Finite Absorption Time (F.A.T.) Group

The founder of the Laboratory of Biopharmaceutics-Pharmacokinetics at the National and Kapodistrian University of Athens and founder of the PharmaInformatics Unit at ATHENA Research Center Emeritus Professor Panos Macheras has carried out extensive research during his career in Biopharmaceutcis, Pharmacokinetics and Pharmacometrics (see link.springer.com/journal/10928/46/2). For example, the adoption by EMA of the bioequivalence limits for highly variable drugs is associated with his work "On the leveling-off properties of the new bioequivalence limits for highly variable drugs of the EMA guideline. V. Karalis, M. Symillides, P. Macheras, Eur. J. Pharm. Sci. 44, 497-505 (2011) 10.1016/j.ejps.2011.09.008 [PDF].

During the last five years Panos has developed together with Athanasios Tsekouras, Associate Professor, National and Kapodistrian University of Athens, the Finite Absorption Time (F.A.T.) concept. This work leads to a re-writing of oral pharmacokinetics, has applications in PBPK and Pharmacometrics, and has serious implications for bioavailability/bioequivalence and biowaivers issues.

The list of the publications associated with the Finite Absorption Time (F.A.T.) concept is quoted below. These studies unequivocally demonstrate that drugs given orally are absorbed in finite time. In this context, a Physiologically Based Finite Time Pharmacokinetic (PBFTPK) software has been constructed [5]. Interested scientists in academia and industry or postgraduate students can reach Panos Macheras (macheras@pharm.uoa.gr) and/or Athanasios Tsekouras (thanost@chem.uoa.gr) for the analysis of oral data using the PBFTPK software. In addition, scientists from academia and industry and MSc, PhD students can reach us for the regulatory implications of the F.A.T. concept on bioavailability, bioequivalence, biowaivers issues such as, re-analysis of bioavailability/bioequivalence studies, re-construction of the study design in the light of the F.A.T. concept, re-consideration of biowaivers and IVIVC studies.

A book entitled "Revising Oral Pharmacokinetics, Bioavailability and Bioequivalence Based on the Finite Absorption Time Concept" written by P. Macheras and A. A. Tsekouras was published by Springer in 2023. It covers in great detail all models affected by the F.A.T. concept and can be used for teaching purposes.

Further work has been included in two chapters of another book published in 2023: Advances in Pharmacokinetics and Pharmacodynamics P. Macheras, Editor, AAPS - Springer, Cham, DOI: 10.1007/978-3-031-29541-6.

All those interested in the experimental and theoretical analysis of drug absorption phenomena using the F.A.T. concept as well as using the new book for their courses can become members of the Finite Absorption Time-Group (F.A.T.-G) we have created, by sending us email or by filling out the next form.

Last name:
First name:
E-mail address:
Fields of interest:
Biopharmaceutics (BP)
Pharmacokinetics (PK)
Pharmacodynamics (PD)
Pharmacometrics (PM)
Bioavailability (BA)
Bioequivalence (BE)
Physiologically based Pharmacokinetics (PBPK)
Physiologically based Finite Time Pharmacokinetics (PBFTPK)
Finite Absorption Time (FAT)
Dissolution studies (DS)
in vitro - in vivo correlations (IVIVC)
Data fitting (DF)
Data simulation (DS)
Other:

References

  1. On an Unphysical Hypothesis of Bateman Equation and its Implications for Pharmacokinetics
    Panos Macheras
    Pharm. Res. 36, 94 (2019)
    [DOI: 10.1007/s11095-019-2633-4] [PDF]
  2. Revising Pharmacokinetics of Oral Drug Absorption: I Models Based on Biopharmaceutical/Physiological and Finite Absorption Time Concepts
    Panos Macheras, Pavlos Chryssafidis
    Pharm. Res. 37, 187 (2020)
    [DOI: 10.1007/s11095-020-02894-w] [PDF]
    Correction to: Revising Pharmacokinetics of Oral Drug Absorption: I Models Based on Biopharmaceutical/Physiological and Finite Absorption Time Concepts
    Panos Macheras, Pavlos Chryssafidis
    Pharm. Res. 37, 206 (2020)
    [DOI: 10.1007/s11095-020-02935-4] [PDF]
  3. Revising Pharmacokinetics of Oral Drug Absorption: II Bioavailability-Bioequivalence Considerations
    Pavlos Chryssafidis, Athanasios A. Tsekouras, Panos Macheras
    Pharm. Res. 38, 1345-1356 (2021)
    [DOI: 10.1007/s11095-021-03078-w] [PDF]
    Correction to: Revising Pharmacokinetics of Oral Drug Absorption: II Bioavailability-Bioequivalence Considerations
    Pavlos Chryssafidis, Athanasios A. Tsekouras, Panos Macheras
    Pharm. Res. 38, 1633 (2021)
    [DOI: 10.1007/s11095-021-03101-0] [PDF]
  4. Re-examining digoxin bioavailability after half a century: Time for changes in the bioavailability concepts
    Athanasios A. Tsekouras, Panos Macheras
    Pharm. Res. 38, 1635-1638 (2021)
    [DOI: 10.1007/s11095-021-03121-w] [PDF]
    Correction to: Re-examining digoxin bioavailability after half a century: Time for changes in the bioavailability concepts
    Athanasios A. Tsekouras, Panos Macheras
    Pharm. Res. 38, 2185 (2021)
    [DOI: 10.1007/s11095-021-03148-z] [PDF]
  5. Re-writing oral pharmacokinetics using physiologically based finite time pharmacokinetic (PBFTPK) models
    P. Chryssafidis, A. A. Tsekouras, P. Macheras
    Pharm. Res. 39, 691-701 (2022)
    [DOI: 10.1007/s11095-022-03230-0] [PDF]
  6. Columbus' egg: Oral drugs are absorbed in finite time
    P. Macheras, A. A. Tsekouras
    Eur. J. Pharm. Sci. 176, 106265 (2022)
    [DOI: 10.1016/j.ejps.2022.106265] [PDF] [Supplementary Information]
  7. Physiologically based pharmacokinetic models under the prism of the finite absorption time concept
    Di Wu, Athanasios A. Tsekouras, Panos Macheras, Filippos Kesisoglou
    Pharm. Res. 40, 419-429 (2023)
    [DOI: 10.1007/s11095-022-03357-0] [PDF]
  8. The Finite Absorption Time (FAT) Concept en route to PBPK modeling and pharmacometrics
    Athanasios A. Tsekouras, Panos Macheras
    J. Pharmacokin. Pharmacodyn. 50, 5-10 (2023)
    [DOI: 10.1007/s10928-022-09832-w] [PDF]
  9. Re-examining Naloxone Pharmacokinetics After Intranasal and Intramuscular Administration Using the Finite Absorption Time Concept
    Athanasios A. Tsekouras, Panos Macheras
    Eur. J. Drug Metabol. Pharmacokin. 48, 455-462 (2023)
    [DOI: 10.1007/s13318-023-00831-x] [PDF]
  10. Revamping Biopharmaceutics-Pharmacokinetics with Scientific and Regulatory Implications for Oral Drug Absorption
    N. Alimpertis, A. A. Tsekouras, P. Macheras
    Pharm. Res. 40, (2023)
    [DOI: 10.1007/s11095-023-03578-x] [PDF] [Supplementary Information]
  11. IVIVC revised
    N. Alimpertis, A. Simitopoulos, A. A. Tsekouras, P. Macheras
    Pharm. Res. 41, 235-246 (2024)
    [DOI: 10.1007/s11095-024-03653-x] [PDF]
  12. Coupling Drug Dissolution with BCS
    A. Simitopoulos, A. A. Tsekouras, P. Macheras
    Pharm. Res. 41, 481-491 (2024)
    [DOI: 10.1007/s11095-024-03661-x] [PDF]
  13. Application of the Finite Absorption Time (F.A.T.) Concept in the Assessment of Bioequivalence
    A. A. Tsekouras, P. Macheras
    Pharm. Res. 41, 1412-1425 (2024)
    [DOI: 10.1007/s11095-024-03727-w] [PDF]
  14. FDA and EMA Oversight of Disruptive Science on Application of Finite Absorption Time (F.A.T.) Concept in Oral Drug Absorption: Time for Scientific and Regulatory Changes
    E. Toulitsis, A. A. Tsekouras, P. Macheras
    Pharmaceutics 16, 1435 (2024)
    [DOI: 10.3390/pharmaceutics16111435] [PDF] [Supplementary Information]

Related activities

29th PAGE meeting, on-line, in the cloud (2, 3, 6, 7 September 2021)
Satellite webinar 1/9/2021
F.A.T. presentation at ATHENA R.C. on 23/5/2022.
30th PAGE meeting, Ljubljana, Slovenia (28 June - 1 July 2022)
See posters:
IV-01 Nikolaos Alimpertis, Revising the assessment of bioequivalence in the light of finite absorption time (FAT) concept: The axitinib case
IV-16 Pavlos Chryssafidis, Re-writing oral pharmacokinetics using physiologically based finite time pharmacokinetic (PBFTPK) models
Satellite webinar 28/6/2022: From PBPK to PBFTPK (Physiologically Based Finite Time Pharmacokinetic) models organized by ATHENA R.C. REC
EUFEPS Seminar 6 July 2022: From the Finite Absorption Time (FAT) concept to the physiologically based finite time pharmacokinetic (PBFTPK) models
9th BBBB International Conference on Pharmaceutical Sciences, Ljubljana, Slovenia, 15-17/9/2022.
Laszlo Endrenyi's memorial meeting, Athens, Greece (rescheduled for 22 May 2023) [Announcement - Program - Pictures - Recordings] - Endrenyi memorabilia
The 31st PAGE meeting 27-30/6/2023
Pictures from the meeting: Alimpertis talk 1, 2; Panos Macheras addressing questions from the audience, at the ATHENA booth and at the poster session
AAPS 2023 meeting, Orlando, FL, 20-25/10/2023
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Information of interest to PBFTPK users