 17 4 /., ) ( I 5 ( ) ( 3 /r) ( 4 >, ) (7 6 /o) l q

Claims (1)

1. Claims 1. A liquid bandage comlsilioil for the trealnent I burns and

   wounds comprising at least one silicone wax component hi combination evilly at Ical one silicone polymer component 2. A liquid bandage coulositicn according to clahn 1, wherein said silicone polymer component its compris.cl ol al Ic,asl one lilt silicone polymer.

   3. A liquid bandage condition according lo cl;thD.i I and 2, wherein the silicone wax component is.scluble ON ilhin the silicone l>lyncr c<'nponent.

   4. A liquid bandage coml>'sitirn according lo clahns I - 3, wherein the liquid silicone polymer is a polydimetllylsikx;!ne lolyner having;r Thematic viscosity of between 10 and 15,000 centistokes al 2()"C 5. A liquid bandage composition accortJhlg lo I;hn 4, wherein the silicone polymer component comprises tsvo or Marc liquid silicone polymers having a kinematic viscosity of between 2() and 12,5()() ccntistokes at 2()"(' 6. A liquid bandage conlositi>n according lo;!)' lrcceding claim, wherein the liquid silicone polymer component c<>nstitules between S()',, anal ') 3.5% by weight of the total composition 7. A liquid bandage conlositi'n according tic tiny receclhg claim, wherein the liquid silicone polymer component c<>,stitr;tes between.>',;; arid ')8% by weight of the total composition.

   8. A liquid bandage conpositin according Emmy preceding claim, wherein the silicone wax component conslilules between 0.5% and 0(,' by \veight of the total composition.

   9. A liquid bandage conposition according lo My preceding claim, wherein the silicone wax component constilutes bewccn 2.0 ; and 1>'/, Icy weight of the total composition 10. A liquid bandage composition aCCOrdin 10,TnY preceding claim, wherein the silicone wax components and mild silicone polymer c o',llnenls ar e mixed at a temperature of 85 + 5 r 11. A liquid bandage conipositicn according tic any preceding claim, wherein the compositior further conpri.ses al Iciest one low molecule! weigh silicone compound 12. A liquid bandage composition according t, cluing I 1, wherein the said low molecular weight silicone compound is calmer alone or ill crnbhation with hexamethyldisiloxane or octamethyltri.siloxanc 13. A liquid bandage conposilion according, t' Items 1 1 and 12, wherein the said lo molecular weight silicone crnip'uncl ccnlris.s () t' 3()Xo by weight of the total composition 14. A liquid bandage conposilion according to cluing 13, wherein the said low molecular weight silicone compound conprises 5 to 25% by weir lit of the total composition l 15. A liquid banciage COlilpOSitiO11 according lo tiny preceding claim, wherein the admixture of silicone waxes and lipid silicone polymers is mixed with the said low molecular weight silicone compound at ambient temperature 16. A liquid bandage conilosilio' accordin,. to my prccedhg claim, wherein the composition further comprises at Icast one agent to luiller rice tl,,c rate of water transmission through the composition 17. A liquid b;-ndayc ccnlosition according lo el.i, 16, wherein the said agent is at least one long chain alkyl alcol,<>l, wliciler saturated fir saturatecl 18. A liquid l andagc conlosition according to t'lahn 17, wherein the said agent comprises any of the following eitlcr aloe or in co',liatio, l- dodecanol, 1-tetradecanol (myristyl alcohol), I-hexadecanol (ceryl alcohol), olevl alcol-'l anti l-octadecanol (stearyl alcohol).

   19 A liquid bandage composition according to chains 16, wherein the said agent is at least one alkyl ester oi a king cini c.rboxylic acidly \vletler saturated or unsaturated 20. A liquid bandage conlosilio', according to claim 19, wherein the said agent comprises any of the following either alone or in combi;tion methyl Curate, isopropyl myristate, methyl linoleate, ethyl linolen.ric and lexaclecyl lcx.cleconate (cetyl palmitate) 21 A liquid bandage conlositio according t' clan 16, wherein the said is at least one long chain carboxylic acid, wlcthcr saturated or uis. ituratecl 22 A liquid bandage con-,losilion according t> claim 21, wherein the said agent comprises any of the following either atomic or in combii.tio tetraclecanoic (myrstic) acid, hexadecanoic (palmitic) acid, oc(.icleca,cic (stearic) ;icid7 9-octadecenoic (oleic) acid, 9,12- octadecaclienoic (linoleic) acicl, 3,6,9,-octadcc;tricnoic (alpha linolenic) acid and 6,9,12 octadecatrienoic (ganglia liulenic) acid 23. A liquid bandage colosition accorclhg to t'l.tin] 16, wherein the said agent is at least one seed oil that is rich hi long cl,,ain carhoxylic.icitis, whether saturated or unsaturated.

   24. A liquid banclaye con,,losition according to clam 23, wherein the said agent comprises any of the following either alo,nc or in combination AIbaraka seed oil, Black currant seed oil, Borage seed oil, Evcni,,g lriurose oil arid flick 13clthorn seed oil A liquid bandage con,,lositio' according to My preceding claim, wherein the composition further comprises at Icait one agent that acts.rs.n, anti-bacterial or anti- microbial agent.

   26 A liquid bandage colosilio'' according to' cl char 35, wherein said an anti-bacterial or anti- microbial agent conillrises any of the l>llo\\hg either alone or in combination: silver sulphadiazine, silver colaiing zeolites' sillier containing phosphate glasses and anti- microbial essential oils 1b 7. A liquid bandage compo.sitirn according t<, cl,in 26, wherein said anti-microbial essential oils comprises any of flee loll'wing either Bloc or in combination: lavender oil, tea tree oil, lemongrass oil, bay oil Ad oregano oil.

   28. A liquid bandage conpo.silioimaccorcling Ski idly prccedhO claim, wherein the composition is white in colour in bulk yet is lansparent wlc' rppJied to the skin as a film.

   29. A liquid bandage conpositiomaccording t c lesion 0S, wherein the opacity of the bulk colour of the composition acts to StOlJiliZ.C a constituent silver containing anti-microbial agent Iron; light sensitive degrdair->n II]CrebY avoiding rliscolocration.

   30. A liquid bandage conp>siti according t<, My preceding claim, wherein the composition may be applied to a n.turc scar to bring albeit. cosmetic improvement in the appearance of the scar.

   31. A liquid bandage copositi according to any preceding claim, wherein the composition may comprise an additive selected frolic Bloc groups comprising pharmaceuticals, anti- inflammatory agents, rllr.rvi'let light absorlcrs cuollients, vitamins and herbal extracts.

   32. A liquid bandage conpositicn according t<, My precedhg claim, wherein the composition has an absolute viscosity c'I 1()() centipoise t '7.(),() ()() centipoise.

   33. A liquid bandage conpositi accordin<, t;i'V preceding claim, wherein the composition has an absolute viscosi ty 1.()() centipoise t> I ()(),() ()() centipoise.

   34. A liquid bandage conpositii', accorclig<' i<; oily preceding claim, wherein the composition has an absolute viscosity 1 I,OOO centipcisc tr' 5(),()00 centipoise.

   35. A liquid bandage conpositi according, ally preceding claim, wherein the composition having a viscosity in excess 1 50,()0() cc,lip'isc float exhibits thixotropy rendering it easy to spread on the surface >I tle shin 36. A liquid bandage compositions accortlin t' ally Acceding claim, wherein the composition is applied topically to tick target site of a wound or l urn or scar.

   37. A liquid bandage compositii accordhg tic My prececling claim, wherein the composition is dispensed Irom a spra! to bloc target site,I;, x orncl or burn or scar.