The University of Texas System

Aronex Pharmaceuticals, Inc.

Reeta Mehta

Gabriel Lopez-Berestein

Rudolph L Juliano

Roy L Hopfer

Kapil Mehta

Evan M Hersh

Robert P Lenk

Victor Fainstein

Robert P Link

A method is disclosed for preparing a stable preliposomal powder which, when reconstituted with water or saline solution, forms a suspension of liposomes containing a polyene drug, such as nystatin. The method involves the steps of combining at least one phospholipid with a first organic solvent to form a first solution, adding a clarifying amount of water to the first solution, combining a polyene with a second organic solvent to form a second solution, combining the first and second solutions to produce a substantially clear combined solution, and then removing the organic solvents, leaving a powder.

Liposomal-polyene preliposomal powder and method for its preparation

The present invention involves a liposomal agent for treating disseminated fungal infection in an animal. This liposomal agent comprises a variety of polymer antifungal compounds, particularly hamycin. These antifungal compounds are encapsulated within a liposome decreasing toxicity. This liposome is preferably a stable multilamellar vesicle. The method of administration is preferably parenteral, but may be oral or topical.

Lipsome-incorporation of polyenes

The present invention involves a liposomal agent for treating disseminated fungal infection in an animal. This liposomal agent comprises the polyene antifungal compound mepartricin. The mepatricin is encapsulated within a liposome. The liposome in which the mepartricin is incorporated is preferably a stable multilamellar vesicle. The liposome broadly comprises one or more lipids one or more of phosphomonoglyceride, phosphatidic acid and sphingolipid. The lipids are preferably one or more of phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, sphingomyelin or phosphatidic acid. The lipids are most preferably one or more of dimyristoylphosphatidylchlorine, dimyristoylphosphatidylglycerol, phosphatidylcholine and phosphatidylglycerol. The liposome of the present invention may comprise a sterol most preferably cholesterol. An important aspect of the present invention involves a method for treating disseminated fungal infection in an animal. This method comprises administering to an animal subject to disseminated fungal infection a fungicidally effective amount of mepartricin encapsulated within a liposome. The liposome is composed as described above. The administering is preferably parenteral in most instances but may be oral or topical if specific colonies of fungus are thereby more directly reached. This treatment method is most useful when the animal is a human suffering from disseminated fungal infection. The method of treatment involves a fungicidally effective amount of liposome-incorporated mepartricin of between about 1 mg mepartricin/kg body weight and about 6 mg mepartricin/kg body weight.

Liposome-incorporated mepartricin

A method is disclosed for treatment of disseminated fungal infection in a mammal comprising the administration of a fungicidally effective amount of Amphotericin B encapsulated in a substantially sterol-free liposome to the infected mammal. Also provided is an agent for treatment of disseminated fungal infection in a mammal comprising Amphotericin B encapsulated in a liposome which consists essentially of lipids other than sterols.

Composition and method for treatment of disseminated fungal infections

The present invention involves a process for producing fine powder suitable for the preparation of antifungal polyene microlide-containing liposomes upon suspension in an aqueous solution. This process comprises the following steps. Quantities of polyene macrolide and phospholipids are dissolved respectively in a first solvent and a second solvent to form a first solution and a second solution. The first solution and the second solution are mixed in a desired ratio to form a mixture. The first solvent and the second solvent are then removed from the mixture, for example by evaporation, to form a residue. The residue is then dissolved in a third solvent comprising tertiary butanol and methylene chloride to form a third solution. The third solvent is then removed from the third solution to form a remnant. The remnant is then dissolved in a solvent consisting essentially of tertiary butanol to form a fourth solution. The fourth solution is then filtered through a filter having orifices of between about 0.05 and 0.5 micrometers in diameter to produce a filtrate. The filtrate is lyophilized to remove the tertiary butanol and a fine powder remains. This fine powder may be used to form polyene macrolide-containing liposomes by simple incubation or suspension in an aqueous solution.

Polyene microlide pre-liposomal powders

The present invention involves a liposomal agent for treating disseminated fungal infection in an animal. This liposomal agent comprises the polyene antifungal compound nystatin. The nystatin is encapsulated within a liposome. The liposome in which the nystatin is incorporated is preferably a stable multilamellar vesicle. The liposome broadly comprises one or more lipids one or more of phosphomonoglyceride, phosphatidic acid and sphingolipid. The lipids are preferably one or more of phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, sphingomyelin or phosphatidic acid. The lipids are most preferably one or more of dimyristoylphosphatidylcholine, dimyristoylphosphatidylglycerol, phosphatidylcholine and phosphatidylglycerol. The liposome of the present invention may comprise a sterol most preferably cholesterol. An important aspect of the present invention involves a method for treating disseminated fungal infection in an animal. This method comprises administering to an animal subject to disseminated fungal infection a fungicidally effective amount of nystatin encapsulated within a liposome. The liposome is composed as described above. The administering is preferably parenteral in most instances but may be oral or topical if specific colonies of fungus are thereby more directly reached. This treatment method is most useful when the animal is a human suffering from disseminated fungal infection. The method of treatment involves a fungicidally effective amount of liposome-incorporated nystatin of between about 1 mg nystatin/kg body weight and about 6 mg nystatin/kg body weight. In a most preferred embodiment the treatment method comprises liposomes consisting essentially of dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol in a ratio of about 7:3.

Liposome-incorporated nystatin

Method for treatment of disseminated fungal infection in a mammal comprising the administration of a fungicidally effective amount of Amphotericin B encapsulated in a substantially sterol-free liposome to the infected mammal. Also provided is an agent for treatment of disseminated fungal infection in a mammal comprising liposome-encapsulated Amphotericin B, said liposome being comprised of lipids other than sterols.

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Houston, TX, United States of America

Reeta Mehta