US2183493A - Germicidal and antiseptic composition - Google Patents

Description

Patented Dec. 12, 193

Mahlon I. Rentschler,

- oman AND ANTISEPTIC COOS!- TION Wilioughby, and Donald B. Bradner, Hamilton, Ohio, assignors to The Hamilton Laboratories, Inc., Hamilton, Ohio, a corporation of Delaware Application January 2'], 1936,

Serial No. 61,113

5 Claims. This invention relates to germicidal and antiseptic compositions; and it comprises composi- .tions containing a phenylmercuric radical and free tribasic inorganic acid such as boric or phos- 5 phoric acid;

Phenylmercuric compounds are among the most powertul germicldes known. And in general they have asurprisingly small irritant effect on the skln,;eve,n with solutions of rather high concentration. There is, however, some irritant tendency and with a sensitive skin or sensitive tissue it must be taken into consideration' In extreme cases, burns or blisters have been produced on the skin by the use of unduly concengg trated solutions for prolonged periods, necessitating the use of weakersolutions. Further, solu-. tions of phenylmercuric compounds, while quite stable are not indefinitely so; many on long standing, that is, in a few months, undergo ingo ternal changes which may result in a separation of metallic mercury. The same class of changes occur in considerably less time, at a temperature of 100 C.

We have found that the irritant efiect of even as strong solutions of these compounds may be greatly reduced and the stability greatly increased by the use of a little inorganic tribasic acid in the solution as such.

The present invention is applicable to phenyl- 30 mercuric compounds of the general type, CBHSHgX, wherein X is an anion. Among the phenylmercuric compounds particularly useful as geimicides embraced in the present invention may be listed the hydroxide, the basic nitrate, the

an chlorid, the acetate, etc.

The tribasic inorganic acid to be used is generally phosphoric acid or boric acid; boric acid being particularly desirable. In the event that the phenylmercuric compound is a hydroxide,

9 which is a basic body more than enough boric acid is added to neutralize the base. The same is true in using phosphoric acid. With saline compositions of the phenylmercuric type, a little free acidity of the tribasic acid is all that 4,5 is wanted. There is evidence to show that an excess of.- acid, that is a little free acid, is in general desirable. Thus as regards the stabilizing efiect, it is found that the. addition of 0.1 per cent of boric acid to an aqueous solution, 121500 50 phenyl mercuric basic nitrate has a great stabilizlng effect. Such a solution remains stable at room temperatures indefinitely long without any visible sign of decomposition or loss of germicidal effectiveness. A similar solution, without the boric acid, will give a deposit of metallic mercury in a few months. With a simple aqueous solution, two days exposure to a temperature of 100 C. causes a deposit but with the amount of boric,acid stated present, no deposit was found even in heating as long as 18 days, in each case g using enough acid to have a little in excess. As regards reduction. of any irritant efiect upon human tissue in germicidal phenylmercuric solutions, it has been found that a large drop of 111500 solution of phenylmercuric basic nitrate, 10 containing 0.1 per cent boric acid, may be applied to the skin of the average individual and allowed to dry thereon without producing any irritation or visible mark. In drying down, of course, the solution becomes. progressively more conceni5 trated. A similar solution but without boric acid, will in many instances, and particularly with sensitive skins, develop an irritating redness; sometimes even a blister. It has been found that solutions considerably more concentrated than the 20 stated 1:1500 solution, even up to a triple concentration, when. containing boric acid and applied in this way, do not burn or irritate. As an extreme example, 1 part phenylmercurlc borate and 5 parts ordinary crystallized boric acid dissolved in 500 parts of dilute alcohol (50 per cent alcohol and 50 per cent water) may be applied to the ordinary skin without producing redness. Similarly, a solution of 1 part phenylmercuric hydroxide and 4 parts commercial g9 sirupy phosphoric acid in 1500 parts of water is not irritating. This solution contains phenylmercuric phosphate with some excess phosphoric acid.

The tribasic acid used may not be wholly in a free state since, for example, the boric acid may be partially neutralized with soda and monosodium phosphate (an acid phosphate) may be employed in equivalent amounts, in lieu of the free acid. 40

The present improvement is useful with nonaqueous germicidal compositions containing phenylmercury compounds as well as aqueous, as for I instance with liquids containing alcohol, glycerine, glycol, etc. It is also useful with salves; for as example 1 part phenylmercuric basic nitrate, 1.5 parts boric acid in 1500 parts of an ointment having an oxycholesterin base has proved highly satisfactory.

What we claim is: I

1. An improved germicidal preparation consisting of a solution of a phenyl mercuric salt and a tribasic inorganic acid, said tribasic inorganic acid being present in greater proportion thanv the phenyl mercuric salt, and in an amount sufficient to stabilize the phenyl mercuric salt against deterioration by age.

2. The composition of claim 1 in which the acid is boric acid.

3. The composition of claim 1 in which the acid is phosphoric acid.

4. The composition of claim 1 in which the phenyl mercuric salt is a salt of a tribasic inorganic acid.

5. An improved germicidal preparation conmes es sisting of a solution of a phenyl mercuric salt of a tribasic inorganic acid. and an acid inorganic salt of a tribaslc inorganic acid, said acid tribasic salt being present in greater proportion than. the

'phenyl mercuric salt, and in an amount sumcient to stabilize the phenyl mercuric salt agamst deterioration by age.

ON J. RENISCBEER. DUNALD E.