AU635937C - A preparation for the treatment of fungal infections - Google Patents

Description

A PREPARATION FOR THE TREATMENT OF FUNGAL INFECTIONS

Field of the Invention

The present invention concerns a preparation for the treatment of fungal infections in the oral cavity of dentures wearers. The preparation contains an antimycotic agent.

Background of the Invention

An inflammatory condition called stomatitis prothetica is a common complaint in users of dentures. According to Budtz-Jδrgensen, E. (Community Dent. Oral Epidemiol., 1975, 3: 115-119), the frequency is 65% among elderly users of dentures.

Stomatitis prothetica is the designation for the ucosal inflamma¬ tions frequently observed in users of dentures, particularly in those parts of the mouth coming into contact with the denture. The condition may occur as a simple inflammation, restricted to a few parts, or it may be spread over the whole area in contact with the denture. The condition commonly occurs underneath the dental plate covering the hard palate, where it may cause swelling.

Sometimes the inflammation spreads to the lips and corners of the mouth, where it may give rise to stinging and burning (cheilosis angularis).

In most cases, stomatitis prothetica is caused by a fungal infec¬ tion, normally Candida albicans, (thrush, a yeast-like fungus) (Budtz-Jδrgensen, E., Community Dent. Oral Epidemiol., 1975, 3: 115- 119). Microscopic examination of the denture and tissue samples from the palate clearly shows evidence of growth.

Clinical and histological evidence clearly shows that the condition is a hypersensitive reaction to C. albicans, which is a species of yeast-like fungus normally occurring in adults. In this connection it should be noted that a reduction in the number of Candida colo¬ nies leads to a relative improvement in the condition. It is clear that the treatment of stomatitis prothetica consists of the partial or complete removal of the fungal infection. Local antimycotic therapy is one way of achieving this.

A large number of medicaments designed for local treatment of fungal conditions in the oral cavity are available today.

One preparation is nystatin ointment, which is applied to the upper part of the dental plate fitting against the palate. The ointment should be applied three times a day for one week. A powder form of nystatin for sprinkling on to the dentures has also been proposed.

Amphotericin B, another preparation for local treatment of fungal-infections, may be given as lozenges, to be taken 4 to 8 times daily.

Miconazole gel should be applied to the part of the denture fitting against the mucosa, 4 times a day for a fortnight. The denture should be inserted immediately after application, and any superfluous gel should be held in the mouth as long as possible before swallowing.

The above therapies are certainly effective but are very inconvenient to the patients. Moreover, the condition recurs soon after the course of treatment has been completed, because C. albicans is widely present in the human body. An antimycotic preparation with another type of administration is clearly needed to circumvent the above disadvantages.

U.S. Patent 3,476,854 describes treatment of dentures with liners and tissue conditioners, consisting of plastic compositions having resins selected from lower alky! methacrylates, silicone, vinyl co-polymers and polyamide, in which an antifungal agent is dispersed. The antifungal agents are zinc and copper salts of monocarboxylic fatty acids, up to medium chain length fatty acids, benzoic acid, benzyl benzoate, salicylic acid and benzyl salicylate. However, the purpose of this composition is not to incorporate a drug delivery system in a liner to treat fungal infections in the mouth, but only to avoid fungal growth on the denture surface. PCT Application WO 87/02580, EP 29871 and DE 3,720,147 describe treatment of onychomycosis with a nail coating containing a film-forming, water-insoluble material and an antimycotic agent. The film forming material is e.g. polyvinylacetate, mixed polymers of vinyl acetate and acrylic or crotonic acid, polymers of fatty vinyl esters or methacrylate polymers. The antimycotic agents are tioconazole, econazole, miconazole, ketoconazole or clotrimazole. In all three cases, the purpose is, however, to form a drug delivery system, in which the antimycotic agent should penetrate directly into the nail from the varnish coating.

EP 55396 describes a method for spraying the skin with a fungicide composition comprising 0.1 - 1% active ingredient, 2 - 10% spreading agent, 1 - 8% solubilizer and cellulose ether as a film forming agent. Japanese Patent Application 59-83867 describes a similar method and composition with the active ingredient being clotrimazole. In these two last-mentioned patents as well, the drug should penetrate from the film forming layer directly into the skin.

Summary of the Invention

The aim of the present invention is to provide an antimycotic preparation for treatment of fungal infection in the oral cavity of denture wearers having a long-term antimycotic effect, which does not cause the patient major inconvenience.

The invention provides for this aim by virtue of its specific character as a lacquer, which, in addition to one or more antimyco¬ tic agents, comprises a water-insoluble film-forming agent, a plasticizer and a solvent. The lacquer may advantageously comprise from about 1 to about 30 wt.% of at least one antimycotic agent, preferably from about 2 to about 10 wt.%; from about 1 to about 20 wt.% of at least one water-insoluble film-forming agent, preferably from about 5 to about 15 wt.%; and from about 1 to about 25 wt.% of at least one plasticizer, preferably from about 10 to about 20 wt.%. The balance of the composition comprises at least one solvent and optional ingredients. Shellac is one optional ingredient, which may be present in the amount of from about 0 to about 10 wt.%, pre¬ ferably from about 0.5 til about 5 wt.%. Shellac is useful for its adhesive properties.

The lacquer is such that when it is applied to an artificial denture, it forms a stable coating on the denture which provides for the extended release of antimycotic agent to the wearer's oral mucosa.

By "film-forming agent" is meant any compound which is capable of being deposited upon evaporation of a solvent containing said compound, thereby forming a film on a surface, such as on artificial dentures.

The invention further comprises a method for treating fungal infections in the mouth cavity of users of artificial dentures comprising applying the foregoing lacquer to artificial dentures. The lacquer is applied to the dentures by any convenient method. Typically, the lacquer should be applied by painting it onto the portion of the denture fitting against the mucosa. The lacquer should be permitted to dry thoroughly before insertion of the denture into the mouth of the user.

Detailed Description of the Invention

The invention is based upon the fact that by application of a lacquer according to the invention to the surfaces in contact with the oral mucosa after the denture has been put into place, the antimycotic agent will be released in therapeutically effective concentrations over a period of 2-3 weeks. This means that, with the present invention, patients will only need to treat their dentures with the preparation at relatively long intervals.

The lacquer is adapted to form, once applied to the denture and dried, a stable coating on the denture which has advantageous flexibility and mechanical properties. Moreover, the coating thus formed releases the antimycotic agent to the denture wearer's oral mucosa over an extended period of time, functioning as a thin drug-releasing matrix. The extended drug-release profile provides the wearer with continuous, extended protection from fungal growth in and around the oral mucosa, after only a single application of lacquer. The precise duration of continuous drug release, and the protection from fungal growth thus provided, may vary from one denture wearer to another. The duration over which the drug is released also depends upon the nature of the antimycotic agent, the nature of the other lacquer composition components, the relative amounts of those components, and the like. However, it has been found, according to the present invention, that release of antimyco¬ tic agent may advantageously proceed for one, two or possibly three weeks after a single application.

The water-insoluble film-forming agent may include, for example, water-insoluble derivatives of cellulose such as the lower alkyl (i.e., C,-C,) ethers of cellulose, e.g., methyl-, ethyl- and propyl- cellulose; polyvinyl acetate; or (poly)acrylic acid derivatives, such as C,-C₅ esters of acrylic or methacrylic acid. Shellac may be included as an optional further film-forming agent.

The solvent may comprise any suitable solvent capable of dissolving the water-insoluble film-former, such as, for example, lower alco- hols (i.e., C,-C. alcohols) such as methanol, ethanol, 1-propanol or 2-butanol, preferably ethanol; and esters of such lower alcohols with acetic acid, such as, for example, ethyl acetate, isopropyl acetate, or n-propyl acetate.

The plasticizer is preferably a hydrophilic plasticizer, as opposed to a lipophilic plasticizer. Hydrophilic plasticizers are preferred since they are believed to provide a lacquer which has appropriate flexibility and mechanical stability. Moreover, it is believed that the use of a hydrophilic agent as the plasticizer favors the ex- tended release of the antimycotic agent from the lacquer over time, once the lacquer is applied to the denture surface. Preferred hydrophilic plasticizers include, for example, glycerol, propane¬ diol, polyethylene glycol (molecular weight 200 to 2000), glycerol ono-oleate, triethyl citrate, trimethyl citrate, C₂-C₂₆ monogly- cerides, and glyceryl triacetate. Most preferably, the plasticizer comprises glycerol mono-oleate.

The antimycotic agent employed should be stable and durable in the lacquer. Examples of such antimycotic agents include: miconazole, econazole, ketoconazole, tioconazole, and clotrimazole.

The effectiveness of the antimycotic preparation has been investi¬ gated in the following preliminary clinical studies:

Eight-Patient Study

The following study was carried out in a hospital in Maimo, Sweden, with long-term geriatric patients during the period 12-28 September, 1988. Eight patients participated in the study. The patients were chosen according to a protocol, whose inclusion criterion was manifest stomatitis prothetica due to Candida infection, as diagnosed with "Oricult-N".

In Examination No. 1, all the patients exhibited a clinically moderate to pronounced redness of the oral mucosa. Substantial fungal growth (more than 100 colonies) was detected by means of "Oricult-N" yeast detection kit (Orion Diagnostica, Espoo, Finland). Denture lacquer prepared according to Example 1, below, was applied to the cleaned dentures. Five sets of dentures were cleaned with water; three sets were cleaned with hydrogen peroxide, alcohol and water. The dentures were allowed to dry for 1-6 hours before being replaced in the mouth.

Examination No. 2 was carried out one week later. There was a clinically reduced inflammation of the oral mucosa, and an objectively ascertained decrease in the number of colonies, verified with "Oricult-N". In one patient, who had worn his denture in the mouth about 90% of the time, the count for Candida colonies was completely negative.

Examination No. 3 was carried out one week subsequent to Examination No. 2. The number of colonies had increased over the number detected during Examination No. 2. Clinically, the inflammation was not as significant as Examination No. 1.

Examination No. 4 was carried out after yet another week. The result did not differ from that of Examination No. 3, and the number of colonies had not been affected by the cleaning of the dentures before the appl ication .

Five-Patient Study

In another clinical study, the participants were five female users of dentures with diagnosed oral Candida infection. The patients' dentures were painted with a denture lacquer prepared according to Example 1, below. The number of Candida colonies was counted both on the denture and on the adjacent oral mucosa, at intervals for four weeks. The results are set forth in Table 1:

TABLE 1

NUMBER OF CANDIDA COLONIES

At the start At 1 week At 2 weeks* At 4 weeks

Patient

No. Denture Mucosa Denture Mucosa Denture Mucosa Denture Mucosa

1 >100 28 0 0 traces 0 >100 50

2 >100 >100 0 0 0 0 VG 55

3 VG abt. 100 0 0 0 0 >100 25

4 abt. 80 abt. 70 0 0 0 0 >100 60

5 VG VG VG VG VG 30 >100 75

VG = vigorous growth

* = after this count, the dental lacquer was removed

The first culture was carried out before application of the lacquer, and both denture and oral mucosa were tested for growth. The patients were asked to keep their dentures in place as much as possible and, if they removed them, to store the denture in humid conditions, although not immersed in a fluid.

At the start of the study, the count was positive for all patients, both from the dentures and from the oral mucosa. After treatment for one week, the count was negative for all patients, except patient number 5. In this patient, there was substantial fungal growth both on the mucosa and on the denture before the start of treatment. The oral mucosa showed a reduction in the number of colonies at 2 weeks' treatment.

At 2 weeks, the count was still negative in all the patients except No. 5. The lacquer was then removed and tested for residual concentration of miconazole.

After another fourteen days, there was a recurrence of Candida in the patients.

Table 2 shows the quantity of miconazole released from the dental lacquer during the same study.

TABLE 2

Denture Miconazole Miconazole Miconazole No. applied recovered released 1 22.8 mg 12.03 mg 10.77 mg 2 27.0 mg 2.16 mg 24.84 mg 3 35.0 mg 5.1 mg 29.90 mg 4 38.7 mg 4.9 mg 33.80 mg 5 45.6 mg 0.2 mg 45.40 mg

It may be concluded from these examinations that the lacquer has a definite therapeutic effect.

The following examples illustrate the preparation of different types of dental lacquers according to the invention, but should not be considered as limiting the scope of the invention.

Example 1

5 g of miconazole is di ssolved in 86 ml of ethanol , and 6 g of ethyl cel l ul ose, 1 g of shell ac, and 2 g of glycerol mono-ol eate are added. The sol ution i s stirred until compl etely dissolved. The l acquer appears as a semi -transparent, vi scous sol ution .

The lacquer i s dispensed from a gl ass bottl e with a brush in the l id.

Exampl e 2

A lacquer is prepared as in Example 1, but using the same amount of ketoconazole in place of miconazole as the active ingredient.

Example 3

4 g of econazole is dissolved in 33 ml of isopropanol and 33 ml of ethyl acetate. To this is added 2 g of glycerol mono-oleate and 28 g of polyvinyl acetate. The solution was stirred until completely dissolved.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.

Claims (34)

CLAIMSWhat is claimed is:

1. A lacquer for the treatment of fungal infections in the mouth cavity of useres of artificial dentures, containing an antimycotic agent, a film-forming agent insoluble in water, a solvent and a plasticizer.

2. A preparation according to claim 1, in which said water- insoluble film-forming agent has been selected from among derivatives of cellulose, polyvinyl acetates, and polyacrylic acid.

3. A preparation according to claim 1, in which said antimycotic agent has been selected from among miconazole, ketoconazole, econazole, tioconazole, and clotrimazole.

4. A preparation according to claim 1, in which said solvent has been selected from among lower alcohols, particularly ethanol and esters of lower aliphatic acids, such as ethyl acetate, isopropyl acetate, and n-propyl acetate.

5. A preparation according to claim 1, in which said plasticizer is glycerol mono-oleate.

6. A preparation according to claims 1-5, comprising shellac in the amount of from about 0 to about 10 percent by weight, preferably from about 0.5 to about 5 percent by weight.

7. A preparation according to claim 6, comprising a mixture of shellac and as a film-forming agent ethyl cellulose.

8. A preparation according to claims 1-7, in which the antimycotic agent is miconazole.

9. An artificial denture lacquer for the treatment of fungal infections in the mouth cavity of users of artificial dentures, comprising from about 1 to about 30 wt.% of at least one antimycotic agent, from about 1 to about 30 wt.% of at least one water-insoluble film-forming agent, from about 1 to about 25 wt.% of at least one plasticizer, and at least one solvent.

10. A lacquer according to claim 9, in which the water-insoluble film-former is selected from the group consisting of C_j - C₃ alkyl ethers of cellulose, polyvinyl acetate, C, - C₅ esters of acrylic or methacrylic acid, and combinations thereof.

11. A lacquer according to claim 9, in which the antimycotic agent is selected from the group consisting of miconazole, ketoconazole, econazole, tioconazole, clotrimazole, and combinations thereof.

12. A lacquer according to claim 9, in which the solvent comprises a C, - C. alcohol.

13. A lacquer according to claim 12, wherein the solvent comprises ethanol .

14. A lacquer according to claim 9, wherein the solvent comprises an ester formed from a C, - C. alcohol and acetic acid.

15. A lacquer according to claim 9, in which said plasticizer is a hydrophilic plasticizer.

16. A lacquer according to claim 15, wherein the hydrophilic plasticizer is glycerol mono-oleate.

17. A lacquer according to claim 10, wherein the water-insoluble film-former is selected from the group consisting of ethyl cellulo- se, and combinations thereof.

18. A lacquer according to claim 17, wherein the antimycotic agent comprises miconazole.

19. A lacquer according to claim 9, wherein the solvent comprises an ester formed from a C, - C. alcohol and acetic acid.

20. A lacquer according to claim 9, comprising from about 2 to about 10 wt.% of at least one antimycotic agent, from about 5 to about 15 wt.% of at l east one water insoluble film-forming agent, from about 10 to about 20 wt.% of at least one plasticizer, and at l east one solvent.

5 21. A l acquer according to cl aim 20, wherein the water- insol uble film-former comprises ethyl cel l ulose.

22. A l acquer according to claim 20, wherein the pl asticizer comprises glycerol mono-ol eate.

10

23. An antimycotic coating on an artificial denture formed by applying to said denture a lacquer according to claim 9.

24. An antimycotic coating on an artificial denture formed by 15 applying to said denture a lacquer according to claim 11.

25. An antimycotic coating on an artificial denture formed by applying to said denture a lacquer according to claim 15.

^• 20 26. An antimycotic coating on an artificial denture formed by applying to said denture a lacquer according to claim 16.

27. An antimycotic coating on an artificial denture formed by applying to said denture a lacquer according to claim 18.

25

28. A method for treating fungal infections in the mouth cavity of users of artificial dentures, comprising applying to said artificial dentures a lacquer according to claim 1.

30 29. A method for treating fungal infections in the mouth cavity of users of artificial dentures, comprising applying to said artificail dentures a lacquer according to claim 9.

30. A method for treating fungal infections in the mouth cavity of 35 users of artificial dentures, comprising applying to said artificial dentures a lacquer according to claim 11.

31. A method for treating fungal infections in the mouth cavity of users of artificial dentures, comprising applying to said artificial dentures a lacquer according to claim 15.

32. A method for treating fungal infections in the mouth cavity of users of artificial dentures comprising applying to said artificial dentures a lacquer according to claim 16.

33. A method for treating fungal infections in the mouth cavity of users of artificial dentures, comprising applying to said artificial dentures a lacquer according to claim 18.

34. A method for treating fungal infections in the mouth cavity of users of artificial dentures, comprising applying to said artificial dentures a lacquer according to claim 20.