WO2007135390A1

WO2007135390A1 - Prevention of plaque formation

Info

Publication number: WO2007135390A1
Application number: PCT/GB2007/001840
Authority: WO
Inventors: Jonathan Douglas Lane; Ian Hill
Original assignee: Sinclair Pharmaceuticals Limited
Priority date: 2006-05-18
Filing date: 2007-05-17
Publication date: 2007-11-29
Also published as: GB0609901D0; WO2007135390A8

Abstract

A compound having the formula (I) or a salt thereof in the manufacture of a medicament for the removal or prevention of plaque formation, wherein R1 is a straight or branched alkyl group containing 8 to 16 carbon atoms at the 2- or 3-position of the morpholino ring, and R2 is a straight or branched alkyl group containing 2 to 10 carbon atoms, substituted with a hydroxy group except in the alpha-position, the sum of the carbon atoms in the groups R1 and R2 being at least 10 and preferably 10 to 20, wherein the medicament further comprises a bacterial adhesin peptide or an antibody that binds to a bacterial adhesin peptide.

Description

PREVENTION OF PLAQUE FORMATION

Field of the Invention

The present invention relates to the prevention of plaque formation. Background to the Invention The occurrence of dental caries and parodontitis (sometimes referred to as periodontitis) appears to be the result of complex biological interactions of various microorganisms forming a part of the dental plaque, i.e. the deposit normally formed on the surfaces of the teeth. Chronic parodontitis, apparently the most common cause of tooth loss, is an inflammatory process of the supporting tissues of the teeth and about as prevalent as caries.

Formation of dental caries and parodontitis are caused primarily by the formation of dental plaque. Plaque is a deposit upon the tooth surface that contains primarily bacteria and saliva components. The structure of dental plaque changes from a soft initial stage to the formation of a harder, water- insoluble, plaque which can cause caries as well as parodontitis. In an effort to maintain oral and dental hygiene, a large variety of different substances are presently used. Such substances can be used in toothpastes, tablets, mouthwashes and the like.

A wide variety of chemical and biological agents have been suggested for the removal of dental plaque after it is formed or for the inhibition of the formation of dental plaque. However, mechanical removal of dental plaque has remained the most effective method. For the inhibition of dental plaque in other ways, the use of a wide range of chemicals, including antibiotics, chemotherapeutical agents and disinfectants, fluorine compounds, organic phosphatases, chelate-forming agents and emulsifiers has been suggested. Examples of such agents are penicillin (antibiotic), chlorohexidine and 8- hydroxyquinoline (disinfectants), ethylenediamine tetraacetate (chelate-forming agent), and NaF (strengthening of the tooth enamel).

Some of these previously suggested agents have exhibited insignificant anti-plaque effects while others, such as antiseptic and antibiotic agents, can certainly be effective but often cause side effects that are worse than the condition removed. It is now clear that the causes of the plaque-formation are very complicated and for the chemical removal of plaque it has been found necessary to employ compounds of a very specific chemical structure. To be useful for this purpose the compounds must have properties including a low antibacterial effect and very low toxicity and should lack undesired side effects such as discolouration of the tooth enamel.

Delmopinol is a morpholino compound that has utility in the treatment of the oral cavity, especially tooth surface, and for the removal or inhibition of dental plaque. The compound and its manufacture are disclosed in US4894221 , the content of which is incorporated herein by reference.

Delmopinol, and its derivatives, are not thought to have an antibacterial activity.

The bacterial adhesin peptide p1025 is disclosed in Kelly et al, Nature Biotech, 1999; 17:42-47, the content of which is incorporated herein by reference. The peptide is found in Streptococcus mutans and can be used to prevent binding of S. mutans in the oral cavity. However, its use so far has been found to be concentration dependent, with concentrations above 1mg/ml being required.

Passive immunisation using monoclonal antibodies against Streptococcus mutans has been found to prevent recolonisation by indigenous S. mutans in the mouth of humans (Ma et al, Infection and Immunity, October 1990, vol 58(10); p3407-3414). However, it is clear that improved methods of preventing bacterial binding in the oral cavity are required. Summary of the Invention

The present invention is based on the realisation that delmopinol, and its derivatives, can be used to prevent plaque formation more efficiently when formulated with a bacterial adhesin peptide, e.g. p1025, or an antibody that binds to a bacterial adhesin peptide.

According to a first aspect of the present invention, a compound having formula (I), or a salt thereof , is used in the manufacture of a medicament for the prevention or removal of plaque,

wherein R₁ is a straight or branched alkyl group containing 8 to 16 carbon atoms at the 2- or 3-position of the morpholino ring, and R₂ is a straight or branched alkyl group containing 2 to 10 carbon atoms, substituted with a hydroxy group except in the alpha-position, the sum of the carbon atoms in the groups R₁ and R₂ being at least 10 and preferably 10 to 20 and wherein the medicament further comprises a bacterial adhesin peptide or antibody that binds to a bacterial adhesin peptide.

According to a second aspect of the invention, a composition comprises a compound of formula (I) and a bacterial adhesin peptide. According to a third aspect of the invention, a composition comprises a compound of formula (I) and an antibody that binds to a bacterial adhesin peptide.

According to a fourth aspect of the invention, a method for removing plaque or preventing plaque formation comprises administering a composition comprising a compound of formula (I) and a bacterial adhesin peptide and/or an antibody that binds to a bacterial adhesin peptide.

Description of the Invention

The compounds for use in the present invention have the general formula (I)

wherein R₁ is a straight or branched alkyl group containing 8 to 16 carbon atoms at the 2- or 3-position of the morpholino ring, and R₂ is a straight or branched alkyl group containing 2 to 10 carbon atoms, substituted with a hydroxy group except in the alpha-position, the sum of the carbon atoms in the groups R₁ and

R₂ of the morpholino compound is at least 10, preferably between 10 and 20.

In a further preferred embodiment, the R₂ group terminates with the hydroxy group. The claimed morpholino compounds are known per se and can be manufactured by any known method, for example that disclosed in US4894221 ,

US5082653 and WO90/14342, the content of each of which are incorporated herein by reference.

The preferred morpholino compound for use in the invention is 3-(4- propyl-heptyl)-4-(2-hydroxyethyl)morpholine, which is commonly known as

Delmopinol (CAS No. 79874-76-3).

The morpholino compounds can be used in their free base form or as a pharmaceutically acceptable salt thereof. Examples of pharmaceutically acceptable salts are the salts of acids such as acetic acid, phosphoric acid, phosphoric acid, boric acid, hydrochloric acid, maleic acid, benzoic acid, citric acid, malic acid, oxalic acid, tartaric acid, succinic acid, glutaric acid, gentisic acid, valeric acid, gallic acid, beta-resorcyclic acid, acetyl salicylic acid, salicylic acid, perchloric acid, barbituric acid, sulfanilic acid, phytic acid, p-nitro benzoic acid, stearic acid, palmitic acid, oleic acid, myristic acid, lauric acid and the like. The most preferred salts are those of hydrochloric acid. A preferred compound is delmopinol hydrochloride (CAS No. 98092-92-3).

In one aspect of the present invention, the compound of formula (I) is formulated with a bacterial adhesin peptide. Bacterial adhesins are bacterial molecules that bind the bacterial microorganism to a surface during infection. There are many bacterial adhesin proteins now known in the art, including FimH adhesins, pili adhesins, Lary adhesins (including FimA) and streptococcal antigen l/ll (SA l/ll).

The bacterial adhesin peptide may be any suitable peptide, but will preferably be an adhesin found in bacterial strains know to colonise the oral cavity, in particular Streptococcal species such as Streptococcus mutans. In a preferred embodiment, the peptide is p1025, as disclosed in Kelly etal (supra), the content of which is incorporated herein by reference. P 1025 is a synthetic adhesin peptide having the amino acid sequence:

QLKTADLPAGRDETTSFVLV (SEQ ID NO. 1).

The adhesin may be present in a composition together with a compound of formula (I), in any suitable dose. Preferably, the adhesin is present in an amount from 0.01 mg/ml to 10 mg/ml, more preferably in an amount from 0.01 mg/ml to 1 mg/ml.

An antibody, or combination of antibodies, that binds to a bacterial adhesin peptide may be used instead of the adhesin peptide. As used herein, the term "antibody" has the standard meaning in the art, i.e. it is an immunoglobulin protein (or peptide) that binds to an antigen. Full length antibodies and fragments of antibodies are within the scope of the term "antibody". Suitable fragments include, but are not limited to, Fab and single chain Fv fragments. In a preferred embodiment, the antibody is a monoclonal antibody. Antibody fragments must retain the ability to bind to a bacterial adhesin peptide. Preferably, the antibody binds with high affinity, for example in the range of 1 μ M to 1 nM, or even higher affinity. Methods of measuring the affinity of an antibody for an antigen (i.e. binding partner, in this case a bacterial adhesin protein) are well known in the art, for example radio-ligand binding assays.

Antibodies obtained by any method are within the scope of the invention. Non-limiting examples of methods for producing antibodies include immunisation of a host animal with an antigen and collection of produced antibody, and recombinant methods of antibody production, which are well known in the art. Antibodies produced by genetically modified plants are also within the scope of the invention. Methods of making these plant-derived antibodies are well known in the art, see for example, US6852319.

In a further embodiment, a combination of an adhesin peptide and antibody to an adhesin peptide may be used, together with a compound of formula (I).

The combination of delmopinol and p1025 or an antibody to p1025 is shown to have an improved synergistic effect compared to the use of the individual components. The use of delmopinol allows the peptide or antibody to be present in effective concentrations which may be lower than the conventional amounts. The peptide or antibody may be present in an amount less than 10mg/ml, for example less than 5mg/ml or less than 1mg/ml. The compound of formula (I) in combination with the bacterial adhesin peptide or antibody are useful in therapy. In a preferred embodiment, the compositions of the invention are useful in the therapy of plaque and plaque associated diseases such as parodontitis. For the avoidance of doubt, the compositions of the invention are useful both in the removal of existing plaque and in the prevention of plaque formation, i.e. the term "therapy" includes prophylactic therapy.

The compound of formula (I) and the bacterial adhesin peptide or antibody may be brought into contact with the oral cavity in a conventional way, in any suitable form or amount that achieves the desired effect. Preferably, the components are present in a mouthwash, toothpaste, gel, dentifrice, gum or similar preparation that will be apparent to the skilled person. Most preferably, the components are in an aqueous mouthwash. This can be applied to the oral cavity by the patient, without the need for medical supervision. Preferably, the mouthwash is held in the mouth for at least 5 seconds, preferably greater than 10 seconds, for example one minute or more, to allow the components to contact the sites of plaque formation. Contacting the oral cavity with a composition according to the invention therefore removes plaque and/or prevents plaque formation.

Further components may also be present, including at least one anti- microbial, preferably anti-bacterial, agent. Suitable agents include the antibiotics tetracycline, doxycycline and ampicillin. Other agents suitable for treating oral infections will be apparent to one skilled in the art.

An anti-inflammatory agent may also be present. Anti-inflammatory agents are well known in the art and may be used. Preferably, the anti- inflammatory agent is a non-steroidal anti-inflammatory drug (NSAID), such as aspirin (acetylsalicylic acid) or ibuprofen. In an alternative embodiment, a steroidal anti-inflammatory agent, for example cortisone, may be used. In a further embodiment, mechanical agitation, preferably brushing or rubbing the area containing the plaque, is performed simultaneously with or shortly, preferably immediately, after contacting the oral cavity with the components of the invention. The medicament or composition of the invention may be delivered in any suitable form or amount that achieves the desired effect.

Claims

1. Use of a compound having the formula (I) or a salt thereof in the manufacture of a medicament for the removal or prevention of plaque formation,

wherein R₁ is a straight or branched alkyl group containing 8 to 16 carbon atoms at the 2- or 3-position of the morpholino ring, and R₂ is a straight or branched alkyl group containing 2 to 10 carbon atoms, substituted with a hydroxy group except in the alpha-position, the sum of the carbon atoms in the groups R₁ and R₂ being at least 10 and preferably 10 to 20, wherein the medicament further comprises a bacterial adhesin peptide or an antibody that binds to a bacterial adhesin peptide.

2. Use according to claim 1 , wherein the compound is delmopinol.

3. Use according to claim 1 or claim 2, wherein the adhesin is streptococcal.

4. Use according to claim 3, wherein the streptococcal species is Streptococcus mutans.

5. Use according to any preceding claim, wherein the adhesin is p1025.

6. Use according to any preceding claim, wherein the medicament is in aqueous form.

7. Use according to claim 6, wherein the medicament is a mouthwash.

8. Use according to any of claims 1 to 5, wherein the medicament is a toothpaste or gum.

9. Use according to any preceding claim, wherein the adhesin peptide or antibody that binds to the adhesin peptide is present in an amount of less than 10mg/ml.

10. A composition comprising a compound having the formula (I) as defined in claim 1, and a bacterial adhesin peptide.

11. A composition according to claim 10, wherein the compound is delmopinol.

12. A composition according to claim 10 or claim 11, wherein the adhesin peptide is as defined in any of claims 3 to 5 or claim 9.

13. A composition comprising a compound having the formula (I) as defined in claim 1 , and an antibody that binds to a bacterial adhesin peptide.

14. A composition according to claim 13, wherein the compound is delmopinol.

15. A composition according to claim 13 or claim 14, wherein the adhesin peptide is as defined in any of claims 3 to 5 or claim 9.

16. A method for removing plaque or preventing plaque formation comprising administering a compound of formula (I) and a bacterial adhesin peptide and/or an antibody that binds to a bacterial adhesin peptide.