WO2002011679A1

WO2002011679A1 - Compositions for topical applications and production thereof

Info

Publication number: WO2002011679A1
Application number: PCT/US2001/024763
Authority: WO
Inventors: Curtis E. Jones Ii; James E. Wynn
Original assignee: Distinguished Medical Research, Inc.
Priority date: 2000-08-07
Filing date: 2001-08-07
Publication date: 2002-02-14
Also published as: AU2001279223A1

Abstract

Hypoallergenic compositions comprising high concentrations of propylene glycol and an emollient are described as vehicles for the topical application of an active ingredient having a medicinal or cosmetic activity or function. Methods of producing the compositions are also described.

Description

COMPOSITIONS FOR TOPICAL APPLICATIONS AND PRODUCTION THEREOF

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e)(1) to U.S. Provisional Application Serial No. 60/223,473, filed August 7, 2000.

GENERAL FIELD OF THE INVENTION This invention is generally in the field of compositions or vehicles for topical application of selected compounds. More particularly, this invention provides compositions that are formulated to provide an effective and controllable topical application and/or dermal absorption of compounds that have a medicinal activity or cosmetic function.

BACKGROUND OF THE INVENTION

The relative simplicity of procedure, control over dosage, and absence of invasiveness make topical application to the skin or other tissue surface a highly attractive mode for administering a compound to an individual. Topical admmstration has been useful for administering a variety of compounds, including various cosmetics and pharmaceutical compounds. Typically, a compound is applied to the skin or exposed tissue surface of an individual in a topical formulation, which acts as a vehicle to contain the compound and also to promote penetration of the compound into the skin (or other tissue surface) and underlying skin layers (transdermal) or tissues. In such topical formulations, the compound providing the beneficial effect or activity is commonly referred to as the "active ingredient". The manufacture of topical pharmaceutical formulations historically has involved the production of a base composition into which is incorporated a particular pharmaceutically active ingredient(s) as well as other components (excipients) that may provide other desirable features to the formulation, such as viscosity and aroma.

Topical formulations for application of one or more active ingredients may take any of a variety of forms, such as liquids, creams, gels, jellies, and lotions. Liquid formulations containing a desired compound are generally least preferred for topical application as these will flow so easily on skin or other tissue surface as to make control of local application and dosing difficult. Creams, gels, jellies, and lotions are forms of topical compositions that are generally more desirable than liquid compositions as these are sufficiently viscous to provide slower flow rates and more control of local application and dosing of the desired compound. Such forms of topical compositions may also provide the added advantage of retaining a suspended compound in a form that provides slow or staged delivery at the site of application to provide an effective means of dosing over an extended period of time. There are four major traditional classes of topical bases or vehicles for use in topical administration of an active ingredient. These four classes are: oleaginous ointment bases (e.g., formulations containing significant amounts of petrolatum), absorption ointment bases (e.g., formulations containing significant amounts of lanolin), emulsion ointment bases (e.g., cold cream or other hydrophilic ointment), and water-soluble ointment bases (e.g., formulations containing predominantly polyethylene glycol, "PEG"). These vehicles are generally produced by combining low melting point liquids and semi-solids (e.g., water, glycerin, one or more low molecular weight PEGs, mineral oils, petrolatum) with high melting point solids (e.g., waxes, higher alcohols, one or more high molecular weight PEGs) and with varying levels of surface active agents for enhanced stability and elegance. Production of these bases is most commonly achieved by a process of simple melt mixing where soluble ingredients are heated to melting and subsequently combined with normally insoluble ingredients under constant and thorough stirring. The mixture is then allowed to slowly cool to room temperature, thereby producing a semi-solid base formulation.

Despite the recognized advantages to topical application and despite known examples of topical vehicles containing various pharmaceutically active or cosmetically desirable compounds, the use of topical vehicles remains nevertheless limited. One reason for this limitation is that many of the methods used to incorporate a compound into a topical vehicle employ one or more heating steps (e.g., in melting solids) at temperatures that would alter or even destroy the beneficial activity or property of the compound incorporated into the vehicle. Thus, the production of traditional base formulations is severely limited by the temperature constraints. Processing temperatures of 60°C to 80°C are normally required for stable, elegant products, i.e., products of desired viscosity and consistency to control application and dosing of the active ingredient that is incorporated into the base. These processing conditions, however, can result in unacceptable discoloration and/or loss of activity or function for a variety of compounds for which topical application would be a desirable or preferred route of administration. Another limitation on effective topical application is the need for more effective penetration or absorption of an active ingredient into the skin. In many current topical formulations, penetration or absorption of a compound is practically limited by the concentration of the primary penetration enhancing agent that can be used in a formulation. Typically, the concentration of a preferred primary penetration enhancing agent in a formulation must be low enough so that application of the formulation to the skin of an individual does not result in the development of an intolerable skin irritation or topical allergic response, either of which may render the skin too sensitive for multiple or continuous applications. For example, propylene glycol is a commonly preferred primary penetration enhancing agent used in the production of vehicles for cosmetics and for the topical delivery of pharmaceutical medicaments. Propylene glycol can also serve as a co-solvent to enhance the solubility of active ingredients or poorly soluble excipients in the manufacture of cosmetics and pharmaceutical products. The effect of propylene glycol and other semi-polar solvents as penetration enhancers for topical and transdermal gel systems has been investigated in the past. Although relatively high concentrations of propylene glycol would appear to enhance penetration of a compound through the skin, such formulations (e.g., containing 60-80% (weigh olume) propylene glycol) must be generally avoided owing to one or more forms of propylene glycol intoxication, including skin sensitizations (see, e.g. , Commens, Br. J. Dermatol, 122: 77-80 (1990); Wahlberg et al., Acta Derm. Venereol (Stockholm), 64: 286-290 (1984); Hannuksela et al., Contact Dermatitis, 14: 221-227 (1986)). Furthermore, a paradoxical effect has at times been observed in certain past formulations of some compounds formulated with a relatively high content (e.g., greater than 60% (w/v)) of propylene glycol in which penetration actually decreases.

More recently, clear gel formulations containing 30% - 88% (by weight) propylene or butylene glycol in combination with other selected components for unspecified pharmaceutical or cosmetic applications have been described (see, U.S. Patent No. 5,948,420). The other components of such clear gel formulations include a water-soluble or water-swellable cationic polymer, a hydrophobic ester, glycerin and other polyols in a predominantly anhydrous mixture. Such cationic formulations are purported to produce gels of high clarity that may be used for applying cosmetic or personal care products. However, no details have been provided for a specified improvement for pharmaceutical delivery systems. One possible disadvantage of the gel of this system is that owing to its high anhydrous nature, it produces an exothermic reaction on exposure to moisture. Thus, the possible detrimental effect of heat released by such an exothermic reaction on any other compound incorporated into the gel must be considered if such formulations are to be used. Furthermore, whether such formulations containing the higher ranges of propylene glycol (e.g., 60% and higher) may still cause skin irritations is not known.

Accordingly, needs remain for topical vehicle formulations that provide the advantages of a relatively high content of a primary penetration enhancing agent, such as propylene glycol, without adversely affecting the incorporated active ingredient(s) and without the development of an intolerable irritation to the skin or other tissue surface to which the formulations are meant to be applied.

SUMMARY OF THE INVENTION The present invention provides compositions (also referred to as "topical compositions", "topical vehicle formulations", "vehicles", "topical formulations", "formulations", "bases", and similar terms), which comprise a relatively high content of a semi-polar solvent, which is also a primary penetration enhancing agent, such as propylene glycol, in combination with an emollient. Compositions of the invention may be used in formulating for topical application (including transdermal application) one or more desired compounds (also referred to as "active ingredients"), such as pharmaceutically active or cosmetically desirable compounds. The compositions described herein provide enhanced penetration of an active ingredient into the skin or underlying skin layers or tissue while minimizing or preventing an intolerable skin irritation (e.g., skin sensitization or allergic response), which could otherwise occur due to the relatively high content of the semi-polar solvent used in the compositions. Accordingly, compositions of the invention are particularly well suited for use where multiple or prolonged topical applications are desired to obtain the benefit of an active ingredient.

In one embodiment, the compositions of the invention are also particularly useful for incorporating an active ingredient with a relatively low or minimal amount of dilution.

In another embodiment, compositions of the invention also provide an improved shelf life for an active ingredient that has one or more characteristics or properties that are susceptible to deterioration in water or compositions having a relatively high (e.g., greater than about 40% by weight) water content.

Preferably, the semi-polar solvent and primary penetration enhancing agent used in the compositions of the invention is propylene glycol. More preferably, compositions of the invention comprise propylene glycol in a concentration ranging from about 80% (weight volume, "w/v") to about 99% (w/v) and an emollient, which prevents or inhibits the development of an intolerable skin irritation, such as a skin sensitization or an allergic response, which could otherwise develop due to topical application of the relatively high concentration of propylene glycol. Particularly preferred compositions of the invention comprise propylene glycol at a concentration of at least about 84% (w/v), at least about 85% (w/v), at least about 86% (w/v), at least 87% (w/v), at least about 88% (w/v), or at least about 89% (w/v) and an emollient.

Preferred emollients useful in the compositions of the invention include, without limitation, various alcohol compounds, such as cetyl alcohol; theobroma oil (cocoa butter); monoglycerides, such as glyceryl monooleate (GMO) and glyceryl monostearate (GMS); diglycerides; urea; fatty acids; and combinations thereof. In addition to the fatty acyl glycerides GMO and GMS, other fatty acyl glyceride molecules may be used as emollients in the compositions described herein, including but not limited to glyceryl monolinoleate (also referred to as "monolinoleoyl glycerol" or "GML") and glyceryl monocaprate (also referred to as "monocaproyl glycerol" or "GMC").

In a preferred embodiment, a composition of the invention comprises propylene glycol present at about 80% (w/v) or greater and an emollient present in the range of about 2% (w/v) to about 8% (w/v). In another embodiment, a composition of the invention further comprises a water- swellable, polar polymer, which may provide the predominant source of the viscosity to the composition. Preferably, the water-swellable, polar polymer is an anionic polymer or a polyethylene glycol (PEG). Most preferably, the water-swellable, anionic polymer used in the compositions of the invention is an acrylic acid polymer. In another preferred embodiment, compositions of the invention comprise a water- swellable, polar polymer at a concentration of between about 0.5% (w/v) to about 5% (w/v). More preferably, the water-swellable polymer is present in the compositions of the invention at a concentration in the range of about 0.5% (w/v) and 4% (w/v), and even more preferably, in the range of about 0.5% (w/v) to about 3% (w/v). Compositions of the invention may also comprise a wetting agent, such as sodium lauryl sulfate, which may be particularly useful to promote hydration or suspension of water-swellable, polar polymers.

Compositions described herein may be produced without the need to employ or the capacity to generate temperatures that may adversely affect the desired active ingredient(s), which is incorporated into the compositions. Accordingly, the invention provides methods of producing the compositions of the invention comprising an in-process temperature that does not adversely affect the active ingredient. Preferably, the methods of the invention comprise an in-process temperature that does not exceed 50°C. More preferably, the methods of the invention comprise an in-process temperature that remains at about 50°C or less. Any of a variety of compounds may be used as an active ingredient that is incorporated into the base compositions of the invention for topical application to an individual. Active ingredients that may be incorporated into the vehicle compositions of the invention include, without limitation, analgesics, motion enhancing agents, antiseptics, anti-cancer compounds, antibiotics, anti-viral compounds, anti-fungal compounds, anti-inflammatory compounds, tissue growth- promoting compounds, scar removing compounds, liposomes, sunscreens, coloring agents or dyes, depilatories, deodorants, antiperspirants, fragrances, insect repellants, and combinations thereof.

In a preferred embodiment, the active ingredient present in the compositions described herein is one or more derivatives or ester compounds of cocaine, such as ecgonine, benzoylecgonine, ecgonidine, and derivatives and combinations thereof, which may be found as a mixture in the commercial pharmaceutical composition ESTEROM™. Such compounds promote or enhance range of motion of a joint or limb and may be particularly effective to treat rheumatoid arthritis or osteoarthritis.

DETAILED DESCRIPTION The invention provides compositions that are useful for the topical administration of one or more selected compounds. Compositions described herein are "topical vehicle formulations" (also referred to as "topical compositions", "vehicles", "topical formulations", "formulations", "bases", and similar terms) that comprise a relatively high concentration of a semi-polar solvent that is also a primary penetration enhancing agent, such as propylene glycol, and an emollient. Compositions of the invention may also comprise a water-swellable, high molecular weight, hydrophilic polymer, such as an acrylic acid polymer or uncharged, polar polymer, such as polyethylene glycol ("PEG"). The compositions are particularly useful for delivering compounds having only a moderate to low solubility in aqueous solutions.

In order that the invention may be more fully understood, the following terms are described below.

The term "active ingredient", "active agent", and similar terms, are used and understood herein to mean any compound or combination of compounds that is desired to be administer topically to a mammalian individual, e.g., a human, to obtain a beneficial result on the skin, other tissue surface, or tissue underlying the surface to which the composition is applied. The benefit of an active ingredient to an individual may be cosmetic or pharmaceutical in nature.

The term "emollient" is used and understood to mean any compound or combination of compounds that prevents or inhibits the development or occurrence of an intolerable skin irritation (including skin sensitizations and allergic responses), which could otherwise develop due to skin contact with a relatively high concentration of a semi-polar solvent or penetration enhancing agent, such as propylene glycol. An emollient useful in the compositions of the invention is similar to or includes lipids found in mammalian skin and has the ability to be deposited in the skin. Typically, emollients are also able to soften and/or sooth the skin to which they are applied. Emollients are thus compatible with the lipids in the skin and, when present in sufficient amounts in the compositions of the invention, are able to prevent or inhibit development of a propylene glycol- mediated skin irritation. Emollients useful in the compositions of the invention include those compounds that have historically been recognized as emollients in cosmetic and pharmaceutical manufacturing including, without limitation, various higher alcohol compounds (such as cetyl alcohol); theobroma oil (i.e., cocoa butter); monoglycerides (such as glyceryl monooleate (GMO) and glyceryl monostearate (GMS)); urea; fatty acids; and combinations thereof. Other fatty acyl glyceride molecules may also be used as emollients, alone or in combination, and include, without limitation, glyceryl monolinoleate (also referred to as "monolinoleoyl glycerol" or "GML") and glyceryl monocaprate (also referred to as "monocaproyl glycerol" or "GMC"). A fatty acyl glyceride content in the range of about 2% (w/v) to about 8% (w/v) is particularly useful in manufacturing compositions of the invention, although a content higher or lower than this range may also be used.

An emollient is particularly beneficial for preparing topical vehicle formulations of the invention comprising a relatively high content, e.g., greater than 80% (w/v), of propylene glycol to inhibit or prevent the development of an intolerable, propylene glycol-mediated skin irritation (sensitization) or topical allergic response. Whether or not a compound or formulation will cause a significant sensitization or an allergic response on the skin of a human or other mammal can readily be determined using a standard repeated open application test (ROAT) (see, Hannuksela et al., Contact Dermatitis, 74: 221-227 (1986)). A ROAT is particularly preferred for testing skin irritancy caused by dermal contact with compositions comprising the relatively high concentrations of propylene glycol found in topical vehicle formulations of the invention. Typically, a ROAT is carried out to compare the level of skin irritancy between similar compositions, which differ in only one component, such as the presence or absence an emollient, or different concentrations of an emollient. Thus, for the topical vehicle formulations described herein, a ROAT is considered a more accurate test than the standard patch test for skin irritancy (Fisher, "The role of patch testing in allergic contact dermatitis," in Contact Dermatitis (second edition) (Lea & Febiger Publishers, Philadelphia, 1973), p. 25).

The term "excipient" is used and understood to mean any compound or combination of compounds that is optionally incorporated into a composition of the invention to provide a property other than that supplied by the active ingredient. A compound may be an active ingredient in one composition and an optional excipient in another composition.

The term "penetration enhancing agent" is used and understood to mean any compound that promotes penetration or absorption of an active ingredient into the skin or underlying tissue of a mammal. A "primary penetration enhancing agent" is a compound that is incorporated into the compositions described herein for the primary purpose of promoting penetration or absorption of an active ingredient into the skin or underlying tissue of a mammal. Preferred penetration enhancing agents useful in the compositions described herein include, without limitation, propylene glycol (PG); fatty acids; and fatty acyl glycerides (such as glyceryl monooleate and glyceryl monostearate). Most preferably, propylene glycol is the primary penetration enhancing agent of the compositions of the invention. A primary penetration enhancing agent, such as propylene glycol, may also serve as a solvent or co-solvent in which to dissolve, suspend, or disperse an active ingredient and/or excipient of the compositions described herein. Accordingly, a primary penetration enhancing agent of the compositions of the invention may also be referred to as a "semi-polar solvent" and vice versa, provided the compound has both properties.

The compositions of the invention have a relatively low aqueous (i.e., 5 % (w/v) or less) and an unusually high semi-polar solvent content (greater than or equal to about 80% (w/v)). A particularly preferred semi-polar solvent useful for making the compositions of the invention is propylene glycol. On a weight per volume (w/v) basis, the propylene glycol content of the compositions of the invention is well in excess of any conventional product formulation currently used for topical administration. The concentration of propylene glycol of the compositions of the invention is generally in the range of about 80% to about 99% (w/v). Particularly preferred concentrations of propylene glycol in the compositions of the invention comprise at least about 84% (w/v), at least about 85% (w/v), at least about 86%, at least 87% (w/v), at least about 88% (w/v), or at least about 89% (w/v).

The preferred concentration of propylene glycol for a composition of the invention may also depend on the particular form in which a composition of the invention is manufactured. For example, for a gel composition, the concentration of propylene glycol is preferably about 87% (w/v). For a cream composition, the concentration of propylene glycol is preferably in the range of about 84% to about 89% (w/v). For a lotion composition, the concentration of propylene glycol is preferably about 86% (w/v). In some cases, the final form of a particular composition of the invention may be influenced not only by the concentration of propylene glycol but also the concentration and nature of an excipient, water, and/or active ingredient incorporated into the composition.

The compositions of the invention may optionally comprise a water-swellable, polar polymer (also referred to as "stiffening agent") that may provide the major source of viscosity for different vehicles described herein. Preferred water-swellable, polar polymers useful in making the compositions described herein include those polymers that are known in the cosmetic and pharmaceutical manufacturing arts. Preferably, the water-swellable, polar polymer is also cross- linked, for example, with allyl ethers of pentaerythritol or equivalents thereof, to form various types of matrices. Typically water-swellable, polar polymers used in the compositions described herein swell in volume by adsorbing and retaining water molecules. A water-swellable, polar polymer provides compositions described herein with various degrees of viscosity, which advantageously restricts or retards the flow of a composition when applied to a particular area on the skin or other tissue surface.

Water-swellable, polar polymers useful in the compositions of the invention include anionic (acidic) polymers and uncharged, polar polymers. Preferred water-swellable, anionic polymers useful in the compositions described herein are anionic (i.e., acidic) acrylic polymers at physiological pH (usually in the range of about pH 5-7), such as in CARBOPOL™ 940 anionic acrylic acid polymer. A preferred uncharged, polar, water-swellable polymer useful in compositions of the invention is polyethylene glycol ("PEG"). Useful concentrations of a water- swellable, polymer in compositions of the invention include about 1% (w/v), about 1.5% (w/v), and about 3% (w/v). Preferably, a water-swellable polymer in the compositions of the invention is present in the range of about 0.5% to about 5% (w/v), more preferably in the range of about 0.5% to about 4% (w/v), and even more preferably about 0.5% to about 3% (w/v).

The compositions described herein provide elegant topical delivery systems for any of a variety of active ingredients. An active ingredient preferably has a desirable medicinal (including veterinary) or cosmetic property. Active ingredients that may be used in the compositions described herein include, without limitation, compounds selected from the group consisting of analgesics, enhancers of range of motion, narcotics, antiseptics, anti-cancer compounds, antibiotics, anti-viral compounds, anti-fungal compounds, anti-inflammatory compounds, tissue growth- promoting compounds, liposomes, sunscreens, topical coloring agents, dyes, depilatories, deodorants, antiperspirants, fragrances, insect repellants, and combinations thereof. It is also understood that depending on the intended use of a particular composition, a compound that is only an optional exicipient in one composition may serve as the active ingredient in another composition of the invention. For example, a fragrance or ester compound may be used as the active ingredient in a cosmetic composition, but serve as an excipient to provide a more attractive odor to a medicinal composition. Likewise, antibiotics or antiseptics may serve as active ingredients in topical compositions for wounds and other superficial injuries, or as preservatives (i.e., excipients) in other compositions to prevent microbial contamination and, thereby, increase shelf life of a particular composition. In a preferred embodiment, the active ingredient is an enhancer of range of motion which is a derivative or ester compound of cocaine, such as ecgonine, benzoylecgonine, ecgonidine, derivatives of any of these preceding compounds, and combinations thereof. Such a combination is found in the commercial preparation ESTEROM™ (Entropin, Inc., Indio, California; see, e.g., U.S. Patent Numbers 5,376,667; 5,525,613; 5,559,123; 5,663,345; 5,763,456). A composition of the invention comprising such enhancers of range of motion may be topically applied over a joint or limb to enhance the range of motion in that joint or limb. Accordingly, such compositions are particularly useful in treating individuals suffering from rheumatoid arthritis, osteoarthritis, and other conditions characterized by stiffness in joints.

The invention provides compositions in the various major, art-recognized forms of vehicles that are used for topical administration of an active ingredient. Non-limiting examples of a preferred composition for a gel, cream, lotion, and water-soluble ointment formulations of the invention are provided below. In some of the examples below, a maximum content for an active ingredient is indicated ("active ingredient"). Any unused portion of the maximum content for the active ingredient may be made up with additional water. Alternatively, an active ingredient may be provided as dissolved or dispersed in either the water or propylene glycol component (see, e.g., cream formulation no. 2, below).

Gel Formulation propylene glycol 87.30% (w/v) water 4.85% (w/v) active ingredient 4.85% (w/v) acrylic acid polymer 3.00% (w/v)

Cream Formulations Cream Formulation No. 1 propylene glycol 84.60% (w/v) water 4.70% (w/v) active ingredient 4.70% (w/v) acrylic acid polymer 1.00% (w/v) and glyceryl monostearate 5.00% (w/v)

Cream Formulation No. 2 propylene glycol 88.64% (w/v) water 4.66% (w/v) acrylic acid polymer 1.50% (w/v) glyceryl monostearate 3.00% (w/v) urea 2.00% (w/v) menthol 0.20% (w/v)

Lotion Formulations

Lotion Formulation No. 1 propylene glycol 86.40% (w/v) water 4.80% (w/v) active ingredient 4.80% (w/v) acrylic acid polymer 1.50% (w/v) cetyl alcohol 2.50% (w/v)

Lotion Formulation No. 2 propylene glycol 84.90% (w/v) water 4.80% (w/v) active ingredient 4.80% (w/v) acrylic acid polymer 1.50% (w/v) glyceryl monooleate 4.00% (w/v)

Water-soluble Ointment propylene glycol 81.00% (w/v) water 4.50% (w/v) active ingredient 4.50% (w/v) PEG 20M (polyethylene glycol) 10.00% (w/v)

The compositions of the invention may advantageously be prepared in methods that may be carried out at relatively low in-process temperatures that do not adversely affect most active ingredients. Generally, the methods of manufacturing compositions of the invention use an in- process temperature that does not exceed 50°C. More preferably, the methods of the invention comprise an in-process temperature that remains at about 50°C or less.

Despite the relatively high concentration of propylene glycol that may be used in preferred compositions of the invention, such preferred compositions do not produce an intolerable or significant skin irritation, such as skin sensitivity or allergic response, such as rash or other irritation, which would prohibit repeated or long-term applications of the compositions described herein. Such skin irritations may be manifested in a variety of ways, including rash, burning sensation, swelling, erythema, inflammation, and combinations thereof. Thus, the compositions described herein are termed "hypoallergenic" to indicate the benign nature of the compositions when applied to the skin of most individuals.

The compositions described herein may be used in methods to prophylactically or therapeutically treat a condition or disease affecting the skin or in the underlying tissues or organs of an individual. Whether a particular condition or disease of an individual may be treated using a composition of the invention will of course depend primarily on the activity of the active ingredient incorporated into the composition and consideration of factors that are peculiar to the individual, such as age, weight, overall health, and extent of disease or condition. Such factors may be best assessed by a healthcare professional familiar with the individual.

Additional embodiments and features of the invention will be apparent from the following non-limiting examples.

EXAMPLE 1. General Formulations for Topical Vehicle Formulations. Jelly Formulation

The production of a jelly formulation is possible with the addition of a swellable gelling agent to produce an attractive viscosity. The jellies have been produced using a swellable polymeric agent of high molecular weight acrylic acid cross-linked with allyl ethers of pentaerythritol in concentrations ranging from approximately 0.5 (w/v) - 5% (w/v) (CARBOPOL™ acrylic acid polymer; Spectrum, Milwaukee, WI). These polymers may be used as free acids or salt forms following neutralization.

Composition Example #1 propylene glycol 87.30% (w/v) water 4.85% (w/v) active ingredients 4.85% (w/v) and CARBOPOL™ 940 (acrylic acid polymer) 3.00% (w/v)

Emulsion Ointment Base

An emulsion-like formulation is produced with the addition of lipophilic substances such as distilled monoglycerides in concentrations ranging from approximately 1-10% (w/v).

Composition Example #2 propylene glycol 84.60% (w/v) water 4.70% (w/v) active ingredient 4.70% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.00% (w/v) glyceryl monostearate 5.00% (w/v)

Lotion Formulation A lotion formulation is produced with the addition of higher alcohol excipients and intermediate molecular weight hydrophilic polymers in concentrations ranging from approximately 1-10%.

Composition Example #3 propylene glycol 86.40% (w/v) water 4.80% (w/v) active ingredient 4.80% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.50% (w/v) cetyl alcohol 2.50% (w/v)

Water-soluble Ointment Base

A water-soluble ointment may be produced with the addition of a high molecular weight hydrophilic polymer in concentrations ranging from approximately 5-10% (w/v).

Composition Example #4 propylene glycol 81.00% (w/v) water 4.50% (w/v) active ingredients 4.50% (w/v)

PEG 20M (polyethylene glycol) 10.00% (w/v) Oleagineous Ointment Base

An oleagineous ointment base may be produced using traditional lipophilic agents such as petrolatum in concentrations ranging from approximately 5-10%).

Example #5 propylene glycol 81.00% (w/v) water 4.50% (w/v) active ingredient 4.50%) (w/v) white petrolatum 10.00% (w/v)

The viscosity range for this group of products is approximately 180 cps (centipoise) to 1.2 million cps over the range of excipient concentrations of 0.5-10%> (w/v) with optimal viscosity being approximately 5,000-100,000 cps.

EXAMPLE 2. Methods and compositions for producing vehicles for topical application of ESTEROM™ cocaine derivative compounds.

The final production method involved an extension of the method of production of ESTEROM™ cocaine derivative compounds (see, e.g., U.S. Patent Nos. 5,376,667; 5,535,623; 5,559,123; 5,663,345; 5,763,456) at an in-process temperature of 50°C in which composition ingredients (excipients) may then be added with constant stirring and allowed to dissolve, melt, hydrate or otherwise be incorporated into a uniform mixture. The final product may then be allowed to cool to room temperature and allowed to stiffen, swell, or congeal to provide the consistency of the final product which can then be packaged or subjected to post-production processing if necessary.

PLACEBO FORMULATIONS

Placebo Formulations are formulations in which the propylene glycol and water content may be replaced by a preparation of ESTEROM™ cocaine derivative compounds, which already possesses a high concentration of propylene glycol, to give the indicated final concentration of propylene glycol.

FORMULATION #1 propoylene glycol 92.91% (w/v) water 4.89% (w/v) CARBOPOL™ 940 (acrylic acid polymer) 1.5% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

1. Weigh and heat propylene glycol and water to 50°C with constant stirring.

2. Weigh CARBOPPOL™ 940 acrylic acid polymer

3. Weigh sodium lauryl sulfate (SLS).

4. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer. 5. Place the CARBOPOL™ 940 acylic acid polymer/SLS dispersion and menthol into the propylene glycol/water with constant stirring until the gel swells and is uniformly smooth. 6. Remove from heat, package, and allow gel to set at room temperature.

Placebo Formulation #1. Formulation #1 is a relatively clear to slightly hazy gel. The final consistency appears to be too fluid to resist flow when placed on the skin. The formulation needs to be stiffened allow patients easy manipulation of the dose. The menthol odor is not overwhelming or offensive but could be softened.

FORMULATION #4 propylene glycol 88.64% (w/v) water 4.66% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1 % (w/v) glyceryl monostearate (GMS) 5% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

1. Weigh and heat propylene glycol and water to 50°C with constant stirring.

2. Place GMS into propylene glycol/water mixture and allow to disperse and emulsify with vigorous stirring.

3. Weigh CARBOPOL™ 940 acrylic acid polymer.

4. Weigh SLS and menthol.

5. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer.

6. Add the CARBOPOL™ 940 acrylic acid polymer/SLS dispersion and menthol, stir well until the gel swells and is uniformly smooth.

7. Remove from heat, package, and allow to set at room temperature.

Placebo Formulation #4. Formulation #4 is a viscous, white, cream. The cream will flow upon inversion but easily maintains its shape when placed on the skin. The formulation has a slightly greasy feel when applied that disappears with continued rubbing for approximately

30-45 seconds. The residue is only very slightly tacky to the touch but would not limit a patient from continuing normal functions after application. The menthol odor is barely noticeable.

FORMULATION #5 propylene glycol 91.01% (w/v) water 4.79% (w/v)

CARBOPOL 940 (acrylic acid polymer) 1.5% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) cetyl alcohol 2% (w/v) menthol 0.2% (w/v)

Manufacturing Process: 1. Weigh and heat propylene glycol and water to 50°C with constant stirring.

2. Weigh cetyl alcohol and place into propylene glycol/water, allow to melt and disperse.

3. Weigh CARBOPOL™ 940 acrylic acid polymer and menthol.

4. Weigh sodium lauryl sulfate (SLS).

5. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer 6. Place the CARBOPOL™ 940 acrylic acid polymer/SLS dispersion and menthol into the propylene glycol/water and stir well until the gel swells and is uniformly smooth. 7. Remove from heat, package, and allow to set at room temperature.

Placebo Formulation #5. Formulation #5 is a relatively fluid, slightly opaque lotion system. The system is currently too fluid to allow easy manipulation by patients. The formulation needs to be stiffened slightly.

FORMULATION #8 propylene glycol 85.31% (w/v) water 4.49% (w/v)

CARBOPOL™ 940 (acrylic acid polylmer) 1.5% (w/v) glyceryl. monooleate (GMO) 8.5% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

1. Weigh and heat propylene glycol and water to 50° C with constant stirring.

2. Weigh the GMO and place into propylene glycol/water and allow to melt and disperse.

3. Weigh CARBOPOL™ 940 acrylic acid polymer and menthol. 4. Place the CARBOPOL™ 940 acrylic acid polymer and menthol into the propylene glycol/water and stir well until the gel swells and is uniformly smooth. 5. Remove from heat, package, and allow to set at room temperature.

Placebo Formulation #8. Formulation #8 is a relatively fluid, slightly opaque lotion system. The system is currently too fluid to allow easy manipulation by patients. The formulation needs to be stiffened slightly.

FORMULATION #9 propylene glycol 88.64% (w/v) water 4.66% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.5% (w/v) glyceryl monostearate (GMS) 3% (w/v) urea 2% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

1. Weigh and heat propylene glycol and water to 50°C with constant stirring.

2. Weigh urea and place into propylene glycol/water and dissolve under constant stirring.

3. Weigh GMS, melt and quickly add dropwise to propylene glycol/water under constant stirring.

4. Weigh the CARBOPOL™ 940 acrylic acid polymer and menthol.

5. Place the CARBOPOL™ 940 acrylic acid polymer and menthol into the propylene glycol/water and stir well until the gel swells and is uniformly smooth.

6. Remove from heat, package, and allow to set at room temperature. Placebo Formulation #9. Formulation #9 was a prepared as above but substituting orange oil for menthol. It is a very viscous cream that is resistant to flow even on inversion. While the consistency is very attractive, the formulation remains extremely greasy upon application even with extensive and vigorous rubbing. Similar formulations with other emollients have not exhibited this quality to the extent that this particular formulation has.

FORMULATION #11 propylene glycol 91.5% (w/v) water 4.80% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.0% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v)

PEG 8000 (polyethylene glycol) 2% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

1. Weigh and heat propylene glycol and water to 50°C with constant stirring.

2. Weigh PEG 8000 alcohol and place into propylene glycol/water, allow to melt and disperse. 3. Weigh CARBOPOL™ 940 acrylic acid polymer and menthol.

4. Weigh sodium lauryl sulfate (SLS).

5. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer

6. Place the CARBOPOL™ 940 acrylic acid polymer/SLS dispersion and menthol into the propylene glycol/water and stir well until the gel swells and is uniformly smooth. 7. Remove from heat, package, and allow to set at room temperature.

Placebo Formulation #11. Formulation #11 is a viscous liquid. The formulation will be reproduced using a higher molecular weight PEG to fortify the consistency.

FORMULATION #12 propylene glycol 88.64%) (w/v) water 4.66% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.5% (w/v)

PEG 8000 (polyethylene glycol) 2% (w/v) urea 2% (w/v) and menthol 0.2% (w/v)

3. Weigh PEG and place into propylene glycol/water and dissolve under constant stirring.

4. Weigh the CARBOPOL™ 940 acrylic acid polymer and menthol.

6. Remove from heat, package, and allow to set at room temperature.

Placebo Formulation #12. Formulation #12 is a relatively clear to hazy, highly viscous gel that will flow very slowly with inversion. This formulation, made with a fragrance oil rather than menthol exhibits an attractive consistency, however, the formulation remains greasy even with extensive and vigorous rubbing.

ACTIVE FORMULATIONS

Active Formulations containing ESTEROM™ cocaine derivative compounds, which contain a relatively high amount of propylene glycol.

ACTIVE FORMULATION #1

ESTEROM™ 97.5% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.5% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) menthol 0.5% (w/v)

Manufacturing Process:

1. Weigh and heat ESTEROM™ cocaine derivative compounds to 50°C with constant stirring.

2. Weigh CARBOPOL™ 940 acrylic acid polymer.

3. Weigh sodium lauryl sulfate (SLS).

4. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer.

5. Place the CARBOPOL 940 acrylic acid polymer/SLS dispersion and menthol into the ESTEROM™ cocaine derivative compounds solution with constant stirring until the gel swells and is uniformly smooth.

6. Remove from heat, package, and allow to set at room temperature.

Active Formulation #1. Formulation #1 is relatively hazy gel. The final consistency appears to be too fluid to resist flow when placed on the skin. The formulation may be stiffened to allow easy manipulation of the dose. The active ingredient appears to significantly affect the structure of the gel.

ACTIVE FORMULATION #1 A

ESTEROM™ 99.2% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 0.5% (w/v) triethanolamine 0.1% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

2. Weigh CARBOPOL™ 940 acrylic acid polymer. 3. Place the CARBOPOL™ 940 acrylic acid polymer into the ESTEROM™ cocaine derivative compounds solution with constant stirring until the gel swells and is uniformly smooth.

4. Weigh and add menthol allow to disperse.

5. Add triethanolamine and continue stirring. 6. Remove from heat, package, and allow to set at room temperature.

Active Formulation #1 A. Formulation #1 A is a hazy gel. The final consistency is too fluid to resist flow when placed on the skin. The formulation may be stiffened to allow easy manipulation of the dose. The active ingredient appears to significantly affect the structure of the gel, which is a stiff jelly at these concentrations in the placebo formulations.

ACTIVE FORMULATION #1B

ESTEROM™ 96.4% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 3.0% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) and menthol 0.1% (w/v)

Manufacturing Process: 1. Weigh and heat ESTEROM™ cocaine derivative compounds to 50°C with constant stirring.

2. Weigh CARBOPOL™ 940 acrylic acid polymer.

3. Weigh sodium lauryl sulfate (SLS).

4. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer 5. Place the CARBOPOL™ 940/SLS dispersion and menthol into the ESTEROM™ cocaine derivative compounds solution with constant stirring until the gel swells and is uniformly smooth. 6. Remove from heat, package, and allow to set at room temperature.

Active Formulation #1B. Formulation #1B is a highly viscous slightly hazy jelly. The formulation is highly resistant to flow and is easily dispensed and handled. The formulation has a sticky feel when first applied that then turns into a slightly greasy residue with continued rubbing. A reduction of the polymer content to 2-2.5% (w/v) is believed to be optimal. The product has a very delicate menthol odor.

ACTTVE FORMULATION #4

ESTEROM™ 93% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1% (w/v) glyceryl monostearate (GMS) 5% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) menthol 0.5% (w/v)

Manufacturing Process:

2. Weigh and add the GMS with vigorous stirring allow to disperse.

3. Weigh CARBOPOL™ 940 acrylic acid polymer.

4. Weigh SLS and menthol.

5. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer. 6. Add the CARBOPOL™ 940 acrylic acid polymer/SLS dispersion and menthol, stir well until the gel swells and is uniformly smooth.

7. Remove from heat, package, and allow to set at room temperature.

Active Formulation #4. Formulation #4 is an off-white viscous cream. The formulation has a slightly greasy feel when applied that disappears with continued rubbing. The residue is only very slightly tacky to the touch but would not limit normal functions after application. The menthol odor is a bit strong and may be decreased.

ACTIVE FORMULATION #5

ESTEROM™ 95.0% (w/v)

CARBOPOL™ 940 (acrylic acid polymer) 1.5% (w/v) sodium lauryl S0₄ (SLS) 0.5% (w/v) cetyl alcohol 2.8% (w/v) menthol 0.2% (w/v)

Manufacturing Process:

1. Weigh and heat ESTEROM™ cocaine derivative compounds to 50°C with constant stirring. 2. Weigh cetyl alcohol and place into the solution of ESTEROM™ cocaine derivative compounds, allow to melt and disperse.

3. Weigh CARBOPOL™ 940 acrylic acid polymer and menthol.

4. Weigh sodium lauryl sulfate (SLS).

5. Thoroughly dry mix the SLS in the CARBOPOL™ 940 acrylic acid polymer. 6. Place the CARBOPOL™ 940 acrylic acid polymer/SLS dispersion and menthol into the ESTEROM™ cocaine derivative compounds and stir well until the gel swells and is uniformly smooth. 7. Remove from heat, package, and allow to set at room temperature.

Active Formulation #5. Formulation #5 is a viscous white lotion, resists flow on inversion, is easy to dispense and handle. This lotion has a pleasant feel on the skin with minimal greasiness and residue. ADDITIONAL COMPOSITIONS CONTAINING ESTEROM™

The development of a formulation containing 10% (w/v) ESTEROM™ cocaine derivative compounds will allow greater flexibility in the formulation of stable and elegant topical products with relaxed constraints relating to the dilution of active ingredients. The current disclosure allows the production of formulations that will maintain active concentrations of approximately 9-9.94% (w/v). However, compositions of the invention will also permit a relatively wide range of ESTEROM™ content, e.g., ranging from about 5% to about 9.94% (w/v).

SUPPLEMENTATION The supplementation of the compositions disclosed herein with additional excipients will allow the production of more elegant topical formulations, including topical formulations that permit enhanced dermal penetration of the active ingredient incorporated therein. The use of wetting agents (e.g., sodium lauryl sulfate), emulsifying agents (e.g., Tweens, Spans, DSS) and various other stiffening agents (e.g., stearyl alcohol) will produce compositions having an elegant appearance, increased stability, and favorable skin feel that closely resemble traditional topical preparations. In addition to the issues of palatability, the use of various excipients as well as one or more penetration enhancing agents to increase dermal absorption of an active ingredient may provide an enhanced penetration of the active ingredient by subtle alterations in the normal structure and function of the skin. Such additional supplementations should not interfere with the ability of the emollient to decrease the probability of skin irritancy (sensitization or allergic response) due to the presence of the unusually high concentrations of semi-polar solvent, particularly propylene glycol, in the compositions described herein.

All publications cited above are incorporated herein by reference.

Claims

Claims:

1. A topical vehicle formulation comprising a semi-polar solvent, an emollient, and, optionally, a water-swellable, polar polymer, wherein said semi-polar solvent is present at a concentration in the range of about 80% (weight/volume) to about 99% (w/v).

2. The topical vehicle formulation according claim 1, wherein the semi-polar solvent is propylene glycol.

3. The topical vehicle formulation according to claim 2, wherein said emollient is present at a concentration in the range of about 2% (w/v) to about 8% (w/v).

4. The topical vehicle formulation according to claim 2, wherein said emollient is selected from the group consisting of a fatty acyl glyceride, cetyl alcohol, urea, theobroma oil, and combinations thereof.

5. The topical vehicle formulation according to claim 4, wherein said fatty acyl glyceride is glyceryl monostearate, glyceryl monooleate, glyceryl monolinoleate, or glyceryl monocaprate.

6. The topical vehicle formulation according to claim 2, wherein said propylene glycol is present in the range of about 84% (w/v) to about 89% (w/v).

7. The topical vehicle formulation according to claim 2, wherein said water-swellable, polar polymer, when present, is present at a concentration in the range of about 0.5% (w/v) to

5% (w/v).

8. The topical vehicle formulation according to claim 7, wherein said water-swellable, polar polymer is an anionic polymer.

9. The topical vehicle formulation according to claim 8, wherein said anionic polymer is an acrylic acid polymer.

10. The topical vehicle formulation according to any of claims 1-9, further comprising an active ingredient.

11. The topical vehicle formulation according to claim 10, wherein said active ingredient is selected from the group consisting of analgesics, enhancers of range of motion, narcotics, antiseptics, anti-cancer compounds, antibiotics, anti-viral compounds, anti-fungal compounds, anti- inflammatory compounds, tissue growth-promoting compounds, liposomes, sunscreens, topical coloring agents, dyes, depilatories, deodorants, antiperspirants, fragrances, insect repellants, and combinations thereof.

12. The topical vehicle formulation according to claim 11, wherein said enhancer of range of motion is ecgonine, benzoylecgonine, ecgonidine, derivatives thereof, or combinations thereof.

13. A topical vehicle formulation comprising: propylene glycol 87.30% (w/v), water 4.85% (w/v), active ingredient 4.85% (w/v), and acrylic acid polymer 3.00% (w/v).

14. A topical vehicle formulation comprising: propylene glycol 84.60% (w/v), water 4.70% (w/v), active ingredient 4.70% (w/v), acrylic acid polymer 1.00%) (w/v), and glyceryl monostearate 5.00% (w/v).

15. A topical vehicle formulation comprising: propylene glycol 88.64% (w/v), water 4.66%> (w/v), acrylic acid polymer 1.50% (w/v), glyceryl monostearate 3.00% (w/v), urea 2.00% (w/v), and menthol 0.20% (w/v).

16. A topical vehicle formulations comprising: propylene glycol 86.40% (w/v), water 4.80% (w/v), active ingredient 4.80% (w/v), acrylic acid polymer 1.50% (w/v), and cetyl alcohol 2.50% (w/v).

17. A topical vehicle formulations comprising: propylene glycol 84.90% (w/v), water 4.80% (w/v), active ingredient 4.80% (w/v), acrylic acid polymer 1.50% (w/v), and glyceryl monooleate 4.00% (w/v).

18. A topical vehicle formulations comprising: propylene glycol 81.00% (w/v), water 4.50% (w/v), active ingredient 4.50% (w/v), and

PEG 20M 10.00% (w/v).

19. A method of preparing a topical vehicle formulation comprising the step of: combining a group of compounds comprising propylene glycol, an emollient, and, optionally, a water-swellable, polar polymer at a temperature not exceeding about 50°C to form said topical vehicle formulation.

20. The method of preparing a topical vehicle formulation according to claim 19, wherein said group of compounds further comprises an active ingredient.

21. The method according to claim 19 or claim 20, wherein a sufficient amount of said propylene glycol is used to prepare a topical vehicle formulation wherein the final concentration of propylene glycol in the topical vehicle formulation is in the range of about 80% (w/v) to about 99% (w/v).

22. The method according to claim 19 or claim 20, wherein a sufficient amount of said propylene glycol is used to prepare said topical vehicle formulation wherein the final concentration of propylene glycol in said topical vehicle formulation is in the range of about 84% (w/v) to about 89% (w/v).

23. The method according to claim 19 or claim 20, wherein the final concentration of said emollient in the topical vehicle formulation is in the range of about 2% (w/v) to about 8%(w/v).

24. The method according to claim 23, wherein said emollient is selected from the group consisting of a fatty acyl glyceride, cetyl alcohol, urea, theobroma oil, and combinations thereof.

25. The method according to claim 24, wherein said fatty acyl glyceride is glyceryl monostearate, glyceryl monooleate, glyceryl monocaprate, glyceryl monolinoleate, or glyceryl monocaprate.

26. The method according to claim 19 or claim 20, wherein said water-swellable, polar polymer, when present, is an anionic polymer.

27. The method according to claim 26, wherein said anionic polymer is an acrylic acid polymer.

28. The method according to claim 20, wherein said active ingredient is selected from the group consisting analgesics, enhancers of range of motion, narcotics, antiseptics, anti-cancer compounds, antibiotics, anti-viral compounds, anti-fungal compounds, anti-inflammatory compounds, tissue growth-promoting compounds, liposomes, sunscreens, topical coloring agents, dyes, depilatories, deodorants, antiperspirants, fragrances, insect repellants, and combinations thereof.

29. The method according to claim 28, wherein the enhancer of range of motion is ecgonine, benzoylecgonine, ecgonidine, derivatives thereof, or combinations thereof.

30. Use of a topical vehicle formulation according to any one of claims 1-18 in the manufacture of a medicament.

31. Use of a topical vehicle formulation according to any one of claims 1 - 18 to enhance range of motion of a joint or limb.