EP1959931A2 - Compositions and methods for dermally treating pain - Google Patents
Compositions and methods for dermally treating painInfo
- Publication number
- EP1959931A2 EP1959931A2 EP06848632A EP06848632A EP1959931A2 EP 1959931 A2 EP1959931 A2 EP 1959931A2 EP 06848632 A EP06848632 A EP 06848632A EP 06848632 A EP06848632 A EP 06848632A EP 1959931 A2 EP1959931 A2 EP 1959931A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- formulation
- volatile solvent
- pain
- drug
- solidified layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/0012—Galenical forms characterised by the site of application
- A61K9/0014—Skin, i.e. galenical aspects of topical compositions
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P21/00—Drugs for disorders of the muscular or neuromuscular system
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P25/00—Drugs for disorders of the nervous system
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P29/00—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
- A61K47/06—Organic compounds, e.g. natural or synthetic hydrocarbons, polyolefins, mineral oil, petrolatum or ozokerite
- A61K47/08—Organic compounds, e.g. natural or synthetic hydrocarbons, polyolefins, mineral oil, petrolatum or ozokerite containing oxygen, e.g. ethers, acetals, ketones, quinones, aldehydes, peroxides
- A61K47/10—Alcohols; Phenols; Salts thereof, e.g. glycerol; Polyethylene glycols [PEG]; Poloxamers; PEG/POE alkyl ethers
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
- A61K47/06—Organic compounds, e.g. natural or synthetic hydrocarbons, polyolefins, mineral oil, petrolatum or ozokerite
- A61K47/16—Organic compounds, e.g. natural or synthetic hydrocarbons, polyolefins, mineral oil, petrolatum or ozokerite containing nitrogen, e.g. nitro-, nitroso-, azo-compounds, nitriles, cyanates
- A61K47/18—Amines; Amides; Ureas; Quaternary ammonium compounds; Amino acids; Oligopeptides having up to five amino acids
Definitions
- the present invention relates generally to formulations and methods for treating musculoskeletal or neuropathic pain. More particularly, the present invention relates to adhesive formulations having a viscosity suitable for application to a skin surface and which form a transdermal drug-delivering solidified layer on the skin.
- Pain can be caused by a variety of sources.
- neuropathic pain can be caused by diseases such as viral infections and diabetes.
- post herpetic neuralgia is caused by herpes viral infection and typically causes moderate to severe pain in the infected skin area to the subject.
- Topical products such as creams or patches containing appropriate drugs, may be used to control neuropathic pain; however, patches and traditional semisolid formulations such as creams and ointments both have significant shortcomings.
- Semisolid formulations usually contain solvent(s), such as water and ethanol, which are volatile and thus evaporate shortly after application. The evaporation of such solvents can cause significant decrease or even termination of dermal drug delivery, which can be undesirable in many cases.
- semisolid formulations are often "rubbed into” the skin, which does not necessarily mean the drug formulation is actually delivered into the skin. Instead, this phrase often means that a very thin layer of the drug formulation is applied onto the surface of the skin. Such thin layers of traditional semisolid formulations applied to the skin may not contain sufficient quantity of the active drug to achieve sustained delivery over long periods of time, which can be desirable in treating neuropathic pain. Additionally, traditional semisolid formulations are often subject to unintentional removal due to contact with objects such as clothing, which may compromise the sustained delivery and/or undesirably soil clothing.
- neuropathic paint The musculoskeletal system is also a common source of pain.
- current topical dosage forms for those drugs are not typically adequate for this application.
- semisolid NSAID and local anesthetic formulations such as creams and gels, usually contain solvent(s), such as water and ethanol, which are volatile and thus evaporate shortly after application. The evaporation of such solvents can cause significant decrease or even termination of topical drug absorption
- a patch containing an appropriate drug can be used to treat neuropathic or musculoskeletal pain.
- subjects often have to cut the patch to fit the shape and size of the skin area to be treated, which is inconvenient.
- Another shortcoming of patches is that they are usually neither sufficiently stretchable nor flexible for every application location. If the patch is applied on a skin area that is significantly stretched during body movements, such as joints and muscles, separation between the patch and skin may occur, thereby compromising the delivery of the drug.
- a patch on a skin surface may hinder the expansion of the skin during body movements and cause discomfort and/or aggravate pain.
- patches are not ideal dosage forms for skin areas subject to expansion and stretching during body movements.
- reservoir patches even when a drug is compatible with a particular liquid or semisolid solvent system carried by the thin bag of the patch, the solvent system still has to be compatible to the adhesive layer coated on the permeable or the semi-permeable membrane otherwise the drug may be adversely affected by the adhesive layer or the drug/solvent system may reduce the tackiness of the adhesive layer.
- reservoir patches are usually more expensive to manufacture than matrix patches.
- dermal (including transdermal) patches are usually not stretchable or flexible, as the backing film (in matrix patches) and the thin fluid bag (in reservoir patches) are typically made of polyethylene or polyester, both of which are relatively non-stretchable materials.
- patches are not ideal dosage forms for skin areas over muscle and joints that are subject to expansion and stretch during body movements.
- a formulation for treating musculoskeletal or neuropathic pain can comprise a drug suitable for treating musculoskeletal or neuropathic pain, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system comprising at least one volatile solvent, and a non-volatile solvent system comprising at least one non-volatile solvent, wherein the non-volatile solvent system is capable of facilitating transdermal delivery of the drug at a therapeutically effective rate over a sustained period of time.
- the formulation can have a viscosity suitable for application and adhesion to a skin surface prior to evaporation of the volatile solvent system, and further, the formulation applied to the skin surface can form a solidified layer after at least partial evaporation of the volatile solvent system.
- the drug can continue to be delivered at the therapeutically effective rate to treat musculoskeletal pain or inflammation after the volatile solvent system is at least substantially evaporated.
- a method of dermally delivering a drug for treating musculoskeletal or neuropathic pain can comprise applying a formulation to a skin surface.
- the formulation can be a formulation as described in the previous embodiment. Additional steps include solidifying the formulation to form a solidified layer on the skin surface by at least partial evaporation of the volatile solvent system; and dermally delivering the drug from the solidified layer to the skin surface at therapeutically effective rates for treating the pain or inflammation of joints or muscles over a sustained period of time.
- a solidified layer for treating pain can comprise a drug effective for treating musculoskeletal or neuropathic pain, a non-volatile solvent system, and a solidifying agent.
- the non-volatile solvent system can include at least one non-volatile solvent, wherein the non-volatile solvent system is capable of facilitating the delivery of the drug at therapeutically effective rates over a sustained period of time.
- the solidified layer preferably can be stretchable by 5% in at least one direction without cracking, breaking, and/or separating from a skin surface to which the layer is applied.
- FIG. 1 is a graphical representation of the cumulative amount of diclofenac delivered transdermal ⁇ across human cadaver skin over time from a formulation in accordance with embodiments of the present invention where steady-state delivery is shown over 28 hours;
- FIG. 2 is a graphical representation of the cumulative amount of ropivacaine delivered transdermally across human cadaver skin over time from a formulation with similar composition in accordance with embodiments of the present invention, where steady-state delivery is shown over 30 hours.
- Skin is defined to include human skin (intact, diseased, ulcerous, or broken), finger and toe nail surfaces, and mucosal surfaces that are usually at least partially exposed to air such as lips, genital and anal mucosa, and nasal and oral mucosa.
- musculoskeletal pain or inflammation includes pain and/or inflammation of joints, tendons, ligaments, muscles, bones, synovial fluids, and/or soft tissues which are part of the musculoskeletal system.
- neuroopathic pain includes pain associated with the nervous system, including the brain, spinal cord, or the peripheral nervous system. Neuropathic pain can be chronic or acute and can occur as a result of trauma, disease, or other factors.
- drug(s) refers to active agents that can be used with the formulations of the present invention and are effective in treating either neuropathic or musculoskeletal pain.
- drugs which can be used to treat musculoskeletal pain include NSAIDs, local anesthetics, steroid drugs, and/or 5-HT2A receptor antagonists.
- An example of a 5-HT2A receptor antagonist includes but is not limited to ketanserin.
- NSAIDS include but are not limited to ketoprofen, piroxicam, diclofenac, indomethacin, and COX inhibitors.
- local anesthetics include but are not limited to lidocaine, bupivacaine, ropivacaine, and tetracaine.
- Examples of steroid drugs for use in the present invention include but are not limited to dexamethasone, hydrocortisone, prednisone, prednisolone, methylprednisolone, halobetasol propionate, betamethasone dipropionate, betamethasone, prodrugs thereof, or combinations thereof.
- drugs suitable for treating neuropathic pain include, without limitation, local anesthetics including lidocaine, bupivacaine, ropivacaine, and tetracaine; steroids including dexamethasone; alpha-2 agonists including clonidine; tricyclic anti-depressants including amitriptyline, anticonvulsants, N-methyl-D-aspartate (NMDA) antagonists including dextromethorphan, memantine, amantadine, ketamine, methadone, dextropropoxyphene, and ketobemidone; antiviral drugs including acyclovir, penciclovir, famciclovir, valacyclovir steroids; 5-HT2A receptor antagonist including ketanserin; or combinations thereof.
- local anesthetics including lidocaine, bupivacaine, ropivacaine, and tetracaine
- steroids including dexamethasone
- alpha-2 agonists including clonidine
- drug When referring generally to a "drug,” it is understood that there are various forms of a given drug, and those various forms are expressly included. In accordance with this, various drug forms include polymorphs, salts, hydrates, solvates, and cocrystals.
- one physical form of a drug may possess better physical-chemical properties making it more amenable for getting to, into, or through the skin, and this particular form is defined as the "physical form favorable for dermal delivery.”
- the steady state flux of diclofenac sodium from flux enabling non-volatile solvents is much higher than the steady state flux of diclofenac acid from the same flux enabling nonvolatile solvents. It is therefore desirable to evaluate the flux of the physical • forms of a drug from non-volatile solvents to select a desirable physical form/non-volatile solvent combination.
- NSAID or “non-steroidal anti-inflammatory drug” include all the non-steroidal anti-inflammatory agents, general COX inhibitors, COX-2 selective, inhibitors, and COX-3 selective inhibitors.
- transdermal drug delivery or “dermal delivery of drug(s)” shall include both transdermal and topical drug delivery, and includes the delivery of drug(s) to, through, or into the skin.
- Transdermal delivery of drug can be targeted to skin tissues just under the skin, regional tissues or organs under the skin, systemic circulation, and/or the central nervous system.
- flux such as in the context of "dermal flux” or “transdermal flux,” respectively, refers to the quantity of the drug permeated into or across skin per unit area per unit time. A typical unit of flux is microgram per square centimeter per hour.
- One way to measure flux is to place the formulation on a known skin area of a human volunteer and measure how much drug can permeate into or across skin within certain time constraints.
- Various methods ⁇ in vivo methods) might be used for the measurements as well.
- the method described in Example 1 or other similar method ⁇ in vitro methods can also be used to measure flux.
- flux values set forth herein can mean that measured by either in vivo or in vitro methods.
- the term "flux-enabling" with respect to the non-volatile solvent system refers to a non-volatile solvent system (including one or more non-volatile solvents) selected or formulated specifically to be able to provide therapeutically effective flux for a particular drug(s).
- a flux enabling non-volatile solvent system is defined as a non-volatile solvent system which, alone without the help of any other ingredients, is capable of delivering therapeutic sufficient levels of the drug across, onto or into the subject's skin when the non-volatile solvent " system is saturated with the drug.
- a flux enabling non-volatile solvent system is a non-volatile solvent system that can provide therapetucially sufficient daily doses over 24 hours when the nonvolatile solvent system is saturated with the drug and is in full contact with the subject's skin with no more than 500 cm 2 contact area.
- the contact area for the non-volatile solvent system is no more than 100 cm 2 .
- Testing using this saturated drug-in-solvent state can be used to measure the maximum flux- generating ability of a non-volatile solvent system.
- the drug solvent mixture needs to be kept on the skin for a clinically sufficient amount of time. In reality, it may be difficult to keep a liquid solvent on the skin of a human volunteer for an extended period of time. Therefore, ah alternative method to determine whether a solvent system is "flux-enabling" is to measure the in vitro drug permeation across the hairless mouse skin or human cadaver skin using the apparatus and method described in Example 1. This and similar methods are commonly used by those skilled in the art to evaluate permeability and feasibility of formulations.
- whether a non-volatile solvent system is flux-enabling can be tested on the skin of a live human subject with means to maintain the non-volatile solvent system with saturated drug on the skin, and such means may not be practical for a product.
- the non-volatile solvent system with saturated drug can be soaked into an absorbent fabric material which is then applied on the skin and covered with a protective membrane.
- Such a system is not practical as a pharmaceutical product,, but is appropriate for testing whether a non-volatile solvent system has the intrinsic ability to provide sufficient drug flux, or whether it is flux-enabling.
- the solidified layer can also be "flux enabling" for the drug while some of the nonvolatile solvents remain in the solidified layer, even after the volatile solvents (including water) have been substantially evaporated.
- a non-volatile solvent system would be "flux enabling" if it is capable of generating a flux of at least about 20 mcg/cm 2 /hour in a setup same or similar to that described in Example 1.
- tetracaine and ropivacaine For tetracaine and ropivacaine .
- a non-volatile solvent system would be "flux enabling” if it is capable of generating a flux of at least about 5 mcg/cm 2 /hour in a setup the same or similar to that described in Example 1.
- a non-volatile solvent system would be "flux enabling” if it is capable of generating a flux of at least about 5 mcg/cm 2 /hour in the same or similar setup to that described in Example 1.
- non-volatile solvent system suitable for the selected drug can be a single chemical substance or a mixture of two or more chemical substances.
- the non-volatile solvent system of ISA+trolamine can generate more flux than the non-volatile solvent system of pure ISA, though both are probably suitable for certain applications.
- an "effective amount,” “therapeutically effective amount,” “therapeutically effective rate(s),” or the like, as it relates to a drug refers to sufficient amounts or delivery rates of a drug which achieves any appreciable level of therapeutic results in treating a condition for which the drug is being delivered. It is understood that “appreciable level of therapeutic results” may or may not meet any government agencies' efficacy standards for approving the commercialization of a product. It is understood that various biological factors may affect the ability of a substance to perform its intended task. Therefore, an "effective amount,” “therapeutically effective amount,” or “therapeutically effective rate(s)” may be dependent in some instances on such biological factors to some degree.
- “Therapeutically effective flux” is defined as the permeation flux of the selected drug that delivers sufficient amount of drug into or across the skin to be clinically beneficial in that some of the patient population can obtain some degree of benefit from the drug flux. It does not necessarily mean that most of the patient population can obtain some degree of benefit or the benefit is high enough to be deemed “effective” by relevant government agencies or the medical profession. More specifically, for drugs that target skin or regional tissues or organs close to the skin surface (such as joints, certain muscles, or tissues/organs that are at least partially within 5 cm of the skin surface),
- therapeutically effective flux refers to the drug flux that can deliver a sufficient amount of the drug into the target tissues within a clinically reasonable amount of time.
- therapeutically effective flux refers to drug flux that, via clinically reasonable skin contact area, can deliver sufficient amounts of the selected drug to generate clinically beneficial plasma or blood drug concentrations within a clinically reasonable time.
- Clinically reasonable skin contact area is defined as a size of skin application area that most subjects would accept. Typically, a skin contact area of 400 cm 2 or less is considered reasonable.
- the flux needs to be at least 4000 mcg/400cm 2 /10 hour, which equals 1 mcg/cm 2 /hr.
- different drugs have different "therapeutically effective flux.” Additionally, therapeutically effective flux may be different in different subjects and or at different times for even the same subject. However, for each drug, there is usually a consensus among the skilled in the art on the range of doses or fluxes that are sufficient in most subjects at most times.
- the solidifying agent is defined as a nonvolatile solvent (or a non-volatile solvent system) that acts as a plasticizer for the solidifying agent.
- a "plasticizer” is an agent which is capable of providing the flexibility and/or elasticity of the solidified formulation layer after the volatile solvent system has at least substantially evaporated. Plasticizers also have the capability to reduce the brittleness of solidified formulation by making it more flexible and/or elastic.
- propylene glycol is a plasticizing nonvolatile solvent for a solidifying formulation with ketoprofen as the drug and polyvinyl alcohol as the selected solidifying agent.
- propylene glycol in a solidifying formulation of ketoprofen with Gantrez S-97 or Avalure UR 405 as solidifying agents does not provide the same plasticizing effect.
- the combination of propylene glycol and Gantrez S-97 or Avalure UR 405 is less compatible and results in less desirable formulation for topical applications. Therefore, whether a given non-volatile solvent is "plasticizing" depends on which solidifying agent(s) is selected.
- flux-enabling non-volatile solvent can be a single chemical substance or a mixture of two or more chemical substances.
- the steady state flux value for clobetasol propionate in Table C is a 9:1 for propylene glycokisostearic acid mixture that generated much higher clobetasol flux than propylene glycol or ISA alone (see Table B). Therefore, the 9:1 propylene glycohisostearic acid mixture is a "high flux- enabling non-volatile solvent” but propylene glycol or isostearic acid alone is not.
- adheresion or "adhesive” when referring to a solidified layer herein refers to sufficient adhesion between the solidified layer and the skin so that the layer does not fall off the skin during intended use on most subjects.
- adheresive or the like when used to describe the solidified layer means the solidified layer is adhesive to the body surface to which the initial formulation layer was originally applied (before the evaporation of the volatile solvent(s)). In one embodiment, it does not mean the solidified layer is adhesive on the opposing side.
- whether a solidified layer can adhere to a skin surface for the desired extended period of time partially depends on the condition of the body surface.
- the adhesive solidified layer of the current invention may not be able to maintain perfect contact with the body surface and deliver the drug over a sustained period of time for every subject under any conditions on the body surface.
- a standard is that it maintains good contact with most of the body surface, e.g. 70% of the total area, over the specified period of time for most subjects under normal conditions of the body surface and external environment.
- a solidified layer that exhibits acceptably elasticity and adhesion to skin can be attached to human skin over a flexible skin location, e.g., elbow, finger, wrist, neck, lower back, lips, knee, etc., and will remain substantially intact on the skin upon stretching of the skin. It should be noted that the solidified layers of the present invention do not necessarily have to have any elasticity in some embodiments.
- peelable when used to describe the solidified layer, means the solidified layer can be lifted from the skin surface in one large piece or several large pieces, as opposed to many small pieces or crumbs.
- the term "sustained” relates to therapeutically effective rates of dermal drug delivery for a continuous period of time of at least 30 minutes, and in some embodiments, periods of time of at least about 2 hours, 4 hours, 8 hours, 12 hours, 24 hours, or longer.
- the use of the term “substantially” when referring to the evaporation of the volatile solvents means that a majority of the volatile solvents which were included in the initial formulation have evaporated.
- a solidified layer is said to be “substantially devoid” of volatile solvents, including water, the solidified layer has less than 10 wt%, and preferably less than 5 wt%, of the volatile solvents in the solidified layer as a whole.
- Volatile solvent system can be a single solvent or a mixture of solvents that are volatile, including water and solvents that are more volatile than water.
- volatile solvents that can be used in the present invention include iso-amyl acetate, denatured alcohol, methanol, ethanol, isopropyl alcohol, water, propanol, C4-C6 hydrocarbons, butane, isobutene, pentane, hexane, acetone, chlorobutanol, ethyl acetate, fluro-chloro- hydrocarbons, turpentine, methyl ethyl ketone, methyl ether, hydrofluorocarbons, ethyl ether, 1 ,1 ,1 ,2 tetrafluorethane 1 ,1 ,1 ,2,3,3,3-heptafluoropropane, 1 ,1 ,1 ,3,3,3 hexafluoropropane, or combinations
- Non-volatile solvent system can be a single solvent or mixture of solvents that are less volatile than water. It can also contain substances that are solid or liquid at room temperatures, such as pH or ion-pairing agents. After evaporation of the volatile solvent system, most of the non-volatile solvent system should remain in the solidified layer for an amount of time sufficient to dermally delivery a given drug to, into, or through the skin of a subject at a sufficient flux for a period of time to provide a therapeutic effect. In some embodiments, in order to obtain desired permeability for an active drug and/or compatibility with solidifying agents or other ingredients of the formulation, a mixture of two or more non-volatile solvents can be used to form the non-volatile solvent system.
- the combination of two or more non- volatile solvents to form a solvent system provides a higher transdermal flux for a drug than the flux provided for the drug by each of the non-volatile solvents individually.
- the non-volatile solvent system may also serve as a plasticizer of the solidified layer, so that the solidified layer is elastic and flexible.
- solvent vehicle describes compositions that include both a volatile solvent system and non-volatile solvent system.
- the volatile solvent system is chosen so as to evaporate from the adhesive peelable formulation quickly to form a solidified layer, and the non-volatile solvent system is formulated or chosen to substantially remain as part of the solidified layer after volatile solvent system evaporation so as to provide continued delivery of the drug.
- the drug can be partially or completely dissolved in the solvent vehicle or formulation as a whole.
- the drug can also be partially or completely solubilizable in the non-volatile solvent system once the volatile solvent system is evaporated.
- Formulations in which the drug is only partially dissolved in the non-volatile solvent system after the evaporation of the volatile solvent system have the potential to maintain longer duration of sustained delivery, as the undissolved drug can dissolve into the non-volatile solvent system as the dissolved drug is being depleted from the solidified layer during drug delivery.
- Adhesive solidifying formulation refers to a composition that has a viscosity suitable for application to a skin surface prior to evaporation of its volatile solvent(s), and which can become a solidified layer after evaporation of at least a portion of the volatile solvent(s).
- the solidified layer once formed, can be very durable.
- the formulation once solidified on a skin surface, can form a peel.
- the peel can be a soft, coherent solid that can be removed by peeling large pieces from the skin relative to the size of the applied formulation, and often, can be peeled from the skin as a single piece.
- the application viscosity is typically more viscous than a water-like liquid, but less viscous than a soft solid.
- Examples of preferred viscosities include materials that have consistencies similar to pastes, gels, ointments, and the like, e.g., viscous liquids that flow but are not subject to spilling.
- a composition is said to have a viscosity "suitable for application" to a skin surface, this means the composition has a viscosity that is high enough so that the composition does not substantially run off the skin after being applied to skin, but also has a low enough viscosity so that it can be easily spread onto the skin.
- a viscosity range that meets this definition can be from about 100 cP to about 3,000,000 cP (centipoises), and more preferably from about 1 ,000 cP to about 1 ,000,000 cP.
- an additional agent or substance to the formulation so as to provide enhanced or increased adhesive characteristics.
- the additional adhesive agent or substance can be an additional non-volatile solvent or an additional solidifying agent.
- Non-limiting examples of substances which might be used as additional adhesion enhancing agents include copolymers of methylvinyl ether and maleic anhydride (Gantrez polymers), polyethylene glycol and polyvinyl pyrrolidone, gelatin, low molecular weight polyisobutylene rubber, copolymer of acrylsan alkyl/octylacrylamido (Dermacryl 79), and various aliphatic resins and aromatic resins.
- washable when used with respect to the adhesive formulations of the present invention refers to the ability of the adhesive formulation to be removed by the application of a washing solvent using a normal or medium amount of washing force.
- the required force to remove the formulations by washing should not cause significant skin irritation or abrasion.
- gentle washing force accompanied by the application of an appropriate washing solvent is sufficient to remove the adhesive formulations disclosed herein.
- the solvents which can be used for removing by washing the formulations of the present invention are numerous, but preferably are chosen from commonly acceptable solvents including the volatile solvents listed herein. Preferred washing solvents do not significantly irritate human skin and are generally available to the average subject.
- washing solvents include but are not limited to water, ethanol, methanol, isopropyl alcohol, acetone, ethyl acetate, propanol, or combinations thereof.
- the washing solvents can be selected from the group consisting of water, ethanol, isopropyl alcohol, or combinations thereof.
- Surfactants can also be used in some embodiments.
- drying time refers to the time it takes for the formulation to form a non-messy solidified surface after application on skin under standard skin and ambient conditions, and with standard testing procedure. It is noted that the word “drying time” in this application does not mean the time it takes to completely evaporate off the volatile solvent(s). Instead, it means the time it takes to form the non-messy solidified surface as described above.
- Standard skin is defined as dry, healthy human skin with a surface temperature of between about 30 0 C to about 36 0 C.
- Standard ambient conditions are defined by the temperature range of from 20 0 C to 25°C and a relative humidity range of from 20% to 80%.
- the term "standard skin” in no way limits the types of skin or skin conditions on which the formulations of the present invention can be used.
- the formulations of the present invention can be used to treat all types of "skin,” including undamaged (standard skin), diseased skin, or damaged skin.
- skin conditions having different characteristics can be treated using the formulations of the present invention, the use of the term "standard skin” is used merely as a standard to test the compositions of the varying embodiments of the present invention.
- formulations that perform well e.g., solidify, provide therapeutically effective flux, etc.
- the "standard testing procedure” or “standard testing condition” is as follows: To standard skin at standard ambient conditions is applied an approximately 0.1 mm layer of the adhesive solidifying formulation and the drying time is measured. The drying time is defined as the time it takes for the formulation to form a non-messy surface such that the formulation does not lose mass by adhesion to a piece of 100% cotton cloth pressed onto the formulation surface with a pressure of between about 5 and about 10 g/cm 2 for 5 seconds.
- Solidified layer describes the solidified or dried layer of an adhesive solidifying formulation after at least a portion of the volatile solvent system has evaporated.
- the solidified layer remains adhered to the skin, and is preferably capable of maintaining good contact with the subject's skin for substantially the entire duration of application under standard skin and ambient conditions.
- the solidified layer also preferably exhibits sufficient tensile strength so that it can be peeled off the skin at the end of the application in one piece or several large pieces (as opposed to a layer with weak tensile strength that breaks into many small pieces or crumbles when removed from the skin).
- a formulation for treating musculoskeletal pain or inflammation can comprise a drug suitable for treating musculoskeletal pain or inflammation, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one non-volatile solvent, wherein the non-volatile solvent system is capable of facilitating transdermal delivery of the drug at a therapeutically effective rate over a sustained period of time.
- the formulation can have a viscosity suitable for application and adhesion to a skin surface as a layer prior to evaporation of the volatile solvent system, and further, the formulation applied to the skin surface can form a solidified layer after at least partial evaporation of the volatile solvent system.
- the drug can continue to be delivered at the therapeutically effective rate to treat musculoskeletal pain or inflammation after the volatile solvent system is at least substantially evaporated.
- a method of dermally delivering a drug for treating pain or inflammation of joints or muscles can comprise applying an adhesive solidifying formulation to a skin surface adjacent to the tissue suffering from the pain or inflammation (for example, the skin surface of a knee suffering from arthritis or the skin of lower back which is suffering from lower back pain) .
- the adhesive solidifying formulation can comprise a drug suitable for treating musculoskeletal pain or inflammation, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one non-volatile solvent, wherein the non-volatile solvent system is capable of facilitating dermal delivery of the drug at a therapeutically effective rate over a sustained period of time.
- the formulation can have a viscosity suitable for application and adhesion to the skin surface prior to evaporation of the volatile solvent system. Additional steps include solidifying the formulation to form a solidified layer on the skin surface by at least partial evaporation of the volatile solvent system; and dermally delivering the drug from the solidified layer to the skin surface at therapeutically effective rates for treating the pain or inflammation of joints or muscles over a sustained period of time.
- a solidified layer for treating musculoskeletal pain or inflammation can comprise a drug effective for treating musculoskeletal pain or inflammation, a non-volatile solvent system, and a solidifying agent.
- the non-volatile solvent system can include at least one non-volatile solvent, wherein the non-volatile solvent system is capable of facilitating the delivery of the drug at therapeutically effective rates over a sustained period of time.
- the solidified layer can be stretchable by 5% in at least one direction without cracking, breaking, and/or separating from a skin surface to which the layer is applied.
- a formulation for treating musculoskeletal pain or inflammation can comprise ropivacaine, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can include a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one solvent selected from the group consisting of triacetin, span 20, isostearic acid, or combinations thereof.
- the ropivacaine can either be in base or salt form.
- the formulation has a viscosity suitable for application to a skin surface prior to evaporation of the volatile, solvent system, and can be applied to the . skin surface to form a solidified, coherent, flexible, and continuous layer after at least partial evaporation of the volatile solvent system.
- the ropivacaine can continue to be delivered at a transdermal flux of at least 5 mcg/cm 2 /hour after the volatile solvent system is at least substantially all evaporated.
- the transdermal flux can be at least 10 mcg/cm 2 /hour after the volatile solvent system is at least substantially all evaporated from the . solidified layer.
- a formulation for treating musculoskeletal pain or inflammation can comprise lidocaine, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can include a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one solvent selected from the group consisting of propylene glycol and dipropylene glycol.
- the lidocaine can be in either base or salt form.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system, and can be applied to the skin surface to form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the lidocaine can continue to be delivered at a transdermal flux of at least 20 mcg/cm 2 /hour after the volatile solvent system is at least substantially all evaporated fro the solidified layer.
- a formulation for treating musculoskeletal pain or inflammation can comprise ketoprofen, a solvent vehicle, and a solidifying agent.
- the solidifying agent can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one solvent selected from the group consisting of propylene glycol and glycerol, isostearic acid, and triacetin.
- the ketoprofen can be in either base or salt form.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system, and can be applied to the skin surface to form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the ketoprofen can continue to be delivered at a transdermal flux of at least 10 mcg/cm 2 /hour after the volatile solvent system is at least substantially all evaporated fro the solidified layer.
- a formulation for treating musculoskeletal pain or inflammation can comprise tetracaine, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one solvent selected from the group consisting of propylene glycol and isostearic acid.
- the tetracaine can be in either base or salt form.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system, and can be applied to the skin surface to form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the tetracaine can continue to be delivered. at a transdermal flux of at least 5 mcg/cm 2 /hour after the volatile solvent system is at least substantially all evaporated fro the solidified layer.
- a formulation for treating musculoskeletal pain or inflammation can comprise lidocaine and tetracaine, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one solvent selected from the group consisting of propylene glycol and dipropylene glycol, and isostearic acid.
- the tetracaine and lidocaine can be in either base or salt form.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system, and can be applied to the skin surface to form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the tetracaine and lidocaine can continue to be delivered at a transdermal flux of at least 5 mcg/cm 2 /hour, respectively, after the volatile solvent system is at least substantially all evaporated from the solidified layer.
- a formulation for treating musculoskeletal pain or inflammation can comprise a drug include at least one member from the group consisting of lidocaine, tetracaine, ropivacaine, ketoprofen, diclofenac, or combinations thereof; a solvent vehicle; and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including a volatile solvent whose boiling point is below 20 0 C, and a non-volatile solvent system comprising at least one non-volatile solvent.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system, and can be applied to the skin surface to a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the drug can continue to be delivered at a therapeutically effective rate after the volatile solvent system is at least substantially all evaporated.
- a formulation for treating neuropathic pain can comprise a drug suitable for treating neuropathic pain, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can include a volatile solvent system comprising at least one volatile solvent, and a non-volatile solvent system comprising at least one non-volatile solvent.
- the non-volatile solvent system facilitates dermal delivery of the drug at a therapeutically effective rate over a sustained period of time.
- the formulation can have a viscosity suitable for application and adhesion to a skin surface as a layer prior to evaporation of the volatile solvent system.
- the formulation applied to the skin surface can form a solidified layer after at least partial evaporation of the volatile solvent system. Further, the drug can continue to be delivered at the therapeutically effective rate after the volatile solvent system is at least substantially evaporated.
- a method for treating neuropathic pain can comprise the step of applying a layer of an adhesive formulation to a skin surface of a subject.
- the formulation can comprise a drug suitable for treating neuropathic pain, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one non-volatile solvent.
- the non-volatile solvent system facilitates dermal delivery of the drug at a therapeutically effective rate over a sustained period of time.
- the formulation can have a viscosity suitable for application and adhesion to a skin surface prior to evaporation of the volatile solvent system.
- Additional steps include solidifying the formulation to form a solidified layer on the skin surface by at least partial evaporation of the volatile solvent system; and dermally delivering the drug from the solidified layer to the subject at therapeutically effective rates over a sustained period of time to reduce the neuropathic pain.
- a solidified layer for treating neuropathic pain can comprise a drug suitable for treating neuropathic pain, a non-volatile solvent system suitable for the drug, and a solidifying agent.
- the solidified layer can have sufficient elasticity, flexibility, and adhesion to the skin so that it is not separated from the skin even if the skin surface is stretched or bent during. a subject's normal daily activities.
- the solidified layer can be stretchable by 5% in one direction without cracking, breaking, and/or separating from a skin surface to which the layer is applied.
- a formulation for treating neuropathic pain can comprise ropivacaine, a solvent vehicle, and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system can include at least one solvent selected from the group consisting of an amine base, triacetin, span 20, isostearic acid, or a mixture thereof.
- the solidifying agent can include butyl and methyl methacrylate copolymers.
- the formulation can have a viscosity suitable for application to a skin surface as a layer prior to evaporation of the volatile solvent system. Further, formulation layer applied to the skin surface can form a solidified, coherent, flexible, and continuous layer after at least partial evaporation of the volatile solvent system.
- the ropivapaine can also continue to be delivered at a therapeutically effective rate after the volatile solvent system is at least substantially all evaporated.
- a formulation for treating neuropathic pain associated with viral infections can comprise a drug, a solvent vehicle, and a solidifying agent.
- the drug can include at least one member selected from the group consisting of acyclovir, valacyclovir, and pencyclovir.
- the solvent vehicle can include a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system comprising at least one solvent selected from the group of oleic acid, isostearic acid, and olive oil.
- the solidifying agent can be selected from the group consisting of ethyl acrylate-methyl methacrylate- trimethylammonioethyl methacrylate chloride copolymers, butyl and methyl methacrylae copolymers, and ethyl cellulose.
- the formulation can have a viscosity suitable for application to a skin surface as a layer prior to evaporation of the volatile solvent system. Further, formulation applied to the skin surface can form a solidified, coherent, flexible, and continuous layer after at least partial evaporation of the volatile solvent system.
- the drug can also continue to be delivered at a therapeutically effective rate after the volatile solvent system is at least substantially all evaporated.
- a formulation for treating neuropathic pain can comprise a local anesthetic selected from the group consisting of lidocaine, tetracaine, and a combination thereof; a solvent vehicle; and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system including at least one solvent selected from the group consisting of propylene glycol and dipropylene glycol.
- the local anesthetic can be in either base or salt form, and the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system.
- the formulation applied to the skin surface can form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system, and the local anesthetic can continue to be delivered at a therapeutically effective rate after the volatile solvent system is at least substantially all evaporated.
- a formulation for treating neuropathic pain can comprise a drug selected from the group consisting of amitriptyline, ketamine, and combinations thereof; a solvent vehicle; and a solidifying agent.
- the solvent vehicle can comprise a volatile solvent system including at least one volatile solvent, and a non-volatile solvent system comprising at least one nonvolatile solvent.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system.
- the formulation applied to the skin surface can form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the drug can continue to be delivered at a therapeutically effective rate after the volatile solvent system is at least substantially all evaporated.
- a formulation for treating neuropathic pain can comprise a drug selected from the group consisting of lidocaine, tetracaine, ropivacaine, amitriptyline, ketamine, and combinations thereof; a solvent vehicle; and a solidifying agent.
- the solvent vehicle can include a volatile solvent system comprising a volatile solvent whose boiling point is below 20 0 C, and a non-volatile solvent system comprising at least one non-volatile solvent.
- the formulation can have a viscosity suitable for application to a skin surface prior to evaporation of the volatile solvent system, and when applied to the skin surface, can form a solidified, coherent, flexible and continuous layer after at least partial evaporation of the volatile solvent system.
- the present invention is related to novel formulations, methods, and solidified layers that are typically in the initial form of semi-solids (including creams, gels, pastes, ointments, and other viscous liquids), which can be easily applied onto the skin as a layer, and can quickly (from 15 seconds to 4 minutes under standard skin and ambient conditions) to moderately quickly (from 4 to 15 minutes under standard skin and ambient conditions) change into a solidified layer, e.g., a coherent and soft solid layer for drug delivery for reducing musculoskeletal pain.
- semi-solids including creams, gels, pastes, ointments, and other viscous liquids
- the solidified layer thus formed is capable of delivering drug into or across the skin at therapeutically effective rates, over a sustained period of time, e.g., hours to tens of hours, so that most of the drug delivery occurs after the solidified layer is formed. Additionally, the solidified layer typically adheres to the skin, but has a solidified, minimally-adhering, outer surface which is formed relatively soon after application and which does not substantially transfer to or otherwise soil clothing or other objects that a subject is wearing or that the solidified layer may inadvertently contact.
- the solidified layer can also be formulated such that it is highly flexible and stretchable, and thus capable of maintaining good contact with the skin surface, even if the skin is stretched during body movement, such as at a knee, finger, elbow, wrist, finger, hip, neck, back, joints, or other areas where skin is typically stretched.
- the various components e.g., drug, solvent vehicle of volatile solvent system and non-volatile solvent system, solidifying agent(s), etc.
- certain variables can be considered.
- the volatile solvent system can be selected from pharmaceutically or cosmetically acceptable solvents known in the art.
- the volatile solvent system can include ethanol, isopropyl alcohol, water, dimethyl ether, diethyl ether, butane, propane, isobutene, 1 ,1 , difluoroethane, 1 ,1 ,1 ,2 tetrafluorethane, 1 ,1 ,1 ,2,3,3,3-heptafluoropropane, 1 ,1 ,1 ,3,3,3 hexafluoropropane, ethyl acetate, acetone, or combinations thereof.
- the volatile solvent system can include iso-amyl acetate, denatured alcohol, methanol, propanol, isobutene, pentane, hexane, chlorobutanol, turpentine, cytopentasiloxane, cyclomethicone, methyl ethyl ketone, or combinations thereof.
- the volatile solvent system can include a mixture or combination of any of the volatile solvents set forth in the embodiments above.
- volatile solvents should be chosen to be compatible with the rest of the formulation. It is desirable to use an appropriate weight percentage of the volatile solvent(s) in the formulation. Too much of the volatile solvent system prolongs the drying time. Too little of the volatile solvent system can make it difficult to spread the formulation on the skin.
- the weight percentage of the volatile solvent(s) can be from about 10 wt% to about 85 wt%, and more preferably from about 20 wt% to about 50 wt%.
- the non-volatile solvent system can also be chosen or formulated to be compatible with the solidifying agent, the drug, the volatile solvent, and any other ingredients that may be present.
- the solidifying agent can be chosen so that it is dispersible or soluble in the non-volatile solvent system.
- non-volatile solvent systems and solvent vehicles as a whole will be formulated appropriately after experimentation.
- certain drugs have good solubility in poly ethylene glycol (PEG) having a molecular weight of 400 (PEG 400, non-volatile solvent) but poor solubility in glycerol (non-volatile solvent) and water (volatile solvent).
- PEG 400 cannot effectively dissolve poly vinyl alcohol (PVA), and thus, is not very compatible alone with PVA, a solidifying agent.
- a non-solvent system including PEG 400 and glycerol (compatible with PVA) in an appropriate ratio can be formulated " , achieving a compatibility compromise.
- compatibility non-volatile solvent/solidifying agent incompatibility is observed when Span 20 is formulated into a formulation containing PVA. With this combination, Span 20 can separate out of the formulation and form an oily layer on the surface of the solidified layer.
- appropriate solidifying agent/nonvolatile solvent selections are desirable in developing a viable formulation and compatible combinations.
- Non-volatile solvent(s) that can be used alone or in combination to form non-volatile solvent systems can be selected from a variety of pharmaceutically acceptable liquids.
- the non-volatile solvent system can include glycerol, propylene glycol, isostearic acid, oleic acid, propylene glycol, trolamine, tromethamine, triacetin, sorbitan monolaurate, sorbitan monooleate, sorbitan monopalmitate, butanol, or combinations thereof.
- the non-volatile solvent system can include benzoic acid, butyl alcohol, dibutyl sebecate, diglycerides, dipropylene glycol, eugenol, fatty acids such as coconut oil, fish oil, palm oil, grape seed oil, isopropyl myristate, mineral oil, oleyl alcohol, vitamin E, triglycerides, sorbitan fatty acid surfactants, triethyl citrate, or combinations thereof.
- benzoic acid butyl alcohol, dibutyl sebecate, diglycerides, dipropylene glycol, eugenol, fatty acids such as coconut oil, fish oil, palm oil, grape seed oil, isopropyl myristate, mineral oil, oleyl alcohol, vitamin E, triglycerides, sorbitan fatty acid surfactants, triethyl citrate, or combinations thereof.
- the non-volatile solvent system can include 1 ,2,6-hexanetriol, alkyltriols, alkyldiols, acetyl monoglycerides, tocopherol, alkyl dioxolanes, p-propenylanisole, anise oil, apricot oil, dimethyl isosorbide, alkyl glucoside, benzyl alcohol, bees wax, benzyl benzoate, butylene glycol, caprylic/capric triglyceride, caramel, cassia oil, castor oil, cinnamaldehyde, cinnamon oil, clove oil, coconut oil, cocoa butter, cocoglycerides, coriander oil, com oil, coriander oil, corn syrup, cottonseed oil, cresol, cyclomethicone, diacetin, diacetylated monoglycerides, diethanolamine, dietthylene glycol monoethyl ether, diglycerides
- the non-volatile solvent system can also serve as plasticizer in the adhesive formulation so that when the solidified layer is formed, the layer is flexible, stretchable, and/or otherwise skin friendly.
- Plasticizers also have the capability to reduce the brittleness of solidified formulation by making it more flexible and/or elastic.
- propylene glycol is a plasticizing non-volatile solvent for a solidified layer with polyvinyl alcohol as the selected solidifying agent and ketoprofen as the drug.
- propylene glycol in a solidifying formulation with Gantrez S-97 or Avalure UR 405 as solidifying agents does not provide the same plasticizing effect.
- non-volatile solvent is "plasticizing” depends on which solidifying agent(s) is selected. Certain volatile and/or nonvolatile solvent(s) that are irritating to the skin may be desirable to use to achieve the desired solubility and/or permeability of the drug. It is also desirable to add compounds that are both capable of preventing or reducing skin irritation and are compatible with the formulation. For example, in a formulation where the volatile solvent is capable of irritating the skin, it would be helpful to use a non-volatile solvent that is capable of reducing skin irritation. Examples of solvents that are known to be capable of preventing or reducing skin irritation include, but are not limited to, glycerin, honey, and propylene glycol.
- the formulations of the present invention may also contain two or more non-volatile solvents that independently are not adequate non-volatile solvents for a. drug but when formulated together become an adequate non-volatile solvent.
- One possible reason for these initially non adequate non-volatile solvents to become adequate non-volatile solvents when formulated together may be due to the optimization of the ionization state of the drug to a physical form which has higher flux or the non-volatile solvents act in some other synergistic manner.
- One further benefit of the mixing of the non-volatile solvents is that it may optimize the pH of the formulation or the skin tissues under the formulation layer to minimize irritation.
- non-volatile solvents examples include but are not limited to isostearic acid /trolamine, isostearic acid /diisopropyl amine, oleic acid/trolamine, and propylene glycol /isostearic acid.
- the selection of the solidifying agent can also be carried out in consideration of the other components present in the adhesive formulation.
- An appropriate solidifying agent is compatible with the formulation such that the formulation is in liquid or semi-liquid state (e.g. cream, paste, gel, ointment) before any evaporation of the volatile solvent(s) and becomes a soft, coherent adhesive solidified layer after the evaporation of at least some of the volatile solvent(s).
- the solidifying agent can be selected or formulated to be compatible with the drug and the solvent vehicle (including the volatile solvent(s) and the non-volatile solvent system), as well as provide desired physical properties to the solidified layer once it is formed.
- the solidifying agent can be selected from a variety of agents.
- the solidifying agent can include polyvinyl alcohol with a MW range of 20,000-70,000 (Amresco), esters of polyvinylmethylether/maleic anhydride copolymer (ISP Gantrez ES-425 and Gantrez ES-225) with a MW range of 80,000-160,000, neutral copolymer of butyl methacrylate and methyl methacrylate (Degussa Plastoid B) with a MW range of 120,000-180,000, dimethylaminoethyl methacrylate-butyl methacrylate- methyl methacrylate copolymer (Degussa Eudragit E100) with a MW range of 100,000-200,000, ethyl acrylate-methyl methacrylate-trimethylammonioethyl methacrylate chloride copolymer with a MW greater than 5,000 or similar MW to Eudragit RLPO (Degussa), Zein (prolamine) with a MW greater than
- the solidifying agent can include ethyl cellulose, hydroxy ethyl cellulose, hydroxy methyl cellulose, hydroxy propyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, methyl cellulose, polyether amides, corn starch, pregelatinized corn starch, polyether amides, shellac, polyvinyl pyrrolidone, polyisobutylene rubber, polyvinyl acetate phthalate, or combinations thereof.
- the solidifying agent can include ammonia methacrylate, carrageenan, cellulose acetate phthalate aqueous such as CAPNF from Eastman, carboxy polymethylene, cellulose acetate (microcrystalline), cellulose polymers, divinyl benzene styrene, ethylene vinyl acetate, silicone, guar gum, guar rosin, gluten, casein, calcium caseinate, ammonium caseinate, sodium caseinate, potassium caseinate, methyl acrylate, microcrystalline wax, polyvinyl acetate, PVP ethyl cellulose, acrylate, PEG/PVP, xantham gum, trimethyl siloxysilicate, maleic acid/anhydride colymers, polacrilin, poloxamer, polyethylene oxide, poly glactic acid/poly-l-lactic acid, turpene resin, locust bean gum, acrylic copolymers, polyurethane dispersions, dextrin, polyvinyl alcohol-pol
- the solidifying agent can include a combination of solidifying agents set forth in the any of the above discussed embodiments.
- Other polymers may also be suitable as the solidifying agent, depending on the solvent vehicle components, the drug, and the specific functional requirements of the given formulation.
- Other polymers may also be suitable as the solidifying agent, depending on the solvent vehicle components, the drug, and the specific functional requirements of the given formulation.
- the additional adhesive agent or substance can be an additional non-volatile solvent or an additional solidifying agent.
- Non-limiting examples of substances which might be used as additional adhesion enhancing agents include copolymers of methylvinyl ether and maleic anhydride (Gantrez polymers), polyethylene glycol and polyvinyl pyrrolidone, gelatin, low molecular weight polyisobutylene rubber, Copolymer of Acrylsan alkyl/Octylacrylamido (Dermacryl 79), and various aliphatic resins and aromatic resins.
- the non-volatile solvent system and the solidifying agent are preferably compatible with each other.
- Compatibility can be defined as i) the solidifying agent does not substantially negatively influence the function of the non-volatile solvent system; ii) the solidifying agent can-hold the non-volatile solvent system in the solidified layer so that substantially no non-volatile solvent oozes out of the layer, and iii) the solidified layer formed with the selected non-volatile solvent system and the solidifying agent has acceptable flexibility, rigidity, tensile strength, elasticity, and adhesiveness.
- the weight ratio of the nonvolatile solvent system to the solidifying agent can be from about 0.1 :1 to about 10:1 , or from about 0.5:1 to about 2:1.
- the thickness of the formulation layer applied on the skin should also be appropriate for a given formulation and desired drug delivery considerations.
- the layer is too thin, the amount of the drug may not be sufficient to support sustained delivery over the desired length of time. If the layer is too thick, it may take too long to form a non-messy outer surface of the solidified layer. If the drug is very potent and the solidified layer has very high tensile strength, a layer as thin as 0.01 mm may be sufficient. If the drug has rather low potency and the solidified layer has low tensile strength, a layer as thick as 2-3 mm may be needed. Thus, for most drugs and formulations, the appropriate thickness can be from about 0.01 mm to about 3 mm, but more typically, from about 0.05 mm to about 1 mm.
- the flexibility and stretchability of a solidified layer, or optionally solidified peelable layer can be desirable. Skin areas over joints and certain muscle groups are often significantly stretched during body movements. Such movement prevents non-stretchable patches from maintaining good skin contact. Lotions, ointments, creams, gels, pastes, or the like also may not be suitable for use for the reasons cited above. As such, in transdermal delivery of NSAIDs and other drugs for treating musculoskeletal pain in joints and/or muscles, the solidifying formulations of the present invention can offer unique advantages and benefits.
- a further feature of the solid-forming formulations is related to the drying time. If a formulation dries too quickly, the user may not have sufficient time to spread the formulation into a thin layer on the skin surface before the formulation is solidified, leading to poor skin contact. If the formulation dries too slowly, the subject may have to wait a long time before resuming normal activities (e.g. putting clothing on) that may remove un-solidified formulation. Thus, it is desirable for the drying time to be longer than about 15 seconds but shorter than about 15 minutes, and preferably from about 0.5 minutes to about 4 minutes.
- Another feature of the formulations of the current invention is related to solidifying formulations comprising a drug for musculoskeletal pain or inflammation of joint or muscles, a non-volatile solvent system comprising at least one non-volatile solvent, a solidifying agent, and a volatile solvent system comprising a volatile solvent whose boiling point is below 20 C (such a solvent is referred to as gaseous volatile solvent).
- the formulation can be stored in a pressurized container and be sprayed on the skin surface with the help of the gaseous volatile solvent.
- Some hydrofluorocarbons commonly used as gaseous volatile solvents in pharmaceutical or cosmetic industries can work in this design.
- the gaseous volatile solvents may include, but not limited to dimethyl ether, butane, 1 ,1, Difluoroethane, 1 ,1 ,1 ,2 tetrafluorethane, 1 ,1 ,1 ,2,3,3,3-heptafluoropropane, 1 ,1 ,1 ,3,3,3 hexafluoropropane, or a mixture thereof.
- the formulation may also be expelled out of the container and applied on the skin via a manual pump. Formulations including a gaseous volatile solvent are expected to "dry" much faster.
- the formulations of the current invention may further comprise a pH modifying agent for adjusting the pH of the formulation to a point or a range most suitable for the delivery of the drug. This feature can be important for a drug that is ionizable.
- the adhesion to skin and elasticity of the material is such that the solidified layer may not easily separate from the skin.
- the solidified layer can be stretched in at least one direction by up to about 5% or even 10% or more without cracking, breaking, or separating form a skin surface to which the solidified layer is applied.
- the solidified formulation layer of the present invention can be prepared in an initial form that is easy to apply as a semisolid dosage form. Additionally, the dosage form can be applied to be relatively thick and can contain much more active drug than a typical layer of traditional cream, gel, lotion, ointment, paste, etc., and further, is not as subject to unintentional removal. After the evaporation of the volatile solvent(s) and the formation of the solidified layer, the drug in the solidified layer can be delivered at desired delivery rates over sustained periods of time. Further, as the solidified layer remains adhesive and can be peelable, easy removal of the solidified layer can occur, usually without the aid of a solvent or surfactant.
- the adhesion to skin and elasticity of the material is such that the solidified layer will not separate from the skin upon skin stretching at highly stretchable skin areas, such as over joints and muscles.
- the solidified layer can be stretched by 5% or even 10% or greater in one direction without cracking, breaking, and/or separating form a skin surface to which the solidified layer is applied.
- a solidified layer including ketoprofen, diclofanec, or another NSAID, or lidocaine, ropivacaine, or another local anesthetic can be formulated for treating acute injuries of joints such as joints of the angle, knee, wrist, back, hip, and fingers.
- a solidified layer with the same active drugs can be used to treat chronic disorders, such as arthritis (including osteoarthritis and rheumatoid arthritis) induced pain of the finger and/or toe joints.
- Still another embodiment involves a formulation containing a drug selected from the NSAID class, such as ketoprofen, piroxicam, diclofenac, and indomethacin, which is applied topically to treat symptoms of back pain, muscle tension, or myofascial pain or a combination thereof.
- a drug selected from the NSAID class such as ketoprofen, piroxicam, diclofenac, and indomethacin
- the NSAID is gradually released from the formulation to provide pain relief over a sustained period of time.
- the formulation can become a coherent, soft solid after about 5 minutes and remains adhered to the body surface for the length of its application. It is easily removed any time after drying without leaving residual formulation on the skin surface.
- solidifying formulations for the delivery of drugs that treat the causes or symptoms of diseases involving joints and muscles can also benefit from the systems, formulations, and methods of the present invention.
- Such diseases include, but not limited to, osteoarthritis (OA), rheumatoid arthritis (RA), joint and skeletal pain of various other causes, myofascial pain, muscular pain, and sports injuries.
- Drugs or drug classes that can be used for such applications include, but are not limited to, non-steroidal anti-inflammatory drugs (NSAIDs) such as ketoprofen, piroxicam, diclofenac, arid indomethacin; COX inhibitors such as non-selective COX inhibitors, COX-2 selective NSAIDs and agents, COX-3 selective NSAIDs and agents; local anesthetics such as lidocaine, bupivacaine, ropivacaine, and tetracaine; 5HT-2A receptor antagonists such as ketanserin; and steroids such as dexamethasone, hydrocortisone, prednisone, prednisolone, methylprednisolone, halobetasol propionate, betamet
- the solidifying formulations and the methods of the current invention are expected to be particularly useful for treating inflammation and/or pain of small joints such as the joints of toes, wrists, ankles, elbow, and especially fingers, as well as chronic musculoskeletal pain that is not necessarily associated with inflammation. Because the pathway from the skin surface to the joints are shorter for smaller joints, therapeutically beneficial amounts of the drugs are more likely reach smaller joints before being taken away by the blood circulation. In addition, as the fingers are often used, bent, and contacted by many objects during normal activities, it is difficult to keep a conventional dosage form or formulation, such as a patch or cream, on the fingers. Furthermore, some physical therapy devices, such as ThermaCareTM heating pads, are too big for finger joints.
- one method of the present invention uses the solidifying formulations containing NSAI D(s), local anesthetic(s), and/or steroid(s) for treating inflammation or pain of small joints, and particularly of finger joints.
- treatment of larger joints or areas of the body can also be treated, such as the back, neck, shoulder, or hip, is also efficacious.
- Another embodiment entails a solidifying formulation containing a drug from the class of alpha-2 antagonists which is applied topically to treat neuropathic pain.
- the alpha-2 agonist is gradually released from the formulation to provide pain relief over a sustained period of time.
- the formulation can become a coherent, soft solid and remains adhered to the body surface for the length of its application. It is easily removed after drying without leaving residual formulation on the skin surface.
- Another embodiment involves a formulation containing capsaicin which is applied topically to treat neuropathic pain.
- the capsaicin is gradually released from the formulation for treating this pain over a sustained period of time.
- the formulation can become a coherent, soft solid and remain adhered to the body surface for the length of its application, It is easily removed any time after drying without leaving residual formulation on the skin surface.
- a further embodiment involves a solidified formulation containing at least one alpha-2 agonist drug, at least one tricyclic antidepressant agent, and/or at least one local anesthetic drug which is applied topically to treat neuropathic pain.
- the drugs are gradually released from the formulation to provide pain relief over a sustained period of time.
- the formulation can become a coherent, soft solid and remain adhered to the body surface for the length of its application. It is easily removed any time after drying without leaving residual formulation on the skin surface.
- the delivery of drugs for treating neuropathic pain can also benefit from the methods, systems, and formulations of the present invention.
- a patch containing a local anesthetic agent is used for . treating neuropathic pain, such as pain caused by post-herpetic neuralgia. Due to the limitations of the patch as discussed above, a solidified layer prepared in accordance with the present invention provides some unique benefits, as well as provide a potentially less expensive alternative to the use of such a patch.
- Possible drugs delivered for such applications include, but are not limited to, local anesthetics such as lidocaine, prilocaine, tetracaine, bupivicaine, etidocaine; and other drugs including ketamine, amitriptyline, capsaicin, tricyclic antidepressants, alpha-2 agonists such as clonidine, or combinations thereof.
- local anesthetics such as lidocaine, prilocaine, tetracaine, bupivicaine, etidocaine
- other drugs including ketamine, amitriptyline, capsaicin, tricyclic antidepressants, alpha-2 agonists such as clonidine, or combinations thereof.
- the drug can be an antiviral agent and the solidified layer is capable of generating a flux of the antiviral agent of at least 2 mcg/cm 2 /h.
- the drug can be a local anesthetic and the solidified layer is capable of generating a flux of the local anesthetic of at least 5 mcg/cm 2 /h.
- the drug can be an alpha-2 agonist and the solidified layer is capable of generating a flux of the alpha-2 agonist of at leasti mcg/cm 2 /h.
- the drug is capsaicin and the solidified layer is capable of generating a flux of capsaicin of at least 5 mcg/cm 2 /h.
- the drug is ketamine and the solidified layer is capable of generating a flux of ketamine of at least 1 mcg/cm 2 /h.
- Solidifying formulations of the current invention may provide additional benefits.
- a formulation for treating neuropathic pain in accordance with the current invention may include lidocaine and tetracaine.
- the lidocaine and tetracain can be present in either the salt form or in the base form.
- the non-volatile solvent system includes at least one of propylene glycol and dipropylene glycol, and isostearic acid.
- Similar formulations may comprise other combinations of drugs, such as amitriptyline and ketamine, amitriptyline and a ' local anesthetic, etc.
- the solidified layers of the present invention can keep a substantial amount of the non-volatile solvent system, which is optimized for delivering the drug, on the body surface.
- This feature can provide unique advantages over existing products. For example, in some semi-solid formulations, upon application to a skin surface the volatile solvents quickly evaporate and the formulation layer solidifies into a hard lacquer-like layer. The drug molecules are immobilized in the hard lacquer layer and are substantially unavailable for delivery into the skin surface. As a result, it is believed that the delivery of the drug is not sustained over a long period of time. In contrast to this type of formulation, the solidified layers formed using the formulations of the present invention keep the drug molecules quite mobile in the non-volatile solvent system which is in contact with the skin surface, thus ensuring sustained delivery.
- Hairless mouse skin (HMS) or human epidermal membrane (HEM) is used as the model membranes as noted for the in vitro flux studies described in herein.
- Hairless mouse skin (HMS) is used as the model membrane for the in vitro flux studies described in herein.
- Freshly separated epidermis removed from the abdomen of a hairless mouse is mounted carefully between the donor and receiver chambers of a Franz diffusion cell.
- the receiver chamber is filled with pH 7.4 phosphate buffered saline (PBS).
- PBS pH 7.4 phosphate buffered saline
- the experiment is initiated by placing test formulations on the stratum corneum (SC) of the skin sample.
- Franz cells are placed in a heating block maintained at 37 0 C and the HMS temperature is maintained at 35 0 C.
- Skin flux ( ⁇ g/cm 2 /h) is determined from the steady-state slope of a plot of the cumulative amount of permeation versus time. It is to be noted that human cadaver skin can be used as the model membrane for the in vitro flux studies as well. The mounting of the skin and the sampling techniques used as the same as described above for the HMS studies.
- Formulations of ropivacaine (base) in various non-volatile solvent systems are evaluated. Excess ropivacaine is present. The permeation of ropivacaine from the test formulations through HMS is presented in Table 2 below.
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed, the steady-state delivery would likely continue well beyond 8 hours.
- Formulations of diclofenac sodium in various non-volatile solvent systems are evaluated. Excess diclofenac sodium is present. The permeation of diclodenac sodium from the test formulations through HMS is presented in Table 3 below.
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed, the steady-state delivery would likely continue well beyond 8 hours.
- Steady state flux of diclofenac sodium from the above non-volatile solvents are obtained by placing 200 mcL on the stratum corneum side (donor) of hairless mouse skin.
- the in vitro studies are carried out as described in Example 1.
- the non-volatile solvent glycerol has a steady state flux value comparable to the estimated therapeutic steady state flux value of 1 mcg/cm 2 /h and may be considered a flux-enabling solvent.
- the steady state flux values of isopropyl myristate, ethyl oleate, propylene glycol, and Span 20 are at least 10 times the flux value reported for glycerol and are considered flux enabling.
- Formulations of diclofenac acid in various non-volatile solvent systems are evaluated. Excess diclofenac acid is present. The permeation of diclofenac from the test formulations through HMS is presented in Table 4 below.
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed, the steady-state delivery would likely continue well beyond 8 hours.
- Steady state flux of diclofenac acid from the above non-volatile solvents are obtained by placing 200 mcL on the stratum corneum side (donor) of hairless mouse skin.
- the in vitro studies are carried out as described in Example 1.
- the non-volatile solvent glycerol has no reported steady state flux value and is not considered a flux enabling non-volatile solvent viable nonvolatile solvent candidate.
- the steady state flux values of isopropyl myristate, ethyl oleate, propylene glycol, and Span 20 are no more than 10 times the flux value reported for currently available marketed products, and as such, could be considered flux-enabling solvents.
- the steady state flux values for diclofenac acid from each of the above non-volatile solvents are much lower than the steady state flux values obtained with diclofenac sodium. Therefore, if therapeutically effective flux values need to be increased, utilizing a flux-enabling non-volatile solvent and the salt form of diclofenac would likely yield higher steady state flux values than using the acid form of diclofenac.
- Examples 5-7 Prototype peel formulations are prepared as follows. Several peel formulations are prepared in accordance with embodiments of the present invention in accordance with Table 5, as follows:
- the solidifying agents are dissolved in the volatile solvent (e.g., dissolve polyvinyl alcohol in water, Eudragit polymers in ethanol), •
- the non-volatile solvent is mixed with the solidifying agent/volatile solvent mixture.
- the flux-enabling non-volatile solvent/solidifying agent/volatile solvent combination is compatible as evidenced by a homogeneous, single phase system that exhibited appropriate drying time, and provided a stretchable peel and steady state flux for the drug (see Example 8 below).
- HMS hairless mouse skin
- HEM human epidermal membrane
- FIGS. 1 and 2 provide a graphical representation of the cumulative amount of diclofenac and ropivacaine, respectively, delivered transdermal ⁇ across human cadaver skin.
- the formulations tested were similar to those described in Examples 6 and 7. In these particularly embodiments, steady-state delivery is shown over 28 hours, and over 30 hours, repsectively.
- Examples 13-14 A peel-forming formulation for dermal delivery of ropivacaine is prepared which includes a specified amount of ropivacaine in an excipient mixture to form an adhesive formulation in accordance with embodiments of the present invention.
- the peel formulations contained the following components: Table 8 Ro ivacaine eelable formulations
- ethanol is used as the volatile solvent
- ISA, glycerol, and PG mixture is used as the non- volatile solvent system.
- ISA, PG and glycerol serve as a plasticizer in the peelable formulation after the ethanol (volatile solvent) has evaporated.
- the steady state flux of ropivacaine from formulation Examples 13 and 14 demonstrate the importance of the non-volatile solvent in dictating the flux-generating power of the entire formulation.
- Ropivacaine base solubility in isostearic acid (ISA) is experimentally determined to be slightly above 1 :4, meaning 1 gram ropivacaine base can completely dissolve in 4 gram isostearic acid.
- Solution A includes 1 part ropivacaine base and 4 parts isostearic acid.
- Solution B includes 1 part ropivacaine base, 4 parts isostearic acid, and 1 part trolamine. (all parts are in weight). All ropivacaine in Solution A is dissolved, but only a portion of ropivacaine in solution B is dissolved.
- the transdermal flux across hairless mouse skin generated by the solutions is measured by a typical Franz Cell system, with the following results:
- a solidifying formulation for dermal delivery of ropivacaine is prepared from the following ingredients:
- Example 16 The formulation prepared in accordance with Example 16 is applied to HMS as described in Example 1 , and the ropivacaine flux was measured. A summary of the results is listed in Table 12, as follows:
- the ropivacaine peel formulation prepared in accordance with Example 16 possessed acceptable application properties, e.g., ease of removal of peel from the sample tube, ease of spreading on intended skin application site, etc., and forms a solidified film in 2-3 minutes after being applied to normal human skin surface as a thin layer with a thickness of about 0.1 mm.
- the solidified layer becomes more easily peelable in 2 hours, and the peel remains affixed to the skin surface without any unintended removal of the peel for at least 12 hours. At the end of intended use, the peel is easily removed in one continuous piece.
- a solidifying formulation for dermal delivery of lidocaine (base) is prepared which includes a saturated amount of lidocaine in an excipient mixture to form an adhesive formulation in accordance with embodiments of the present invention.
- the peel formulation is prepared from the ingredients as shown in Table 13.
- lidocaine formulation in the present Example 18 has similar physical properties to the examples noted above.
- the transdermal flux across hairless mouse skin is acceptable and steady-state delivery is maintained over 8 hours.
- Solidifying formulations for dermal delivery of ropivacaine are prepared which includes an excipient mixture to form an adhesive solidifying formulation in accordance with embodiments of the present invention.
- the peel formulations are prepared from the ingredients as shown in Table 15.
- Examples 19-22 show the importance of the triacetin, isostearic acid, Span 20 combination in the formulation.
- formulations were made without Span 20, triacetin, and isostearic acid respectively.
- the in vitro flux of ropivacaine was impacted.
- the synergistic combination of the non volatile solvents is an important in obtaining the maximum in vitro flux of ropivacaine.
- This solidifying formulation has the following ingredients in the indicated weight parts:
- polyvinyl alcohol (USP grade MW 31,000-50,000, from Amresco) is a solidifying agent
- ethyl cellulose and Dermacryl 79 are auxiliary solidifying agents
- lsostearic acid and glycerol form the non-volatile solvent system while ethanol and water form the volatile solvent system.
- Ropivacaine is the drug.
- Ropivacaine is mixed with ISA.
- PVA is dissolved in water at temperature of about 60-70 C. 4. All of the above mixtures are combined together in one container and glycerol is added and the whole mixture is mixed well.
- the resulting formulation is a viscous fluid.
- a layer of about 0.1 mm thick is applied on skin, a non-tacky surface is formed in less than 2 minutes.
- a stretchable adhesive formulation for transdermal delivery of ketoprofen (which is suitable for delivery via skin for treating inflammation or pain of joints and muscles) is prepared which includes saturated amount of ketoprofen in an excipient mixture (more ketoprofen than that can be dissolved in the excipient mixture) to form an adhesive formulation, some of which is prepared in accordance with embodiments of the present invention.
- the excipient mixture which is a viscous and transparent fluid, is prepared using the ingredients as shown in Table 18.
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed the steady state flux would extend beyond the 8 hours measured.
- ethanol and water formed the volatile solvent system, while a 1 :1 mixture of glycerol and PEG 400 formed the non-volatile solvent system.
- PEG 400 is a slightly better solvent than glycerol for ketoprofen, while glycerol is much more compatible with PVA than PEG 400.
- the non-volatile solvent system of glycerol and PEG 400 are used together to provide a non-volatile solvent system for the drug, while being reasonably compatible with PVA.
- PVA and PVP act as the solidifying agents.
- glycerol and PEG 400 also serve as plasticizers in the adhesive formulation formed after the evaporation of the volatile solvents. Without the presence of glycerol and PEG 400, a film formed by PVA and PVP alone would be rigid and non-stretchable.
- Example 25 the adhesive peelable formation formed has similar physical properties as that of Example 24, though the transdermal flux across hairless mouse skin is higher. This suggests that the solidifying agent, 1 :1 PVA:PVP-K-90 in Example 24 and pure PVA in Example 25, have an impact on permeation.
- Example 26 delivers less ketoprofen than the formulations of Examples 24 or 25
- the formulation of Example 27 delivers much less ketoprofen than the formulations in Examples 24 and 25.
- One possible reason for the reduced flux is believed to be the reduced permeation driving force caused by the high concentration of PEG 400 in the non-volatile solvent system, which resulted in too high of solubility for ketoprofen.
- Example 28 A stretchable adhesive formulation for transdermal delivery of ketoprofen
- ketoprofen in an excipient mixture to form an adhesive formulation, some of which is prepared in accordance with embodiments of the present invention.
- the peel formulation is prepared from the ingredients as shown in Table 20.
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed the steady state flux would extend beyond the 8 hours measured.
- a stretchable adhesive formulation for transdermal delivery of ketoprofen (which is suitable for delivery via skin on joints and muscles) is prepared which includes saturated amount of ketoprofen in an excipient mixture (more ketoprofen than that can be dissolved in the excipient mixture) to form an adhesive formulation, some of which are prepared in accordance with embodiments of the present invention.
- the excipient mixture which is a viscous and transparent fluid, is prepared using the ingredients as shown in Table 22.
- the solidifying agents are dissolved in the volatile solvent (i.e., dissolve Eudragit polymers in ethanol). • The flux adequate non-volatile solvent (glycerol, PEG) is mixed together with the solidifying agent/volatile solvent mixture.
- Example 29-31 The formulations prepared in accordance with Example 29-31 are applied to HMS as described in Example 1 , and the ketoprofen flux is measured. A summary of the results is listed in Table 23, as follows:
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed the steady state flux would extend beyond the 8 hours measured.
- the ketoprofen adhesive solidifying formulations prepared in accordance with Examples 29-30 possessed acceptable solidified film properties (e.g., formed a solidified layer in 2-3 minutes). With Example 31 , the ketoprofen formulation does not form a solidified layer 30 minutes after application. This demonstrates that order to obtain desired flux and wear properties in a peel formulation, a delicate balance between solidifying agents, non-volatile solvents, and volatile solvents is evaluated and considered in developing a formulation.
- An adhesive solidifying formulation for transdermal delivery of ketoprofen which can form elastic solidified layers and is suitable for delivery via skin on joints and muscles, is prepared which includes saturated amount of ketoprofen in an excipient mixture (more ketoprofen than that can be dissolved in the excipient mixture) to form an adhesive formulation, some of which are prepared in accordance with embodiments of the present invention.
- the excipient mixture which is a viscous and transparent fluid, is prepared using the ingredients as shown in Table 24.
- Formulations A and B are prepared in the following manner:
- PVA solidifying agent
- the flux adequate non-volatile solvent glycerol, PG
- the flux adequate non-volatile solvent is mixed together with the solidifying agent/volatile solvent mixture.
- Formulations A and B are placed on the skin of human volunteers. After a period of several hours, long enough for the volatile solvent to evaporate, the peels were removed by the volunteers and the peelability properties were evaluated. In all instances the volunteers reported that formulation example A could not be removed in one or two pieces, but was removed in numerous small pieces. Formulation example B. removed in one or two pieces.
- the lack of cohesion nature of formulation A is attributed to the lower molecular weight PVA sample (Celvol). Low molecular weight PVA does not possess the same cohesive strength as higher molecular weight PVA material (Amresco) due to the reduced size of the polymer chain leading to a reduction in the degree of cross linking and physical interactions between individual PVA polymer chains. The reduced PVA chain interactions lead to a weaker solidified layer that is unable to withstand the mechanical forces it is subjected to upon removal.
- a stretchable adhesive formulation for transdermal delivery of ketoprofen (which is suitable for delivery via skin on joints and muscles) was evaluated which includes a placebo excipient mixture which will form an adhesive formulation, some of which are prepared in accordance with embodiments of the present invention.
- the excipient mixture which is a viscous and transparent fluid, is prepared using the ingredients as shown in Table 25.
- Peel formulations in Examples 1 and 2 are prepared in the following manner:
- PVA solidifying agent
- the amount of water in the formulation did not significantly influence the time for the formulation to dry. However, it was noted during the study that the formulation was difficult to expel from the sample tube. After approximately 4 weeks after the formulation in examples 1 and 2 were made the sample tubes were retrieved and were evaluated for ease of dispensing the formulation. It was noted that the formulation was impossible to expel from the tube, lnterpolymer complexation between Gantrez S-97 and PVA through electrostatic interactions, hydrophobic interactions, hydrogen bonding, or Van der Waals interactions is hypothesized to be the reason(s) for the observed thickening. Moreover, the extent of this interaction may be dependent on the stoichiometric ratio of the two polymers. It is believed that the water content of the formulations is too low for obtaining acceptable long term physical stability, although the formulation shorter term viscosity was acceptable. This demonstrates the value of having sufficient amount of the volatile solvent system in the formulation in some embodiments.
- Example 36-39 A stretchable adhesive formulation for transdermal delivery of ketoprofen
- excipient mixture which will form an adhesive formulation, some of which are prepared in accordance with embodiments of the present invention.
- the excipient mixture which is a viscous and transparent fluid, is prepared using the ingredients as shown in Table 27.
- Peel formulations In Examples 1-4 are prepared in the following manner:
- PVA solidifying agent
- ketoprofen is added and the final mixture is vigorously mixed again for several minutes.
- Formulations noted above were placed in laminate packaging tubes and stored at 25 C/60% RH and 40 C/ 75% RH conditions until pulled for testing. Physical testing was performed on each formulation. Table 28 summarizes the data generated on each formulation.
- Examples 36 and 37 had the lowest water content of the four formulations and within 4 weeks of storage attained high viscosity values.
- the only difference between Examples 36 and 37 is the amount of ethanol in the formulations. It was hypothesized that reducing the level of ethanol may reduce the physical thickening of the formulation due to an incompatibility between the PVA and ethanol.
- the viscosity data show that the higher ethanol formulation (Example 36) had lower initial viscosity, but over the 4 weeks storage the viscosity of both Example 36 and 37 attained viscosity values that were too high for a viable formulation.
- Another hypothesis for the formulation thickening is that PVA is not compatible in high concentrations when dissolved in water. Additional formulations with higher water content were prepared to determine if an optimal water amount would keep the formulation from thickening up over time.
- Example 38 viscosity after 16 weeks has not reached the viscosity values of the initial viscosity values of Examples 36 and 37.
- Placebo versions of the formulations above were applied on study volunteers and the drying time was assessed by placing a piece of cotton to the application site and then applying a 5 gram weight on the cotton. The cotton and weight was removed after 5 seconds. This procedure was started approximately 3 - 4 minutes after application and at 10 to 60 second intervals thereafter until the cotton was removed without lifting the peel or leaving residue behind.
- Table 29 The results of the study are summarized in Table 29 below.
- Solidifying formulations for dermal delivery of ropivacaine HCI are prepared which include excipient mixtures in accordance with embodiments of the present invention.
- the formulations are prepared from the ingredients as shown in Table 30.
- the ingredients listed above are combined according to the following procedure.
- the ropivacaine HCI, water, and the amine base triethylamine or diisopropanolamine
- the amine base triethylamine or diisopropanolamine
- isostearic acid, triacetin, Span 20, and cetyl alcohol (Examples 41 and 42), or isopropanol (Example 40) are added to the formulation and mixed well.
- the polymer Plastoid B is added last and heated to about 60 0 C until the Plastoid B is completely dissolved. Once the polymer solution cooled to room temperature, the formulation is stirred vigorously for 2-3 minutes.
- ketoprofen from the test formulations through HMS is presented in Table 32 below.
- Skin flux measurements represent the mean and standard deviation of three determinations. Flux measurements reported were determined from the linear region of the cumulative amount versus time plots. The linear region was observed to be between 4-8 hours. If experimental conditions allowed, the steady-state delivery would likely continue well beyond 8 hours. Steady state flux of ketoprofen from the above non-volatile solvents are obtained by placing 200 mcL on the stratum corneum side (donor) of hairless mouse skin. The in vitro studies are carried out as described in Example 1.
- the non-volatile solvents glycerol and polyethylene glycol 400 had low steady state flux values and would not be considered "flux-enabling.”
- Span 20 maybe considered flux-enabling, and propylene glycol or oleic acid provided the highest flux and are considered flux-enabling non-volatile solvent systems.
- Assessment of flux-enabling solvents is based on the estimated therapeutically effective flux of 16mcg/cm 2 /h for ketoprofen. Steady state flux values of a drug from the non-volatile solvent that are below the therapeutically effective flux are not considered flux-enabling while steady state flux values of a drug from a non-volatile solvent above the therapeutically effective flux value is considered flux-enabling.
- Solidifying formulations for dermal delivery of amitriptyline and a combination of amitripyline and ketamine are prepared which include excipient mixtures to form an adhesive solidifying formulation in accordance with embodiments of the present invention.
- the formulations are prepared from the ingredients as shown in Table 33.
- the adhesive formulation of amitriptyline and amitriptyline/ketamine formulations in the present example have similar physical properties to the formulations in examples noted above.
- Example 49 A formulation similar to the formulation of Example 18 composition (with no lidocaine) is applied onto a human skin surface at an elbow joint and a finger joint, resulting in a thin, transparent, flexible, and stretchable film. After a few minutes of evaporation of the volatile solvents (ethanol and water), a solidified layer is formed.
- the stretchable film has good adhesion to the skin and does not separate from the skin on joints when bent, and can easily be peeled away from the skin.
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US8741332B2 (en) | 2004-06-07 | 2014-06-03 | Nuvo Research Inc. | Compositions and methods for dermally treating neuropathic pain |
US8907153B2 (en) | 2004-06-07 | 2014-12-09 | Nuvo Research Inc. | Adhesive peel-forming formulations for dermal delivery of drugs and methods of using the same |
US8741333B2 (en) | 2004-06-07 | 2014-06-03 | Nuvo Research Inc. | Compositions and methods for treating dermatitis or psoriasis |
US9283177B2 (en) * | 2007-01-16 | 2016-03-15 | Juventio, Llc | Topical anesthetic for rapid local anesthesia and method of applying a topical anesthetic |
US8759391B2 (en) | 2007-01-16 | 2014-06-24 | Juventio, Llc | Topical anesthetic for rapid local anesthesia |
CN101970427A (en) | 2008-02-29 | 2011-02-09 | Vm生物医药公司 | Method for treating pain syndrome and other disorders |
WO2010008600A1 (en) * | 2008-07-16 | 2010-01-21 | Dermworx Incorporated | Topical drug delivery system |
US9012477B2 (en) * | 2009-01-06 | 2015-04-21 | Nuvo Research Inc. | Method of treating neuropathic pain |
EP2413837A4 (en) * | 2009-04-01 | 2013-10-23 | Jie Zhang | Methods for treating myofascial, muscle, and/or back pain |
US9186334B2 (en) | 2009-05-04 | 2015-11-17 | Nuvo Research Inc. | Heat assisted lidocaine and tetracaine for transdermal analgesia |
EP2427160A4 (en) | 2009-05-04 | 2012-12-19 | Zars Pharma Inc | Methods of treating pains associated with neuroma, nerve entrapment, and other conditions |
US9693976B2 (en) | 2010-01-14 | 2017-07-04 | Crescita Therapeutics Inc. | Solid-forming local anesthetic formulations for pain control |
US20130324502A1 (en) | 2011-02-10 | 2013-12-05 | Moberg Pharma Ab | Novel formulations for dermal, transdermal and mucosal use 1 |
US11786455B2 (en) | 2011-05-10 | 2023-10-17 | Itochu Chemical Frontier Corporation | Non-aqueous patch |
ES2743524T3 (en) | 2011-05-10 | 2020-02-19 | Itochu Chemical Frontier Corp | Non-aqueous patch |
US9925264B2 (en) | 2011-05-10 | 2018-03-27 | Itochu Chemical Frontier Corporation | Non-aqueous patch |
US20140100285A1 (en) * | 2011-05-26 | 2014-04-10 | Novartis Ag | Compositions of percutaneous administration of physiologically active agents |
CN102302418B (en) * | 2011-09-21 | 2013-01-23 | 韩褆 | Water-saving type multifunctional hand-washing disinfectant |
MX367430B (en) * | 2011-09-27 | 2019-07-11 | Itochu Chemical Frontier Corp | Non-aqueous patch. |
CN103142458B (en) | 2013-01-22 | 2015-09-09 | 莱普德制药有限公司 | Without prescription and the preparation method of additive analgesia sustained release drug delivery systems |
GB201317718D0 (en) | 2013-10-07 | 2013-11-20 | Buzzz Pharmaceuticals Ltd | Novel formulation |
JP6209749B2 (en) * | 2015-12-10 | 2017-10-11 | 伊藤忠ケミカルフロンティア株式会社 | Non-aqueous patch |
US11141387B2 (en) | 2017-01-05 | 2021-10-12 | Medrx Co., Ltd. | Memantine-containing transdermally absorbable liquid |
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Also Published As
Publication number | Publication date |
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CA2633515C (en) | 2011-10-18 |
JP2009524586A (en) | 2009-07-02 |
AU2006326018B2 (en) | 2013-04-18 |
CA2633515A1 (en) | 2007-06-21 |
WO2007070679A2 (en) | 2007-06-21 |
EP1959931A4 (en) | 2012-08-22 |
AU2006326018A1 (en) | 2007-06-21 |
WO2007070679A3 (en) | 2009-01-08 |
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