US2095092A - Ointment - Google Patents

Description

Patented Oct. 5, 1 937 UNITED STATES OINTMENT Larry J. Barton, Oakland, Calif., assignor to C10- rox Chemical (30., Oakland, Calif., a corporation -of Delaware No Drawing. Application February 21, 1936, Serial No. 65,112

5 Claims. (Cl. 167-63) My invention relates to an ointment, and more particularly to the type of antiseptic or germicidal ointment containing as an active agent, a halogenated compound having available chlorine or other halogen, such for example as hypochlorites.

The property of hypohalogenite solutions, such as sodium or any other alkali metal or alkaline earth hypohalogenite solutions, of curing those classes of skin disease caused by a fungus or other parasitic growth, is well known. One of the most common of such infections frequently termed athletes foot is very prevalent and is rapidly increasing. Heretofore, mild or relatively dilute solutions containing about 1 (one) percent by weight of hypochlorite have been employed in foot baths for such infections, in places such as schools, swimming pools, and gymnasiums.

Obviously, the treatment of athletes foot by a mild liquid solution of the hypochlorite offers certain inconveniences. For example, if one wants to apply the hypochlorite to an infected foot, this must be done over an extended period of time, in order for the solution to be effective. If the solution is made too strong, to shorten the time of treatment, injury to the skin will result. Also, clue to the oiliness of the skin, surface tension, and the minute cracks of the skin in which the parasites multiply, it has been found that with a mild liquid solution, the liquid will not penetrate to the seat of the trouble unless the foot is held in the solution for an excessive period which is enough to cause other or uninfected parts of the foot to become tender and sore.

For other types of skin infection such as common types of ring worm, and for types of skin irritation such as heat rash, prickly heat, and cold sores which cannot with practicability be soaked in a hypochlorite solution, other points of difilculty are encountered such as rapid drying of the solution upon application to the skin, its tendency to roll away from the infected part, and its characteristic of quick evaporation with attendant loss of strength.

The ideal method of application of the hypochlorite is in the form of a salve or ointment paste which can, for example, be applied to an infected i foot over night, and which can be applied to other infected parts of the skin, in a similar manner. Also, in ointment form, the hypochlorite can be applied to the exact point desired and holds itself in intimate contact at the desired point of in- .fection. As a result, the germicidal action of the hypochlorite is localized exactly where desired, and rapidly eliminates the cause of the trouble. Although efforts have been made in the past to provide a hypochlorite or similar hypohalogenite in ointment form, there has, heretofore, existed the problem of a satisfactory base for the ointment.

This is so because hypochlorites and similar halogenated alkali metalor alkaline earth hydroxides, are inorganic salts and are all powerful oxidizers. Hence, they rapidly react with most substances, the result being a rapid breakdown of the hypohalogenite. Ointment bases heretofore used have had the property of reacting with the hypohalogenite or affecting it catalytically to cause breakdown thereof. Also, most bases, heretofore employed, have been reacted upon by the hypohalogenite, thereby permitting only small quantities of the hypohalogenite to be incorporated in the ointment. An example of such type of base is bentonite disclosed in the patent to Banks No. 1,813,109. Contact with bentonite causes decomposition of a compound such as sodium hypochlorite, thereby limiting the amount that can be incorporated in a bentonite base ointment, to about .05 to .l% hypochlorite by weight of the ointment. This is probably due to the presence of oxides such as iron, manganese, nickel and chromium oxides which occur in bentonite, perhaps to catalytic action thereof. Furthermore, hypohalogenites break down or increase in unstability approximately as the square of the concentration. That is, for example, a 2 (two) percent concentration by weight of hypochlorite will break down four times as fast as a 1 (one) percent concentration. This is a factor, therefore, in the provision of a suitable base for a hypochlorite or similar hypohalogenite ointment, which will enable a concentrated amount of hypohalogenite to be incorporated therewith.

Another problem which existed in connection with bases for hypohalogenite ointments was that the base should have certain properties in itself; and it was, heretofore, difficult to obtain a base having such properties and still satisfy the other requirements. For example, the base when incorporated in an ointment with an aqueous solution of a hypohalogenite, should form an ointment which will have a soft, bland smooth texture and be neither crystalline, rough nor gritty. Also, the base should be absolutely nonpoisonous and non-corrosive when used in contact with the skin; and preferably, the base should have beneficial therapeutic qualities itself, as well as have the property of leaving a smooth, soft, adhesive film which remains in close contact with the skin as the ointment dries.

It is one of the objects of my invention to provide an improved hypochlorite or similar hypohalogenite ointment in which the base for the ointment will be unaffected by the hypohalogenite and the hypohalogenite will be unaffected by the base, to thereby provide a composition of great stability and permit the incorporation of a more or less concentrated amount of the hypohalogenite in the base.

Another object of the invention is the provision of an improved ointment, of the character described, in which the hypohalogenite can be incorporated in suiiicient amounts, so as to have a decided therapeutic action against fungus and parasitic infection, and yet is one containing nothing of a poisonous or corrosive nature when used in contact with the skin.

Another object is the provision of an improved ointment, of the character described, which is non-gritty, of pleasing color and which will dry to a smooth paste when applied to the skin.

Other objects will appear as the description progresses.

As a suitable base which will fulfill all of the foregoing requirements, I have found that cer-, tain metallic compounds which have the property of absorbing liquids and are neutral in their action with reference to the hypohalogenite, and which are in a completely oxidized state, can be inter mixed with the hypohalogenite to provide the desirable hypohalogenite ointment, although this would normally notbe expected because of the amnity that hypochlorites and similar hypohalogenites have on most metallic compounds. A neutral metalic oxide in completely oxidized state produces the best results, such as zinc oxide and titanium oxide; and of the two, zinc oxide has been found preferable.' In addition to the zinc and titanium compounds, certain salts of bismuth provide suitable bases. For example, bismuth sulphocarbolate, bismuth hydrated oxide, bismuth oxychloride and bismuth subgallate may be employed. Zinc carbonate also will serve as a satisfactory base. These metallic compounds, it will be observed, are not in the ferrous group;

I compounds of metals in the ferrous group are unsatisfactory as bases.

All of the described compounds which can be employed as bases, satisfy all of the necessary requirements as to stability in the presence of an aqueous or similar solution of a hypocholrite or equivalent hypohalogenite. They possess the physical property of producing a smooth paste with such solutions; and in addition have a beneficial action on skin diseases or irritations. These compounds may be mixed in any suitable proportions with each other and with the hypohalogenite solution; and when mixed with each other, they may be used with equal results as when used alone. These compounds are representative of many actually tested. It was found that although metal compounds, such as zinc and titanium in completely oxidized form produce the best results, the compounds suitable outside of being of metal do not fall within a single subgeneric class. Although those mentioned produce satisfactory results, other non-ferrous metal compounds which have the property of absorbing the solution of hypohalogenite, have no irritating effect on the skin, which are neutral to the hypohalogenite so as not to react therewith or cause it to decompose, and which are nonpoisonous and otherwise fulfill the described functional requirements, may be used.

Although the ointment may be formed direct from the base mixed with any desirable proportions of the hypohalogenite solution of any desired strength or concentration, and placed in a container for distribution, I have found that the ointment has a tendency to harden'upon continued opening of the container over a comparatively long period of time. This hardening would not occur when the ointment was used within" a reasonable period after the container was first opened. In order to obviate this disadvantage, I have found that an inert viscous vehicle such as petroleum jelly or other similar heavy petroleum compound such as heavy mineral oil, when incorporated in the ointment in suitable amounts depending on the final viscosity desired, will maintain moistness of the ointment in the container and produce a salve or ointment that will remain soft and bland even after continued use over a comparatively long period of'time. Such mineral oil has no adverse effect on the hypohalogenite and is not adversely affected by the hypohalogenite.

, To prepare my ointment, a solution of a hypochlorite or similar hypohalogenite which in practical commercial form consists essentially of an aqueous solution of sodium hypochlorite, although any other alkali metal or alkaline earth metal can be substituted in place of the sodium and any other halogen such as bromine or iodine substituted for the chlorine, is first intermixed thoroughly with the base in any suitable manner. Suflicient quantity of the base should be used to provide a final mixture of suitable stiifness or viscosity inasmuch as a liquid is to be intermixed therewith. Approximately 40 to 50 parts of the preferred hypochlorite solution by weight, to approximately 50 to 60 parts of the dry, powdered base will usually produce a composition of the desired stiffness or viscosity. The proportions will of course vary according to the weight of the dry base itself, and its fineness. The desired mixture is one which should be moist yet fairly stiff or viscous, and which may be readily spread by the fingers, and yet not be either too dry or too thin.

In order to have a final product of the requisite smoothness, it is desirable to start with a powdered base free from any lumps or hard particles. Preferably, the powdered base should not be coarser than 60 mesh; the best results being obtained ranging from 100 to 200 mesh. Zinc oxide is the base preferably employed; and, as previously related, an aqueous solution of sodium hypochlorite is preferably intermixed therewith because of its commercial availability.

The strength of hypochlorite in the final ointment is regulated by the strength of the hypochlorite solution initially used to absorb the dry base, and I have found I may make an ointment consisting of the base and hypochlorite which will contain from small amounts to as high as 10 (ten) percent of hypochlorite by weight. The latter can be done by employing a hypochlorite solution containing about 20 (twenty) percent ofhypochlorite by weight. For all practical purposes, an ointment containing not over 2 (two) percent by weight of hypochlorite, will satisfy the majority of uses. For this concentration, the hypochlorite solution may contain from 2 (two) percent to 4 (four) percent by weight of hypochlorite. Although the solution of hypochlorite or alkali free solution such as is described in my copending application Serial No. 4,885, filed February 4, 1935, and which may be made by halogenating or chlorinating a sodium hydroxide or other basic hydroxide solution to a point at which the quantity of free basic hydroxide disappears or approximates zero with the solution still alka line because of its greater inherent stability, and because caustic has a detrimental effect on the skin.

When the viscous inert vehicle, such as petroleum jelly or heavy mineral oil, is to be incorporated in the ointment, as is preferably done for the reasons previously explained, to obtain the the same final concentration of hypochlorite in ointment as would exist in any given ointment without the addition of the inert viscous vehicle, higher concentrations of the hypohalogenite solution must obviously be employed because I have found that it is desirable to incorporate sufiicient of the viscous vehicle to provide from 5 (five) percent to 25 (twenty-five) percent by weight of the ointment, with the preferable amount of about 10 (ten) percent. The percentage of .viscous vehicle will of course vary with the stiffness or viscosity of the final product desired. If it is desired to produce a product that can be expelled from a metallic tube by squeezing thereof, then of course the higher percentage of viscous vehicle should be employed. A much lower percentage should be used if a comparatively stifi final product is desired; and in the latter case moreof the base can be intermixed with the hypochlorite solution.

Petroleum jelly is the preferred inert viscous vehicle; and preferably white petroleum jelly is employed because it will not affect the white color of the mixture of base and hypohalogenite solution. To incorporate the petroleum jelly in the ointment, the best method is to add gradually the petroleum jelly in a molten condition, to the mixture of the base and hypohalogenite solution while the latter are being intermixed together by stirring thereof. The molten condition of the petroleum jelly is obtained by first heating it. After complete addition of the petroleum jelly, the stirring or mixing of the ingredients is continued until there is a uniform mixture, and the petroleum jelly has reached its normal viscosity as a result 'of cooling to normal room temperature. The same procedure is recommended for the addition of other inert viscous vehicles, such as the heavy mineral oil.

I shall now describe the preferred composition, and its preparation. The preferred composition compr ses an intimate mixture of zinc oxide as the base, an aqueous sodium hypochlorite solution as the active agent, and white petroleum jelly as the inert viscous vehicle. The preparation of this composition may proceed as follows:

The zinc oxide, in substantially dry condition, is pulverized and screened through a mesh of the desired fineness. To approximately 50 to 60 parts by weight of this white powder in a suitable container, there is added 40 to 50 parts by weight of an aqueous solution of sodium hypochlorite, approximating 2 (two) percent of contained sodium hypochlorite by weight of the solution. As this liquid is added, the material is thoroughly mixed by suitable means until there is complete and uniform absorption of the zinc oxide in the hypochlorite solution. After the zinc oxide has become thoroughly absorbed in the hypochlorite solution, and while the stirring or mixing is continued, about 8 to 12 parts by weight of molten petroleum jelly is added. The mixing is continued until the petroleum jelly is uniformly and thoroughly intermixed with the zinc oxide absorbed in the hypochlorite solution; the resultant composition being a smooth, soft, white colored ointment of the desired analysis. The ointment is now placed in proper containers for the market.

In the case where petroleum jelly is not to be. incorporated in the ointment, the same initial procedure is followed, and terminated at the point where there is a complete absorption of the zinc oxide in the hypochlorite solution. For

other bases, concentrations of the active agent, inert viscous vehicles and/or hypohalogenites, the same procedures may be followed.

The ointment prepared in accordance with my invention will have a pleasing white color, and be very clean, cool and sanitary in appearance. It can be applied locally to any point of the body, and is readily rubbed into all minute cracks and fissures in the skin, penetrating deeply to the point of infection, thereby completely killing any fungus or parasitic growth. The hypohalogenite is held in intimate contact with the. seat of infection which is the main point to be desired. After being thoroughly rubbed into the skin at the seat of infection, the ointment will gradually dry leaving a substantially dry antiseptic adhering closely to the infected part. This is important in that such substantially dry dressing quickly absorbs any liquid matter issuing from the infected surface, and thereby aids in preventing spreading of the infection.

Due to the endothermic action of the hypohalogenite, the ointment is very cooling when applied to the skin and thus is especially useful for those burning or itching classes of skin irritations such as prickly heat, heat rash, cold sores, bites and stings of insects, burns, poison oak and poison ivy, which quickly dry up under its antiseptic action.

I claim: I

1. A stable ointment containing a solution of a hypohalogenite, a base including at least one compound selected from a group consisting of zinc oxide, titanium oxide, zinc carbonate, bismuth sulphocarbolate, bismuth hydrated oxide, bismuth oxychloride and bismuth subgallate, said ointment containing more than 0.1% by weight of said hypohalogenite.

2. A stable ointment containing a solution of a hypohalogenite, a base including at least one compound selected from a group consisting of zinc oxide, titanium oxide, zinc carbonate, bismuth sulphocarbolate, bismuth hydrated oxide, bismuth oxychloride and bismuth subgallate, and a viscous petroleum fraction for maintaining said ointment of pasty consistency, said ointment containing more than 0.1% by weight of said hypohalogenite.

3. A stable ointment containing a solution of a I 50 caustic-free hypohalogenite, a base including at least one compound selected from a group consisting of zinc oxide, titanium oxide, zinc carbonate, bismuth sulphocarbolate, bismuth hydrated oxide, bismuth oxychloride and bismuth subgallate, said ointment containing more than 0.1% by weight of said hypohalogenite.

4. A stable ointment containing a solution of an alkali metal hypochlorite, a. base including at least one compound selected from a group consisting of zinc oxide, titanium oxide, zinc carbonate, bismuth sulphocarbolate, bismuth hydrated oxide, bismuth oxychloride and bismuth 'subgallate, said ointment containing more than 0.1% byweight of said hypochlorite.

5. A stable ointment containing a solution of caustic-free sodium hypochlorite, a base including at least one compound selected from a group consisting of zinc oxide, titanium oxide, zinc carbonate, bismuth sulphocarbolate, bismuth hydrated oxide, bismuth oxychloride and. bismuth subgallate, said ointment containing more than 0.1% by weight of said hypochlorite.- LARRY J. BARTON.