Sterile otic formulations

Abstract

The present disclosure describes a sterile formulation and method for treating an ear infection, especially otomycosis and otitis externa, by administering a one-time only treatment comprising an antibiotic, and antifungal, and an optional anti-inflammatory in a thick, otic carrier. In one embodiment, the sterilization comprises e-beam irradiating ingredients the formulation while heat-sterilizing other ingredients before combining under sterile condition.

Claims

1. A single-dose formulation for treating ear infection, comprising: a) active ingredients for treating fungal and bacterial infections, comprising: i) ciprofloxacin; ii) an azole antifungal; and, iii) dexamethasone; b) an otically acceptable carrier that includes at least one thickener so that the single-dose formulation is capable of a one-time delivery to the ear canal of a mammal in a flowable fluid form but upon introduction into the ear canal the formulation remains in the ear canal for at least 3 days releasing said active ingredients.

2. The formulation of claim 1, wherein said azole antifungal is sterilized with heat treatment, and said fluoroquinolone antibacterial is sterilized with heat treatment or ionizing radiation.

3. The formulation of claim 2, wherein said azole antifungal and said fluoroquinolone are both sterilized with heat treatment, and said heat treatment comprises heating the azole antifungal and/or the fluoroquinolone to at least 120° C. for 1-3 hours.

4. The formulation of claim 3, wherein the optional corticosteroid is added to the heat-treated azole antifungal and fluoroquinolone after the temperature is cooled to about 50-70° C.

5. The formulation of claim 4, wherein said optional corticosteroid is sterilized with e-beam irradiation at <15 kGy before adding to the heat treated azole antifungal and fluoroquinolone.

6. The formulation of claim 1, wherein said carrier comprises about 10-90% of said thickener.

7. The formulation of claim 1, wherein said carrier comprises 75-90% mineral oil and 10% to 25% of wax.

8. The formulation of claim 1, wherein said carrier comprises 82% of said mineral oil and 18% of paraffin.

9. The formulation of claim 1, wherein said formulation comprises 0.1% to 2% by weight of said azole antifungal that is selected from the group consisting of: clotrimazole, ketoconazole, itraconazole, fluconazole, miconazole, econazole, butoconazole, oxiconazole, sulconazole, terconazole, and the combination thereof.

10. The formulation of claim 1, wherein said formulation further comprises 50,000 to 200,000 unit/ml of a polyene antifungal, wherein said polyene antifungal is nystatin.

11. The formulation of claim 1, wherein said carrier comprises about 40% mineral oil and about 60% PCCA Plasticizer base, wherein said PCCA Plasticizer comprises butylated hydroxytoluene, polyethylene and mineral oil.

12. A sterile single-dose formulation for treating ear infection, comprising: a) active ingredients for treating fungal and bacterial infection comprising: i) about 0.3% by weight of ciprofloxacin; ii) about 1% by weight of a clotrimazole; iii) about 0.1% by weight of a dexamethasone; and b) about 10-25% of wax; and c) about 75-90% of mineral oil; d) wherein said ciprofloxacin and clotrimazole are sterilized with heat treatment at a temperature of at least 120° C. for 1-3 hours.

13. A method of treating otitis externa, comprising administering a single dose of the formulation of claim 1 to a patient's ear.

14. A method of treating otitis externa, comprising administering a single dose of the formulation of claim 12 to a patient's ear.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows RP-HPLC Chromatogram of RHM-11 and the individual components at 254 nm.

(2) FIG. 2 shows RP-HPLC Chromatogram of RHM-11 and the individual components at 278 nm.

(3) FIG. 3 shows comparative RP-HPLC Chromatogram of RHM-12 and Quinazole Rx 7049360.

DETAILED DESCRIPTION

(4) The present disclosure provides a novel sterile formulation and method for treating ear fungal infections, especially otitis externa. The sterile formulation and method of the present disclosure make it possible to treat and even eradicate the chronic otitis externa by one-time only administration of the formulation to the ear canal.

(5) The disclosure provides a novel sterile formulation for treating fungal ear infection, comprising an antifungal, an antibiotic and an optional anti-inflammatory agent in a thick carrier at ear or body temperature.

(6) In one embodiment, azole active ingredients, such as synthetic imidazoles like clotrimazole, and fluoroquinolone such as ciprofloxacin, in carrier including mineral oil and paraffin wax are first heat sterilized at about 110-130° C. for about 1-3 hours in a sterile vessel while being stirred, mixed and homogenized. After the heat treatment is completed, the vessel is cooled to about 50-80° C., while the stirring, mixing and homogenizing continues.

(7) Dry, micronized and sterile dexamethasone powder, which may be pre-sterilized by e-beam irradiation, is then added to the vessel. The completely mixed and homogenized contents of the vessel are then cooled and added to syringes under sterile conditions. The syringes are then capped and sealed in sterile and opaque foil packages for labeling and transport.

(8) Electron beam processing or e-beam irradiation is a process that uses electrons, usually of high energy, to treat an object for a variety of purposes. This may take place under elevated temperatures and nitrogen atmosphere. Possible uses for electron irradiation include sterilization and to cross-link polymers. Electron energies typically vary from the keV to MeV range, depending on the depth of penetration required. The irradiation dose is usually measured in Gray (Gy) but also in megarads (Mrads), where 1 Gy is equivalent to 100 rad.

(9) The heat sterilization temperature and duration can vary, as long as proper sterilization results can be obtained. In one embodiment, the temperature is 110 to 130° C., and the duration is 1 to 3 hours. In another embodiment, the temperature is about 121° C. and the duration is about 1.5 hours.

(10) The cooling temperature prior to adding the dexamethasone is preferably not too high to cause degradation to dexamethasone, while still high enough to maintain sterility. In one embodiment, the cooling temperature is 50 to 70° C. In another embodiment, the cooling temperature is about 60° C.

(11) In a preferred embodiment, the disclosure provides a novel sterile formulation for treating fungal ear infection, comprising 0.01% to 1% by weight of a fluoroquinolone, 0.1% to 2% by weight of an azole antifungal, 0.1% to 2% by weight of a thiocarbamate, optionally 0.01% to 2.5% by weight of a corticosteroid, and 50,000 to 200,000 unit/ml of a polyene antifungal; 10% to 70% of thickener, and 30% to 90% of mineral oil. Other therapeutically appropriated bases can also be also be utilized in the present disclosure in place of the thickener without affecting the efficacy of the formulation.

(12) A particularly preferred formulation is triturated and micronized dexamethasone that can be e-beam sterilized at about 5 kGy, but can be higher, e.g., <15 kGy. 3 mg/ml ciprofloxacin, 10 mg/ml clotrimazole in a mixture of wax and mineral oil are first heat-sterilized by heating the mixture to about 121° C. for 1.5 hours. After the ciprofloxacin and clotrimazole mixture is cooled to about 60° C., dexamethasone (which may or may not be e-beam sterilized) is added. In an alternative embodiment, 10 mg/ml clotrimazole in a mixture of wax and mineral oil is first heat-sterilized by heating the mixture to about 121° C. for about 1.5 hours. 3 mg/ml Ciprofloxacin in a mixture of wax and mineral oil is sterilized by ionizing radiation; triturated and micronized dexamethasone is also sterilized separately by ionizing radiation. After cooling the clotrimazole mixture to about 60° C., sterilized ciprofloxacin and dexamethasone are then added.

(13) In a preferred embodiment, the fluoroquinolone is selected from the group consisting of: ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin, moxifloxacin and the combination thereof, and more preferably the fluoroquinolone is ciprofloxacin or ofloxacin.

(14) In a preferred embodiment, the azole antifungal is selected from the group consisting of: clotrimazole, ketoconazole, itraconazole, fluconazole, miconazole, econazole, butoconazole, oxiconazole, sulconazole, terconazole, and the combination thereof, and more preferably the azole antifungal is clotrimazole, ketoconazole, itraconazole, miconazole or the combination thereof. New generation azole antifungals including posaconazole and voriconazole can also be used.

(15) In a preferred embodiment, the thiocarbamate antifungal is tolnaftate.

(16) In a preferred embodiment, the corticosteroid is selected from the group consisting of: amcinonide, betamethasone benzoate, betamethasone dipropionate, betamethasone valerate, clobetasol propionate, clocortolonepivalate, desonide, desoximetasone, dexamethasone, dexamethasone sodium phosphate, diflorasonediacetate, fluocinonide, fluocinoloneacetonide, flurandrenolide, fluticasone propionate, halcinonide, halobetasol propionate, hydrocortisone, hydrocortisone butyrate, hydrocortisone valerate, mometasonefuroate, prednisolone acetate, triamcinolone acetonide, and the combination thereof. More preferably, the corticosteroid is dexamethasone, hydrocortisone, triamcinolone acetonide or the combination thereof.

(17) In a preferred embodiment, the polyene antifungal is nystatin.

(18) In a preferred embodiment, the carrier comprises mineral oil and a thickener. In a particularly preferred embodiment, it comprises 11-21% or 18% paraffin in mineral oil.

(19) In a preferred embodiment, the method for treating ear infection comprises the following step: applying, one time only, a sterile formulation into the ear canal of a mammal, said formulation as described herein, together with thickener and mineral oil; wherein the formulation is viscous enough to stay inside the ear canal for 2 to 7 days after applying to the ear canal of the mammal, and wherein the formulation releases the active ingredients continuously for at least 3 days. In some embodiments, before applying the formulation to the ear canal, the method further comprises the step of debriding infectious and inflammatory debris from the ear canal.

(20) In another embodiment, the disclosed is a sterile formulation for treating ear infection, comprising: one or more antifungal agents; one or more antibacterial agents; one or more anti-inflammatory agents; and a carrier, wherein said carrier retains said active ingredients in an ear for 2-7 days and then egresses or is absorbed.

(21) In a preferred embodiment, the sterile formulation comprises ciprofloxacin, dexamethasone and clotrimazole in an aurally acceptable carrier. Preferably, 0.1-10% ciprofloxacin, 0.1-10% dexamethasone and 0.1-10% clotrimazole are used, most preferred is 0.3% ciprofloxacin, 1% clotrimazole, and 0.1% dexamethasone in a suitable carrier as described herein.

(22) In a preferred embodiment, the mammal that can be treated with the formulation and method of the present disclosure includes humans, canines, felines, bovines, ovines, porcines, equines, as well as other mammals commonly treated by veterinarians for ear infections.

(23) Other embodiments that are included in the scope of the disclosure include any one or more of the following, in any combination: A formulation for treating ear infection, comprising active ingredients for treating fungal and bacterial infections, comprising: a fluoroquinolone antibacterial; an azole antifungal; and an optional corticosteroid; a otically acceptable carrier that includes at least one thickener so that the formulation is capable of delivery to the ear canal of a mammal in a flowable fluid form but upon introduction into the ear canal the formulation remains in the ear canal for at least 3 days releasing said active ingredients. Preferably, this formulation is partially sterilized with heat and optionally partially sterilized by ionizing radiation before combined together. A formulation for treating ear infection, wherein the fluoroquinolone antibacterial and the azole antifungal are heat-sterilized at a temperature of at least 120° C. for 1.5 hours and cooled to 60-80° C., then combined with an e-beam sterilized corticosteroid under sterile condition. A formulation for treating ear infection, comprising active ingredients for treating fungal and bacterial infection comprising: about 0.3% by weight of ciprofloxacin; about 1% by weight of a clotrimazole; optionally about 0.1% by weight of a dexamethasone; in a thick carrier about 10-25% of wax; and about 75-90% of mineral oil. A formulation wherein said carrier comprises about 10-90% of said thickener. A formulation wherein said carrier comprises 75-90% mineral oil and 10% to 25% of wax. A formulation wherein said carrier comprises 82% of said mineral oil and 18% of paraffin. A formulation wherein said formulation comprises 0.01% to 2% by weight of said fluoroquinolone that is selected from the group consisting of: ciprofloxacin, ofloxacin, levofloxacin, norfloxacin, gatifloxacin, gemifoxacin, moxifloxacin and combinations thereof. A formulation wherein said fluoroquinolone is ciprofloxacin, ofloxacin or the combination thereof. A formulation wherein said formulation comprises 0.1% to 2.5% by weight of said azole antifungal that is selected from the group consisting of: clotrimazole, ketoconazole, itraconazole, fluconazole, miconazole, econazole, butoconazole, oxiconazole, sulconazole, terconazole, and the combination thereof. A sterile formulation wherein said azole antifungal is clotrimazole, ketoconazole, itraconazole, miconazole and the combination thereof. A formulation wherein said formulation comprises 0.01% to 2.5% by weight of said corticosteroid that is selected from the group consisting of: amcinonide, betamethasone benzoate, betamethasone dipropionate, betamethasone valerate, clobetasol propionate, clocortolonepivalate, desonide, desoximetasone, dexamethasone, dexamethasone monosodium phosphate, diflorasonediacetate, fluocinonide, fluocinoloneacetonide, flurandrenolide, fluticasone propionate, halcinonide, halobetasol propionate, hydrocortisone, hydrocortisone butyrate, hydrocortisone valerate, mometasonefuroate, prednisolone acetate, triamcinolone acetonide, and the combination thereof. A formulation wherein said corticosteroid is dexamethasone, hydrocortisone, triamcinolone acetonide or the combination thereof. A formulation wherein said formulation comprises 50,000 to 200,000 unit/ml of a polyene antifungal, wherein said polyene antifungal is nystatin. A formulation as herein described wherein said dexamethasone is sterilized with e-beam irradiation at about 5 kGy. A method wherein said formulation include clotrimazole or other azole drug. A method wherein said formulation include clotrimazole or other azole drug and ciprofloxacin or other fluoroquinolone drug. A method wherein said formulation include clotrimazole, ciprofloxacin and optionally dexamethasone, wherein said ciprofloxacin and clotrimazole are sterilized with heat treatment at a temperature of at least 120° C. for 1.5 hours. A method of treating otis externa, comprising administering a single dose of the formulation herein described to a patient's ear.

Heat Treatment

(24) Heat treatment of Ciprofloxacin (Cip), Clotrimazole (Clot) and Dexamethasone (Dex) in the paraffin/mineral oil matrix has been tested. The composition was heat treated at 121° C. for more than 1.5 hours. The results indicate that Ciprofloxacin (Cip) and clotrimazole (Clot) did not show significant degradation. Dexamethasone or dexamethasone mono sodium phosphate, on the other hand, degraded under those heat treatment conditions to a significant extent (data not shown).

Heat and Ethanol Treatments

(25) To investigate the feasibility of manufacturing a sterile drug product using heat sterilization at 121° C., the drug product matrix with Ciprofloxacin and Clotrimazole was heated, and after reducing the temperature to 50-80° C., an ethanol solution of Dexamethasone was added to the drug matrix, wherein the ethanol solution can be sterile filtered before addition to prevent degradation of this heat sensitive Dexamethasone. Ethanol can be subsequently removed by applying low pressure to the reaction vessel.

(26) Formulations (ENTRx 401) were manufactured in the laboratory. The batch sizes of the ENTRx 401 formulations ranged from 2 mL to 250 mL (Table 1). ENTRx 401 formulations containing all three drug substances Ciprofloxacin (Cip) (3 mg/mL), Clotrimazole (Clot) (10 mg/mL) and Dexamethasone (Dex) (1 mg/mL) were prepared by adding the Cip and Clot to the liquid mineral oil and wax solution at 60° C. followed by heating to 121° C. and stirring for up to 5 hours.

(27) An ethanol solution of Dex was prepared at 11-12.5 mg/mL and slowly added to the matrix at 50-80° C. under reduced pressure, which resulted in the removal of the ethanol by evaporation. The chemical stability of each individual API component in the ENTRx 401 prototype formulations was evaluated at different time points during the heat sterilization process by RP-HPLC analysis using RP-HPLC methods adapted from the US Pharmacopeia.

(28) Quinazole Rx 7049360 is a composition that contains Ciprofloxacin (3 mg/mL), Clotrimazole (Clot) (10 mg/mL) and dexamethasone monosodium phosphate (DexP) (1 mg/mL) and is used as a standard for comparison to the experimental formulations.

(29) In one experiment (RHM-11) (FIGS. 1 and 2), 4.5 g of wax and 20.5 mL of mineral oil were placed in a round bottom flask, heated to 60-70° C. while stirring and adding 75 mg of Cip and 250 mg of Clo and keeping it for 1.5 hours at 120-125° C. After cooling to 86° C., a solution of a solution of 26 mg of dexamethasone in 2.2 ml of ethanol was slowly added while stirring vigorously. The temperature was raised to 100° C. for 10 minutes and vacuum was applied to remove the ethanol prior to cooling the material. The end point of removal of the ethanol was determined visually by observing the condensing ethanol on the condenser. Cooling was initiated 5 minutes after ethanol condensation was no longer observed.

(30) In another experiment (RHM-12) a Büchi rotary evaporator equipped with a HPLC tubing through the stop cock reaching from the outside of the rotary evaporator to the inside of a flask was used to allow addition of ethanol solution while under vacuum. 45 g of paraffin wax and 205 mL of mineral oil were placed in a beaker and heated to 60° C., 750 mg of Cip and 2500 mg of Clot were added and the mixture was heated to 120° C. for 1.5 hours. The material was then transferred into a 500 mL round bottom flask, the water bath of the Büchi evaporator was set to 62° C. and the round bottom flask was allowed to equilibrate for 15 min while spinning to allow the material to cool down.

(31) A vacuum was applied and 250 mg of Dex dissolved in 20 mL of ethanol was slowly added over a period of 30 min. During the addition under vacuum the ethanol immediately evaporated when it came in contact with the spinning flask as evidenced by foaming of the material. The beaker containing the solution was then rinsed with 5 mL of ethanol and the rinse solution was slowly added to the flask as well. After the addition, a full vacuum (10-12 Torr) was applied for 20 minutes to drive the additional ethanol out of the DP matrix. The material was then cooled down while being stirred.

(32) The instrumental set up for these experiments uses a beaker with a stir bar on a stirrer with heating capacity and a thermometer. The heat sterilization process was developed following a succession of small scale experiments in a beaker under different temperature and time conditions and at different scales ranging from 2 mL to 250 mL to find the desired conditions to execute the ultimate experiment in the Büchi Evaporator (Table 1). The experimental conditions and progression of the experiments including observations, results and conclusions are described in Table 1.

(33) TABLE-US-00002 TABLE 1 Progression of Heat Sterilization Experiments Leading to Buchi Evaporator Experiment Experiment Code (Scale) API's Method/Conditions Observation/Results/Notes JFT-1 (2 mL) Cip; Added suspension of all three Ethanol does not form a homogenous solution Clot; drugs to matrix at 100° C.; kept with liquid wax and mineral oil Dex DP at 100 to 120° C. for up to 5 Ethanol can be removed by evaporation at high hours temperature above boiling point Solubility of Clot in ethanol sufficient; solubility of Dec (phosphate) and Cip insufficient Water as solvent for drug is not recommended; drug precipitates in water droplets during evaporation JFT-2 (10 mL) Cip; Added all three drugs as sieved Stirring is important to keep drug products in Clot; powders to matrix at 90° C.; suspension Dex kept DP at 122 to 125° C. for up Some drug will dissolve at higher temperature to 4 hours followed by cooling and some will not and remain suspended to room temperature Cooling even during stirring is very in- homogenous; hardens first at glass wall and progresses to center of beaker Stirring at all times during temperature changes is important to keep DP homogenous First finding that Clot and Cip survives high temperature treatment (heat sterilization) but Dex does not RHM-2 (5 mL) Cip; Sample 1-matrix only Samples were made at 60° C. and then heated Clot; Sample 2-matrix + Cip to 121° C. DexP Sample 3-matrix + Clot Samples were pulled at 1, 2 and 3 hours Sample 4-matrix + Dex Cip and Clot were stable under those Sample 5-matrix + Cip, Clot, conditions Dex Dex did degrade to a significant extent RHM4-1 Cip; Cip added as solid at 60° C. Minimal impurities, impurity profile looks (50 mL) Clot; Clot added as solid at 60° C. equivalent to quinazole DexP DexP added as solid at 60° C. 60° C. for 30 min RHM4-2 Cip; Cip added as solid at 121° C. Sample is identical to RHM-4-1 (50 mL) Clot; Clot added as solid at 121° C. 121° C. for 10 min DexP DexP added as solid at 121° C. RHM4-4 Cip; Cip added as solid at 121° C. There is no protecting effect of N2 atmosphere (50 mL) Clot; Clot added as solid at 121° C. 121° C. for 1.5 Hours Dex P DexP added as solid at 121° C. DexP added under N.sub.2 blanket under N.sub.2 RHM8-2 (33 mL-100 mL Cip; Cip added as solid at 121° C. 121° C. for 1.5 Hours split in three Clot; Clot added as solid at 121° C. 60° C. for 1 hr parts) Dex P DexP added as solution in No significant difference between this water at 60° C. formulation and Quinazole Lower peak area of DexP (inhomogenous distribution) RHM8-3 (33 mL-100 mL Cip; Cip added as solid at 121° C. 121° C. for 1.5 Hours split in three Clot; Clot added as solid at 121° C. 60° C. for 1 hr parts) Dex P DexP added as solution in No significant difference between this water at 60° C., vacuum formulation and Quinazole Water does not evaporate with the vacuum in a significant manner Lower peak area of DexP (inhomogenous distribution) RHM-10 Cip; Cip added as solid at 121° C. Dexamethasone instead of Dexamethasone (50 mL) Clot; Clot added as solid at 121° C. monosodium phosphate used DexP DexP added as solid at 60° C. 121° C. for 1.5 hours Temperature dropped to 60° C. No significant degradation of any of the API's RHM-11 Cip; Cip added as solid at 121° C. Dexamethasone instead of Dexamethasone (25 mL) Clot; Clot added as solid at 121° C. monosodium phosphate used DexP DexP added as solution in 121° C. for 1.5 hours ethanol at 60° C. Temperature dropped to 60° C. Vacuum was applied Temperature was brought up to 80° C. for 10 min to evaporate ethanol No significant degradation of any of the API's RHM-12 Cip; Cip added as solid at 121° C. Dexamethasone instead of Dexamethasone (250 mL) Clot; Clot added as solid at 121° C. monosodium phosphate used DexP DexP added as solution in A Büchi rotary evaporator was used ethanol at 60° C. Process conditions: 121° C. for 1.5 hours Vacuum was applied and the ethanol solution was added under vacuum. Significant evaporation of the ethanol under those conditions was achieved Full vacuum was applied for 20 min to drive off ethanol No significant degradation of any of the API's

(34) The chemical stability of all three APIs, when formulated as described above, in the Büchi Evaporator was found to be acceptable (Table 2). The RP-HPLC chromatograms of RHM-12 were comparable to the Quinazole (Rx 7049360) shown in FIG. 1. It should be noted that this formulation of Quinazole used Dexamethasone monosodium phosphate (DexP) while Dexamethasone (Dex) was used for RHM-12. The impurity profile is almost identical with some very minor impurities at the retention times (RT) of 15 and 26 minutes, respectively (FIG. 3).

(35) The physical stability of ENTRx 401 based on appearance and visual inspection was comparable to ENTRx 401 prepared and provided by ENTRx. However, a stratification or separation of phases was observed in the formulations that were left on the bench for several days at ambient temperatures. RHM-12 after storage at ambient temperature above 25° C. stratified into two phases. This was observed regardless of the experimental conditions and/or raw materials used. It was also observed with Quinazole (by ENTRx) compared side by side with RHM-12 on the lab bench at ambient temperatures.

(36) It was noted that the temperature in the lab outside of working hours was significantly higher than during working hours. Two samples of Quninzole or RHM-12 were mixed thoroughly and one was placed in controlled room temperature storage (20±3° C.) and the other was placed on the bench. Within two days, the bench top samples stratified again while the material stored at controlled room temperature (20±3° C.) remained homogeneous. When these samples was taken out of the controlled storage and placed on the bench stratification occurred within two days. These results indicate that there is a temperature sensitivity of the DP matrix leading to phase separation of the matrix independent whether the DP matrix was initially subjected to high heat (121° C.) or not. Analysis of top and bottom layer indicates that the API content is not homogeneous. In some instances, the APIs appear to have been settling at the bottom of the container as well.

(37) The purity of the APIs in RMH-12 and Quinazole was estimated based on the purity and impurity profiles of the individual APIs formulated separately in the DP matrix assuming that if degradation occurs that the degradation rate will be independent in the presence of one or more API in the DP matrix with no protective or destabilizing synergistic effects. Comparative RP-HPLC analyses of RHM-12 and Quinazole produced by different processes showed no major differences in the content and impurity profiles of the APIs except Dex was used in RHM-12 and DexP in Quinazole (FIG. 3). Exposure of the individual APIs in the DP matrix for up to 6 months at 2-8° C., 20° C. and 40° C. did not result in any measurable degradation and any differences among the three temperature conditions (Table 3).

(38) Potential ethanol residuals in the DP matrix of RHM-12 and a control DP matrix not previously exposed to ethanol were tested by a validated GC-MS method. The results confirm that ethanol can be efficiently removed at 60° C. under vacuum in a Büchi Evaporator as the residual ethanol was found to be less than 40 ppm in RHM-12 which was found to be the detection limit of ethanol in the DP matrix (Table 2).

(39) TABLE-US-00003 TABLE 2 Purity of Drug Product and Ethanol Content in Heat Sterilized ENTRx 401 Estimation of Estimation of Approximate Heat Ethanol Experiment Purity (254 nm) Purity (278 nm) RP-HPLC Sterilization Content code (sale) API's added (%) (%) RTs (min) (hours) (PPM) RHM-12 Cip (powder) Cip: 99.22% Cip: 99.782% Cip: 4.1 Yes (1.5 <40 (250 mL) Clot Clot: 99.92% Clot: 99.76% to 4.2 hours) ppm (powder) Dex: 96.34% Dex: 99.14% Clot: 26.1 Dex to 16.2 (solution) Dex: 20.2 to 20.3 Quinazole Cip (powder) Cip: 99.61% Cip: 99.94% Cip: 4.1 No N/A (100 mL) Clot Clot: 99.28% Clot: 99.67% to 4.2 (powder) Dex: >99.5% Dex: >98.65% Clot: 26.1 Dex to 16.2 (solution) Dex: 13.7 to 13.8 DP Matrix No APIs N/A N/A N/A Y (control, 250 mL) Note: Main and impurity peaks in RHM-12 and Quinazole were assigned based on RTs and RTTs of peaks obtained with individual APIs standards, individual APIs in DP matrix and individual APIs in DP matrix exposed to 60° C. for 6 months (see Table 3). Purity of Clot is estimated as its only sole y impurities co-elutes with main peak of Cip.

(40) TABLE-US-00004 TABLE 3 Purity of Individual APIs in DP Matrix at 6 Months and Three Different Temperatures Purity Purity Purity Purity API Conditions 1(%) 2(%) API Conditions 1(%) 2(%) CIP Standard 99.69 99.54 DEXP Standard 100.00 99.75 CIP  4° C. 99.68 99.52 DEXP  4° C. 98.83 99.82 CIP 20° C. 99.68 99.51 DEXP 20° C. 98.74 99.66 CIP 40° C. 99.73 99.55 DEXP 40° C. 99.30 99.48 CLOT Standard 98.58 100.00 DEX Standard 99.10 CLOT  4° C. 99.49 100.00 CLOT 20° C. 99.82 100.00 CLOT 40° C. 99.71 100.00

(41) To investigate whether the viscosity and the melting characteristics of the ENTRx 401 drug product changes as a result of the heat sterilization process, viscosity measurements of the DP matrix were conducted with a Brookfield spindle viscometer and an adapter to measure small sample quantities. Rather than looking at the absolute viscosity the purpose of the experiment was to examine if there is a viscosity difference between the materials. Although the composition was determined to be non-Newtonian fluid and the viscosity therefore could not be accurately measured, both materials, RHM-12 and Quinazole Rx#7049360 (as control) were measured at 34-35° C. and at 40° C. and in both cases almost identical results were obtained (data not shown). Therefore, it is believed that the heat sterilization does not affect the viscosity characteristics of the composition.

Medical Treatments

(42) About 100 patients (work is ongoing and thus the exact number of patients is subject to change) diagnosed with otomycosis, chronic and acute otitis externa were selected for the treatment using the three formulations, ages from 26 months old to 78 years old. The formulations tested are repeated below:

(43) TABLE-US-00005 Ciprofloxacin 0.30% (297 mg) Ciprofloxacin 0.30% Nystatin 100,000 units/ml Nystatin 100,000 units/ (1707 mg) ml Itraconazole 1% (990 mg) Clotrimazole 1% (990 mg) Dexamethasone 0.10% (99 mg) Dexamethasone 0.10% Tolnaftate 1% (990 mg) Tolnaftate   1% Mineral Oil ~40% Mineral Oil ~40% PCCA Plasticizer ~60% PCCA Plasticizer ~60% Ciprofloxacin 0.30% Ciprofloxacin 0.30% Clotrimazole   1% Clotrimazole   1% Dexamethasone 0.10% Dexamethasone 0.10% Mineral Oil ~40% Mineral Oil   82% PCCA Plasticizer ~60% Paraffin   18%

(44) After debriding the infectious and/or inflammatory debris from the ear canal, an appropriate amount of a formulation from above was administered to the infected ear canal such that all available space in the outer ear was filled. The formulations were stored in a syringe before use, and can be stored at room temperature without deteriorating the therapeutic effect. The syringe is preferably attached to an 18 gauge metal or rigid plastic tip with the distal 1 cm being soft and very flexible to avoid inadvertent injury to the ear drum of outer ear structures. However, other suitable delivery devices can also be used without deviating from the spirit of the present invention.

(45) First the ENT doctor carefully placed the flexible needle inside the patient's auditory canal. Upon pressing the plunger, the therapeutic formulation was dispensed into the auditory canal and remains therein. Because of the flexible nature and rounded tip of the needle, doctors can minimize possible scratching when applying the therapeutic formulation. The dispensed thick fluid will fill in the space within the auditory canal, thereby contacting the infected area therein while preventing secondary infection in the ear canal.

(46) After administration of the formulation, each patient was examined to ensure that the formulation remained within the ear canal. Cotton balls were provided at the outer ear canal (conchal bowl) to catch egress, but no attempt was made to “plug” the ear canal. Follow-up examination was performed between 7 to 14 days after initial treatment. In several instances, residue of the formulation was observed at day 14, indicating the formulation did maintain within the ear canal for as long as 14 days. Patients reported that symptoms relief occurred usually within three days, while hearing returned to normal within 5 to 7 days after treatment.

(47) Visual examination as well as questionnaire from patients confirmed that no sign of infection existed after day 14 for all patients but two, who also had 98% of symptoms resolved. In other words, the formulation achieved at least 98% cure rate with a single treatment. The formulation of the present invention can continuously release the active ingredient to the infected area, thereby treating as well as preventing proliferation of secondary fungal/bacterial infection that may be caused by the condition within the ear canal occupied by the formulation.

(48) In summary, at least 100 patients have been tested with the above formulations. Only 2 out of 100 patients failed to completely resolve their symptoms and nearly all in 2-4 days. The two patients who failed, required systemic antibiotics and essentially had complicated otitis externa or cellulitis. Further, patients on follow-up are already forming normal cerumen in an incredibly short interval. This is a sign of return to normal epithelial function that is typically not seen for weeks after otitis externa, and may indicate the emollient effects of the mineral oil formulation. It is a notable clinical finding that the inventors have NEVER seen with ear drops of any kind.

(49) Preparing the formulation of the present disclosure can be performed with various compounding methods, as long as the final product has the desired characteristics, such as remaining flowable at both room temperature and body temperature, while remaining in the ear canal for a prolonged period of time and providing a continuous release of active ingredients. In particular, the methods of US20130178801 can be used, followed by e-beam irradiation at room temperature to the indicated dosage, or a combination of heat and ethanol sterilization can be used as described herein.

(50) The novel sterilization of the ingredients is therefore believed to prevent further infection caused by unsterilized medication, especially in the case where the medication is supposed to stay in the ear for at least three days. The sterilized drug composition provides potent, effective, long-lasting and single treatment for ear infection that prevents repeated infection due to unsterilized medication. Furthermore, the sterilized drug composition is compliant with FDA regulation regarding otic medications.

(51) The following references are incorporated by reference in their entirety. 1. Narayan S, Swift A. Otitis externa: a clinical review. Br J Hosp Med (Loud). 2011 October; 72(10):554-8. 2. Osguthorpe J D, Nielsen D R. Otitis externa: Review and clinical update. Am Fam Physician. 2006 Nov. 1; 74(9):1510-6. 3. Rosenfeld R M, Singer M, Wasserman J M, Stinnett S S. Systematic review of topical antimicrobial therapy for acute otitis externa. Otolaryngol Head Neck Surg. 2006 April; 134(4 Suppl):S24-48. 4. Stergiopoulou T, Meletiadis J, Sein T, Papaioannidou P, Tsiouris I, Roilides E, et al. Comparative pharmacodynamic interaction analysis between ciprofloxacin, moxifloxacin and levofloxacin and antifungal agents against Candida albicans and Aspergillus fumigatus. J Antimicrob Chemother. 2009 February; 63(2):343-8. 5. Stergiopoulou T, Meletiadis J, Sein T, Papaioannidou P, Tsiouris I, Roilides E, et al. Isobolographic analysis of pharmacodynamic interactions between antifungal agents and ciprofloxacin against Candida albicans and Aspergillus fumigatus. Antimicrob Agents Chemother. 2008 June; 52(6):2196-204. 6. Hahn Y H, Ahearn D G, Wilson L A. Comparative efficacy of amphotericin B, clotrimazole and itraconazole against Aspergillus spp. An in vitro study. Mycopathologia. 1993 September; 123(3):135-40. 7. Johnson M D, MacDougall C, Ostrosky-Zeichner L, Perfect J R, Rex J H. Combination antifungal therapy. Antimicrob Agents Chemother. 2004 March; 48(3):693-715. 8. Munguia et al., Ototopical antifungals and otomycosis: A review, International J. of Pediatric Otorhinolaryngology (2008) 72, 453-459. 9. Robert Sander, Otitis Externa: A practical Guide to Treatment and Disclosure, Am. Fam. Physician., 2001 Mar. 1; 63(5):927-937. 10. U.S. Pat. No. 7,220,431 & U.S. Pat. No. 8,030,297 11. US20130178801 12. Genete G., et al., Development And Validation Of HPTLC Assay Method For Simultaneous Quantification Of Hydrocortisone And Clotrimazole In Cream And Applying For Stability Indicating Test, J. Chilean Chem. Soc. 57(3) 1199-1203 (2012).

(52) While preferred embodiments of the present disclosure have been shown and described herein, such embodiments are provided by way of example only. Various alternatives to the embodiments can be optionally employed without deviating from the spirit of the present disclosure. The scope of the disclosure is defined by the following claims.