US3274054A - Antiviral compositions and method of administration - Google Patents

Description

United States Patent 3,274,054 ANTIVIRAL COMPOSITIONS AND METHOD OF ADMINISTRATION Andrew Stephen Tomcufcik, Tappan, Robert Bruce Angier, Pearl River, Martin Forbes, New City, and Howard Frederick Lindh, Monsey, N.Y., assignors to American Cyauamid Company, Stamford, Conn., a corporation of Maine No Drawing. Filed June 28, 1963, Ser. No. 291,282 11 Claims. (Cl. 167-65) This invention relates to methods of and new compositions for treating viral infections in warm blooded animals.

Heretofore no chemotherapeutic agents have been found which have proved effective in treating systemic virus infections. We have now found that compositions containing as an active ingredient a compound of the following formula are useful in treating viral infections in warm blooded animals:

R is hydrogen or lower alkyl, R and R are hydrogen or lower alkyl, R and R are lower alkyl, X is lower alkylene, Z is oxygen or sulfur and acid addition and quaternary salts thereof.

The free bases of the compounds of this invention are, in general, oily liquids or low melting solids. They are, in general, soluble in water and in the usual organic solvents, such as lower alkanols, acetone, lower alkyl esters of lower alkanols, benzene, toluene, ethers and the like.

The free bases of the compounds of this invention form acid addition salts with acids such as hydrochloric, hydrobromic, sulfuric, acetic, citric, tartaric, lactic, succinic, maleic, phosphoric, malic, gluconic, ascorbic, 1,1- methylene-bis-(2-naphthol-3-carboxylic acid), butanel,2,3,4-tetracarboxylic acid and the like. Such acid addition salts are in general soluble in water, but not soluble in non-polar organic solvents such as ethers and petroleum ethers; and they may be prepared, in general, by adding an anhydrous acid to an anhydrous solution of the basic compound in ether or alcohol and thereafter isolating the precipitated salt by filtration.

The compounds of the present invention can be prepared by methods described hereinafter in the examples and in the prior art. The most general method for preparing the present compounds is the reaction of l-carbethoxy-4-lower alkylpiperazine with a di-loweralkylamino lower fatty acid alcohol. Other methods are shown hereinafter in the examples.

One of the compounds of the present invention, diethylaminoethyl 4-methyl-l-piperazinecarboxylate, has shown a reproducible protective effect in experimental influenza A virus infections in mice. The results of tests are sum marized in the following Table I.

3,274,054 Patented Sept. 20, 1966 TABLE I.-EFFECT OF Z-DIETHYLAMINOETHYL 4-METHYLPIPERAZINE-l-CARBOXY LATE IN IN- FLUENZA INFECTION IN MICE Single dose treatment Survivors/Group on 14th day after Infection Single Dose, rug/kg.

Oral Subcutaneous Treatment Treatment 15 Controls (0.85% NaOl) 5 1o0 1 Animals: Taconic male white mice; 16-20 grams body weight. Inigztion: Intranasal; 0.05 ml. of a 10' broth dilution of virus stock 0. Treatment: Single dose directly after infection; oral doses by tubing of 0 1.0 ml. volume of aqueous solution; subcutaneous doses by injection of 0.5 ml. volume of aqueous solutions; all solutions adjusted to pH 7.0.

The above Table I summarizes the results with a single dose as treatment directly after infection. The following Table II summarizes results with three dose oral treatment.

TABLE II.EFFECT OF Z-DIETHYLAMINOETHYL 4 METHYLPIPERAZINE l CARBOXYLATE IN THE INFLUENZA INFECTION IN MICE Three dose oral treatment Infection Intranasal; 0.05 ml. of a 10- broth dilution of virus stock No. 67.

Treatment: Oral tubing of 1.0 ml. volume of aqueous solutions at 0, 24 and 48 hours after infection.

Other compounds of the present invention were injected subcutaneously and the results obtained are summarized in the following Table III.

TABLE III.EFFECT OF OTHER COMPOUNDS ON 50 SURVIVAL RATIO OF MICE INFECTED WITH INFLUENZA A (PR-8 VIRUS) Survival Name Dose, rug/kg. Ratio on 14th Day Dimethylaminoethyl 4-methylpiperazine- 800 5/15 -carboxylate. 3-Dimethylarninopropyl4methy1pipera- 800 5/15 zinel-carboxylate. 0 Z-Dimethylaminoisopropyl 4-methyl- 800 5/15 piperazine-l-carboxylate. Controls (0.85% NaCl) 5/105 Animals: Taconie Farms male white mice; 19-25 grams body weight Infection: Intranasal; 0.05 ml. of a lCldilution in brain heart infusion broth of stock PR-8 virus. Treatment: Compounds dissolved in water, pH adjusted to 7.0. Indicated dose imected subcutaneously immediately after infection. Controls received 0.85% NaCl solution.

The compounds of the present invention described above Will be dispensed in compositions comprising the active ingredient and excipients including a carrier. While the amount of active ingredient to be given daily will depend on many factors such as the size, weight, age, kind, and severity of infection, etc. of the warm blooded animal, a daily intake ranging from 5 to 500 milligrams per kilogram of body weight will produce good results. The dosage unit may vary from 0.05 to 2 g. and may 'be in a form to be administered one or more times per day, or in smaller forms for multiple daily, or other more frequent administration. Any of the usual dosage unit forms of pharmaceutical compositions can be useful, for example, tablets, Oblets, hard or soft shell capsules, parenteral solutions or suspensions, oral solutions or syrups,

etc. I

Tablets or Oblets may include, in addition to active ingredient, any of the following excipients. A binder such as acacia, corn starch, gelatin, or the like. A disintegrating agent such as corn starch, potato starch, alginic acid, or the like. A lubricant such as stearic acid, magnesium stearate, talc or the like. Also a sweetening agent such as saccharin or sucaryl, and/ or a flavoring such as peppermint oil, oil of Wintergreen, or orange or cherry flavoring can be used.

Capsules may include, in addition to active ingredient, a lubricant and also an inert filler such as lactose, sucrose, corn starch or the like.

Solutions, usually include an acid such as hydrochloric, citric, tartaric, succinic, maleic, ascorbic, phosphoric or the like, or a suitable bufler thereof. Suspensions include a surfactant such as polyoxyethylene sorbitan monooleate (a complex mixture of polyoxyethylene ethers of mixed partial oleic esters of sorbitol anhydrides); oxyethylated tertiary octylphenol formaldehyde polymer; p-isooctylpolyoxyethylenephenol polymers or the like; a suspending agent such as polyethylene glycol 4000 USP (a condensation polymer of ethylene oxide and water, represented by the formula: HOCH (CH OCH ),,CH OH, wherein n varies from about 70 to 85, the molecular weight being about 4000), carboxy methylcellulose (sodium carboxymethylcellulose USP, the sodium salt of carboxymethyl ether of cellulose having a closely controlled number of sodium carboxymethyl (CH COONa) groups introduced into the cellulose molecule to bring about solubility in water); methylcellulose (cellulose methyl ether prepared from wood pulp or chemical cotton by treatment with alkali and methylation of the alkali cellulose with methyl chloride), and the like; and a buffer such as a phosphate, citrate, or tartrate buffer. Both solutions and suspensions may include a stabilizer such as disodium salt of ethylenediaminetetraacetic acid, sodium sulfite, monothioglycerol, or the like; and a perservative such as benzyl alcohol, parabens (methyl and propyl esters of phydroxybenzoic acid), or the like.

Oral solutions may include a suspending agent or viscosity control such as magnesium aluminum silicate, carboxymethylcellulose or the like as Well as a buffer, preservative, etc. Solutions and suspensions may be of the aqueous sugar or sorbitol type. It is also known in pharmaceutical practice to employ a propyleneglycol type solvent for use with drugs.

The invention is further illustrated by means of the following examples.

Example I.Preparati0n of Z-dimelhylaminoethylpiperazine-I-carboxylate In a flask connected to a condenser and receiver is placed 817 g. of Z-dimethylaminoethanol, which contains 8 g. of dissolved sodium, and 474 g. of l-carbethoxypiperazine. The mixture is heated first between 6070 C. for 7 hours at 32-38 mm. pressure and then at 140 C. for 7 hours at atmospheric pressure. The resultant solution is carefully fractionated at reduced pressure to remove excess 2-dimethylaminoethanol and unreacted l-carbeth- 4 oxypiperazine. A crude fraction, boiling point 140-160 C. at 1525 mm. is collected and redistilled to yield 2- dimethylaminoethyl piperazine-l-carboxylate, a colorless oil, boiling point 114-117 C./0.51 mm., 21 1.4823.

Example lI.-Preparation of Z-diethylaminoethylpi perazine-I -carboxy late Four g. of sodium are dissolved in 928 g. of 2-diethylaminoethanol and 474 g. of l-carbethoxypiperazine are added to the solution. The mixture is then heated in a manner similar to that described in Example I, first at reduced pressure, in this case at 40 mm. for 7 hours at 88 C., and then at the boiling point of Z-diethylaminoethanol for 7 hours at atmospheric pressure. The Z-diethylaminoethyl piperazine-l-carboxylate is a colorless oil, boiling point l44.5-147 C./4 mm., n 1.4803.

Example IlI.Preparati0n of Z-diethylaminoelhyl 4-methylpiperazine-1-earb0xylate A mixture of 468 g. of Z-diethylaminoethanol containing 4 g. of dissolved sodium and 172 g. of 1-carbethoxy-4- methylpiperazine is heated under reduced pressure and at atmospheric pressure in a manner similar to that described in Example 11. Purified material consists of 2-diethylaminoethyl 4-methylpiperazine-l-carboxylate, a colorless oil, boiling point l27-128 C./ 1 mm., 11 1.4700.

Example I V.Preparati0n of Z-diethylaminoethyl 4-methylpiperazine-I-carb0xylate dihydrochloride A salt is prepared by passing hydrogen chloride gas into an ethereal solution of 2-diethylaminoethyl 4- methylpiperazine-l-carboxylate of Example III. The product, 2- diethylaminoethyl 4-methylpiperazine l-carboxylate dihydrochloride, is obtained as a white solid which melts after recrystallization from alcohol-ether at 196.3- 198.3 C. with effervescence.

Example V.Preparation of 3-diethylam-in0propyl 4-methylpiperazine-1-carb0xylate Metallic sodium (0.4 g.) is dissolved in 51.5 g. (0.39 mole) of 3-diethylamino-l-propanol followed by the addition of 17.2 g. (0.10 mole) of 1-carbethoxy-4-methylpiperazine. The solution is heated in an oil bath at 90 C. for seven hours under reduced pressure (25-50 mm. of Hg) and then refluxed for ten hours at atmospheric pressure. The excess aminoalcohol is removed on a steam bath at 20 mm. of mercury and the residue is distilled through a small Vigreux column. The fraction boiling at 114l23 C. (0.6 mm. of Hg) is collected; yield 11.2 g., n =1.4702. This product is redistilled through a Nester-Faust spinning band column, yield 7.5 g., boiling point 126-l28 C. (0.9 mm. of Hg), n =1.4712.

Example Vl.-Preparation of Z-dimethylaminoisopropyl 4-methylpiperazine-1-carb0xylate Metallic sodium (0.4 g.) is dissolved in 41.3 g. (0.4 mole) of l-dimethylamino-2-propanol. To this solution is added 17.2 g. (0.1 mole) of 1-carbethoxy-4-methylpiperazine and then heated for six hours at 80-90 C. A stream of dry air is passed through the reaction mixture at the beginning of the heating period. This causes 15 ml. of the aminoalcohol to distill over which is added back to the reaction. At the end of the six hours several ml. of distillate are collected before refluxing for an additional eight hours. The mixture is filtered and the filtrate is distilled through a Nester-Faust spinning band column, yield 2.4 g., boiling point 84-88 C. (10.4 mm. of Hg), n 1.4662.

Example VII.-Preparati0n 0f Z-dimethylaminoethyl 4-methylpiperazine-1 -carb0xylate To 36 g. (0.4 mole) of Z-dimethylaminoethanol is added 4.6 g. (0.2 mole) of sodium followed by brief refluxing to complete solution. The solution is then cooled to room temperature, diluted with 50 ml. of diglyme and 22.5 g. (0.11 mole) of 4-methylpiperazine-l-carbonyl chloride Example VIII.-Preparation= 09 Z-diethylaminoetlzyl 4-methylpiperazine-I-carb0thi0late dihydrochloride 2-diethylaminoethanethiol hydrochloride (32.8 g., 0.193 mole) is dissolved in 25 ml. of water and covered with 100 ml. of ether. Approximately 50-60 g. of anhydrous potassium carbonate is added followed by vigorous shaking. The ether layer is decanted and the remaining slurry is shaken with three additional 100 ml. portions of ether. The combined ether extracts are dried over magnesium sulfate, then evaporated to dryness to yield 23.8 g. (0.164 mole) of the freee base. This material is dissolved in 70 ml. of diglyme, 3.8 g. (0.164 mole) of sodium is added and warmed on a steam bath to effect solution. The solution is cooled to room temperature, 16.3 g. (0.082 mole) of 4-methylpiperazine-l-carbonyl chloride is added, and the reaction mixture is stirred at room temperature for one-half hour, then refluxed for two hours. The insoluble portion is filtered off and washed with 100 ml. of diglyme. The filtrate and washings are combined and the diglyme is removed on a steam bath at 20 mm. of Hg. The residue is again filtered from some solid material and the filtrate is distilled through a Nester-Faust spinning band colum. The fraction boiling at 120-122 (0075-010 mm. of Hg) is collected; yield 12.4 g. of Z-diethylaminoethyl 4 methylpiperazine-l-carbothiolate, n =1.5110.

The above product is dissolved in 50 ml. of anhydrous ether and treated with 300 ml. of anhydrous ether which has previously been saturated with anhydrous hydrogen chloride in an ice-bath. The resulting gum which separates is triturated to a solid, filtered and recrystallized from ethanol-ether; yield 12.7 g., melting point 229- 234 C. dec.

Example 1X.Preparation 0f Z-diethylaminoethyl 2,4,5- trimethy lpiperazz'lze-I -carb0xylale Metallic sodium (0.4 g.) is dissolved in 46.8 g. of 2- diethylaminoethanol followed by the addition of 20.0 g. of 1-carbethoxy-2,4,S-trimethylpiperazine. This is treated in a manner similar to Example V. The product obtained is 2-diethylaminoethyl-2,4,S-trimethylpiperazine-l-carboxylate.

Example X Parenteral solutions of the compounds of the present invention can be used as a method of administration. An illustrative formulation is the following.

Percent w./v. Diethylaminoethyl 4-methyl-l-piperazinecarboxylate 25-100 Hydrochloric acid as needed to obtain pH, q.s.

to pH 4.5-5.5. Sequestrene, disodium 0.05 Benzyl alcohol reagent 0.9-1.5

Pyrogen-free distilled water to make 100.00 ml.

Example XI The compounds of this invention may be administered in oral syrup preparations such as the following.

Percent w./v. Diethylaminoethyl 4-methyl-l-piperazinecarboxylate 25-100 Sodium phosphate monobasic, sodium phosphate dibasic, q.s. to pH 4.5-5.5.

Methylparabens 0.08 Propylparabens 0.02 Sucrose 10-40 Red Dye FDC #2 0.005 Cherry flavor 0.05

Distilled water, q.s. ad ml.

The above syrup has a pH of about 4.5-5 .5.

Other ingredients may replace those indicated above for example a suspending agent such as bentonite magma, tragacanth, carboxymethylcellulose, methylcellulose, carbopol 934 (carboxy vinyl polymer of high molecular weight), etc. can be used. The phosphates used above as buffers can be replaced with citrates or tartrates. As preservatives, the parabens can be replaced with alkali metal benzoates, sorbic acid or the like. The sugar and sorbitol could be replaced in Whole or in part with corn syrup, glycerol, other sugars, etc. And alternate dyes and flavors could replace those indicated above.

Example XII The compounds of this invention may be dispensed in hard or soft shell capsules. A useful formulation for preparing such capsules is as follows.

Mix thoroughly and dispense in 50 capsules.

Example XIII The com-pounds of this invention may be dispensed as pharmaceutical tablets or Oblets. A useful formulation for preparing tablets or Oblets is as follows.

Per tablet, g. Diethylaminoethyl 4-methyll-piperazinecarboxylate 50.0 Corn starch 2.0 Methylcellulose (viscosity 400 cps.) 0.50 Magnesium stearate, 1% 0.525

Mix thoroughly and dispense as 100 tablets.

.The above tablets each containing 0.5 g. of active ingredient may be considered to provide an entire single daily dose. Such a tablet might be scored so as to provide fractional daily doses. Alternatively, tablets containing smaller amounts of active ingredient might be prepared for fractional daily or smaller doses.

We claim:

1. A method of treating virus infections in warm blooded animals which comprises administering to said animals an antiviral composition comprising an edible carrier and from 5 to about 500 mg. per kg. based on body weight of said animal, of a substituted piperazine of the formula:

wherein R is selected from the group consisting of hydrogen and lower alkyl, R and R are selected from the group consisting of hydrogen and lower alkyl, R and R are lower alkyl, X is lower alkylene, Z is selected from the group consisting of oxygen and sulfur and acid addition and quaternary salts thereof.

2. The method of claim 1 in which the substituted piperazine is 2-diethylarninoethyl-4 methylpiperazine-1- carboxylate.

3. The method of claim 1 in which the substituted piperazine is 3-diethylaminopropyl-4-rnethy1piperazine-1- carboxylate.

4. A method of claim 1 in which the substituted piperazine is Z-dimethylaminoisopropyl 4-methylpiperazine-1- ca-rb-oxylate.

5. The method of claim 1 in which the substituted piperazine is Z-dimethylaminoethyl 4-methylpiperazinel-carboxylate.

6. The method of claim 1 in which the substituted piperazine is 2-diethylaminoethyl piperazine-l-carboxylate.

7. A composition of matter having antiviral activity, in dosage unit form, comprising a pharmaceutical carrier and from about 0.05 to 2 g. of a substituted piperazine of the formula:

wherein R is selected from the group consisting of hydrogen and lower alkyl, R and R are selected from the group consisting of hydrogen and lower alkyl, R and R are lower alkyl, X is lower alkylene, Z is selected from the group consisting of oxygen and sulfur and acid addition and quaternary salts thereof.

8. A composition of matter in accordance with claim 7 characterized in that the substituted piperazine is 2- diethyla-minoethyl 4-methylpi perazine-l-carboxylate.

9. A composition of matter in accordance with claim 7 characterized in that the substituted piperazine is 3- diethylaminopropyl 4-methylpiperazine-l-carboxylate.

10. A composition of matter in accordance with claim 7 characterized in that the substituted piperazine is 2- dimethylaminoisopropyl 4 methylpiperazine 1 carboxylate.

11. A composition of matter in accordance with claim 7 characterized in that the substituted piperazine is 2- dimethylaminoethyl 4 methylpiperazine 1 carboxylate.

No references cited.

LEWIS GOTTS, Primary Examiner.

SHEP K. ROSE, Assistant Examiner.

Claims (1)

1. A METHOD OF TREATING VIRUS INFECTIONS IN WARM BLOODED ANIMALS WHICH COMPRISES ADMINISTERING TO SAID ANIMALS AND ANTIVIRAL COMPOSITION COMPRISING AN EDIBLE CARRIER AND FROM 5 TO ABOUT 500 MG. PER KG. BASED ON BODY WEIGHT OF SAID ANIMAL, OF A SUBSTITUTED PIPERAZINE OF THE FORMULA: