The present invention relates to a pharmaceutical composition comprising terbinafine.
Terbinafine may be used e.g. in free form or in acid addition salt form. An acid addition salt form may be prepared from the free base form in conventional manner and vice-versa. Examples of suitable acid addition salt form are the hydrochloride, the lactate and the ascorbate. The free base and the hydrochloride are preferred.
Terbinafine is known from e.g. BE-PS-853976 and EP-A-24587. It belongs to the class of allylamine anti-mycotics. It is acknowledged in the art and is commercially available under the trade name Lamisil®.
Terbinafine is highly active upon both topical and oral administration. While numerous pharmaceutical compositions for topical and oral administration have been proposed, there still exists a need for commercially acceptable liquid terbinafine formulations for oral administration, especially for oral administration to children. One particular difficulty in the formulation of terbinafine in liquid pharmaceutical compositions is its unpleasant, e.g. bitter, taste and/or low physical stability.
It is thus desirable to provide liquid oral terbinafine formulations with a high physical stability and acceptable taste.
A promising approach overcoming the above-mentioned difficulties has now been found in the form of emulsions comprising terbinafine as the active agent. Thus pharmaceutically acceptable liquid oral dosage forms of high physical stability and acceptable taste have been obtained by formulating pharmaceutical compositions comprising terbinafine in the form of emulsions.
Accordingly in one aspect the present invention provides a terbinafine pharmaceutical composition which is emulsifiable or self-emulsifying or in form of an emulsion, e.g. an oil in water or water in oil emulsion, preferably an oil in water emulsion, wherein the composition is adapted for oral administration.
The compositions of the present invention comprise terbinafine preferably in base form.
Terbinafine may be present in an amount of 0.1 to 10%, e.g. 1 to 5%, preferably 1.5 to 4% by weight based on the total weight of the composition.
in another aspect the present invention provides a pharmaceutical composition according to the present invention further comprising a lipophilic component, a surfactant and an emulsion stabilizing agent, e.g. an agent preventing breakdown, e.g. creaming, coalescence or sedimentation, of the emulsion.
Suitable lipophilic components according to the present invention are:
Particularly suitable are triglycerides of e.g. C6-12, e.g. saturated fatty acids, e.g. as known and commercially available under the trade name Miglyol®812, Miglyol®812 is a fractionated coconut oil comprising caprylic-capric acid triglycerides and having a molecular weight of about 520 daltons. Fatty acid composition=C6 max. about 3%, C8 about 50 to 65%, C10 about 30 to 45%, C12 max 5%; acid value about 0.1; saponification value about 330 to 345; iodine value max 1. Miglyol® 812 is available from Condea.
The lipophilic component may be present in an amount of 5 to 50%, e.g. 10 to 40%, preferably 15 to 25% by weight based on the total weight of the composition.
In a further aspect the present invention provides a pharmaceutical composition according to the present invention wherein the ratio of terbinafine:lipophilic component may be 1:1 to 20, e.g. 1:2 to 15, preferably 1:4 to 10.
Examples of suitable surfactants for use in this invention are:
It is to be appreciated that surfactants may be complex mixtures containing side products or unreacted starting products involved in the preparation thereof, e.g. surfactants made by polyoxyethylation may contain another side product, e.g. polyethylene glycol.
A surfactant having a hydrophilic-lipophilic balance (HLB) value of 8 to 17, e.g. 10 to 12 is preferred. The HLB value is preferably the mean HLB value.
Particularly suitable for the compositions of this invention are phospholipids, e.g. soy bean- or egg-lecithin, or polyoxyethylene sorbitan fatty acid ester and/or sorbitan fatty acid esters.
It is to be appreciated that according to the present invention one or a mixture of the above-mentioned surfactants can be used. When the surfactant is a mixture of polyoxyethylene(20)sorbitanmonooleate (Tween® 80) and sorbitanmonolaurate (Span® 20), the weight ratio of Tween 80:Span 20 is e.g. 1 to 10:1 to 10, e.g. 1 to 4:1 to 4, e.g. 1 part by weight Tween 80 is used per 4 parts by weight of Span 20, or 4 parts by weight Tween 80 are used per 1 part by weight of Span 20.
The surfactant may be present in an amount of 0.2 to 20%, e.g. 1 to 10%, preferably 1.5 to 5% by weight based on the total weight of the composition.
In a further aspect the present invention provides a pharmaceutical composition according to the present invention wherein the ratio of terbinafine:surfactant may be 1:0.05 to 10, e.g. 1:0.1 to 5, preferably 1:0.5 to 2.
As emulsion stabilizing agents, e.g. agents preventing breakdown, e.g. creaming, coalescence or sedimentation, of the emulsion, e.g. thickening, e.g. viscosity increasing, agents, may be used. Suitable thickening, e.g. viscosity increasing, agents may be of those known and employed in the art, including e.g. pharmaceutically acceptable polymeric materials and inorganic thickening agents, e.g. thixotropic agents, for example, of the following types:
Further suitable for stabilization of the pharmaceutical compositions of this invention is high pressure homogenization. Addition of a thickening agent may be superfluous in these compositions.
Accordingly, in one aspect the present invention provides an emulsifiable terbinafine pharmaceutical composition adapted for oral administration which upon high pressure homogenization forms an emulsion.
The thickening agent, when present, may be present in an amount of 0.1 to 10%, e.g. 0.5 to 5%, preferably 0.75 to 3% by weight based on the total weight of the composition.
In a further aspect the present invention provides a pharmaceutical composition according to the present invention wherein the ratio of terbinafine:emulsion stabilizing agent may be 1:0.05 to 10, e.g. 1:0.1 to 5, preferably 1:0.2 to 2.
Any carbon chain not otherwise specified herein conveniently contains 1 to 18 carbon atoms, e.g. 10 to 18 carbon atoms, when a terminal group or 2 or 3 carbon atoms when a polymer moiety.
It will be appreciated that the present invention encompasses
The compositions of the present invention may comprise water, e.g. purified water, in amount of 20 to 80%, e.g. 30 to 60%, preferably 35 to 55% by weight based on the total weight of the composition.
In another aspect of the present invention the terbinafine pharmaceutical composition may be a self-emulsifying composition which on administration to water may form an emulsion.
The compositions may also include one or more further additives or ingredients e.g. in an amount of from 0.01 to 15% by weight based on the total weight of the composition, in particular anti-oxidants, e.g. ascorbyl palmitate, butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT), or tocopherols, preferably DL-alpha-tocopherol (vitamin E); preserving agents, e.g. sorbic acid, potassium sorbat, benzoic acid, or parabenes, e.g. methyl-, propylparabene, preferably sorbic acid; sweetening agents, e.g. sorbitol, saccharin, acesulfam, aspartame, or sugars, e.g. glucose, fructose saccharose, preferably sorbitol is used, e.g. in form of an aqueous solution which contains 70% sorbitol by weight; flavouring agents, e.g. banana, strawberry, vanilla or chocolate flavour, and so forth.
Determination of workable proportions in any particular instance will generally be within the capability of the man skilled on the art. All indicated proportions and relative weight ranges described above are accordingly to be understood as being indicative of preferred or individually inventive teachings only and not as limiting the invention in its broadest aspect.
Preferably the pH value of the composition of this invention may be e.g. about 4 to 8, e.g. about 5 to 7, preferably about 6.
Details of excipients of the invention are described in Fiedler, H. P. xLexikon der Hilfsstoffe für Pharmazie, Kosmetik und angrenzende Gebietex, Editio Cantor Verlag Aulendorf, Aulendorf, 4th revised and expanded edition (1996); “Handbook of Pharmaceutical Excipients”, 2nd Edition, Editors A. Wade and P. J. Weller (1994), Joint publication of American Pharmaceutical Association, Washington, USA and The Pharmaceutical Press, London, England; or may be obtained from the relevant manufacturers, the contents of which are hereby incorporated by reference.
In a further alternative aspect the invention also provides a process for the production of a pharmaceutical composition as defined above, which process may comprise bringing the lipophilic phase comprising the lipophilic component, the lipophilic surfactant, when present, and terbinafine and the aqueous phase comprising water and the hydrophilic surfactant, when present, into intimate admixture to prepare an emulsion.
Optionally further components or additives, in particular antioxidants, and/or preserving agents, and/or sweetening agents, and/or flavouring agents, and/or thickening agents may be mixed with either the lipophilic phase or the aqueous phase or may be added to the final product as appropriate.
In a further aspect the present invention provides a composition according to the present invention wherein the mean droplet size of lipophilic phase, e.g. fat, e.g. containing the active agent, may be about 0.1 to about 30 μm, e.g. about 0.5 to about 15 μm, e.g. about 0.8 to about 10 μm.
The composition according to the present invention conveniently is an emulsion for oral administration. Naturally as with any emulsion the excipients may increase the viscosity of the composition or the oil and water phases may separate, e.g. creaming or coalescence may be observed. Just before use the compositions may be shaken.
The compositions of the invention may be used directly or after dilution with e.g. milk or juice and administered as a liquid. The compositions may also be administered in a capsule.
In a further aspect the present invention provides a method of orally administering a pharmaceutical composition, said method comprising orally administering to a patient in need of terbinafine therapy a composition according to the present invention.
The present invention provides a composition of surprisingly high physical stability, e.g. for up to two or more years, and surprisingly acceptable taste. The physical stability may be tested as conventional, e.g. the compositions may be tested as such by microscopy, or the droplet size may be determined after dilution of the composition by laser light diffraction, e.g. after storage at room temperature, i.e. at 25° C., and/or after storage at 40° C. The taste of the compositions may be tested in standard clinical studies.
The compositions of this invention are useful for the known indications of terbinafine, e.g. for the following conditions: onychomycosis caused by dermatophyte fungi, tinea capitis, fungal infections of the skin, for the treatment of tinea corporis, tinea cruris, tinea pedis, and yeast infections of the skin caused by the genus Candida, e.g. Candida albicans, systemic mycosis, mycosis by azole-resistant strains, e.g in combination with a 14-alpha-methyldimethylase inhibitor, or infections with Helicobacter pylori.
The composition is particularly effective in treating tinea capitis in e.g. children.
In a further aspect the present invention provides a method for the treatment of fungal infections of the human body comprising administering a pharmaceutically effective amount of a pharmaceutical composition according to the present invention to a subject in need of such treatment
In yet a further aspect the present invention provides the use of a composition according to the present invention in the manufacture of a medicament for the treatment or fungal infections of the human body.
The utility of the pharmaceutical compositions of the present invention may be observed in standard bioavailability tests or standard animal models, for example ascertaining dosages of the present compositions giving blood levels of terbinafine equivalent to blood levels giving a therapeutical effect on administration of known terbinafine oral dosage forms, e.g. a tablet. Typical doses are in the range of 1 mg/kg to 10 mg/kg, e.g. 1.5 mg/kg to 5 mg/kg, or e.g. 3 to 4 mg/kg body weight of terbinafine per day.
The appropriate dosage will, of course, vary depending upon, for example, the host and the nature and severity of the condition being treated. However in general satisfactory results in animals are indicated to be obtained at daily treatments with doses from about 1 mg/kg to about 10 mg/kg animal body weight. In humans an indicated daily dosage is in the range from about 10 mg to about 1000 mg per day, conveniently administered, for example, in divided doses up to four times a day or once daily. Preferred dosages for children weighing <20 kg may be about 62.5 mg once daily, for children weighing 20 to 40 kg about 125 mg once daily, for children weighing >40 kg about 250 mg once daily, and for adults from about 250 mg to about 500 mg once daily.
Following is a description by way of example only of compositions of the invention.
Compositions according to the invention and of the following examples were prepared by mixing the ingredients and homogenizing with the help of a high shear rotor-stator.
Number | Date | Country | Kind |
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0001928.1 | Jan 2000 | GB | national |
Number | Date | Country | |
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Parent | 13487741 | Jun 2012 | US |
Child | 13870114 | US | |
Parent | 12967840 | Dec 2010 | US |
Child | 13487741 | US | |
Parent | 12366962 | Feb 2009 | US |
Child | 12967840 | US | |
Parent | 10182297 | Jul 2002 | US |
Child | 12366962 | US |