# US 9,751,049 B2 · Compositions and methods of cleaning polyvinyl pyrrolidone-based hemodialysis filtration membrane assemblies > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,751,049 B2 - Document ID: US9751049B2 - Status: Granted - Kind: B2 - Application number: 14/623,230 - Filed: 2015-02-16 - Published: 2015-12-03 - Granted: 2017-09-05 - Earliest claimed: 2014-05-30 - Assignees: Novaflux Inc. - Applicants: Princeton Trade and Technology, Inc. - Inventors: Mohamed Emam Labib; Yacoob Tabani - Web page: https://patentgrep.com/patent/US9751049B2 ## CPC - B01D 65/06: with special washing compositions - A61L 2/00: Disinfection or sterilisation of materials or objects, in general; Accessories therefor - A61L 9/00: Disinfection, sterilisation or deodorisation of air (body deodorants A61Q15/00; purifying air by respirators A62B, A62D9/00; separating dispersed particles from gases or vapours B01D45/00 - B01D51/00, B03C3/00; chemical or biological purification of waste gases B01D53/34; production of ozone C01B13/10; air-conditioning systems incorporating sterilisation F24F3/16, F24F8/20) - A61M 1/169: {using chemical substances} - B01D 63/02: Hollow fibre modules - B01D 65/02: Membrane cleaning or sterilisation {; Membrane regeneration} - C11D 3/3956: {Liquid compositions} - C11D 3/48: Medical, disinfecting agents, disinfecting, antibacterial, germicidal or antimicrobial compositions - C11D 7/06: Hydroxides - C11D 7/10: Salts - C11D 7/16: Phosphates including polyphosphates - B01D 71/68: Polysulfones; Polyethersulfones - B01D 2321/04: Backflushing - B01D 2321/08: Use of hot water or water vapor - B01D 2321/162: Use of acids - B01D 2321/164: Use of bases - B01D 2321/168: Use of other chemical agents - B01D 2321/18: Use of gases - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL ## Abstract A method and a composition of cleaning and reprocessing a hemodialysis filtration membrane assembly that employs polyvinylpyrrolidone-containing membranes, the method comprising the step of treating the assembly with an aqueous mixture or a gas-liquid mixture comprising an inorganic base and from 100 to 1,000 ppm of a hypochlorite salt, wherein the mixture has a pH between about 12.0 and about 12.5, an oxidation reduction potential of less than 0.5 volts, a temperature of 40° to 55° C. and wherein the mole % of hypochlorous acid, HOCl, relative to the sum of hypochlorous acid plus hypochlorite anion, —OCl, is less than 0.004%. ## Claims ### Claim 1 A method of cleaning a hemodialysis membrane assembly and removing protein from the pore structure of the membrane, the hemodialysis membrane assembly comprising inlet and outlet ports for a blood compartment, and inlet and outlet ports for a dialysate compartment wherein, in use, blood flows through a plurality of semi-permeable membrane hollow fibers of the blood compartment, each hollow fiber consisting of a lumen and a porous membrane wall, the method comprising: (a) applying a surfactant free composition to the hemodialysis membrane assembly for 5 to 10 minutes at a temperature of about 40° to about 55° C., the composition comprising: an inorganic base; from about 100 to about 1,000 ppm of a hypochlorite salt; between 0.4 ppb and 50 ppb free HOCl; a pH between at least 12.0 and about 12.8; and an oxidation-reduction potential greater than 0.376 volts but less than 0.5 volts; and (b) removing the composition from the hemodialysis membrane assembly with water. ### Claim 2 (depends on 1) The method of claim 1, wherein the hemodialysis membrane assembly comprises a polyvinylpyrrolidone (PVP)-containing membrane. ### Claim 3 (depends on 1) The method of claim 1, further comprising: (c) storing the hemodialysis membrane assembly in acid after step (b); and (d) removing the acid from the hemodialysis membrane assembly. ### Claim 4 (depends on 3) The method of claim 3, wherein peracetic acid solution is used to perform step (c). ### Claim 5 (depends on 1) The method of claim 1, wherein prior to step (a) the composition is in the form of a concentrate, and the method further comprises diluting the concentrate to the composition set forth in step (a). ### Claim 6 (depends on 5) The method of claim 5, wherein the step of diluting the concentrate composition is automated. ### Claim 7 (depends on 1) The method of claim 1, step (a) further comprises: pumping the composition under pressure through a dialysate compartment port and allowing the composition to exit the hemodialysis membrane assembly through the inlet and outlet ports of the blood compartment; wherein cleaning includes alternating cycles involving flow of the composition on the lumen side for a period of time followed by backfiltration through the membrane for another period of time and the composition is maintained simultaneously in contact with entire fiber surfaces of the hollow fibers of the hemodialysis membrane assembly, and the total time of membrane exposure to the cleaning composition does not exceed 10 minutes. ### Claim 8 (depends on 1) The method of claim 1, wherein the composition is applied to the hemodialysis membrane assembly in step (a) as a mixture of gas and the composition for 5 to 7 minutes and is provided to the assembly wherein the composition is delivered to the membrane by backfiltration from the dialysate compartment of the hemodialysis membrane assembly at a temperature of about 40° to about 55° C. and at volumetric flow rates between 100 and 600 ml/minute and the gas fraction comprises compressed air and is delivered through the lumens of the semi-permeable membrane hollow fibers at the ambient temperature and at volumetric flow rates between 56 to 150 liters per minute at STP. ### Claim 9 (depends on 1) The method of claim 1, wherein the hypochlorite salt is sodium hypochlorite, and the inorganic base is sodium hydroxide. ### Claim 10 (depends on 1) The method of claim 1, wherein the composition further comprises an additional salt that is a member selected from the group consisting of phosphates, benzoates, salicylates, citrates and mixtures thereof. ### Claim 11 (depends on 10) The method of claim 10, wherein the composition further comprises about 0.1% to about 0.5% by weight of sodium or potassium triphosphate. ### Claim 12 (depends on 10) The method of claim 10, wherein prior to step (a), the additional salt and the additional salt concentration is determined for a hemodialysis assembly model of the hemodialysis membrane assembly to be cleaned. ### Claim 13 (depends on 1) The method of claim 1, wherein the composition comprises: about 250 to about 1,000 ppm sodium hypochlorite; about 0.1 to about 0.5% sodium triphosphate and sodium hydroxide to provide a pH of about 12.2 to 12.5. ### Claim 14 A surfactant free cleaning composition concentrate effective for cleaning polyvinylpyrrolidone (PVP)-containing dialysis membrane assemblies and removing protein from the pore structure of the membrane without erosion of PVP, said cleaning composition comprising: (a) from about 0.05% to about 4% by weight of a hypochlorite salt; (b) an alkali metal hydroxide to provide alkalinity; (c) the balance being water, wherein the cleaning composition is diluted prior to cleaning the PVP-containing dialysis membrane assemblies without substantial erosion of PVP to a diluted composition comprising: from about 100 to about 1,000 ppm of a hypochlorite salt, between 0.4 ppb and 50 ppb free HOCl, a pH of from at least pH 12.0 to about 12.8, and an oxidation-reduction potential greater than 0.376 volts but less than 0.5 volts, and a ratio of base:hypochlorite of at least 0.5. ### Claim 15 (depends on 14) The cleaning composition of claim 14 wherein the cleaning composition is provided in a 5×, 10×, 20×, 25×, 30×, 40× concentrate and the diluted composition is from about 100 ppm and about 1,000 ppm hypochlorite salt. ### Claim 16 (depends on 14) A composition of claim 14, wherein the composition further comprises 0.5% to about 20% by weight of an additional alkali metal salt of phosphate. ### Claim 17 (depends on 14) A composition of claim 14, wherein said alkali metal hydroxide is sodium hydroxide. ### Claim 18 (depends on 14) A composition of claim 14, wherein the hypochlorite salt is sodium hypochlorite. ### Claim 19 (depends on 1) The method of claim 1, wherein after cleaning steps (a) and (b), recovery of function of the hemodialysis membrane assembly is demonstrable by beta-2 microglobulin, urea, or cytochrome c measurement.