Patents by Inventor Om Dutt Tyagi

Om Dutt Tyagi 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).

  • Patent number: 7511135
    Abstract: A process for preparation of ceftiofur of formula (I) having purity greater than 97% is disclosed.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: March 31, 2009
    Assignee: Lupin Limited
    Inventors: Om Dutt Tyagi, Santosh Kumar Richhariya, Rajesh Kumar Ramchandra Pawar, Yuvaraj Atmaram Chavan
  • Patent number: 7427692
    Abstract: A process for preparation of 7-[D-?-amino-?-(4-hydroxyphenyl)acetamido]-3-(1-propen-1-yl)-3-cephem-4-carboxylic acid viz. Cefprozil of formula (I) in high purity, substantially free of impurities, which comprises preparation of mixed acid anhydride by selecting the sequence and temperature of addition of the reagents and its subsequent condensation with a protected 7-APCA; followed by hydrolysis, isolation and purification to give Cefprozil of formula (I) in the form of a monohydrate.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: September 23, 2008
    Assignee: Lupin Ltd.
    Inventors: Om Dutt Tyagi, Dnyandev Ragho Rane, Tushar Kumar Srivastava, Krishnarao Tukaram Sirsath
  • Publication number: 20080207912
    Abstract: A process for preparation of ceftiofur of formula (I) of high purity and substantially free from impurities is disclosed.
    Type: Application
    Filed: April 30, 2008
    Publication date: August 28, 2008
    Inventors: Om Dutt Tyagi, Santosh Kumar Richhariya, Rajesh Kumar Ramchandra Pawar, Yuvaraj Atmaram Chavan
  • Publication number: 20080167477
    Abstract: The present invention provides novel crystalline polymorphic forms and amorphous form of carvedilol dihydrogen phosphate characterized by different solid state techniques. The novel processes for their preparation are also disclosed.
    Type: Application
    Filed: September 7, 2007
    Publication date: July 10, 2008
    Applicant: MATRIX LABORATORIES LIMITED
    Inventors: Ramakoteswara Rao JETTI, Asha Rani GORANTLA, Om Dutt TYAGI
  • Patent number: 7335767
    Abstract: A process for preparation of ceftiofur sodium of formula (Ib) possessing high stability and having purity of more than 97% and substantially free of impurities, is disclosed. The process comprises: i) reacting cefotaxime or its salts or its esters of formula (VI) wherein R3 is hydrogen, an alkali or alkaline earth metal, or an easily hydrolysable ester, with thiofuroic acid, employed in a molar proportion of 1.5 to 3.0 moles per mole of compound (VI), in the presence of acetonitrile as solvent and in the presence of large excess of methanesulfonic acid, employed in molar proportions of 12 to 18 moles per mole of compound (VI), and at a temperature of between ?5° C. to 30° C.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: February 26, 2008
    Assignee: Lupin Limited
    Inventors: Om Dutt Tyagi, Santosh Kumar Richhariya, Rajesh Kumar Ramchandra Pawar
  • Patent number: 7230097
    Abstract: A process for preparation of 7-[D-?-amino-?-(4-hydroxyphenyl)acetamido]-3-(1-propen-1-yl)-3-cephem-4-carboxylic acid viz. Cefprozil of formula (I) in high purity, substantially free of impurities, which comprises preparation of mixed acid anhydride by selecting the sequence and temperature of addition of the reagents and its subsequent condensation with a protected 7-APCA; followed by hydrolysis, isolation and purification to give Cefprozil of formula (I) in the form of a monohydrate.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: June 12, 2007
    Assignee: Lupin Ltd.
    Inventors: Om Dutt Tyagi, Dnyandev Ragho Rane, Tushar Kumar Srivastava, Krishnarao Tukaram Sirsath
  • Patent number: 7002018
    Abstract: The present invention relates to a simple and efficient process for the preparation of amorphous form of torsemide. The process includes recovering amorphous torsemide from a solution thereof in a suitable solvent comprising alcohols, ketones, chlorinated hydrocarbons, esters, nitriles, cyclic ethers, and mixtures thereof, by spray drying.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: February 21, 2006
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Yatendra Kumar, Om Dutt Tyagi, Nitin Maheshwari
  • Patent number: 6833452
    Abstract: A process for the preparation of highly pure crystalline form of cefuroxime-1-acetoxyethyl ester (cefuroxime axetil) from cefuroxime by reacting an amine salt of cefuroxime with an esterifying reagent.
    Type: Grant
    Filed: July 16, 2001
    Date of Patent: December 21, 2004
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Om Dutt Tyagi, Gyan Chand Yadav, Vijay Kumar Handa
  • Publication number: 20040254223
    Abstract: The present invention relates to a simple and efficient process for the preparation of amorphous form of torsemide, demonstrated in the X-ray diffraction pattern of FIG. 1.
    Type: Application
    Filed: July 30, 2004
    Publication date: December 16, 2004
    Inventors: Yatendra Kumar, Om Dutt Tyagi, Nitin Maheshwari
  • Publication number: 20040152780
    Abstract: The present invention relates to a cost effective and industrially advantageous process for the preparation of amorphous cilastatin sodium.
    Type: Application
    Filed: March 19, 2004
    Publication date: August 5, 2004
    Inventors: Yatendra Kumar, Om Dutt Tyagi, Amit Rohtagi
  • Publication number: 20040132996
    Abstract: A process for preparation of ceftiofur sodium of formula (Ib) 1
    Type: Application
    Filed: October 27, 2003
    Publication date: July 8, 2004
    Applicant: LUPIN LIMITED
    Inventors: Om Dutt Tyagi, Santosh Kumar Richhariya, Rajesh Kumar Ramchandra Pawar
  • Publication number: 20040063792
    Abstract: This invention relates to a novel amorphous form of sertraline hydrochloride and a process for the preparation thereof.
    Type: Application
    Filed: June 4, 2003
    Publication date: April 1, 2004
    Inventors: Brij Khera, Amit Rohatgi, Om Dutt Tyagi, Yatendra Kumar
  • Patent number: 6534494
    Abstract: A process for preparing cefuroxime axetil in substantially amorphous form comprises forming a mixture of crystalline cefuroxime axetil and at least one pharmaceutically acceptable excipient, and subjecting the mixture to milling for a period of time sufficient to convert the crystalline cefuroxime axetil to substantially amorphous form, i.e., the crystallinity is less than 5%. The amorphous cefuroxime axetil has a chemical purity of at least 95%. Desirably, the particles of the milled material are reduced to a size of less than 2.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: March 18, 2003
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Jitendra Krishan Somani, Sanjeev Sethi, Om Dutt Tyagi
  • Patent number: 6384213
    Abstract: There is described a process for the preparation of a pure amorphous form of cefuroxime axetil which involves dissolving crystalline cefuroxime axetil in acetic acid including at least 5% v/v water and recovering said amorphous form of cefuroxime axetil from the solution by the addition of additional water, the solution being added all at once to the additional water being present in a volume which is sufficient to precipitate said amorphous cefuroxime axetil.
    Type: Grant
    Filed: May 19, 2000
    Date of Patent: May 7, 2002
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Vijay Kumar Handa, Om Dutt Tyagi, Uttam Kumar Ray
  • Publication number: 20020016456
    Abstract: A process for the preparation of highly pure crystalline form of cefuroxime-1-acetoxyethyl ester (cefuroxime axetil) from cefuroxime by reacting an amine salt of cefuroxime with an esterifying reagent.
    Type: Application
    Filed: July 16, 2001
    Publication date: February 7, 2002
    Inventors: Om Dutt Tyagi, Gyan Chand Yadav, Vijay Kumar Handa
  • Patent number: 6060599
    Abstract: A process for preparing cefuroxime axetil in substantially amorphous form comprises forming a mixture of crystalline cefuroxime axetil and at least one pharmaceutically acceptable excipient, and subjecting the mixture to milling for a period of time sufficient to convert the crystalline cefuroxime axetil to substantially amorphous form, i.e., the crystallinity is less than 5%. The amorphous cefuroxime axetil has a chemical purity of at least 95%. Desirably, the particles of the milled material are reduced to a size of less than 2 .mu.m. The amorphous cefuroxime axetil prepared by this method may consist of R isomer, S isomer, or a racemic mixture of the R and S isomers.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: May 9, 2000
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Jitendra Krishan Somani, Sanjeev Sethi, Om Dutt Tyagi