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Last Updated: March 29, 2024

Claims for Patent: 6,074,666


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Summary for Patent: 6,074,666
Title: Liposome compositions of porphyrin photosensitizers
Abstract:Liposomal pharmaceutical formulations incorporating porphyrin photosensitizers useful for photodynamic therapy or diagnosis of malignant cells. The liposomal formulations comprise a porphyrin photosensitizer, particularly the hydro-mono benzoporphyrins (BPD) having light absorption maxima in the range of 670-780 nanometers, a disaccharide or polysaccharide and one or more phospholipids.
Inventor(s): Desai; Narendra Raghunathji (Danbury, CT), Agha; Bushra J. (Durham, NC), Kale; Kalidas Madhavrao (Harriman, NY)
Assignee: QLT Phototherapeutics, Inc. (CA)
Application Number:08/489,850
Patent Claims: 1. A liposomal formulation for photodynamic therapy that comprises a bilayer which consists essentially of dimyristoyl phospatidyl choline and egg phosphatidyl glycerol, and a porphyrin macrocycle photosensitizer.

2. A liposomal formulation according to claim 1 wherein said porphyrin is a hydro-monobenzoporphyrin having a light absorption maximum between 670-780 nm.

3. A liposomal formulation according to claim 2 wherein said hydromonobenzoporphyrin is selected from the group consisting of:

BPD-DA wherein R.sup.1 and R.sup.2 thereof are carbomethoxy;

BPD-DB wherein R.sup.1 and R.sup.2 thereof are carbomethoxy;

BPD-MA wherein R.sup.1 and R.sup.2 thereof are carbomethoxy and R is methyl; and

BPD-MB wherein R.sup.1 and R.sup.2 thereof are carbomethoxy and R is methyl.

4. A liposomal formulation according to claim 3 wherein said hydromonobenzoporphyrin is BPD-MA wherein R.sup.1 and R.sup.2 thereof are carbomethoxy and R is methyl.

5. A liposomal formulation according to claim 3 that further comprises one or more sugars.

6. A liposomal formulation according to claim 5 wherein said sugar is a disaccharide.

7. A liposomal formulation according to claim 6 wherein said disaccharide is lactose or trehalose.

8. A liposomal formulation according to claim 5 that is freeze-dried.

9. A liposomal formulation according to claim 8, reconstituted with an aqueous fluid for pharmaceutical administration.

10. A liposomal formulation according to claim 2 wherein the amounts of porphyrin and phospholipids in said composition are, relative to each other on a per weight basis, about 0.2 to 0.4 of porphyrin; 0.94 to 1.88 of dimyristoyl phosphatidyl choline; and 0.65 to 1.30 of egg phosphatidyl glycerol.

11. A liposomal formulation according to claim 5 wherein the amounts of porphyrin, phospholipids, and said one or more sugars in said composition are, relative to each other on a per weight basis, about 0.2 to 0.4 of porphyrin; 0.94 to 1.88 of dimyristoyl phosphatidyl choline; 0.65 to 1.30 of egg phosphatidyl glycerol; and about 8.0 to 12.0 of sugar when said sugar is a disaccharide, or about half that amount if said sugar is a monosaccharide.

12. A liposomal formulation according to claim 5 further comprising butylated hydroxytoluene of ascorbyl palmitate.

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