Medicament for the treatment of viral skin and tumour diseases

The present invention relates to a pharmaceutical which comprises a compound of the formula

##STR00002## where R.sub.1, independent of each other, is an unbranched or branched, saturated, singly or multiply unsaturated, optionally substituted C.sub.11-C.sub.21 alkyl, alkylene or alkynyl radical, preferably a C.sub.11-C.sub.15 alkyl, alkylene or alkynyl radical, in particular a C.sub.11-C.sub.13 alkyl, alkylene or alkynyl radical, especially a C.sub.13-alkyl radical, and

R.sub.2 is, independent of each other, an unbranched or branched C.sub.1-C.sub.8 alkyl, alkylene or alkynyl radical, preferably a C.sub.1-C.sub.6 alkyl, alkylene or alkynyl radical, in particular a C.sub.2-C.sub.4 alkyl, alkylene or alkynyl radical, especially a C.sub.3-alkyl radical, a --[CH.sub.2--(CH.sub.2).sub.m--O].sub.n--H radical where n=1 to 10, preferably n=1 to 5, m=1 to 5, preferably m=1 to 3,

a --CH.sub.2--[CH--(OH)].sub.p--(CH.sub.2--(R.sub.3)] radical, where R.sub.3 is, independent of each other, a hydrogen or a hydroxyl radical, p=1 to 7, preferably p=1 to 4, a pentose radical or a hexose radical,

as a therapeutically active compound, either alone or together with one or more additional pharmaceutical active compounds as a combination preparation, for treating viral skin diseases and/or tumor diseases which are caused, in particular, by human papilloma viruses (HPV) and/or herpes viruses, and also to a topically acting pharmaceutical formulation and its use.

Papilloma viruses (HPV) are DNA viruses which infect the epithelial cells of mammals and thereby induce uncontrolled cell growth. There are a very wide variety of papilloma viruses, which infect humans and different animal species. In this connection, all the viral types infect the basal epithelial cells and remain as episomes or integrate their DNA into the host genome.

It has been known for a long time that papilloma viruses cause genital warts (Condyloma acuminata), ordinary and plantar warts, bowenoid papulosis in men and women, and cervical intraepithelial neoplasias in women.

Depending on the method used, the detection rate for HPV is almost 100%. It is in the main HPV 6 and HPV 11 viruses which are found in warts and genital warts (Condyloma acuminata). Since HPV 16 and HPV 18 are principally observed in malignant, desquamative cell carcinomas, as in the case of cancer of the penis and of the uterine cervix, it is generally accepted that HPV 16 and HPV 18 are linked to malignant HPV diseases.

At present, physical methods are predominantly used for treating genital warts caused by human papilloma viruses. These methods include surgical removal, electrocauterization, cryosurgery and laser therapy to mention but a few. An additional medicinal treatment is the use of Podophyllin, 5-Fluorouracil, Bleomycin, Interferon, Imiquimod, etc.

Surgical treatment suffers from the disadvantage that it is very unpleasant for the patient and can lead to further infection. Up until now, a topical use has involved the risk of side effects since the active compounds employed possess cytotoxic properties or augment the cellular immune defense and can consequently induce local inflammations. This demonstrates that the therapeutic possibilities which have thus far been available are still not satisfactory.

In addition to this, there is the fact that the proportion of recurrences is very high in the case of warts and genital warts and complete healing can only be achieved by means of constant and consistent treatment. For this reason, there is a need for a more reliable and comfortable treatment.

Particularly when treating genital warts, but also in connection with all the other diseases which are caused by the papilloma virus, there is a requirement for a treatment which is easy for the patient to use. For example, a treatment which the patient himself can use at the affected sites and which gives good results in relatively short time, and exhibits only few or no side effects, would be suitable.

Herpes simplex viruses (HSV) are DNA viruses from the alpha subfamily Herpetoviridae. They are divided into two groups, i.e. HSV 1, termed the oral strain, and HSV 2, termed the genital strain. Herpes simplex viruses penetrate, as a nucleocapsid, into the nerve endings and, using the axonal flow, reach the appurtenant ganglia. They are transmitted by smear and droplet infection from herpes lesions or by healthy chronic carriers. Following a primary infection, the viruses can be reactivated once again, symptomatically or a symptomatically, by irritation, for example due to fever, trauma or radiation, of latently infected neurons. This reactivation depends, in particular, on the defensive condition of the body taken as a whole. Herpes simplex viruses can transform cells neoplastically in animals and in cell cultures. The possibility of an interaction between type 2 herpes simplex viruses and the genesis of cervical carcinomas involving type 16 and type 18 human papilloma viruses is presently being discussed.

EP 0 087 161 discloses treating herpes infections by treating them with a mixture consisting of isopropyl myristate and small quantities of 4-{lower alkyl}-2,6-(bis-tert-butyl)phenol containing 2,6-(bis-tert-butyl)-4-hydroxytoluene or 4-(lower alkyl)-2,6-(bis-tert-butyl)phenol.

EP 0 842 660 describes a pharmaceutical composition for treating genital warts which are caused by human papilloma viruses. The composition which is described comprises catechols from tea extracts (Camellia sinensis), predominantly (-)-epigallocatechol-gallate in the form of an ointment or a suppository.

An object of the present invention is therefore to find additional effective antiviral substances and formulations which are suitable for treating viral skin diseases and/or tumor diseases which are caused by papilloma viruses and/or herpes viruses.

It has now been found, surprisingly, that a pharmaceutical which comprises a compound according to the invention of the formula (I) as the pharmaceutically active compound is suitable for treating viral skin diseases and/or tumor diseases.

The present invention consequently relates to a pharmaceutical which comprises a compound of the formula (I) as the pharmaceutically active compound, A-B (I) where A is a radical of the formula (II)

##STR00003## and B is a radical of the formula (III) --O--R.sub.2 (III), and

R.sub.1 is, independent of each other, an unbranched or branched, saturated, singly or multiply unsaturated, optionally substituted C.sub.11-C.sub.21 alkyl, alkylene or alkynyl radical, preferably a C.sub.11-C.sub.15 alkyl, alkylene or alkynyl radical, in particular a C.sub.11-C.sub.13 alkyl, alkylene or alkynyl radical, especially a C.sub.13-alkyl radical, and

R.sub.2 is, independent of each other, an unbranched or branched C.sub.1-C.sub.8 alkyl alkylene or alkynyl radical, preferably a C.sub.1-C.sub.6 alkyl, alkylene or alkynyl radical, in particular a C.sub.2-C.sub.4 alkyl, alkylene or alkynyl radical, especially a C.sub.3 alkyl radical, a --[CH.sub.2--(CH.sub.2).sub.m--O].sub.n--H radical where n=1 to 10, preferably n=1 to 5, m=1 to 5, preferably m=1 to 3,

a --CH.sub.2--[CH--(OH)].sub.p--(CH.sub.2--(R.sub.3)] radical, where R.sub.3 is, independent of each other, a hydrogen or a hydroxyl radical, p=1 to 7, preferably p=1 to 4, a pentose radical or a hexose radical.

In this connection, the radical R.sub.1 and/or the radical R.sub.2 can, independent of each other, be substituted by a halogen, preferably fluorine and/or chlorine, or an unbranched or branched C.sub.1-C.sub.6 alkyl, alkylene or alkynyl radical, preferably a C.sub.1-C.sub.3 alkyl, alkylene or alkynyl radical, in particular a methyl radical.

In this connection, the radical A of the compound (I) can, for example, be derived from hexanoic acid (caproic acid), heptanoic acid, octanoic acid (caprylic acid), nonanoic acid, decanoic acid (capric acid), undecanoic acid, dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, eicosanoic acid, heneicosanoic acid, oleic acid, linoleic acid, linolenic acid and/or arachidonic acid, preferably from caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and/or arachidonic acid, particularly preferably from myristic acid.

The radical B of the compound (I) can, for example, be derived from an unbranched or branched C.sub.1-C.sub.8 alkyl alcohol, in particular ethanol, propanol, isopropanol, n-butanol, tert-butanol, particularly preferably isopropanol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, polyglycerol, a pentose sugar, such as arabitol, adonitol and xylitol, or a hexose sugar, such as sorbitol, mannitol or dulcitol, preferably from ethanol, propanol, isopropanol, butanol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, polyglycerol, arabitol, adonitol, xylitol, sorbitol, mannitol and/or dulcitol.

The compound (I) is preferably isopropyl laureate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, ethyl myristate, propyl myristate, butyl myristate and/or ethyl oleate, in particular isopropyl myristate.

In another preferred embodiment, the compound (I) is a hydrophobic compound. According to the present invention, a hydrophobic compound is understood as being a compound whose solubility in water is at most approx. 0.2 mg/ml, in particular at most approx. 0.1 mg/ml.

The pharmaceutical comprises, for example, at least approx. 5%-75% (w/w), preferably at least approx. 10%-60% (w/w), in particular at least approx. 25%-55% (w/w), and especially at least approx. 35%-50% (w/w) of the compound of the formula (I).

In this connection, the pharmaceutical according to the invention can also contain one or more additional pharmaceutical active compounds as a combination preparation for use which is simultaneous, separate or staggered in time. In this context, preference is given to employing, as additional pharmaceutical active compounds, those compounds which can be used for treating viral skin diseases and/or tumor diseases, such as podophyllin, 5-fluorouracil, bleomycin, interferon or imiquimod, and/or mixtures which comprise at least one catechol.

In a preferred embodiment, the additional pharmaceutical active compound is an amphiphilic or amphipathic active compound. An amphiphilic or amphipathic active compound is understood as being an active compound which is composed of two functional moieties, in particular one hydrophilic moiety and one lipophilic moiety. This property might, in particular, be able to facilitate the passage of the substance through the skin and achieve an improved effect. In this connection, the improved effect may be attributable, for example, to a longer dwell time at the desired site or to a reduction in the dose of the active compound.

In a further preferred embodiment, the additional pharmaceutical active compound comprises at least one catechol of the formula (IV)

##STR00004## in which R.sub.3 is --H or --OH, and R.sub.4 is --H or a group of the formula (V)

##STR00005##

The catechols which are added in this connection may be obtained either synthetically or from natural sources. The natural sources which may especially be mentioned are tea plants. In this context, the natural constituents may be present in differing concentrations depending on the species and variety. In this connection, the catechols which are employed are preferably isolated from Camellia sinensis, Camellia asamica, Camellia bohea, Camellia chinensis or Camellia oleosa. All the components of tea plants, in particular the leaves, can be used for isolating the catechols. The catechols which are employed are preferably isolated from a tea extract.

The catechols which are employed in the present invention are preferably epicatechol, epicatechol gallate, epigallocatechol, epigallocatechol gallate, gallocatechol and gallocatechol gallate, in particular (-)-epicatechol, (-)-epicatechol gallate, (-)-epigallocatechol, (-)-epigallocatechol gallate, (+)-gallocatechol and (-)-gallocatechol gallate.

The catechols can be used both individually and in the form of mixtures having different compositions. A catechol mixture contains approx. 2-20% (w/w), preferably approx. 4-15% (w/w), in particular approx. 10-11% (w/w) of (-)-epicatechol, approx. 2-20% (w/w), preferably approx. 5-15% (w/w), in particular approx. 5-7% (w/w) of (-)-epicatechol gallate, approx. 1-25% (w/w), preferably approx. 3-15% (w/w), in particular approx. 5-7% (w/w) of (-)-epigallocatechol, approx. 40-75% (w/w), preferably approx. 57-67% (w/w), in particular approx. 61-66% (w/w) of (-)-epigallocatechol gallate, approx. 0.05-5% (w/w), preferably approx. 0.1-1% (w/w), in particular approx. 0.1-0.6% (w/w) of (+)-gallocatechol and/or approx. 0.5-20% (w/w), preferably approx. 1-10% (w/w), in particular approx. 1-5% (w/w) of (-)-gallocatechol gallate.

In a preferred embodiment, the catechol mixture is composed of approx. 5.9% (w/w) of (-)-epicatechol, approx. 12.6% (w/w) of (-)-epicatechol gallate, approx. 17.6% (w/w) of (-)-epigallocatechol, approx. 53.9% (w/w) of (-)-epigallocatechol gallate and/or approx. 1.4% (w/w) of (-)-gallocatechol. A composition of this nature is known under the name Polyphenon.RTM. 100.

In a particularly preferred embodiment, the catechol mixture is composed of approx. 10.8% (w/w) of (-)-epicatechol, approx. 6.5% (w/w) of (-)-epicatechol gallate, approx. 9.2% (w/w) of (-)-epigallocatechol, approx. 54.8% (w/w) of (-)-epigallocatechol gallate and/or approx. 4.0% (w/w) of (-)-gallocatechol gallate. A composition of this nature is known under the name Polyphenon.RTM. E.

The pharmaceutical according to the invention comprises, for example, approx. 1-30% (w/w), preferably approx. 2-20% (w/w) and, in particular, approx. 15-18% (w/w) of a catechol and at least approx. 5-90% (w/w), preferably at least approx. 10-70% (w/w), in particular at least approx. 25-60% (w/w) and, especially, at least approx. 35-50% (w/w) of the compound (I).

The familiar methods of pharmaceutical technology are used, in a customary manner, for preparing pharmaceuticals which comprise one or more compounds according to the invention and/or for using these pharmaceuticals in the application according to the invention. For this, the active compounds are worked up, together with suitable, pharmaceutically acceptable auxiliary substances and carrier substances, into the medicinal forms which are suitable for the different indications and sites of administration. In this context, the pharmaceuticals can be prepared such that the rate of release in each case desired, for example a rapid accumulation and/or a delayed-release or depot effect, is achieved.

Customary emulsions, gels, ointments, creams of the mixed-phase or amphiphilic emulsion systems (oil/water-water/oil mixed phase), and also liposomes and transfersomes or plasters, preferably ointments and creams, particularly preferably an ointment, may be mentioned for conventional application to the skin or mucosa. The active compound is preferably applied locally in the region in which there is a skin or mucosal change and/or disease.

In addition to the known uses on the skin and/or mucosa, the following are suitable for use as special pharmaceutical preparations which can be administered topically, locally or regionally: emulsions, creams, ointments, effervescent tablets or suppositories which can be administered genitally, vaginally or rectally, in particular genitally and vaginally. Rectal capsules can also be prepared on the basis of gelatin or other carrier substances. Suitable suppository bases are hardened fats, such as Witepsol.RTM., Massa Estarium.RTM., Novata.RTM., coconut butter, glycerol/gelatin pastes, glycerol/soap gels and polyethylene glycols.

Examples of suitable auxiliary and/or carrier substances are sodium alginate, as a gelatinizing agent for preparing a suitable base, or cellulose derivatives, such as guar or xanthan gum, inorganic gelatinizing agents, such as aluminum hydroxide or bentonites (what are termed thixotropic gel-formers), polyacrylic acid derivatives, such as Carbopol.RTM., polyvinylpyrrolidone, microcrystalline cellulose and carboxymethylcellulose. Amphiphilic low molecular weight and higher molecular weight compounds, and also phospholipids, are also suitable. The gels can be present either as water-based hydrogels or as hydrophobic organogels, for example based on mixtures of low and high molecular weight paraffin hydrocarbons and vaseline. The hydrophilic organogels can be prepared, for example, on the basis of high molecular weight polyethylene glycols. These gelatinous forms are washable. However, the organogels which are preferred are the hydrophobic organogels. Particular preference is given to hydrophobic auxiliary substances and additives, such as petroleum jelly, wax, oleyl alcohol, propylene glycol monostearate and propylene glycol monopalmitostearate. It is, of course, likewise possible to add skin-sedating and/or inflammation-inhibiting additives which are known to the skilled person, such as synthetically prepared active compounds and/or extracts and/or active compounds from medicinal plants, in particular bisobolol and panthenol. It is furthermore also possible to add dyes, for example yellow and/or red iron oxide and/or titanium dioxide for the purpose of matching as regards color.

Emulsifiers which can be employed are anionic, cationic or neutral surfactants, for example alkali metal soaps, metal soaps, amine soaps, sulfonated compounds, invert soaps, higher fatty alcohols, partial fatty acid esters of sorbitan and polyoxyethylene sorbitan, e.g. lanette types, wool wax, lanolin or other synthetic products for preparing the oil/water and/or water/oil emulsions.

It is possible to use vaseline, natural or synthetic waxes, fatty acids, fatty alcohols, fatty acid esters, for example as monoglycerides, diglycerides or triglycerides, paraffin oil or vegetable oils, hydrogenated castor oil or coconut oil, hog fat, synthetic fats, for example based on, caprylic acid, capric acid, lauric acid or stearic acid, such as Softisan.RTM., or triglyceride mixtures, such as Miglyol.RTM., can be used as lipids, in the form of fatty and/or oleaginous and/or waxy components for preparing the ointments, creams or emulsions.

It is possible to use, for example, osmotically active acids and alkaline solutions, for example hydrochloric acid, citric acid, sodium hydroxide solution, potassium hydroxide solution, sodium hydrogen carbonate, and, in addition, buffer systems, such as citrate, phosphate, tris buffer or triethanolamine, for adjusting the pH. It is possible to add preservatives as well, such as methyl benzoate or propyl benzoate (parabens) or sorbic acid, for increasing the stability.

Pastes, powders and solutions may be mentioned as additional forms which can be applied topically. As consistency-imparting bases, the pastes frequently contain hydrophobic and hydrophilic auxiliary substances, preferably, however, hydrophobic auxiliary substances containing a very high proportion of solids. In order to increase dispersity, and also flowability and slipperiness, and also to prevent agglomerates, the powders or topically applicable powders can, for example, contain starch species, such as wheat or rice starch, flame-dispersed silicon dioxide or siliceous earth, which also serve as diluent.

The medicinal forms which are in each case suitable can be produced on the basis of pharmaceutico-physical principles in conformity with formulation guidelines and methods known to a skilled person.

The pharmaceutical according to the invention preferably comprises approx. 35% (w/w) of isopropyl myristate, approx. 15% (w/w) of at least one catechol, approx. 24.5% (w/w) of petroleum jelly, approx. 20% (w/w) of wax, approx. 5% (w/w) of propylene glycol monostearate or propylene glycol monopalmitostearate and approx. 0.5% (w/w) of oleyl alcohol.

The pharmaceutical of the present invention and/or of a pharmaceutical metabolites is used in the treatment of viral skin diseases and/or tumour diseases.

The term pharmaceutical metabolite is to be understood as meaning one or more compounds which arise during use as a result of biological metabolism. These metabolites can be intermediates arising during intermediary metabolism or the end products of metabolism. The metabolites are preferably metabolic products which arise as a result of application to the skin and/or mucosa, in particular hydrolysis products of the compound having the formula (I). Conceivable hydrolysis products can be derived, for example, from radical A and/or radical B.

Viral skin diseases are understood as being skin diseases which are induced or caused by viruses and/or associated with viral infections. They include, for example, skin diseases such as warts, genital warts, benign tumors of the skin and/or mucosa which are caused by papilloma viruses, for example verrucae plantares, verrucae vulgares, verrucae planae juveniles, epidermodysplasia verruciformis, Condylomata acuminata, Condylomata plana, bowenoid papulosis, papillomas on the larynx and oral mucosa, focal epithelial hyperplasia, herpes labialis, Kaposi's sarcoma, varicella and shingles.

These viral skin diseases and/or tumor diseases are caused by at least one papilloma virus or viruses, in particular human papilloma viruses, such as HPV 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19-29, 31, 32, 34, 36-38, 46-50, 56, 58, by at least one herpes virus or herpes viruses, such as herpes simplex virus 1, herpes simplex virus 2, varicella zoster virus, or human herpes virus, such as 1, 2, 3, 4, 7 or 8.

The figures and the following examples are intended to clarify the invention without restricting it. Skilled persons can modify the invention appropriately, within the bounds of customary ability, without departing from the protective scope.

EXAMPLES

Clinical Study for Comparing an Ointment and a Cream Containing Isopropyl Myristate

93 patients (in each case divided equally into men and women) took part in a multicenter clinical study which was carried out at a total of 30 different centers in Germany and Russia. The study was randomized and performed double-blind. The study examined the clinical efficacy of two different formulations of isopropyl myristate (an ointment and a cream) in the treatment of external genital warts.

The formulations which were tested had the following compositions:

Cream 1:

TABLE-US-00001 Substance Quantity (in % w/w) Cera alba 6.996 Monomuls 2.798 Lameform TGI 5.598 Cetiol V 6.996 Isopropyl myristate 13.992 Tocopherol 0.699 Controx KS 0.066 Glycerol 6.996 Disodium EDTA 0.001 Magnesium sulfate 1.399 D-Panthenol 0.699 Purified water 53.678 Red Iron Oxide* 0.025 Yellow Iron Oxide* 0.054 *The dyes were added for matching as regards color.

Ointment 1:

TABLE-US-00002 Substance Quantity (in % w/w) White Petrolatum, USP 34.023 White Wax, NF 25.000 Isopropyl Myristate, NF 35.000 Oleyl Alcohol, NF 0.500 Propylene Glycol 5.000 Monostearate, NF Red Iron Oxide* 0.022 Yellow Iron Oxide* 0.055 Titanium Dioxide, USP* 0.400 *The dyes were added for matching as regards color.

The patients applied the topical study medication three times daily or until the genital warts had completely healed or for a maximum of twelve weeks.

The following data were collected during the study:

TABLE-US-00003 Complete healing (in %) Cream 1 Ointment 1 Male 39.1 42.1 Female 35.0 33.3

Partial healing (in %); this corresponds to at least 75% healing based on the total area of the genital warts.

TABLE-US-00004 Cream 1 Ointment 1 Male 43.5 63.2 Female 50.0 52.4

The results of the study show that a surprisingly high degree of complete healing, or partial healing, takes place as compared with the placebo values from similar studies using different formulations, in association with which the spontaneous regression of genital warts is approx. 20% in the case of women and approx. 5% in the case of men (Aldara.TM. (Imiquimod) Cream, 5% Product Monograph, marketed by 3M Pharmaceuticals, Northridge, Calif., Beutner K R et al. (1998) J Am Acad Dermatol 38, 230-9, Edwards L et al. (1998) Arch Dermatol 134 (1); 25-30).

This therapeutic effect is attributed to the isopropyl myristate, an antiviral effect of which has consequently been demonstrated for the first time.

Clinical Study for Comparing an Ointment and a Cream Containing Isopropyl Myristate and Polyphenon.RTM. E

272 patients (equally divided between men and women in each case) took part in a multicenter clinical study which was carried out at a total of 30 different centers in Germany and Russia. The study was randomized and performed double-blind. The study examined the clinical efficacy of two different formulations of isopropyl myristate and Polyphenon.RTM. E (an ointment and a cream), as against the formulations from Example 1 containing isopropyl myristate, in the treatment of external genital warts.

The Polyphenon.RTM. E-containing formulations which were tested had the following compositions:

Cream 2:

TABLE-US-00005 Substance Quantity (in % w/w) Polyphenon .RTM. E 10.000 Cera alba 5.263 Monomuls 2.105 Lameform TGI 4.211 Cetiol V 5.263 Isopropyl myristate 10.526 Tocopherol 0.526 Controx KS 0.050 Glycerol 5.263 Disodium EDTA 0.001 Magnesium sulfate 1.053 D-Panthenol 0.526 Purified water 55.213

Ointment 2:

TABLE-US-00006 Substance Quantity (in % w/w) Polyphenon .RTM. E 15.000 White Petrolatum, USP 24.500 White Wax, NF 20.000 Isopropyl Myristate, NF 35.000 Oleyl Alcohol, NF 0.500 Propylene Glycol 5.000 Monostearate, NF

The patients applied the topical study medication three times daily or until the genital warts had completely healed or for a maximum of twelve weeks.

During the study, the following data were collected:

TABLE-US-00007 Complete healing (in %) Cream 1 Cream 2 Ointment 1 Ointment 2 Male 39.1 53.9 42.1 61.0 Female 35.0 39.5 33.3 56.8

TABLE-US-00008 Partial healing (.gtoreq.75% in %) Cream 1 Cream 2 Ointment 1 Ointment 2 Male 43.5 64.2 63.2 80.5 Female 50.0 47.4 52.4 81.1

Analysis of the study shows that, when comparing ointment 1 and cream 1, on the one hand, and ointment 2 and cream 2, on the other hand, the combination of isopropyl myristate and Polyphenon.RTM. E leads to a surprising increase in the efficacy of the pharmaceutical.

If the efficacy of ointment 2 is now compared with that of cream 2, it then becomes evident that ointment 2 is markedly more effective than cream 2. This suggests a synergistic effect between the Polyphenon.RTM. E and the isopropyl myristate in the hydrophobic ointment.

As a result of this synergistic effect, the individual active compounds in the formulation can, in order to achieve the same effect, be employed in substantially smaller quantities than the corresponding individual components. Consequently, the use of this synergistic formulation has advantages not only with regard to the effect but also with regard to the cost of preparing this formulation, something which in turn can have a positive effect on the cost of treating the patient.