Oral antifungal preventative, and method of use

The invention relates to an oral composition for prevention of mycotic infections of the oral cavity comprising an antifungal compound embedded in a sustained release carrier such as a cellulosic polymer or a hydrophobic polymer, and a method for use of said composition in preventing microfungal infections in the oral cavity. The invention also provides for the supplementation of said oral composition with an adhesive and a plasticizer to increase antifungal effectiveness.

FIELD OF THE INVENTION 
The invention is directed to an antimycotic composition for the prevention 
of microfungal infections of the oral cavity and to a method for using 
said composition in treating mycotic diseases of the oral cavity caused by 
microfungi. 
BACKGROUND OF THE INVENTION 
Microfungi can be classified as yeasts and filamentous fungi. Microfungi 
are capable of causing a variety of diseases in the oral cavity and the 
surrounding area. Mycotic diseases may arise as part of a systemic 
microfungal infection or may be derived from an independent infection 
which establishes in the oral cavity. Oral mycoses and their treatment are 
an important problem in oral medicine and have been reviewed in Kostiala, 
I. et al., Acta Odontol. Scand. 37:87-101 (1987), incorporated herein by 
reference. 
Many factors can predispose a patient to an opportunistic microfungal 
infection in the oral cavity. For example, general debilitation or poor 
oral hygiene are predisposing factors. Patients who are being treated with 
antibiotics, steroids, or cytostatic therapy, patients with AIDS, diabetes 
mellitus or other immunodeficiency or hormonal diseases, patients with 
malignant tumors or a hematogenous disorder are all at a high risk for 
opportunistic fungal infections. In addition, certain age groups such as 
infants, the elderly, and pregnant women are at a higher risk of oral 
fungal infections. 
Mechanical trauma from an ill-fitted prosthesis is also a major cause of 
oral microfungal infections. One report estimated that Candida was 
involved in 60% of the cases of "denture sore mouth" (denture stomatitis) 
in the elderly (Budtz-Jorgensen, E. et al., Community Dent. Oral 
Epidemiol. 3:115 (1975)). Denture stomatitis appears to be a manifestation 
of a cell-mediated hypersensitivity reaction to the microfungal infection. 
It is important to treat oral mycotic infections as soon as possible. 
Untreated infections may become the foci for systemic dissemination of the 
yeast or fungus, with potentially fatal results in severely compromised 
patients. For example, disseminated candidosis is the second most common 
opportunistic infection in patients with AIDS (Odds, F. C., CRC Crit. Rev. 
Microbiol. 15:1-5 (1987)). 
The most important species of microfungi which have been implicated as 
being involved in superficial or deep mycotic infections in the oral 
cavity include Candida albicans. C. tropicalis, C. stellatoidea, C. 
pseudotropicalis. C. parapsilosis, C. quilliermondii, C. krusei, and C. 
vixwanathii, all of which have been implicated in candidosis; Torulopsis 
glabrata which is the cause of torulpsidosis; Geotrichum candidum, which 
is the cause of geotrichosis; Rhizopus, Mucor, Absidia, and Basidiobolus 
which are the cause of aspergillosis, Cryptococcus neoformans, the cause 
of cryptococcosis; Blastomyces dermatitidis, the cause of blastomycosis; 
Paracoccidioides brasiliensis, the cause of paracoccidioidomycosis; 
Sporothrix schenkii, the cause of sporotrichosis; Rhinosporidium seeberi, 
the cause of rhinosporidoisis; Histoplasma capsulatum, the cause of 
histoplasmosis; Histoplasma duboisii, the cause of African histoplasmosis, 
Coccidiodes immities, the cause of coccidioidomycosis, Trichophyton 
mentagrophytes, T. rubrum, T. tonsurans and T. violaceum, the causes of 
dermatophytosis; and, Rhinocladiella or Phialophora, and Cladosporium, the 
causes of chromomycosis. 
The Candida species is the most virulent of the fungi which infect the oral 
mucosa. Pathogenic Candida species are aerobic yeasts that can also grow 
anaerobically. C. albicans, the Candida species most often responsible for 
infections of the oral cavity, grows in two morphological forms: either as 
a budding yeast, or as a continuously extending hyphae which extends into 
tissue. In the oral cavity, Candida may cause a variety of disorders based 
on localization of the infection such as pulpitis, gingivitis, 
tonsillitis, cheilitis, glossitis, stomatitis, pharyngitis, laryngitis and 
sinusitis. 
Oral candidosis has been classified into different categories based on the 
clinical and histopathological manifestations of the infection (Lehner, 
T., in Clinical Aspects of immunology, P.G.H. Gell, et al., eds., 3rd 
edition, Blackwell Scientific Publications, Oxford, 1975, pp.1387-1427). 
Acute Pseudomembranous candidosis, or thrush, primarily affects children or 
patients with debilitating diseases (Crawson, R. A., Dent. Res. 15:361-364 
(1965). C. albicans is a major causative agent of thrush in the newborn. 
The clinical signs which usually appear first are creamy-white, soft, 
nonkeratotic plaques which appear on the mucosa of the tongue, cheeks, gum 
and pharynx. The plaque is easily rubbed off, leaving an inflamed mucosa 
underneath. There may be no subjective symptoms until the plaque spreads 
to the pharynx, larynx or esophagus, where it may cause dysphaghia, 
soreness and dryness of the tongue, a sore throat or symptoms of 
cheilitis. 
Acute atrophic candidosis is a form of thrush which is consistently 
painful, and which is thought to arise as a consequence of the shedding of 
the fungal plaque from its site of attachment to the tissue. It can be 
found on the dorsum linguae, or associated with angular cheilitis and 
inflammation of cheeks and lips. 
Chronic atrophic candidosis, or denture stomatitis is the term given to 
Candida-based infections of the denture-bearing tissues. Torulopsis 
glabrata is also associated with some forms of denture stomatitis. 
Chronic mucocutaneous candidosis refers to four different types of 
candidosis which are resistant to treatment and which are associated with 
patients with a heterogeneous pattern of immunodeficiencies. These types 
of candidosis include chronic oral hyperplastic candidosis, which 
predominately affects adult males between the ages of 30 and 70; chronic 
localized mucocutaneous candidosis, which starts in childhood as an 
intractable oral Candida infection and later manifects itself as lesions 
in the nails, and skin of the fingers and toes; chronic localized 
mucocutaneous candidosis with granuloma which primarily affects young 
girls, starting in the mouth but later manifesting itself as horny masses 
of the face, scalp and upper respiratory tract; and, chronic localized 
mucocutaneous chadidosis with endocrine disorder, also found most 
frequently in young girls, and associated with lesions of the tongue, 
cheek, oral commissures and nails. 
The establishment of a mycotic infection in the oral cavity presents a 
serious health problem to the host which must be treated and contained. 
Treatment of mycotic diseases is directed to controlling this flora. 
The most widely used approach to date to control microfungi in the oral 
cavity has been mechanical cleaning methods such as brushing the teeth. 
Although this method has proved to be fairly successful in treating 
individuals, there is still a high recurrence rate. There is also the 
problem of motivating people to good oral hygiene habits that they will 
maintain throughout their lives. 
Systemic administration of antimycotics per os or intravenously has been 
used to control mycotic infections, however, discontinuation of therapy 
often results in the return of the pathogens to the oral cavity. Long-term 
systemic antimycotic therapy in doses high enough to control oral 
infections are undesirable for treatment of oral infections because the 
potential dangers and side-effects associated with this form of treatment 
include the development of resistant strains and superimposed infections, 
gastrointestinal irritation, liver damage and neurological symptoms, among 
others. 
Antifungal agents have also been used in the form of mouth rinses, 
dentifrices, solutions and gels but have not proven to be completely 
successful in preventing fungal infections. A main problem with these 
techniques is that the antifungal drug does not remain in the oral cavity 
long enough at efficacious levels. 
Another serious problem with antifungal drugs is that they are by necessity 
directed towards controlling an infection by a eukaryotic fungal cell in a 
eukaryotic host. As a result, drugs effective against the fungus also tend 
to be toxic to the host. Thus it is important to develop methods which 
permit the localized, sustained application of the toxic drug in a manner 
and dosage which is efficacious but which minimizes toxicity the host. 
Especially, it is important to develop methods which use low doses of the 
drug. 
A topical, sustained-release form of an antifungal agent, could help 
maintain a locally efficacious level of the antifungal drug in the oral 
cavity and prevent these side effects. Such a dosage form might also 
prevent undesirable systemic side effects by releasing the drug at a lower 
therapeutic level over a long period of time in a localized manner. 
Ridgway, F. et al.. U.S. Pat. No. 4,725,440, describes a soft, antifungal 
drug-containing pastille or troche which is free of rough edges and will 
not adhere to oral mucosa, but which only releases anti-fungal medications 
within the 15-90 minutes while it dissolves in the mouth. 
Cyr et al., U.S. Pat. No. 3,312,594 describes long lasting troches or 
pastilles for the treatment of oral lesions which include an anhydrous 
adhesive based on pectin, gelatin and carboxymethylcellulose and which, 
when wetted, adhere to the oral mucous membranes. However, the Cyr 
formulation was not well-tolerated by patients (Ridgway, F. et al., U.S. 
Pat. No. 4,725,440). 
Sustained release has been reported to be achieved by embedding 
chlorhexidine in an ethyl cellulose polymer to form a varnish (Friedman, 
M., et al., J. Perio. Res. 17:323-328 (1982); Friedman, M., et al., IADR 
Prog. and Abstr. 59:No. 905 (1980)). This dosage form was used in the 
local treatment of periodontal disease (Soskolne, W. A., et al., J. Perio. 
Res. 18:330-336 (1983)) and in the treatment of plaque prevention in 
patients wearing orthodontic appliances (Friedman, M., et al., J. Dent. 
Res. 64:1319-1321 (1985)). A drawback to this plaque preventative system 
was that although plaque accumulation was decreased by the application of 
a varnish composed of chlorhexidine embedded in an ethyl cellulose 
polymer, the effectiveness of the system in decreasing plaque accumulation 
was present only for a period of four days subsequent to administration of 
the varnish. Friedman et al., (J. Dent. Res., supra), concluded that 
"clearly the conditions in the oral cavity and the formulation used do 
not, at present, facilitate such prolonged prevention of plaque 
accumulation." These authors also suggested that by altering the varnish 
components and method of preparation it might be possible in clinical use 
to sustain the necessary level of antibacterial agent release for longer 
periods. No suggestion was made in this publication as to how this could 
be accomplished. 
Mastic has been used previously for dental purposes. U.S. Pat. No. 
4,668,188 (Wolfenson, G. B.) discloses the use of a curable mastic in the 
production of an oral impression tray for making impressions of teeth and 
jaw structures. Mastics have been used in the production of dental molds 
(VonWeissenfluh, H. U.S. Pat. No. 4,500,288), as an adhesive to secure 
dental articulators (U.S. Pat. Nos. 4,548,581 and 4,382,787, Hoffman, R. 
E.) and as a tooth decay preventative (Wahmi U.S. Pat. No. 4,374,824). 
U.S. Pat. Nos. 4,532,126 and 4,428,927 (Ebert, W. R., et al.) disclose 
chewable, filled, one-piece soft elastic gelatin capsules, made chewable 
by a masticatory substance, such as a synthetic mastic. 
U.S. Pat. No. 4,459,277 (Kosti, C. M.) relates to novel plaque compositions 
for use in evaluating oral hygiene practices. In brief, the patent 
discloses a water-insoluble, water-immiscible dye emulsified in fine 
droplets or rupturable capsules. The patent discloses the use of mastic 
resin as well as alginates, and other gums as an insoluble media for dye 
dispersion. In particular, sodium carboxymethylcellulose is disclosed. 
Also disclosed is the possibility of incorporating antibacterial agents 
such as stannous fluoride into the compositions. Significantly, the Kosti 
patent is concerned with diagnostic rather than therapeutic applications. 
The patent fails to suggest compositions exhibiting long-term preventive 
activity. 
The background art fails to identify any compositions of matter comprising 
an effective antifungal agent together with a long-term sustained-release 
carrier, in combination with an adhesive polymer such as a mastic and a 
plasticizer such as polyethylene glycol, for use as an antifungal 
preventative varnish in the oral cavity by humans and other animals, under 
conditions in which the antimycotic agents have no deleterious medical 
side effects, and do not cause staining of the teeth. Another highly 
desirable characteristic not found in the art of record is that the 
antifungal agent should be released from the composition, not only in a 
sustained fashion, but over a sufficiently long period of time so as not 
to require excessive application of the composition. 
SUMMARY OF THE INVENTION 
With this need in mind, the present inventor set out to find an oral 
antimycotic preventative composition which contains an antifungal agent 
effective against those microfungi that are responsible for oral 
infections, said composition being such that the antifungal agent can be 
released at efficacious levels in a sustained, long-term fashion, and such 
that the antifungal composition has the property of long-term adhesion to 
the oral tissue and teeth, and such that the antifungal composition 
remains plastic during the entire period of application. With this goal in 
mind, the inventor has discovered an antifungal preventative composition 
with these desirable characteristics, the composition comprising an 
antifungal agent embedded in a sustained release carrier composed of a 
cellulose polymer, in a pharmaceutically acceptable vehicle, optionally 
containing a plasticizer such as polyethylene glycol and/or an adhesive 
polymer such as gum mastic. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
This invention relates to oral compositions that provide sustained, 
efficient, inexpensive, localized antifungal activity in the oral cavity 
at efficacious levels without deleterious side effects, and methods for 
using such compositions. 
By "oral cavity" is meant the mouth and the surrounding esophageal area. 
Therefore, for example, the oral cavity includes the tongue, gums, palate, 
throat, teeth, tonsils and periodontal tissue. 
By "sustained-release" is meant the continuous release of an active 
substance at efficacious levels for a prolonged period of time, such as 
2-4 weeks or longer. The release of the active substance may be constant 
or pulsed, as long as efficacious levels of the active substance are 
provided to the surrounding milieu for the desired period of time. 
By an "efficacious level" is meant a level or concentration of a drug or 
other active agent which is high enough to be effective in treating the 
condition the drug was designed to treat. 
By "oral varnish" is meant a composition which is topically applied to a 
hard surface such as a tooth or orthodontic appliance and which dries as a 
film adhering to that surface, in a manner which resists removal under 
normal conditions, such as eating or brushing the teeth. 
The compilation of the components of the aforementioned oral composition is 
based upon the specific properties of each of the individual components, 
wherein each component of the combination increases the antifungal 
effectiveness of other members of the combination. 
The oral composition of the invention assists in the prevention of 
microfungal infections of the oral cavity and periodontal tissue, and in 
the relief of symptoms resulting from existing microfungally-caused 
problems, by attacking the pathogenic yeast and fungi responsible for the 
infection in the oral cavity. A variety of antifungal agents are suitable 
for the present invention. Preferred are the polyene antifungals, 
especially nystatin and amphotericin B. Examples of other antifungal 
agents applicable to the methods of the invention include 5-fluorocytosine 
and imidazole- and triazole-derivative antifungal agents, especially 
naftifine, terbinafine, tolnaftate, tolciclate, isoconazole, sulconazole, 
miconazole, clotrimazole, econazole, bifonazole, oxiconazole, 
thioconazole, ketoconazole, itraconazole, fluconazole, and terconazole, 
all known to the art. See, for example, Kostiala, I. et al., Acta Odontol. 
Scand. 37;87-101 (1979); and Bossche, H. V., CRC Crit. Rev. Mircobiol. 
15:57-72 (1987). 
In another embodiment, combinations of more than one antifungal agent are 
used in the composition of the invention. Combinations of antifungal 
agents can be prepared, for example, for the purpose of providing 
treatment or protection against a broad spectrum of microfungal species, 
or for the purpose of attacking a specific microfungal species with drugs 
acting through different modes of action. Combination of antifungal agents 
may also allow a lower dose of a given antifungal agent to synergistically 
act with a lower dose of another antifungal agent in a manner which is 
efficacious in combination but not separately. 
The antimycotic composition may be formulated to include other drugs such 
as antibacterial or antiseptic agents known to the art. See, for example, 
the section on "Quaternary Ammonium and Related Compounds" in the article 
on "Antiseptics and Disinfectants" in Kirk-Othmer Encyclopedia of Chemical 
Technology, 2nd ed. (Vol. 2, pp. 632-5), incorporated herein by reference. 
Such materials have been sued in oral compositions to counter bacteria in 
the oral cavity. Among the most common and efficacious of these 
antibacterial, quaternary ammonium compounds are cethylpyridinium chloride 
and benzalkonium chloride. Other cationic ammonium antibacterial agents of 
this type are mentioned, for instance, in U.S. Pat. Nos. 2,984,639, 
3,325,402, 3,431,208, 3,703,583, and 4,339,430, British Patent No. 
1,319,396, and German Patent No. 2,332,383. Most preferred is 
cetylpyridinium chloride, which is efficacious, compatible with the other 
components of the oral composition, and inexpensive by virtue of being a 
non-prescription drug. None of these compounds has been used before in 
sustained release, long-acting compositions. By long acting is meant a 
composition which provides efficacious levels o the active drug contained 
therein for a period of weeks, preferably at least 4 weeks, or 30 days. 
It is also a feature of this invention that the aforementioned antifungal 
agent is released to the sites of fungal lesions and pockets in a 
long-term sustained release manner so as to reduce the required frequency 
of use. Long-term sustained release is desirable because it improves 
patient compliance with the treatment protocol and it is more convenient 
for the patient. Hence the success of the treatment is more probable. The 
method of the invention needs only a single application of the oral 
varnish composition of the invention to remain efficacious for a period of 
weeks. Other methods require a multi-dose application of paste every few 
days or ingestion of lozenges every four hours by the patient. At best, 
the pastes remain effective for 2-3 days and the lozenges only for hours. 
In addition, by the composition and method of the invention, because of the 
long-term sustained release of the drug, much lower amounts of the 
antifungal drug are required for efficacious results. Conventional therapy 
uses doses of nystatin as high as 10.sup.8 IU/dose. The concentrations of 
nystatin preferred in the invention are 2.times.10.sup.5 I.U., with an 
acceptable range of 2.times.10.sup.5 -10.sup.6 I.U. Because of the lower 
doses of nystatin, the side effects of the drug are eliminated or 
minimized. For example, at the efficacious concentrations of nystatin 
taught by the compositions and methods of the invention, in clinical 
evaluations there was no bitter-taste noted. The bitter taste of the drug 
is one of the major complaints of patients taking conventional nystatin 
therapy. 
Lastly, the physical form and manner of presentation of the composition of 
the invention is highly advantageous for a patient with an oral 
microfungal infection. Often the area of the infection is so sore so as to 
make the direct application of a paste or even sucking lozenges, troches 
or pastilles very painful; rinsing with a mouthwash does not leave 
efficacious levels of the drug in the oral cavity. In other cases, oral 
treatments with mouthwashes, lozenges, pastes, troches or pastilles is 
very difficult or just not practical, for example with infants or animals. 
The compositions and methods of the invention solve this problem by 
applying the antifungal drug to the teeth, gingival tissues or orthodontic 
appliance, for slow, long-term sustained release at efficacious levels 
into the salival fluids of the oral cavity. In addition the composition of 
the invention is colorless and visually undetectable by those unaware of 
the treatment. 
Long term sustained release is accomplished by embedding the active drug 
agent(s) in a polymer. The specific polymer used is not critical. Long 
term sustained release, may, in accordance with the present invention, be 
accomplished by embedding an anti-fungal agent in any biologically 
suitable polymer. For example, a hydrophobic polymer, a hydrophilic 
polymer, or a combination of hydrophilic and hydrophobic polymers, may be 
used to form sustained releases formulations that would be suitable as a 
varnish for oral administration in accordance with the present invention. 
One or more proteinaceous polymers (such as gelatin, etc.), cellulosic 
polymers, acrylic polymers, etc. may be employed. Suitable polymers are 
disclosed in U.S. patent applications Ser. Nos. 07/189,918; 07/304,091; 
07/369,223; and 07/432,667; which applications are herein incorporated by 
reference in their entirety. 
Cellulosic or acrylic polymers are especially preferred for forming a 
varnish for oral administration. The use of these polymers provides the 
advantage of allowing lower doses of a drug to be used and thus 
eliminating or minimizing side effects such as staining of teeth and 
dentures and unpleasant taste. A variety of suitable hydrophobic polymers 
are known in the art of oral compositions. Preferred are the insoluble and 
inexpensive polymers: hydrophobic type (poly-ethylene, polymethacrylate, 
polyamide-nylon, poly(ethylene-vinyl acetate) cellulose nitrate, silicones 
and others). Most preferred is ethyl cellulose. Another suitable polymer 
is methylacrylic acid polymer. 
The composition of the invention is preferably applied to teeth or dental 
appliances which act as a solid support and point of release for the 
antifungal agent in the composition throughout the treatment period. The 
tooth or orthodontic appliance varnished with the antifungal composition 
of the invention may be placed in direct contact with the site of 
infection, as for example, by placing dentures on top an infected or 
irritated gum for the treatment of denture stomatitis. Alternatively, the 
varnished tooth or dental appliance may act as a reservoir which releases 
efficacious levels of the antifungal agent in the salival fluids to other 
infected sites within the oral cavity or throat. Therefore, in a highly 
preferred embodiment, there is direct contact between the composition of 
the invention and the site of microfungal infection. In another preferred 
embodiment, the composition of the invention is applied to a site removed 
from the infected area but within the range of the efficacious levels of 
antifungal drugs released by said composition. Orthodontic appliances 
within the scope of the invention include dentures, bridges, braces, 
anchoring pins and the like. The appliance can be a temporary or permanent 
appliance. The compositions and methods of the present invention therefore 
provide a therapy for denture stomatitis, oral thrush, and other oral 
fungal diseases and conditions. 
Thus, in a preferred embodiment, an oral composition with the highly 
desirable characteristics mentioned above comprises an antimycotic 
compound such as nystatin embedded in a sustained release cellulosic 
polymer such as ethyl cellulose, in a pharmaceutically effective vehicle. 
For example, nystatin, 100,000 IU (1-5 parts), and ethyl cellulose (5-9 
parts) may be dissolved in ethanol (80 -120 parts) for the preparation of 
sustained release varnish in film form. 
For application to buccal and lingual surfaces of teeth, an ethanolic 
solution of the antimycotic agent and cellulosic polymer (containing up to 
4% of the drug as used in the varnish) are applied with a soft brush or 
with a spray. Ethanol may be evaporated by a gentle stream of warm air. 
Mouthwash forms are not suitable because of inefficient application of the 
composition to affected tissue areas. However, orthodontic appliances such 
as dentures may be dipped in a solution containing the composition of the 
invention. 
For application to orthodontic appliances, a total of about 40 mg of 
antimycotic agent such as nystatin or amphotericin B in an ethanolic 
solution with ethyl cellulose may be applied per appliance by dipping, 
spraying or painting it on with a soft brush, and residual solvent removed 
with a gentle stream of warm air. 
Those skilled in the treatment of diseases of the oral cavity will, without 
undue experimentation, be able to produce ranges of concentrations of 
other appropriate antifungal agents and sustained release polymers. 
The thickness of the film as varnish can be varied according to the desired 
length of efficacious treatment or drug potency. In a preferred embodiment 
the film coating the tooth or appliance is 10-300 .mu.m thick. 
It is another feature of the invention that the oral compositions for 
treatment and prevention of fungal infections also provide for additional 
desirable components. For example, the adhesiveness of the oral 
composition may be improved by the incorporation within said composition 
of gums such as gum mastic in a formulation providing from 1-20% by weight 
of the gum mastic. Other suitable mastics are disclosed in Heyd, D., et 
al., U.S. Pat. No. 4,315,779 and Wahmi, H.V.R., et al. U.S. Pat. No. 
4,374,824. 
In another formulation, other compositions may include 
demulcents/humectants (i.e., plasticizers) such as polyethylene glycol 
400-to-4000, glycerol, sorbitol, or mineral oil in concentrations of about 
1% by weight. Other humectants, detergents, or surface-active agents will 
be known to those skilled in the formulation of oral compositions. 
Thus, in a preferred composition, the oral composition of the invention 
comprises nystatin, ethyl cellulose polymer, an adhesive, a plasticizer, 
and solvent (i.e., aqueous ethanol). In a highly preferred formulation, 
gum mastic is also present. Water, flavorings, and coloring agents may 
also be present as required. Once applied to teeth or other orthodontic 
appliance, the varnish is not easily removed by normal dental hygiene 
protocols, such as brushing. The dry film can only be removed 
mechanically. In addition, because the varnish coats the surface of the 
teeth or orthodontic support with a smooth surface and the same contours 
of the support, it adds no uncomfortable, unfamiliar or otherwise annoying 
geometry to the oral cavity, in the manner that a paste can. 
The composition and methods of the invention may also be applied as a 
preventative or deterrent measure, especially in patients highly 
susceptible to opportunistic infections of the oral cavity by microfungi. 
The varnish of the invention may also be applied extraorally to sites of 
microfungal infection, for example, to infected nails on the fingers and 
toes of patients with chronic mucocutaneous candidosis. Alternatively, the 
composition of the invention, especially in combination with antibacterial 
agents, may be provided on a varnished pad or bandage or patch which is 
placed in contact with the site of infection, for example, topically or 
intravaginally. 
Having now generally described the invention, the same will become better 
understood by reference to certain specific examples which are included 
herein for purposes of illustration only and are not intended to be 
limiting unless otherwise specified.

EXAMPLE 1 
Varnish Preparation 
The following formulations (Table 1) were all prepared by the same general 
procedure as follows: ethyl cellulose and polyethylene glycol polymers 
were dissolved in the suitable solvent. After complete dissolution of the 
polymers, the additional components of the varnish are added. 
EXAMPLE 2 
Evaluation of the Varnish in Vitro Sustained Release Activity of Nystatin 
on Candida Albicans in Vitro 
Films containing Nystatin were cast from the varnish formulation IV on 
glass plates using the technique of Kanic et al., J. Pharm. Sci. 51:77 
(1962). The solvent was allowed to evaporate at room temperature and the 
residual film removed from the plate. A strain of C. albicans isolated 
from clinical material was used in this study. A 1:10 dilution of an 
overnight growth stock suspension of the above organism was mixed with 
mycological culture medium (Sabourand) and poured into petri dishes. Five 
mm diameter disks of the films containing Nystatin were placed on the 
hardened medium. 
After 24 h or 48 h, films were transferred onto another set of petri dishes 
containing the same medium plus C. albicans suspension as in the first 
set. 
Inhibition zones were recorded after incubation periods of 24 and 48 h at 
37.degree. C. All films were used in duplicate. The mean inhibition zone 
is summarized in Table 2. 
TABLE 2 
__________________________________________________________________________ 
Inhibition Zone of Candida Growth by 
Sustained Release Films Containing Nystatin 
__________________________________________________________________________ 
Time (days) 
1 
2 
3 
4 
5 
7 
9 
11 
13 15 
17 
19 
21 
23 
25 
27 
29 
31 
Inhibition 
20 
17 
17 
12 
11 
12 
13 
13 
11 11 
10 
12 
10 
10 
9 
10 
9 
9 
zone (mm) 
__________________________________________________________________________ 
There was no inhibition of Candida growth in control samples containing 
ethyl cellulose films only. The measurements of inhibition were 
discontinued after 31 days. 
EXAMPLE 3 
Clinical Study: Evaluation of the Varnish in vivo 
Preparation of coated denture. The Nystatin varnish (Formulation IV) was 
applied to the denture base facing the mucosa, by means of a soft brush. 
Removal of the solvent was achieved by a gentle stream of hot air. 
The dentures were weighted before and after coating and the total amount of 
coating calculated. Forty mg of Nystatin per denture was the average 
amount of drug used. (Equivalent to 200,000 I.U.) 
In the preliminary clinical evaluation of the system, 5 patients suffering 
from denture stomatitis were selected from an old age home. Three tests 
were performed on each patient: a) 1 swab from upper gum, b) 1 swab from 
denture, and c) 2 ml of saliva was collected. 
Material from the swabs was washed into a solution containing 0.2% 
neopeptone+0.8% Tween 80, which was also used for further dilution of this 
material and of the saliva. Ten ml aliquots of the various dilutions were 
inoculated in duplicate onto plates containing bacteriological blood agar 
(for bacterial isolation) and plates containing mycological medium 
Sabourand (for C. albicans isolation). 
All plates were incubated for 48 h at 37.degree. C. and the number of 
bacterial and yeast colonies recorded. 
The effects of the local application of a sustained-release delivery system 
of nystatin on fungal growth due to denture stomatitis in these patients 
are summarized in Table 3. 
In summary there was an improvement in clinical status of the disease was 
observed, total elimination of Candida in saliva, gum and denture with no 
change in the normal bacteria flora levels. There was an improved 
compliance on the part of the patient; one single application is a much 
more convenient way of treatment compared to the conventional multi-dose 
application, and this new way of treatment is not dependent on the 
patient's cooperation. 
Much lower amounts of Nystatin are necessary for the clinical effect as 
compared to the total of 10.sup.8 I.U. used in conventional therapy. 
Lastly, no side effects, such as the bitter taste of Nystatin were 
observed in the preliminary clinical evaluation of this system 
These results are consistent with inhibition of fungal growth in the oral 
cavity of these patients by this form of the drug and further suggest that 
efficacious concentrations of the drug on the tooth/tissue surface is 
achieved creating a local antimycotic effect. 
TABLE 3 
__________________________________________________________________________ 
THE REDUCTION OF CANDIDA IN DENTURE WEARERS AFTER 
SINGLE APPLICATION OF SUSTAINED RELEASE VARNISH OF MYSTATIN 
0 2 days 3 days 7 days 
Patient 
Bacteria* 
Candida*.sup.(1) 
Bacteria 
Candida 
Bacteria 
Candida 
Bacteria 
Candida 
__________________________________________________________________________ 
1 G 7.1 .times. 10.sup.8 
1.0 7.1 .times. 10.sup.7 
0 1.2 .times. 10.sup.6 
0 8.2 .times. 10.sup.6 
0 
D 5.5 .times. 10.sup.7 
2.9 1.2 .times. 10.sup.8 
0 8.0 .times. 10.sup.7 
0 6.3 .times. 10.sup.7 
0 
S 5.5 .times. 10.sup.7 
2.4 4.1 .times. 10.sup.7 
0.25 7.5 .times. 10.sup.7 
0.9 2.2 .times. 10.sup.8 
1.6 
2 G 2.2 .times. 10.sup.6 
28.8 2.0 .times. 10.sup.6 
0 1.1 .times. 10.sup.7 
0 5.1 .times. 10.sup.6 
0 
D 4.1 .times. 10.sup.6 
19.9 4.1 .times. 10.sup.6 
0 1.2 .times. 10.sup.6 
0 3.2 .times. 10.sup.6 
0 
S 1.4 .times. 10.sup.8 
21.1 1.2 .times. 10.sup.7 
5.2 1.1 .times. 10.sup.7 
3.0 2.3 .times. 10.sup.7 
6.1 
3 G 3.3 .times. 10.sup.7 
16.2 3.2 .times. 10.sup.7 
0 3.1 .times. 10.sup.7 
0 8.0 .times. 10.sup.7 
0 
D 2.6 .times. 10.sup.7 
11.8 2.4 .times. 10.sup.7 
0 1.2 .times. 10.sup.7 
0 2.3 .times. 10.sup.7 
0 
S 3.1 .times. 10.sup.7 
10.1 1.0 .times. 10.sup.7 
6.1 2.2 .times. 10.sup.7 
2.4 8.6 .times. 10.sup.6 
2.0 
4 G 4.2 .times. 10.sup.7 
6.5 4.4 .times. 10.sup.7 
0 8.1 .times. 10.sup.7 
0 6.2 .times. 10.sup.7 
0 
D 6.2 .times. 10.sup.7 
9.2 7.1 .times. 10.sup.7 
0 1.2 .times. 10.sup.8 
0 7.2 .times. 10.sup.6 
0 
S 2.1 .times. 10.sup.8 
4.2 5.2 .times. 10.sup.7 
2.6 6.1 .times. 10.sup.7 
1.8 9.0 .times. 10.sup.7 
2.0 
5 G 4.2 .times. 10.sup.7 
12.6 8.0 .times. 10.sup.6 
0 2.2 .times. 10.sup.7 
0 2.1 .times. 10.sup.7 
0 
D 7.2 .times. 10.sup.7 
17.2 6.2 .times. 10.sup.6 
0 6.1 .times. 10.sup.6 
0 1.6 .times. 10.sup.7 
0 
S 5.2 .times. 10.sup.6 
10.8 3.2 .times. 10.sup.6 
2.8 6.4 .times. 10.sup.6 
5.2 2.0 .times. 10.sup.7 
4.3 
__________________________________________________________________________ 
*Candida and Bacteria determined from the same sample 
##STR1## 
G Gum 
D Denture 
S Sputum 
Having now fully described the invention, it will be understood by those 
with skill in the art that the scope may be performed within a wide and 
equivalent range of conditions, parameters and the like, without affecting 
the spirit or scope of the invention or any embodiment thereof.