John C Reepmeyer

Summary

Affiliation: Food and Drug Administration
Country: USA

Publications

  1. ncbi Structure elucidation of a novel analogue of sildenafil detected as an adulterant in an herbal dietary supplement
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Pharm Biomed Anal 43:1615-21. 2007
  2. doi Analysis of crude heparin by (1)H NMR, capillary electrophoresis, and strong-anion-exchange-HPLC for contamination by over sulfated chondroitin sulfate
    David A Keire
    Food and Drug Administration, Division of Pharmaceutical Analysis, 1114 Market St, Saint Louis, MO 63101, USA
    J Pharm Biomed Anal 51:921-6. 2010
  3. doi Structure elucidation of thioketone analogues of sildenafil detected as adulterants in herbal aphrodisiacs
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, 1114 Market Street, Room 1002, St Louis, MO 63101, USA
    J Pharm Biomed Anal 49:145-50. 2009
  4. ncbi Use of liquid chromatography-mass spectrometry and a chemical cleavage reaction for the structure elucidation of a new sildenafil analogue detected as an adulterant in an herbal dietary supplement
    John C Reepmeyer
    U S Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Pharm Biomed Anal 44:887-93. 2007
  5. doi Modifications and insights into a method for the analysis of the nitrogen mustard mechlorethamine by high-performance liquid chromatography
    John C Reepmeyer
    United States Food and Drug Administration, Center for Drug Evaluation and Research, Office of Phamaceutical Science, Division of Pharmaceutical Analysis, FDA, 1114 Market Street, Room 1002, St Louis, MO 63101, USA
    Anal Chim Acta 616:78-84. 2008
  6. doi Detection of undeclared erectile dysfunction drugs and analogues in dietary supplements by ion mobility spectrometry
    Connie M Gryniewicz
    FDA, Division of Pharmaceutical Analysis, 1114 Market St, St Louis, MO 63101, USA
    J Pharm Biomed Anal 49:601-6. 2009
  7. ncbi Use of a hydrolytic procedure and spectrometric methods in the structure elucidation of a thiocarbonyl analogue of sildenafil detected as an adulterant in an over-the-counter herbal aphrodisiac
    John C Reepmeyer
    U S Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J AOAC Int 92:1336-42. 2009
  8. ncbi Use of liquid chromatography-mass spectrometry and a hydrolytic technique for the detection and structure elucidation of a novel synthetic vardenafil designer drug added illegally to a "natural" herbal dietary supplement
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Chromatogr A 1125:67-75. 2006
  9. doi Analysis of heparin sodium by SAX/HPLC for contaminants and impurities
    Michael L Trehy
    Food and Drug Administration, Division of Pharmaceutical Analysis, Saint Louis, MO 63101, USA
    J Pharm Biomed Anal 49:670-3. 2009
  10. doi Direct intramolecular gas-phase transfer reactions during fragmentation of sildenafil and thiosildenafil analogs in electrospray ionization mass spectrometry
    John C Reepmeyer
    United States Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Division of Pharmaceutical Analysis, FDA, 1114 Market Street, Room 1002, St Louis, MO 63101, USA
    Rapid Commun Mass Spectrom 23:927-36. 2009

Detail Information

Publications13

  1. ncbi Structure elucidation of a novel analogue of sildenafil detected as an adulterant in an herbal dietary supplement
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Pharm Biomed Anal 43:1615-21. 2007
    ..The compound, named methisosildenafil, is a novel synthetic analogue of sildenafil in which the N-methylpiperazine moiety has been replaced with 2,6-dimethylpiperazine...
  2. doi Analysis of crude heparin by (1)H NMR, capillary electrophoresis, and strong-anion-exchange-HPLC for contamination by over sulfated chondroitin sulfate
    David A Keire
    Food and Drug Administration, Division of Pharmaceutical Analysis, 1114 Market St, Saint Louis, MO 63101, USA
    J Pharm Biomed Anal 51:921-6. 2010
    ..5M NaCl solution. This SAX-HPLC approach gave a weight percent LOD of 0.02% and a LOQ of 0.07% and had better performance characteristics than that of the protocol used for APIs...
  3. doi Structure elucidation of thioketone analogues of sildenafil detected as adulterants in herbal aphrodisiacs
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, 1114 Market Street, Room 1002, St Louis, MO 63101, USA
    J Pharm Biomed Anal 49:145-50. 2009
    ..Ten herbal dietary supplements, each as a capsule dosage form, were found to contain 8-151 mg of thiomethisosildenafil per capsule, and one herbal dietary supplement was found to contain 35 mg of thiosildenafil per capsule...
  4. ncbi Use of liquid chromatography-mass spectrometry and a chemical cleavage reaction for the structure elucidation of a new sildenafil analogue detected as an adulterant in an herbal dietary supplement
    John C Reepmeyer
    U S Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Pharm Biomed Anal 44:887-93. 2007
    ..Since the new compound has one less CH(2) group than acetildenafil, it was named nor-acetildenafil...
  5. doi Modifications and insights into a method for the analysis of the nitrogen mustard mechlorethamine by high-performance liquid chromatography
    John C Reepmeyer
    United States Food and Drug Administration, Center for Drug Evaluation and Research, Office of Phamaceutical Science, Division of Pharmaceutical Analysis, FDA, 1114 Market Street, Room 1002, St Louis, MO 63101, USA
    Anal Chim Acta 616:78-84. 2008
    ..The method has been extended to the analysis of mechlorethamine in aqueous solutions...
  6. doi Detection of undeclared erectile dysfunction drugs and analogues in dietary supplements by ion mobility spectrometry
    Connie M Gryniewicz
    FDA, Division of Pharmaceutical Analysis, 1114 Market St, St Louis, MO 63101, USA
    J Pharm Biomed Anal 49:601-6. 2009
    ..The results demonstrate that IMS is a viable method for screening herbal dietary supplements for the presence of ED drug or drug analogue adulterants...
  7. ncbi Use of a hydrolytic procedure and spectrometric methods in the structure elucidation of a thiocarbonyl analogue of sildenafil detected as an adulterant in an over-the-counter herbal aphrodisiac
    John C Reepmeyer
    U S Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J AOAC Int 92:1336-42. 2009
    ..Another key product of hydrolysis was hydroxyhomosildenafil, generated by hydrolysis of the thiocarbonyl group to a carbonyl group (C = S --> C = O). Hydroxyhomosildenafil was detected as a minor component in the dietary supplement...
  8. ncbi Use of liquid chromatography-mass spectrometry and a hydrolytic technique for the detection and structure elucidation of a novel synthetic vardenafil designer drug added illegally to a "natural" herbal dietary supplement
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Chromatogr A 1125:67-75. 2006
    ..The dosage level of piperidenafil in the herbal product was 41 mg per capsule when calculated as the free base...
  9. doi Analysis of heparin sodium by SAX/HPLC for contaminants and impurities
    Michael L Trehy
    Food and Drug Administration, Division of Pharmaceutical Analysis, Saint Louis, MO 63101, USA
    J Pharm Biomed Anal 49:670-3. 2009
    ..1% and 0.8%, respectively. This manuscript is not a policy document and is not intended to replace either of the methods (capillary electrophoresis and NMR) currently required by the FDA...
  10. doi Direct intramolecular gas-phase transfer reactions during fragmentation of sildenafil and thiosildenafil analogs in electrospray ionization mass spectrometry
    John C Reepmeyer
    United States Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Division of Pharmaceutical Analysis, FDA, 1114 Market Street, Room 1002, St Louis, MO 63101, USA
    Rapid Commun Mass Spectrom 23:927-36. 2009
    ..While methyl migration to the thiocarbonyl sulfur atom of thiosildenafil is dominant, methyl migration to the carbonyl oxygen atom of sildenafil may occur to a small extent...
  11. ncbi Analysis of the nitrogen mustard mechlorethamine in topical pharmaceutical preparations by high-performance liquid chromatography
    John C Reepmeyer
    U S Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Chromatogr A 1085:262-9. 2005
    ..08 to 0.52% RSD (n = 6). Recoveries from ointments spiked with 0.02% mechlorethamine hydrochloride were 98.4-100.4%. The chromatograms were clean, showing minimal or no interference from ointment excipients or reagents...
  12. doi Screening of heparin API by near infrared reflectance and Raman spectroscopy
    John A Spencer
    Division of Pharmaceutical Analysis, Food and Drug Administration, Center for Drug Evaluation and Research, St Louis, Missouri 63101, USA
    J Pharm Sci 98:3540-7. 2009
    ..These technologies are meant for screening purposes and not meant to replace either of the methods (capillary electrophoresis and NMR) currently required by USP and FDA...
  13. ncbi Separation and detection of the isomeric equine conjugated estrogens, equilin sulfate and delta8,9-dehydroestrone sulfate, by liquid chromatography--electrospray-mass spectrometry using carbon-coated zirconia and porous graphitic carbon stationary phases
    John C Reepmeyer
    US Food and Drug Administration, Division of Pharmaceutical Analysis, St Louis, MO 63101, USA
    J Chromatogr A 1083:42-51. 2005
    ..An examination of a selected few conjugated estrogens in the complex drug substance by LC-MS on Hypercarb is presented...