# US 7,407,947 B2 · Amphoteric sterols and the use thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,407,947 B2 - Document ID: US7407947B2 - Status: Granted - Kind: B2 - Application number: 10/468,654 - Filed: 2002-02-21 - Published: 2004-06-24 - Granted: 2008-08-05 - Earliest claimed: 2001-02-21 - Assignees: Novosom AG - Inventors: Steffen Panzner; Gerold Endert; Stefan Fankhaenel; Nasr El-Mokdad - Web page: https://patentgrep.com/patent/US7407947B2 ## CPC - C07J 43/00: Normal steroids having a nitrogen-containing hetero ring spiro-condensed or not condensed with the cyclopenta(a)hydrophenanthrene skeleton - A61K 9/1272: comprising non-phosphatidyl surfactants as bilayer-forming substances, e.g. cationic lipids or non-phosphatidyl liposomes coated or grafted with polymers (lipids as modifying agents {A61K47/543}) - A61K 31/58: containing heterocyclic rings, e.g. danazol, stanozolol, pancuronium or digitogenin (digitoxin {A61K31/7048}) - C07J 41/0055: {the 17-beta position being substituted by an uninterrupted chain of at least three carbon atoms which may or may not be branched, e.g. cholane or cholestane derivatives, optionally cyclised, e.g. 17-beta-phenyl or 17-beta-furyl derivatives} - C07J 43/003: {not condensed} - C07J: STEROIDS (seco-steroids C07C) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) ## Abstract An amphoteric compound based on a sterol skeleton, the 3-position of the sterol ring system being substituted by one or more amphoteric groups having an isoelectric point of between about 4 and 9, together with liposomes containing such compounds and their uses. ## Claims ### Claim 1 A sterol derivative according to formula (1): Amphoteric substance -Y- spacer -X- sterol (1), wherein: said amphoteric substance comprises a first portion having a cationic charge with a pKa value between about 4 and about 8.5 and a second portion of anionic charge with a pKa value between about 3 and about 7; said first portion of said amphoteric substance is selected from the group consisting of piperazines, imidazoles, morpholines, purines, and pyrimidines; said second portion of said amphoteric substance comprises a carboxyl group; said spacer is a linear or branched C1-8 alkyl comprising 0-2 ethylenically unsaturated bonds; said linking group X is selected from the group consisting of —(C═O)—O—, —(C═O)—NH— and —NH—(C═O)—O—; said linking group Y is selected from the group consisting of —O—(C═O), —NH—(C═O), —(C═O)—O— and —(C═O)—NH—; said sterol is selected from the group consisting of cholesterol, sitosterol, campesterol, desmosterol, fucosterol, 22-ketosterol, 20-hydroxysterol, stigmasterol, 22-hydroxycholesterol, 25 -hydroxycholesterol, lanosterol, 7-dehydrocholesterol, dihydrocholesterol, 19-hydroxycholesterol, 5α-cholest-7-en-3β-ol, 7-hydroxycholesterol, epicholesterol, ergosterol, and dehydroergosterol; and said sterol derivative has an isoelectric point between about 4.5 and about 8.5. ### Claim 2 (depends on 1) The sterol derivative according to claim 1 wherein said amphoteric substance comprises 1-3 portions of cationic charge and 1-3 portions of anionic charge. ### Claim 3 (depends on 1) The sterol derivative according to claim 1 wherein said sterol derivative has an isoelectric point between about 5 and about 7. ### Claim 4 (depends on 1) The sterol derivative according to claim 1 wherein said amphoteric substance comprises a peptide of 1-10 amino acids, wherein said peptide comprises as a charge carrier one or more amino acids selected from the group consisting of histidine, arginine, lysine, glutamic acid, and aspartic acid. ### Claim 5 (depends on 4) The sterol derivative according to claim 4 wherein the sum of glutamic acid and aspartic acid amino acids of said peptide is greater than the sum of arginine, lysine, and histidine amino acids of said peptide. ### Claim 6 (depends on 4) The sterol derivative according to claim 4 wherein said peptide comprises solely histidine as cationic amino acid, and wherein the sum of glutamic acid amino acids and aspartic acid amino acids is greater than or equal to the number of histidine amino acids. ### Claim 7 (depends on 1) A liposome comprising the sterol derivative of claim 1. ### Claim 8 (depends on 7) The liposome according to claim 7 wherein said liposome comprises less than about 50 mole- % of sterol derivative. ### Claim 9 (depends on 8) The liposome according to claim 8 wherein said liposome comprises between about 2 mole- % and about 50 mole- % of sterol derivative. ### Claim 10 (depends on 9) The liposome according to claim 9 wherein said liposome comprises between about 10 mole- % and about 40 mole- % of sterol derivative. ### Claim 11 (depends on 7) The liposome according to claim 7, wherein the liposome comprises one or more lipids selected from the group consisting of phosphatidyl choline, phosphatidyl ethanolamine, diacylglycerol, tetraether lipid, and PEG lipid. ### Claim 12 (depends on 7) The liposome according to claim 7 wherein said liposome has an average size of between about 50 and about 1000 nm. ### Claim 13 (depends on 12) The liposome according to claim 12 wherein said liposome has an average size of between about 50 and about 300 nm. ### Claim 14 (depends on 13) The liposome according to claim 13 wherein said liposome has an average size of between about 60 and about 130 nm. ### Claim 15 (depends on 7) The liposome according to claim 7 wherein said liposome further comprises an active substance. ### Claim 16 (depends on 15) The liposome according to claim 15 wherein said active substance is selected from the group consisting of a protein, a peptide, a DNA, an RNA, an antisense nucleotide, a decoy nucleotide, and a mixture thereof. ### Claim 17 (depends on 15) The liposome according to claim 15 wherein at least about 80% of said active substance is entrapped inside the liposome. ### Claim 18 (depends on 15) A method of loading the liposome according to claim 15 with said active substance, said method comprising: encapsulating said active substance in said liposome at a binding pH value; and removing unbound active substances at a second pH value. ### Claim 19 (depends on 8) A method of loading the liposome according to claim 8 with an active substance, said method comprising: permeabilizing said liposome by treatment at a pH value sufficient to enable loading of said active substance, and sealing said liposome. ### Claim 20 (depends on 15) A method for the transport and release of an active substance in a subject, said method comprising administering to said subject the liposome of claim 15. ### Claim 21 (depends on 20) The method of claim 20, wherein said administration is intravenous or peritoneal. ### Claim 22 (depends on 7) A depot formulation or circulative depot comprising the liposome of claim 7. ### Claim 23 (depends on 7) A nanocapsule prepared from the liposome of claim 7. ### Claim 24 (depends on 7) A vector for transfecting cells in vivo, in vitro or at vivo, said vector comprising the liposome of claim 7 and a nucleic acid.