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Vol. 20, No. 1, 2011
Issue release date: December 2010
Open Access Gateway
Med Princ Pract 2011;20:51–59
(DOI:10.1159/000319547)

Assessment of the Stability of Novel Antibacterial Triazolyl Oxazolidinones Using a Stability-Indicating High-Performance Liquid Chromatography Method

Phillips O.A. · Sharaf L.H. · Abdel-Hamid M.E. · Varghese R.
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, Jabriya, Kuwait
email Corresponding Author

Abstract

Objectives: To evaluate the stability of 12 triazolyl oxazolidinone (TOZ) derivatives in simulated gastric and intestinal fluids as well as in human plasma at 37 ± 1°C. Materials and Methods: A stability-indicating high-performance liquid chromatography (HPLC) procedure with a C8 column (250 × 40 mm, 5 µm particle size) and a mobile phase of acetonitrile/H2O (50/50 v/v) at 1.0 ml/min was used. Accelerated stability studies were conducted at 37 ± 1°C in 0.1 M HCl solution as simulated gastric fluid and in phosphate buffer solution (pH about 7.4) as simulated intestinal fluid. The stability of TOZs in human plasma at a simulated biological temperature of 37 ± 1°C was evaluated as well. Results: The stability studies indicated that the examined TOZs were stable in the above media, with the exception of compounds 1a [tert- butyl 4-(4-((R)-5-((1H-1,2,3-triazol-1-yl)methyl)-2-oxooxazolidin-3-yl)-2-fluorophenyl)piperazine-1-carboxylate] and 1b [tert-butyl 4-(2-fluoro-4-((R)-5-((4-methyl-1H-1,2,3-triazol- 1-yl)methyl)-2-oxooxazolidin-3-yl)phenyl) piperazine-1-carboxylate], which underwent degradation in simulated gastric fluid. The degradation kinetics revealed degradation parameters (kdeg, t1/2, t90) of 0.180 h–1, 3.85 h, and 0.58 h for 1a and of 0.184 h–1, 3.76 h and 0.57 h for 1b, respectively. Furthermore, the degradation products were identified by mass-spectrometric analysis at mass-to-charge ratios 347.5 and 361.5, respectively, and proton nuclear magnetic resonance analysis. Conclusion: With the exception of compounds 1a and 1b, the TOZs are stable in simulated gastric and intestinal fluids as well as in human plasma. Being carbamate derivatives, compounds 1a and 1b underwent fast and complete degradation in simulated gastric fluid. The obtained results should be considered for future studies of formulation of structurally related TOZs in oral dosage forms.


 goto top of outline Key Words

  • Triazolyl oxazolidinones
  • Stability
  • High-performance liquid chromatography
  • Mass spectrometry

 goto top of outline Abstract

Objectives: To evaluate the stability of 12 triazolyl oxazolidinone (TOZ) derivatives in simulated gastric and intestinal fluids as well as in human plasma at 37 ± 1°C. Materials and Methods: A stability-indicating high-performance liquid chromatography (HPLC) procedure with a C8 column (250 × 40 mm, 5 µm particle size) and a mobile phase of acetonitrile/H2O (50/50 v/v) at 1.0 ml/min was used. Accelerated stability studies were conducted at 37 ± 1°C in 0.1 M HCl solution as simulated gastric fluid and in phosphate buffer solution (pH about 7.4) as simulated intestinal fluid. The stability of TOZs in human plasma at a simulated biological temperature of 37 ± 1°C was evaluated as well. Results: The stability studies indicated that the examined TOZs were stable in the above media, with the exception of compounds 1a [tert- butyl 4-(4-((R)-5-((1H-1,2,3-triazol-1-yl)methyl)-2-oxooxazolidin-3-yl)-2-fluorophenyl)piperazine-1-carboxylate] and 1b [tert-butyl 4-(2-fluoro-4-((R)-5-((4-methyl-1H-1,2,3-triazol- 1-yl)methyl)-2-oxooxazolidin-3-yl)phenyl) piperazine-1-carboxylate], which underwent degradation in simulated gastric fluid. The degradation kinetics revealed degradation parameters (kdeg, t1/2, t90) of 0.180 h–1, 3.85 h, and 0.58 h for 1a and of 0.184 h–1, 3.76 h and 0.57 h for 1b, respectively. Furthermore, the degradation products were identified by mass-spectrometric analysis at mass-to-charge ratios 347.5 and 361.5, respectively, and proton nuclear magnetic resonance analysis. Conclusion: With the exception of compounds 1a and 1b, the TOZs are stable in simulated gastric and intestinal fluids as well as in human plasma. Being carbamate derivatives, compounds 1a and 1b underwent fast and complete degradation in simulated gastric fluid. The obtained results should be considered for future studies of formulation of structurally related TOZs in oral dosage forms.

Copyright © 2010 S. Karger AG, Basel


 goto top of outline References
  1. Grau S, Rubio-Terrés C: Pharmacoeconomics of linezolid. Expert Opin Pharmacother 2008;9:987–1000.
  2. Drew RH: Emerging options for treatment of invasive, multidrug-resistant Staphylococcus aureus infections. Pharmacotherapy 2007;27:227–249.
  3. Wilcox MH: Update on linezolid: the first oxazolidinone antibiotic. Expert Opin Pharmacother 2005;6:2315–2326.
  4. Moellering RC: Linezolid: the first oxazolidinone antimicrobial. Ann Intern Med 2003;138:135–142.
  5. Bozdogan B, Appelbaum PC: Oxazolidinones: activity, mode of action, and mechanism of resistance. Int J Antimicrob Agents 2004;23:113–119.
  6. Sinclair A, Arnold C, Woodford N: Rapid detection and estimation by pyrosequencing of 23S rRNA genes with a single nucleotide polymorphism conferring linezolid resistance in Enterococci. Antimicrob Agents Chemother 2003;47:3620–3622.
  7. Ippolito JA, Kanyo ZF, Wang D, Franceschi FJ, Moore PB, Steitz TA, Duffy EM: Crystal structure of the oxazolidinone antibiotic linezolid bound to the 50S ribosomal subunit. J Med Chem 2008;51:3353–3356.
  8. Tsiodras S, Gold HS, Sakoulas G, Eliopoulos GM, Wennersten C, Venkataraman L, Moellering RB Jr, Ferraro MJ: Linezolid resistance in a clinical isolate of Staphylococcus aureus. Lancet 2001;358:207–208.
  9. Johnson AP, Tysall L, Stockdale MW, Woodford N, Kaufmann ME, Warner M, Livermore DM, Asboth F, Allerberger FJ: Emerging linezolid-resistant Enterococcus faecalis and Enterococcus faecium isolated from two Austrian patients in the same intensive care unit. Eur J Clin Microbiol Infect Dis 2002;21:751–754.
  10. Jones RN, Kohno S, Ono Y, Ross JE, Yanagihara K: ZAAPS International Surveillance Program (2007) for linezolid resistance: results from 5,591 Gram-positive clinical isolates in 23 countries. Diagn Microbiol Infect Dis 2009;64:191–201.
  11. Phillips OA, Udo EE, Ali AAM, Al-Hassawi N: Synthesis and antibacterial activity of 5-substituted oxazolidinones. Bioorg Med Chem 2003;11:35–41.
  12. Phillips OA, Udo EE, Ali AAM, Samuel SM: Synthesis and antibacterial activity of new N-linked 5-triazolylmethyl oxazolidinones. Bioorg Med Chem 2005;13:4113–4123.
  13. Phillips OA, Udo EE, Ali AAM, Samuel SM: Structure-antibacterial activity of arylcarbonyl- and arylsulfonyl-piperazine 5-triazolylmethyl oxazolidinones. Eur Med Chem 2007;42:214–225.
  14. Phillips OA, Udo EE, AbdelHamid ME, Varghese R: Synthesis and antibacterial activity of novel 5-(4-methyl-1H-1,2,3-triazole)methyl oxazolidinones. Eur Med Chem 2009;44:3217–3227.
  15. Reck F, Zhou F, Girardot M, Kern G, Eyermann CJ, Hales NJ, Ramsay RR, Gravestock MB: Identification of 4-substituted 1,2,3-triazoles as novel oxazolidinone antibacterial agents with reduced activity against monoamine oxidase A. J Med Chem 2005;48:499–506.
  16. Hauck SI, Cederberg C, Doucette A, Grosser L, Hales NJ, Poon G, Gravestock MB: New carbon-linked azole oxazolidinones with improved potency and pharmacokinetics. Bioorg Med Chem Lett 2007;17:337–340.
  17. Phillips OA, Abdel-Hamid ME, Al-Hassawi N: Determination of linezolid in human plasma by LC-MS-MS. Analyst 2001;126:609–614.
  18. Slatter JG, Stalker DJ, Feenstra KL, Welshman IR, Bruss JB, Sama JP, Johnson MG, Sanders PE, Hauer MJ, Fagerness PE, Stryd RP, Peng GW, Shobe EM: Pharmacokinetics, metabolism, and excretion of linezolid following an oral dose of [14C] linezolid to healthy human subjects. Drug Metab Dispos 2001;29:1136–1145.
  19. Ji HY, Lee HW, Chang SG, Lee JJ, Rhee JK, Kim WB, Lee HS: Liquid chromatography-tandem mass spectrometry for the determination of a new oxazolidinone antibiotic DA-7867 in human plasma. Biomed Chromatogr 2004;18:86–89.
  20. Phillips OA, Abdel-Hamid ME: Determination of novel triazolylmethyl oxazolidinone concentrations in human plasma by APCI-LC-MS: application to stability study. J Pharmaceut Sci 2008;11:22s–31s.
  21. Greene TW, Wuts PGM: Protective Groups in Organic Synthesis, ed 3. New York, Wiley, 1999, chapt 7, pp 503–550.

 goto top of outline Author Contacts

Oludotun A. Phillips
Department of Pharmaceutical Chemistry, Faculty of Pharmacy
Kuwait University, PO Box 24923
Safat 13110 (Kuwait)
Tel. +965 2498 6070, Fax +965 2534 2807, E-Mail dphillips@hsc.edu.kw


 goto top of outline Article Information

Received: October 11, 2009
Accepted: April 13, 2010
Published online: December 13, 2010
Number of Print Pages : 9
Number of Figures : 5, Number of Tables : 3, Number of References : 21


 goto top of outline Publication Details

Medical Principles and Practice (International Journal of the Kuwait University Health Sciences Centre)

Vol. 20, No. 1, Year 2011 (Cover Date: December 2010)

Journal Editor: Owunwanne A. (Kuwait)
ISSN: 1011-7571 (Print), eISSN: 1423-0151 (Online)

For additional information: http://www.karger.com/MPP


Open Access License / Drug Dosage / Disclaimer

Open Access License: This is an Open Access article licensed under the terms of the Creative Commons Attribution-NonCommercial 3.0 Unported license (CC BY-NC) (www.karger.com/OA-license), applicable to the online version of the article only. Distribution permitted for non-commercial purposes only.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Abstract

Objectives: To evaluate the stability of 12 triazolyl oxazolidinone (TOZ) derivatives in simulated gastric and intestinal fluids as well as in human plasma at 37 ± 1°C. Materials and Methods: A stability-indicating high-performance liquid chromatography (HPLC) procedure with a C8 column (250 × 40 mm, 5 µm particle size) and a mobile phase of acetonitrile/H2O (50/50 v/v) at 1.0 ml/min was used. Accelerated stability studies were conducted at 37 ± 1°C in 0.1 M HCl solution as simulated gastric fluid and in phosphate buffer solution (pH about 7.4) as simulated intestinal fluid. The stability of TOZs in human plasma at a simulated biological temperature of 37 ± 1°C was evaluated as well. Results: The stability studies indicated that the examined TOZs were stable in the above media, with the exception of compounds 1a [tert- butyl 4-(4-((R)-5-((1H-1,2,3-triazol-1-yl)methyl)-2-oxooxazolidin-3-yl)-2-fluorophenyl)piperazine-1-carboxylate] and 1b [tert-butyl 4-(2-fluoro-4-((R)-5-((4-methyl-1H-1,2,3-triazol- 1-yl)methyl)-2-oxooxazolidin-3-yl)phenyl) piperazine-1-carboxylate], which underwent degradation in simulated gastric fluid. The degradation kinetics revealed degradation parameters (kdeg, t1/2, t90) of 0.180 h–1, 3.85 h, and 0.58 h for 1a and of 0.184 h–1, 3.76 h and 0.57 h for 1b, respectively. Furthermore, the degradation products were identified by mass-spectrometric analysis at mass-to-charge ratios 347.5 and 361.5, respectively, and proton nuclear magnetic resonance analysis. Conclusion: With the exception of compounds 1a and 1b, the TOZs are stable in simulated gastric and intestinal fluids as well as in human plasma. Being carbamate derivatives, compounds 1a and 1b underwent fast and complete degradation in simulated gastric fluid. The obtained results should be considered for future studies of formulation of structurally related TOZs in oral dosage forms.



 goto top of outline Author Contacts

Oludotun A. Phillips
Department of Pharmaceutical Chemistry, Faculty of Pharmacy
Kuwait University, PO Box 24923
Safat 13110 (Kuwait)
Tel. +965 2498 6070, Fax +965 2534 2807, E-Mail dphillips@hsc.edu.kw


 goto top of outline Article Information

Received: October 11, 2009
Accepted: April 13, 2010
Published online: December 13, 2010
Number of Print Pages : 9
Number of Figures : 5, Number of Tables : 3, Number of References : 21


 goto top of outline Publication Details

Medical Principles and Practice (International Journal of the Kuwait University Health Sciences Centre)

Vol. 20, No. 1, Year 2011 (Cover Date: December 2010)

Journal Editor: Owunwanne A. (Kuwait)
ISSN: 1011-7571 (Print), eISSN: 1423-0151 (Online)

For additional information: http://www.karger.com/MPP


Open Access License / Drug Dosage

Open Access License: This is an Open Access article licensed under the terms of the Creative Commons Attribution-NonCommercial 3.0 Unported license (CC BY-NC) (www.karger.com/OA-license), applicable to the online version of the article only. Distribution permitted for non-commercial purposes only.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Grau S, Rubio-Terrés C: Pharmacoeconomics of linezolid. Expert Opin Pharmacother 2008;9:987–1000.
  2. Drew RH: Emerging options for treatment of invasive, multidrug-resistant Staphylococcus aureus infections. Pharmacotherapy 2007;27:227–249.
  3. Wilcox MH: Update on linezolid: the first oxazolidinone antibiotic. Expert Opin Pharmacother 2005;6:2315–2326.
  4. Moellering RC: Linezolid: the first oxazolidinone antimicrobial. Ann Intern Med 2003;138:135–142.
  5. Bozdogan B, Appelbaum PC: Oxazolidinones: activity, mode of action, and mechanism of resistance. Int J Antimicrob Agents 2004;23:113–119.
  6. Sinclair A, Arnold C, Woodford N: Rapid detection and estimation by pyrosequencing of 23S rRNA genes with a single nucleotide polymorphism conferring linezolid resistance in Enterococci. Antimicrob Agents Chemother 2003;47:3620–3622.
  7. Ippolito JA, Kanyo ZF, Wang D, Franceschi FJ, Moore PB, Steitz TA, Duffy EM: Crystal structure of the oxazolidinone antibiotic linezolid bound to the 50S ribosomal subunit. J Med Chem 2008;51:3353–3356.
  8. Tsiodras S, Gold HS, Sakoulas G, Eliopoulos GM, Wennersten C, Venkataraman L, Moellering RB Jr, Ferraro MJ: Linezolid resistance in a clinical isolate of Staphylococcus aureus. Lancet 2001;358:207–208.
  9. Johnson AP, Tysall L, Stockdale MW, Woodford N, Kaufmann ME, Warner M, Livermore DM, Asboth F, Allerberger FJ: Emerging linezolid-resistant Enterococcus faecalis and Enterococcus faecium isolated from two Austrian patients in the same intensive care unit. Eur J Clin Microbiol Infect Dis 2002;21:751–754.
  10. Jones RN, Kohno S, Ono Y, Ross JE, Yanagihara K: ZAAPS International Surveillance Program (2007) for linezolid resistance: results from 5,591 Gram-positive clinical isolates in 23 countries. Diagn Microbiol Infect Dis 2009;64:191–201.
  11. Phillips OA, Udo EE, Ali AAM, Al-Hassawi N: Synthesis and antibacterial activity of 5-substituted oxazolidinones. Bioorg Med Chem 2003;11:35–41.
  12. Phillips OA, Udo EE, Ali AAM, Samuel SM: Synthesis and antibacterial activity of new N-linked 5-triazolylmethyl oxazolidinones. Bioorg Med Chem 2005;13:4113–4123.
  13. Phillips OA, Udo EE, Ali AAM, Samuel SM: Structure-antibacterial activity of arylcarbonyl- and arylsulfonyl-piperazine 5-triazolylmethyl oxazolidinones. Eur Med Chem 2007;42:214–225.
  14. Phillips OA, Udo EE, AbdelHamid ME, Varghese R: Synthesis and antibacterial activity of novel 5-(4-methyl-1H-1,2,3-triazole)methyl oxazolidinones. Eur Med Chem 2009;44:3217–3227.
  15. Reck F, Zhou F, Girardot M, Kern G, Eyermann CJ, Hales NJ, Ramsay RR, Gravestock MB: Identification of 4-substituted 1,2,3-triazoles as novel oxazolidinone antibacterial agents with reduced activity against monoamine oxidase A. J Med Chem 2005;48:499–506.
  16. Hauck SI, Cederberg C, Doucette A, Grosser L, Hales NJ, Poon G, Gravestock MB: New carbon-linked azole oxazolidinones with improved potency and pharmacokinetics. Bioorg Med Chem Lett 2007;17:337–340.
  17. Phillips OA, Abdel-Hamid ME, Al-Hassawi N: Determination of linezolid in human plasma by LC-MS-MS. Analyst 2001;126:609–614.
  18. Slatter JG, Stalker DJ, Feenstra KL, Welshman IR, Bruss JB, Sama JP, Johnson MG, Sanders PE, Hauer MJ, Fagerness PE, Stryd RP, Peng GW, Shobe EM: Pharmacokinetics, metabolism, and excretion of linezolid following an oral dose of [14C] linezolid to healthy human subjects. Drug Metab Dispos 2001;29:1136–1145.
  19. Ji HY, Lee HW, Chang SG, Lee JJ, Rhee JK, Kim WB, Lee HS: Liquid chromatography-tandem mass spectrometry for the determination of a new oxazolidinone antibiotic DA-7867 in human plasma. Biomed Chromatogr 2004;18:86–89.
  20. Phillips OA, Abdel-Hamid ME: Determination of novel triazolylmethyl oxazolidinone concentrations in human plasma by APCI-LC-MS: application to stability study. J Pharmaceut Sci 2008;11:22s–31s.
  21. Greene TW, Wuts PGM: Protective Groups in Organic Synthesis, ed 3. New York, Wiley, 1999, chapt 7, pp 503–550.