Patents by Inventor Ludek Ridvan

Ludek Ridvan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230390221
    Abstract: The present invention relates to pharmaceutical compositions comprising metformin with low amounts of nitrosamine impurities and methods for producing the same. More specifically, the present invention relates to methods and compositions that reduce the amount of nitrosable compounds in the active pharmaceutical ingredient and/or reduce the conversion of nitrosable compounds into nitrosamines in the finished dosage form.
    Type: Application
    Filed: October 15, 2021
    Publication date: December 7, 2023
    Applicant: Zentiva K.S.
    Inventors: Jaroslav RIHA, Ludek RIDVAN, Michal DOUSA, Tomas KUBELKA, Petr GIBALA, Frantisek BARTACEK, Pawel STASIAK, Stanislav KALASEK, Anna Kluk, Vít Zvonícek
  • Patent number: 8927771
    Abstract: The present invention relates to novel solid forms of agomelatine (I), specifically novel phaamaceutically acceptable cocrystals thereof, as well as to methods of preparing them. Three pharmaceutically acceptable cocrystals of (I) that have physico-chemical properties acceptable for pharmaceutical development were obtained.
    Type: Grant
    Filed: April 25, 2012
    Date of Patent: January 6, 2015
    Assignee: Zentiva k.s.
    Inventors: Gary James Miller, Ludek Ridvan, Jindrich Richter, Ondrej Dammer, Tomas Chvojka, Tomas Pekarek, Winfried Heyse, Norbert Nagel
  • Patent number: 8779005
    Abstract: The invention deals with new salts of the desvenlafaxine base of formula (I) with oxalic acid, the new salts being the hydrogen oxalate of formula (II) in the proportion of desvenlafaxine:oxalic acid of 1:1 and hemioxalate of formula (III) in the proportion of desvenlafaxine:oxalic acid of 2:1.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: July 15, 2014
    Assignee: Zentiva k.s.
    Inventors: Ludek Ridvan, Petr Hruby, Stanislav Radl, Hana Brusova, Lukas Krejcik, Tomas Pekarek, Natalia Csokova, Anna Zerzanova
  • Publication number: 20140051887
    Abstract: The present invention relates to novel solid forms of agomelatine (I), specifically novel phaamaceutically acceptable cocrystals thereof, as well as to methods of preparing them. Three pharmaceutically acceptable cocrystals of (I) that have physico-chemical properties acceptable for pharmaceutical development were obtained.
    Type: Application
    Filed: April 25, 2012
    Publication date: February 20, 2014
    Inventors: Gary James Miller, Ludek Ridvan, Jindrich Richter, Ondrej Dammer, Tomas Chvojka, Tomas Pekarek, Winfried Heyse, Norbert Nagel
  • Patent number: 8207356
    Abstract: A method for the preparation of a duloxetine hydrochloride salt from a duloxetine base, comprising the steps of: reacting duloxetine base with concentrated hydrochloric acid in ethylmethylketone; and crystallizing duloxetine hydrochloride salt from said concentrated hydrochloric acid in ethylmethylketone.
    Type: Grant
    Filed: October 5, 2011
    Date of Patent: June 26, 2012
    Assignee: Zentiva k.s.
    Inventors: Ludek Ridvan, Kamal Jarrah, Josef Cinibulk, Monika Zatopkova, Lukas Placek
  • Patent number: 8143417
    Abstract: In the preparation of zolmitriptan of formula III the reduction of the diazonium salt to (5)-4-(4-hydrazinobenzyl)-1,3-oxazolidin-2-one of formula IV is performed in a more concentrated mixture and by the effect on an alkali metal disulphite, preferably sodium disulphite. A zolmitriptan toluene solvate, characterized by a toluene content of 9 to 14% by weight according to the gas chromatography determination and by a maximum of the corresponding mass loss at temperatures of about 111° C. in the gravimetric analysis record. A zolmitriptan toluene solvate, showing strong Raman bands at the wave numbers of 1443 and 1354 cm?1, characteristic for the crystal lattice of zolmitriptan with built-in toluene, and further marked bands at 1004 and 786 cm?1, characteristic for toluene.
    Type: Grant
    Filed: February 25, 2008
    Date of Patent: March 27, 2012
    Assignee: Zentiva k.s.
    Inventors: Michal Voslar, Monika Zatopkova, Ludek Ridvan, Tomas Pekarek
  • Publication number: 20120041227
    Abstract: The invention deals with new salts of the desvenlafaxine base of formula (I) with oxalic acid, the new salts being the hydrogen oxalate of formula (II) in the proportion of desvenlafaxine:oxalic acid of 1:1 and hemioxalate of formula (III) in the proportion of desvenlafaxine:oxalic acid of 2:1.
    Type: Application
    Filed: February 3, 2010
    Publication date: February 16, 2012
    Inventors: Ludek Ridvan, Petr Hruby, Stanislav Radl, Hana Brusova, Lukas Krejcik, Tomas Pekarek, Natalia Csokova, Anna Zerzanova
  • Publication number: 20120029212
    Abstract: A method for the preparation of a duloxetine hydrochloride salt from a duloxetine base, comprising the steps of: reacting duloxetine base with concentrated hydrochloric acid in ethylmethylketone; and crystallizing duloxetine hydrochloride salt from said concentrated hydrochloric acid in ethylmethylketone.
    Type: Application
    Filed: October 5, 2011
    Publication date: February 2, 2012
    Inventors: Ludek RIDVAN, Kamal Jarrah, Josef Cinibulk, Monika Zatopkova, Lukas Placek
  • Patent number: 8071791
    Abstract: A method of preparation of (S)-N-methyl-3-(1-naphthyloxy)-3-(2-mienyl)propylamine of Formula (I) and its pharmaceutically acceptable salts, comprising a) reaction of (RS)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine with optically active D-tartaric acid or an acid salt derived from D-tartaric acid forming a mixture of diastereoisomeric salts of N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine and D-tartaric acid (2:1), b) isolation of the salt (S)-N,N-dimethyl-3-(naphthyloxy) -3-(2-thienyl)propylamine/D-tartrate (2:1) from the mixture of diastereoisomeric salts in an organic solvent, water or a mixture thereof and release of (S)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine by action of an inorganic or organic base, c) demethylation of (S)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine by action of an alkylchloroformate of formula ClCOOR (R=C1-C5 alkyl, or C6-C12 aryl or alkylraryl), especially phenyl, ethyl or methyl chloroformate, and d) hydrolytic release of the duloxet
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: December 6, 2011
    Assignee: Zentiva k.s.
    Inventors: Ludek Ridvan, Kamal Jarrah, Josef Cinibulk, Monika Zatopkova, Lukas Placek
  • Patent number: 7709662
    Abstract: A method of preparation of (S)-N-methyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine of formula (I) or its pharmaceutically acceptable salt, in which (RS)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine of formula (III) is reacted with an optically active acid, after which a crystallization is made of that diastereoisomer which yields, by reaction with an inorganic or organic base, (S)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine of formula (S)-III, which is then demethylated using alkylchloroformates, followed by a hydrolysis and optional conversion of the compound of formula (I) to its salt.
    Type: Grant
    Filed: October 21, 2005
    Date of Patent: May 4, 2010
    Assignee: Zentiva k.s.
    Inventors: Ludek Ridvan, Petr Hruby, Lukas Placek, Miroslav Kuchar
  • Publication number: 20100105919
    Abstract: In the preparation of zolmitriptan of formula III the reduction of the diazonium salt to (5)-4-(4-hydrazinobenzyl)-1,3-oxazolidin-2-one of formula IV is performed in a more concentrated mixture and by the effect on an alkali metal disulphite, preferably sodium disulphite. A zolmitriptan toluene solvate, characterized by a toluene content of 9 to 14% by weight according to the gas chromatography determination and by a maximum of the corresponding mass loss at temperatures of about 111° C. in the gravimetric analysis record. A zolmitriptan toluene solvate, showing strong Raman bands at the wave numbers of 1443 and 1354 cm?1, characteristic for the crystal lattice of zolmitriptan with built-in toluene, and further marked bands at 1004 and 786 cm?1, characteristic for toluene.
    Type: Application
    Filed: February 25, 2008
    Publication date: April 29, 2010
    Inventors: Michal Voslar, Monika Zatopkova, Ludek Ridvan, Tomas Pekarek
  • Publication number: 20100069649
    Abstract: A method of purification of (5)-7V-methyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine hydrochloride of formula I, comprising (a) transformation of the substance of formula I to its free base by the action of an organic or inorganic base in an aqueous environment; and (b) transformation of the base of the substance of formula I to crystalline hydrochloride by the action of hydrochloric acid or gaseous HCl in an organic solvent or a mixture of organic solvents. A method of purification of (S)-N-methyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine hydrochloride of formula I, comprising dissolution of this substance in a minimum quantity of methanol containing 0 to 50% of water and its transformation back to the solid phase (precipitation) by addition of a less polar solvent.
    Type: Application
    Filed: December 5, 2007
    Publication date: March 18, 2010
    Inventors: Ludek Ridvan, Josef Cinibulk, Monika Zatopkova, Lukas Placek
  • Publication number: 20090143600
    Abstract: A method of preparation of (S)—N-methyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine of formula (I) or its pharmaceutically acceptable salt, in which (RS)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine of formula (III) is reacted with an optically active acid, after which a crystallization is made of that diastereoisomer which yields, by reaction with an inorganic or organic base, (S)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine of formula (S)-III, which is then demethylated using alkylchloroformates, followed by a hydrolysis and optional conversion of the compound of formula (I) to its salt.
    Type: Application
    Filed: October 21, 2005
    Publication date: June 4, 2009
    Applicant: ZENTIVA, A.S.
    Inventors: Ludek Ridvan, Petr Hruby, Lukas Placek, Miroslav Kuchar
  • Publication number: 20080293952
    Abstract: A method of preparation of (S)—N-methyl-3-(1-naphthyloxy)-3-(2-mienyl)propylamine of Formula (I) and its pharmaceutically acceptable salts, comprising a) reaction of (RS)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine with optically active D-tartaric acid or an acid salt derived from D-tartaric acid forming a mixture of diastereoisomeric salts of N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine and D-tartaric acid (2:1), b) isolation of the salt (S)—N,N-dimethyl-3-(naphthyloxy)-3-(2-thienyl)propylamine/D-tartrate (2:1) from the mixture of diastereoisomeric salts in an organic solvent, water or a mixture thereof and release of (S)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine by action of an inorganic or organic base, c) demethylation of (S)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine by action of an alkylchloroformate of formula ClCOOR (R=C1-C5 alkyl, or C6-C12 aryl or alkylraryl), especially phenyl, ethyl or methyl chloroformate, and d) hydrolytic release of the duloxeti
    Type: Application
    Filed: December 22, 2006
    Publication date: November 27, 2008
    Inventors: Ludek Ridvan, Kamal Jarrah, Josef Cinibulk, Monika Zatopkova, Lukas Placek
  • Publication number: 20070117964
    Abstract: Nanotubes are treated with poly{(5-alkoxy-m-phenylenevinylene)-co-[(2,5-dioctyloxy-p-phenylene)vinylene]} (PAmPV) polymers and derivatives thereof to provide noncovalent functionalization of the nanotubes which increases solubility and enhances other properties.
    Type: Application
    Filed: January 16, 2007
    Publication date: May 24, 2007
    Applicant: The Regents of the University of California
    Inventors: J. Stoddart, Alexander Star, Yi Liu, Ludek Ridvan
  • Patent number: 7220818
    Abstract: Nanotubes are treated with poly{(5-alkoxy-m-phenylenevinylene)-co-[(2,5-dioctyloxy-p-phenylene)vinylene]} (PAmPV) polymers and derivatives thereof to provide noncovalent functionalization of the nanotubes which increases solubility and enhances other properties.
    Type: Grant
    Filed: August 16, 2004
    Date of Patent: May 22, 2007
    Assignee: The Regents of the University of California
    Inventors: J. Fraser Stoddart, Alexander Star, Yi Liu, Ludek Ridvan