US3803300A - Ointment foil and method of preparing the same - Google Patents

Abstract

OINTMENT FOILS FOR APPLICATION TO THE INJURED OR INTACT SKIN ARE PREPARED BY DRYING AN OIL-IN-WATER TYPE EMUL: SION OF CONVENTIONAL IONTMENT INGREDIENTS AT ELEVATED TEMPERATURE TO A WATER CONTENT OF 1% TO 15%, THE FOILS SO OBTAINED ARE FIRM ENOUGH TO BE HANDLED WITHOUT A SUPPORT OR CARRIER, YET FLEXIBLE ENOUGH TO CONFORM TO THE CONTOURS OF THE BODY.

Description

United States Patent O 3,803,300 OINTMENT FOIL AND METHOD OF PREPARIN THE SAME Heinz Pospischil, Oskar-Orth-Str. 22, D-665 Homburg, Saar, Germany No Drawing. Filed Mar. 5, 1971, Ser. No. 121,555 Claims priority, application Germany, Mar. 18, 1970,

P 20 12 775.7 Int. Cl. A45d 40/26; A61f 13/00; A61m 35/00 US. Cl. 424-28 4 Claims ABSTRACT OF THE DISCLOSURE Ointment foils for application to the injured or intact skin are prepared by drying an oil-in-water type emulsion of conventional ointment ingredients atrelevated temperature to a water content of 1% to The foils so obtained are firm enough to be handled without asupport or carrier, yet flexible enough to conform to the contours of the body.

This invention relates to shaped ointment bodies and to a method of preparing the same.

It is common practice to apply to the skin ointments containing therapeutically or cosmetically active agents. The ointments have the consistency of a very soft solid barely capable of maintaining its shape under the forces of gravity or even softer. They are either applied directly to the skin from a container, or they are applied to an absorbent carrier such as a fabric on an industrial scale and applied while supported on the carrier.

The ointments employed in the last-described manner must be practically free from water and have a continuous oily or fatty phase consisting of petroleum jelly, polyethylene glycol or the like because conventional ointments which are of the oil-in-water emulsion water'type The ointment bodies of the invention are foil-shaped in accordance with their normal applications and are emulsions of the oil-in-water type, that is,-they have a fat or oil phase colloidally dispersed in a continuous aqueous phase although their water content may be as low as 1% and should not be higher than 15% by weight.

The components of the foil-shaped bodies other than water are conventional ointment ingredients, such as a pharmaceutically acceptable oily or fatty ointment base in an amount of to 60%, 2% to 12% of an emulsifier capable of emulsifying the base. in Water, 3% to 20% of a film forming agent, 12% to 40%bof a humectant, and 1% to 15 of an active agent of any type conventionally employed in ointments for therapeutic or cosmetic purposes and compatible with the other ingredients.

. As is frequently desirable in ointments, the oil-in-water.

emulsions of the invention may contain enough titanium oxide or zinc oxide to make them opaque. Synthetic surfactants are the preferred emulsifying agents, and may be of the anionic, cationic, or non-ionic types, numerous such agents being in current pharmaceutical use. Methyl cellulose, carboxyrnethyl cellulose, and other cellulose Patented Apr. 9, 1974 derivatives capable of dissolving or of swelling in water, and alginates are the preferred film forming agents.

Because of their low Water content, the foil-shaped ointment bodies of the invention are shape retaining and may be applied manually to the intact or injured skin without the fingers touching the latter and without requiring transfer of the-ointment to gauze or other fabric before application to the skin. Yet, they are flexible enough to conform to the substrate under minimal pressure. Large skin areas can quickly and conveniently be covered.

The foil-shaped ointment bodies of the invention are prepared from oil-in-water emulsions of higher water content having a paste-like consistency by partial evaporation of the original water content when an exposed layer'of the starting emulsion spread on a solid substrate is supplied with thermal energy. The thermal energy is preferably supplied at a rate to keep the temperature of the initially paste-like layer at 50 to C. the actual drying temperature depending on the ingredients used, and the layer being exposed to a vacuum while being supplied with thermal energy at the lowest temperatures of the preferred range.

The oily or fatty phase of the emulsion may consist of any of the usual, pharmaceutically accepted ointment bases such as mineral oil, ozokerite, petroleum jelly, paraflin, fatty alcohols, vegetable oils and their hydrogenation products, fatty acid glycerides, and the like. The emulsifiers suitable for the purpose of the invention include; but are by no means limited to sodium cetostearyl sulfate, 'ethoxylated fatty alcohols, complex emulsifiers such as polyoxyethyleneglycols or propyleneglycol.

The therapeutically or cosmetically active agents ,are compounded with the initial emulsion and may include all therapeutic or cosmetic ingredients conventionally incorporated in oil-in-water ointments such as p-chloro-mcresol, hydroxyquinoline and other disinfectants, antibi otica, sulfonamides ,hexachlorophene, acridine dyes, phydroxybenzoic acid esters, quaternary ammonium compounds such as benzalkonium' chloride, cetylpyridinium chloride. Other active agents compatible with the necessary ingredients of ointment bodies of the invention include tanning agents, allantoin, urea, azulene, various plant'extracts, cortisone derivatives, vitamins, and hormones.

Film forming agents which have been used successfully in the foil-shaped bodies of the invention include polymers having repeating carboxyvinyl groups, methyl cellulose, carboxymethyl cellulose and other water soluble cellulose derivatives, vegetable mucilage, alginates,'polyvinyl pyrrolidone, copolymers of vinyl pyrrolidone and vinyl acetate, agar, carragheen, dextran, and the like.

The initially prepared emulsion is adjusted with water or aqueous ethanol to the consistency of a thin, freeflowing paste. A layer of the paste is spread on a solid substrate of sheet metal, glass, or the like by means of a knife blade, roller, or other coating apparatus and heated to'reduce the residual moisture content'to 1% to 15%. Internally heated drums having a cylindrical surface of polyethylene, polytetrafluoroehtylene, ceramic enamel or glass permit convenient separation of the dried foil from the heated surface.

When water is evaporated from the emulsion layer at atmospheric pressure, best results are usually obtained at a temperature of the substrate between 65 and 110 C. When a lower temperature is needed, the evaporation of the water may be hastened by applying a vacuum. The initial thickness of the emulsion layer is chosen to make the dried foil 0.2 mm. to 2 mm.'thick.

Alternatively, the starting emulsion may be compounded with relatively little water to give it the consistency of a heavy paste which is further dehydrated by stirring in an evacuated kettle until the paste is as thick as dough. This heavy paste is then rolled to the desired thickness and dried to the ultimate water content on heated metal sheets or a heated rotating cylinder.

The foil-shaped bodies of the invention are readily smoothed on the skin so as to make contact over their entire surface. They readily absorb moisture discharged from the skin or blood, and effectively release their active agents to the skin through the large interface. While a fabric carrier is not usually required for applying foil shaped ointment bodies of the invention which have dimensions of length and width of several inches, such carriers may be combined with these foil bodies in any desired manner.

Whether or not a layer of fabric is carried by the foil-shaped bodies, they are preferably sealed in a moisture impervious envelope for storage.

The following examples are further illustrative of the invention, and it will be understood that the invention is not limited thereto. All parts and percentage figures are by weight.

EXAMPLE 1 3 parts petroleum jelly, parts cetostearyl alcohol (a 1:1 mixture of cetyl alcohol and stearyl alcohol), and 1 part of a commercial nonionic surfactant (ethoxylated oleyl alcohol containing 5-10 mole percent ethylene oxide and having a hydroxyl number between 80 and 110) were heated with stirring until a homogeneous melt was obtained. An aqueous mixture was prepared at 70 C. from 2 parts low-viscosity methyl cellulose, 1 part polyvinylpyrrolidone, 6 parts glycerin, 1 part panthenol, 1 part allantoin, 0.1 part benzalkonium chloride, and 80 parts water.

The aqueous and fatty components were combined in in oi1-in-water emulsion by means of a high speed agitator. The emulsion so obtained was ground with 3 parts zinc oxide, the paste-like mass was applied to a polytetrafiuoroethylene-covered steel sheet in a thickness of 2 mm., and the metal sheet was heated to maintain a temperature of 100 C. in the paste layer until the moisture content of the latter had been reduced to about 3 to 4%. The dried film was flexible but sufiiciently shape-retaining to be stripped from the substrate and handled without difficulty.

It was used successfully in mitigating symptoms of U lcus cruris.

EXAMPLE 2 An emulsion was prepared as in Example 1 from an oil phase consisting of 0.2 part paraffin oil, 3 parts ozokerite, 3 parts petroleum jelly, and 5 parts of a :1 surfactant mixture of cetostearyl alcohol and sodium cetylstearyl sulfate, the last-mentioned ingredient being a mixture of equal parts of sodium cetyl sulfate and sodium stearyl sulfate, and cetostearyl alcohol being a corresponding mixture of the alcohols. The aqueous phase 4 EXAMPLE 3 A fatty phase of an emulsion was prepared from 6 parts petroleum jelly, 10 parts cetylstearyl alcohol, 1 part stearic acid, and 2 parts polyoxyethylenesorbitan monooleate by melting and dispersed in an aqueous phase prepared at 70 C. from 4 parts methyl cellulose, 10 parts glycerin, 1 part allantoin, and parts water. The emulsion so prepared was further blended with 0.5 part neomycin sulfate and 0.05 part vitamin E acetate.

An emulsion layer 3 mm. thick was spread on a metal sheet, and the sheet Was placed in a vacuum furnace kept at a temperature of about 50 C. until the residual moisture in the emulsion was reduced to about 5%.

The product was useful as a general purpose ointment for sore skin.

EXAMPLE 4 A similar, but more viscous emulsion was prepared from a molten oil phase consisting of 3.3 parts petroleum jelly, 6.4 parts of the nonionic surfactant of Example 1, 0.5 part polyethyleneglycol (400) stearate, 0.] part butyl p-hydroxybenzoate, and 0.2 part wool fat (adeps lanae), and an aqueous phase consisting of 2.2 parts carboxymethyl cellulose, 1.2 parts polyvinylpyrrolidone, 5 parts polyethyleneglycol 400, 3 parts urea, and 60 parts water of 70 C.

The mass so obtained was partly evaporated in a vacuum kettle with continuous stirring until it had the consistency of a stilf paste or dough. This product was placed on sheets in thin layers and dried to a residual moisture content of 5% at C.

It provided a suitable base for medicinal ointments.

EXAMPLE 5 An emulsion as initially prepared in Example 1 was placed over a layer of surgical gauze spread on metal sheets, whereby the emulsion penetrated into the fabric. The thickness of the applied emulsion layer was about 3 mm. prior to subsequent heating to 100 C., whereby the ultimate moisture content was reduced to about 34%.

While the invention has been described with reference to specific examples for the purpose of the disclosure, it should be understood that it is not limited thereto, but may be practiced, within the scope of the appended claims, otherwise than as specifically described.

What is claimed is:

1. A foil-shaped flexible dried film ointment body of sufficient strength to be handled While unsupported, and applied manually to the intact or injured skin without the fingers touching the latter, yet flexible enough to conform to the contours of the body, being 0.2 mm. to 2 mm. thick, said body essentially consisting of (a) 1% to 15% water;

(b) 20% to 60% of a pharmacologically acceptable oily or fatty ointment base selected from the group consisting of mineral oil, ozokerite, petroleum jelly, paraffin, fatty alcohol, wool fat, vegetable oil, bydrogenated vegetable oil, and fatty acid glycerides other than said vegetable oil or hydrogenated vegetable oil;

(c) 2% to 12% of an emulsifier keeping said base colloidally dispersed in said Water;

(d) 3% to 20% of a film forming agent selected from the group consisting of a polymer having repeating carboxyvinyl groups, methyl cellulose, carboxymethyl-cellulose, alginate, agar, polyvinylpyrrolidone, carragheen, and dextran;

(e) 1% to 40% of a humectant;

(f) 1% to 15% of a therapeutically active agent compatible with said base, said emulsifier, said film forming agent, said humectant, and said water,

(3) said active agent being a disinfectant, an antibiotic, a sulfonamide, a tanning agent, allantoin, urea, azulene, a plant extract, a cortisone derivative, or a vitamin,

(2) all percentage values being by weight of said bod 4. A body as set forth in claim 1, wherein said emulsifier is sodium cetylstearyl sulfate, ethoxylated fatty alcohol, polyoxyethylenesorbitan fatty acid ester, soap, or a cationic surfactant.

References Cited UNITED STATES PATENTS 259,268 6/ 1882 Buczkowski 424-28 X 1,687,643 10/1928 Berliner 424-28 X 1,836,833 12/1931 Amos 424-28 X 1,353,954 9/1920 Henry 424-28 X Washburn 424-28 X Wheeler 424-28 X Williams 206-46 Duane et a1. 15-506 Ehrlich 424-78 Nouvel 424-80 Winterstein 424-63 Neely 424-63 Freyermuth et al 424-63 Lachampt et al. 424-63 X Factor 424-63 Factor et a1. 424-63 Lautfer 424-63 Larde et al 424-78 X SHEP K. ROSE, Primary Examiner Y us. (:1. x11