AU2496984A

AU2496984A - Antiviral composition and method for administering the same

Info

Publication number: AU2496984A
Application number: AU24969/84A
Authority: AU
Inventors: Glen Jackson Dixon
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-02-03
Filing date: 1984-01-24
Publication date: 1984-08-30
Anticipated expiration: 2004-01-24
Also published as: AU554500B2

Description

_Ϊ TIVIRAL OPPOSITION AND METHOD FOR ADfflNISTERΪNG THE SAME Background of the Invention

This invention relates generally to antiviral agents, and more particularly concerns an antiviral agent, which when mixed with a solvent carrier agent, is effec- tive to abate herpes simplex virus disease (commonly 5 referred to as herpes) and other related viral diseases.

Herpes simplex virus, disease as its name indi¬ cates is the result of the infection of the human body by the herpes simplex virus. The herpes simplex virus that affects humans is of two types, type 1 and type 2. Both 10 types of herpes simplex virus infect the human body by penetrating the cellular wall of the body cells and inter¬ fering with the DNA configuration of the cells. The herpes simplex virus takes over the DNA mechanism of the cell so that the virus can replicate itself. In the 15 process of the herpes virus replicating itself within the cell, the cell is destroyed. As a result of the destruction of body cells a blister-like sore appears at the location where the herpes virus entered the body. The type 1 herpes simplex virus is generally 20 acknowledged to produce the characteristic blister-like sores at the mucocutaneous junctions at the mouth, nose and eyes. The type 2 herpes simplex virus is generally acknowledged to create the same sort of blister-like sores on the genitals and anus. The sores can appear, however, 25 at any location on the body such as a wound, where the virus can enter the body.

It is also commonly acknowledged that once the virus has entered the human body it never leaves. After the blister-like sores have healed in about two to three 30 weeks, the herpes virus retreats to and lies dormant in the nerve tissue of the body. Herpes simplex virus from •j- oral herpes sequesters in the trigeminial ganglion, and ■ in genital herpes in the sacral ganglion. As a result, some people experience recurring blister-like sores which 35 are thought to be brought on by stress or other unknown triggering mechanisms within the body. In other people, the virus may lie dormant for long periods of time or for the rest of the person's life. For those people, however, that experience fre¬ quent recurring blister-like sores, especially those with genital herpes, the disease can be especially traumatic. While there are a number of antiviral agents which will destroy the herpes simplex virus in a laboratory setting, none of these antiviral agents have been successful in com¬ bating oral or genital herpes simplex virus disease in a clinical setting. These antiviral agents include adenine arabinoside (ara-A) , ribavirin, acyσlovir (ACV) , 2-deoxγ- d-glucose (DG) and phosphonoacetiσ acid (PAA) . R. Hamilton, The Herpes Book, pages 161-168, (J. P. Tarcher, Inc., 1980); F. Ξ. Kahn, Ed., Vol. 27, Antiobiotics and Chemotherapy, (Harper, Basel, 1980) ; and . M. Shannon and F. M. Sachael, Jr. Vol. II, Pharmacology and Therapeutics, pages 263-390, (Pergamon Press, Ltd., 1980).

At the present time, the Federal Food and Drug Administration (FDA) has approved the use of ara-A in oint¬ ment form for treatment of ocular herpes simplex virus disease. Moreover, ara-A has also been used in the trea - ment of herpes encephalitis by infusing a solution of ara-A in sterile infusion fluid for 12 to 24 hours. Neither of these treatments are effective against oral or genital herpes. "Vidarabine Ophalthalmic Ointment (Vira-A) ", Drug Therapy Bulletin, May 25, 1979, 17(11), pages 43-44; and "Vidarbine Approval for Herpes Simplex Virus

Encephalitis", FDA Drug Bulletin, Dec. 1978 Jan. 1979 8(6) 1136.

Also at the present time, the Burroughs Wellcome Company of Research Triangle Park, North Carolina, has offered for sale an ointment under the trademark Zovirax, the active antiviral agent of which is acyclovir. The acyσlovir antiviral agent in the Zovirax ointment is mixed with a polyethylene glycol base. Burroughs Wellcome*s own literature and advertising state that "in studies of re- current herpes genitalis and herpes labialis in nonimmuno- compromised patients, there was no evidence of clinical benefit ..." The antiviral agent Idϋ (5-iododexyuridine) has been combined with dimethyl sulfoxide (DMSO) and has pur¬ portedly cleared up skin lesions caused by DNA viruses, including herpes simplex and prevent recurrence. F. 0. MacCallum and B. E. Juel-Jensen, British Medical Journal, 2, pages 805-807, (1966) ; B. C. Turnbull and H.C.W. Stringer, New Zealand Medical Journal, 70, pages 317-320, (1969) ; and B. E. Juel-Jensen, F.O. MacCallum, A.M.R. Mackenzie and M.C. Pike, British Medical Journal, 4, pages 776-780 (1970) . P. McGrady, The Persecuted Drug; The Story of DMSO, page 285, Grosset & Dunlap Co., 1973 (1981).

The apparent problem in abating or curing herpes simplex virus disease in a clinical setting results from the difficulty of assuring that the antiviral agent pene- trates the cellular wall into the infrastructure of the cell in order to attack and kill the herpes simplex virus that are literally hiding behind the cellular wall struc¬ ture.

SUMMARY OF THE INVENTION It is thus an object of the present invention to provide a composition of antiviral agent and a solvent carrier agent which, when combined, will translocate throughout the body and penetrate the cellular walls to attack the herpes simplex virus and destroy it.

It is a further object of the present invention to provide a composition of ara-A, an antiviral agent, and DMSO, a solvent carrier agent, which when mixed in proper proportions provides effective clinical abatement of herpes simplex virus disease resulting from both type 1 and type 2 herpes simplex viruses.

Other objects and advantages of the invention will become apparent upon reading the following detailed description of the invention. DETAILED DESCRIPTION OF THE INVENTION

While the invention will be described in con¬ nection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodi¬ ment. On the contrary,' I intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

As previously stated, ara-A (adenine-9-beta-D- arabinofuranoside) is known to be an effective antiviral agent against the herpes simplex virus. It is thought that ara-A does not work to combat herpes simplex virus disease in the clinical setting because ara-A is highly insoluble in water. As a result, the ara-A is not able to mix successfully with the body's fluids, and more impor- tantly, it is not able to penetrate the cellular wall structure to get to the herpes simplex virus which is with¬ in the cell itself.

In order to assure that ara-A can be carried through the cell walls and into the cell structure, it is first necessary to dissolve ara-A in a suitable solvent system. Second, the solvent system media must have the ability to diffuse throughout the body and through the cell walls to carry the dissolved ara-A antiviral agent into the cell and into contact with the herpes simplex virus within the cell structure.

Thus the preferred embodiment of the present invention results from mixing the antiviral agent, ara-A, with DMSO (dimethyl sulfoxide) , a solvent carrier agent. Ara-A is active against a broad spectrum of DNA viruses (these are viruses which contain deoxyribonucleic acid as the predominant nucleic acid type) both in vitro

OMPI (in the test tube) and in vivo (in animal models or in man) . These viruses include the varicella-zoster virus (chicken pox and shingles) , the Epstein-Barr (E-B) virus of infectious momonucleosis, vaccinia virus, cytomegalo- virus and others.

The main reason ara-A is not active against oral and genital herpes is because of its low solubility in water (0.45 mg/ml at 25C) . By using DMSO as the solvent system, it is possible to achieve a concentration of 10 mg/ml or greater. DMSO transports the ara-A directly into the virus infected cell where active viral replication is occurring. The drug interfers with viral DNA synthesis causing inhibition of viral maturation. Specifically, ara- inhibits the enzyme DNA polymerase, an action that inhibits further viral replication.

Regarding toxicity or other side effects on the^' patient, extensive pharmacology and toxicity studies ara-A have been carried out in animals and in man. The acute intraperitoneal LD__Q for this drug ranged from 3900 to 4500 mg/kg in mice and 3300 to 2500 mg/kg in rats. This dose level indicates a low order of toxicity to a single parenteral dose. The acute oral LD₅₀ in both rats and mice is greater than 5000 mg/kg. This amount would be equivalent to more than 750 grams (1 2/3 pounds) in an average 150 pound man. It is not possible to demonstrate toxicity through topical application of this compound. In some cases, however, redness and slight irritation has been noted after topical application. A massive acute overdosage of the intraveneous form of ara-A has been reported without any serious side effect. In the form used in the present invention and with treatment by topical application, it is highly unlikely that any toxic side effects of ara-A would be observed.

DMSO has been studied extensively also, in both animals and humans and is essentially nontoxic. When DMSO

OMPI IPO is applied to the skin in its undiluted state, it sometimes may cause an itching or burning sensation with redness or a rash. This rash, however, usually disappears shortly thereafter with no ill effects. Annals of the New York Academy of Sciences, Vol. 243, (1967). S. W. Jacob, E. E. Rosenbaum and D. C. Wood, Eds., Vol. 1 Dimethyl Sulfoxide 99, (Marcel Depper, Inc., New York, N.Y. 1971); and Annals of the New York Academy of Sciences, Vol. 243, (1975) . In the present invention DMSO is diluted to 70% with demineral- ized water before ara-A is added. At this concentration DMSO is usually nonirritating to normal skin.

DMSO serves two purposes in enhancing the thera¬ peutic action of ara-A. First, DMSO allows a concentration of ara-A that is more than 20 times greater than can be achieved with water alone. Second, and more importantly, DMSO has the unique ability of permeating the interstitial spaces and cell walls to carry the antiviral drug along with it into the cell. It is this percutaneous property of DMSO that is apparently responsible for the extraordinary effeσ- tiveness of this medication.

Treatment of herpes simplex virus disease should J-egin as soon as prodromal symptoms are apparent. The prodrome or prodomal symptoms are the tingling, itching, burning senations that occur a few hours to one to two days prior to manifestation of blisters or lesions. Usually if treatment is started at this early stage, the infection is aborted, and sores do not appear. When treatment is begun after lesions are present, the lesions resolve two to three days quicker than when left untreated. This shorter healing time means freedom from pain and virus shedding in a shorter time.

The medication should be applied every two to four hours for the first two days during waking hours. After that time, application every four to six hours is sufficient. If excessive irritation due to solvent is apparent, the time between applications should be increased to every six to eight hours, for example. The antiviral composition of the present inventio may be applied topically on the affected area with a cotton swab or gauze.

To say that a medication cures herpes would imply that the virus was not only inactivated and cleared from epithelial or mucousal cells, but that it was also cleared from the nerve cells where the virus lays dormant during latent periods. Because it is not known whether or not herpes virus replicates in the nerve cells, it is not known if the present invention inactivates the latent herpes viru in the nerve cells. It is entirely possible that the DMSO used in this medication does carry the antiviral drug into the nerve cell.

If ara-A does enter the nerve cell, and there is virus replication, then presumably the virus would be inhi- bited. Even if there is no virus replication occurring in the nerve cells, it is conceivable that the amount of virus in the body is decreased each time the virus becomes active and is attacked by treating in the prodrome. At some point after repeated treatment, the virus could become virtually nonexistent in the patient.

The formulation for the antiviral agent of the present invention is not critical and is effective over a wide range of concentrations of both ara-A and DMSO. A sample formula that has been used and is effective against both oral and genital herpes is as follows:

Example 1 Ara-A 1.0 gm

DMSO 70.0 ml

Demineralized Water 30.0 ml The higher the concentration of _.DMSO is in the solvent carrier medium; the greater is the amount of ara-A that can be dissolved. Also, the therapeutic effective¬ ness of ara-A increases with concentration up to a point. The active concentration range with regard to DMSO is 50 to 100 percent of the solvent carrier medium. The ara-A range is 1.0 mg/ml to 100 mg/ml. An all encompassing formula, covering all useful concentration ranges by per¬ centage is:

Example 2

Ara-A 0.1 to 10.0 (of total composition) DMSO 50 to 100 (of solvent carrier medium) Demineralized water 0 to 50 (of solvent carrier medium)

Another ingredient or component that might be usefully added to the composition is a local anesthetic such as benzocaine or dibucaine which may be incorporated into the medication for local pain control. The medication of the present invention has been prepared and used both ways. It appears that the presence of benzocaine does not impair the antiviral activity of ara-A. Nor does the benzocaine appear to have any deleterious affect on the patient when administered in DMSO. Also 1-2 percent car- boxymethylcellulose might be added to the mixture to pro¬ vide a gel which may be preferred for topical application for vaginal and cervical herpes.

There are no special procedures involved in the preparation of the antiviral composition of the present invention. Th demineralized water and DMSO can be mixed and the ara-A (and benzocaine if used) dissolved in the DMSO and water solution. The ara-A can be^' added to the pure DMSO, and water added last. When water and DMSO are mixed, the solution becomes warm because there is a posi- tive heat of solution. There is no chemical reaction between ara-A and DMSO under the conditions of preparation. Ara-A can be recovered from the DMSO and water solution virtually 100 percent as unchanged ara-A.

In addition to the preferred embodiment described using ara-A as the antiviral agent, the present invention also encompasses those analogs of ara-A which display sig¬ nificant antiviral activity by interferring viral DNA syn¬ thesis to inhibit viral maturation. Thus, for example, acyclovir and ribavirin, which are similar to ara-A in that all three are purine analogs, will, when mixed with DMSO, provide clinical benefits against oral and genital herpes. Of course, other analogs of ara-A may be expected to pro¬ vide similar benefits when mixed with DMSO.

Claims

I claim:

1. An antiviral composition for treating viral infections in humans including herpes simplex virus disease comprising a solvent carrier which will translocate through¬ out the body and penetrate cell walls and an antiviral agent which interferes with viral deoxynucleic acid syn¬ thesis causing inhibition of viral maturation wherein the solvent carrier includes dimethyl sulfoxide which comprises less than 100 percent of the solvent carrier and wherein the antiviral agent is selected from the group consisting of ara-A, acyσlovir and ribavirin.

2. The antiviral composition of claim 1, wherein the solvent carrier is dimethylsulfoxide.

3. The antiviral composition of σlaim 1 or claim 2, wherein the antiviral agent is selected from the group consisting of ara-A, acyclovir and ribavirin.

4. The antiviral composition of claim 1 wherein the antiviral agent is a purine analog of ara-A.

5. A method for treating viral infections in humans including herpes simplex virus disease comprising the step of topiσally applying to infected portions of the human body an antiviral composition comprising a solvent carrier which will translocate throughout the body and penetrate cell walls and an antiviral agent which inter¬ feres with viral deoxynucleic acid synthesis causing inhi¬ bition of viral maturation, wherein the solvent carrier includes dimethylsulfoxide and wherein the antiviral agent is selected from the group consisting of ara-A, acyσlovir and ribavirin.

6. The method for treating herpes simplex virus disease of σlaim 5, wherein the solvent σarrier of the antiviral σomposition is dimethylsulfoxide.

7. The method for treating herpes simplex virus disease of σlaim 5 or σlaim 6, wherein the antiviral agent

OMPI is selected from the group consisting of ara-A, acyσlovir and ribavirin.

8. The method for treating viral infections in humans including herpes simplex virus disease of σlaim 5, wherein the antiviral agent is a purine analog of ara-A.

9. The method for treating viral infeσtions in humans inσluding herpes simplex virus disease of σlaim 5, wherein the antiviral composition further comprises a local anesthetiσ.

10. The method for treating viral infeσtions in humans inσluding herpes simplex virus disease of σlaim 5, wherein the antiviral σomposition further σomprises a gel forming agent.