US 2007/0148240 Al  2  Jun.28,2007  easily soluble in acids such as hydrochloric acid, acetic acid,  phosphoric acid and methylsulfonic acid.  [0009]  There have been several reports which show  improvement of solubility and bioavailability of itraconzole  and/or saperconazole. For example, U.S. Pat. No. 6,100,285  describes a solvent system for dissolving itraconazole. The  solvent system contains volatile organic acid solvents such  as acetic acid and formic acid, with the solvent itself in an  aqueous solution of the acid.  [0010]  U.S. Pat. No. 5,707,975 discloses a pharmaceutical  formulation for itraconazole and saperconazole which is said  to have improved solubility and bioavailability. The formu› lation uses cyclodextrins or the derivatives of cyclodextrins  (e.g., hydroxypropyl-~-cyclodextrin) as a solubilizer; an  aqueous acidic medium as a bulk liquid carrier (such as  hydrochloric acid to achieve optimum pH of 2.0–0.1); and  an alcoholic co-solvent ( e.g., PEG 400) to dissolve the  compounds.  [0011]  U.S. Pat. No. 5,633,015 (the ’015 patent) discloses  a pharmaceutical formulation for itraconazole and saper› conazole in the form of beads. The beads comprise a central,  rounded or spherical core, a coating film, and a seal-coating  polymer layer. The core has a diameter of about 600 to about  700 µm (25-30 mesh). The coating film contains a hydro› philic polymer (such as hydroxypropyl methylcellulose) and  a drug (e.g., itraconazole and/or saperconazole). The seal› coating polymer layer is applied to the drug coated cores to  prevent sticking of the beads, which would have the unde› sirable effect of a concomitant decrease of the dissolution  rate and of bioavailability. The beads use polyethylene  glycol (PEG), in particular, PEG 20,000, as the seal-coating  polymer.  [0012]  U.S. Pat. No. 6,039,981 discloses a pharmaceutical  composition which comprises a fused mixture of itracona› zole and phosphoric acid, a pharmaceutically acceptable  carrier, and a surfactant. The fused mixture of itraconazole  and phosphoric acid is prepared by heating the mixture to a  temperature ranging from 100 to 170°  C. to obtain a homo› geneous melt mixture.  [0013]  U.S. Pat. No. 6,485,743 discloses a method and  composition of an oral preparation of itraconazole, where  itraconazole and hydrophilic polymer (i.e., polyvinylacetal  dithylarmoacetate and/or aminoalkyl methacrylate copoly› mer) are dissolved in solvent, followed by spray-drying  prior to dispersions.  [0014]  U.S. Pat. No. 6,663,897 discloses a method of  manufacturing an itraconazole oral dosage form that is  substantially free of residual methylene chloride, which  requires the addition of a strong acid (preferably an inor› ganic acid or organic sulphonic acid).  [0015]  The inventors of the present application recently  were granted U.S. Pat. No. 6,673,373 (the ’373 patent),  which is incorporated herein by reference. The ’373 patent  discloses an oral antifungal formulation which contains a  core, a drug emulsion layer, and a protective layer. The drug  emulsion contains an antifungal drug, an emulsion, prefer› ably vitamin E polyethylene glycol succinate, a binder,  preferably hydroxypropyl methylcellulose, and an absorbent  aid, preferably DL-malic acid.  [0016]  The present invention provides an oral pharmaceu› tical formulation which is distinguishable from the above  disclosed prior art compositions. The oral pharmaceutical  formulation contains a core which has a diameter of about  18-20-mesh, which is significantly smaller than the size of  the core described in the ’015 patent. The core of the oral  pharmaceutical formulation in the present invention is  coated with a drug coating layer which contains an antifun› gal drug and a binder. The present formulation is further  characterized by not containing an emulsion and an absor› bent aid in the drug coating layer. Because of the increase in  surface areas due to the use of smaller size (i.e., 18-20 mesh)  cores, the present formulation demonstrates higher absorp› tion and dissolution rates so as to enable the present inven› tors to use 50% less amount of the antifungal drug as used  in Sporanoxfi by Janssen Pharmaceutica (Beerse, BE), the  brand name drug maker, but still achieve the same thera› peutic results. The present invention also has the advantage  of providing the patients with flexible dosage forms due to  its higher absorption and dissolution rates and superior  bioavailability as compared to the commercially available  azole antifungal drugs.  [0017]  The present invention provides an oral pharmaceu› tical formulation which contains (a) a core, preferably  spherical or round shape, having a diameter of 18-20 mesh;  and (b) a drug coating layer which contains an effective  amount of an azole antifungal drug and a binder. The core  and the antifungal drug has a ratio of about 1 :0.2-0.6 by  weight, preferably 1:0.25 to 0.55 by weight. This oral  pharmaceutical formulation is further characterized for not  containing an emulsion (such as polyoxypropylene-poly› oxyethylene block copolymers, polyoxyethylene-sorbitan› fatty acid esters, sodium lauryl sulfate, or vitamin E poly› ethylene glycol succinate) and an absorbent aid (such as  DL-malic acid, citric acid, ascorbic acid, or alginic acid).  [0018]  The azole antifungal drug is preferably dissolved in  organic solvents, including, but not limited to, methylene  chloride, ethanol, or isopropanol. The preferred organic  solvents are methylene chloride and ethanol at a ratio of  about about 1.0 to 1.6-2.0 by volume.  [0019]  Examples of the azole antifungal drugs are itra› conazole, saperconazole, ketoconazole, and fluconazole.  The most favorable drug is itraconazole.  [0020]  The core of the oral pharmaceutical formulation is  preferably made of a core material which is sucrose, lactose,  starch, talc, or microcrystalline cellulose, or a mixture  thereof.  [0021]  The binder used in the drug coating layer of the oral  pharmaceutical formulation is polyvinyl pyrrolidone (PVP),  hydroxypropyl cellulose (HPC), hydroxypropyl methylcel› lulose (HPMC), or methylcellulose (MC), or a mixture  thereof.  It  is preferable that the binder is about 25 to 52% by  weight of the entire oral pharmaceutical formulation.  [0022]  Optionally, the oral pharmaceutical formulation  contains polyvinyl pyrrolidone (PVP K-30) as a plasticizer.  [0023]  It  is further optionally for the oral pharmaceutical  formulation to contain a protective layer which is coated  onto the drug coating layer. The protective layer is about 1  to 7% by weight of the oral pharmaceutical formulation. The  preferred material for the protective layer is polyethylene  glycol (PEG) at a molecular weight of 20,000.  SUMMARY OF THE INVENTION 