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Closed-Loop Doluisio (Colon, Small Intestine) and Single-Pass Intestinal Perfusion (Colon, Jejunum) in Rat—Biophysical Model and Predictions Based on Caco-2

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ABSTRACT

Purpose

The effective rat intestinal permeability (P eff ) was deconvolved using a biophysical model based on parameterized paracellular, aqueous boundary layer, transcellular permeabilities, and the villus-fold surface area expansion factor.

Methods

Four types of rat intestinal perfusion data were considered: single-pass intestinal perfusion (SPIP) in the jejunum (n = 40), and colon (n = 15), closed-loop (Doluisio type) in the small intestine (n = 78), and colon (n = 74). Moreover, in vitro Caco-2 permeability values were used to predict rat in vivo values in the rat data studied.

Results

Comparable number of molecules permeate via paracellular water channels as by the lipoidal transcellular route in the SPIP method, although in the closed-loop method, the paracellular route appears dominant in the colon. The aqueous boundary layer thickness in the small intestine is comparable to that found in unstirred in vitro monolayer assays; it is thinner in the colon. The mucosal surface area in anaesthetized rats is 0.96–1.4 times the smooth cylinder calculated value in the colon, and it is 3.1–3.6 times in the small intestine. The paracellular permeability of the intestine appeared to be greater in rat than human, with the colon showing more leakiness (higher P para ) than the small intestine.

Conclusion

Based on log intrinsic permeability values, the correlations between the in vitro and in vivo models ranged from r2 0.82 to 0.92. The SPIP-Doluisio method comparison indicated identical log permeability selectivity trend with negligible bias.

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Abbreviations

ε/δ :

Porosity of paracellular junction pores divided by the rate-limiting paracellular pathlength (cm−1); size-restricted, cation-selective

(ε/δ) 2 :

Secondary porosity-pathlength ratio (cm−1); charge/size nonspecific “free diffusion” term

Δφ :

Electrical potential drop (mV) across the electric field created by negatively-charged residues lining the junctional pores

ABL:

Aqueous boundary layer—adjacent to the surface of a cell monolayer or luminal side of intestine

A SS :

“smooth surface” area in intestinal segment (= 2π R e ·L) of length L and effective radius R e (cm2)

A eff :

Effective surface area (= k VF ·A SS ) of luminal absorptive surface in the intestine (cm2)

Caco-2:

Human cancer of the colon epithelial cell line

D aq :

Aqueous diffusivity (cm·s−1)

DRW:

Dynamic range window: observable permeability, with P ABL as top limit and P para as bottom limit

E(Δφ):

Function due to electrical potential drop across the cell junction (dimensionless)

f(0), f(+), f(−) :

Concentration fraction in uncharged, positively-, and negatively-charged forms, respectively

F(r HYD /R):

Renkin molecular sieving function, dimensionless fraction in the range of 0 to 1

h ABL :

ABL thickness (μm)

k VF :

Villus-fold surface area expansion factor (dimensionless)

MDCK:

Madin-Darby Canine Kidney epithelial cell line

P ABL :

ABL permeability (cm·s−1)

P app :

In vitro apparent permeability of an epithelial cell monolayer, e.g., Caco-2 (cm·s−1); can be pH dependent

P C :

Lipoidal transcellular permeability (cm·s−1); can be pH dependent

P eff :

Effective intestinal permeability (cm·s−1) in rat single-pass intestinal perfusion (SPIP) or closed-loop Doluisio (CLD) method; can be pH dependent

P 0 :

Intrinsic permeability of uncharged permeant (cm·s−1); pH independent. P 0 may be calculated from the plot of log P app vs. pH, as suggested by Fig. 2. However, if only a single P app -pH point is available, the calculation of P 0 is more complicated, as described in “Material and Methods” section, and further detailed in Appendix.

P para :

Paracellular permeability (cm·s−1); can be slightly pH dependent

R :

Cell junction pore radius (Å)

R e :

Effective radius of the rat intestinal segment (cm)

r HYD :

Hydrodynamic molecular radius (Å)

References

  1. Lennernas H. Intestinal permeability and its relevance for absorption and elimination. Xenobiotica. 2007;37(10–11):1015–51.

    Article  CAS  PubMed  Google Scholar 

  2. Lennernas H. Animal data: the contributions of the Ussing Chamber and perfusion systems to predicting human oral drug delivery in vivo. Adv Drug Deliv Rev. 2007;59(11):1103–20.

    Article  PubMed  Google Scholar 

  3. Dahan A, Amidon GL. Segmental dependent transport of low permeability compounds along the small intestine due to P-glycoprotein: the role of efflux transport in the oral absorption of BCS class III drugs. Mol Pharm. 2009;6(1):19–28.

    Article  CAS  PubMed  Google Scholar 

  4. Dahan A, Miller JM, Amidon GL. Prediction of solubility and permeability class membership: provisional BCS classification of the world's top oral drugs. AAPS J. 2009;11(4):740–6.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Fagerholm U, Johansson M, Lennernas H. Comparison between permeability coefficients in rat and human jejunum. Pharm Res. 1996;13(9):1336–42.

    Article  CAS  PubMed  Google Scholar 

  6. Kim JS, Mitchell S, Kijek P, Tsume Y, Hilfinger J, Amidon GL. The suitability of an in situ perfusion model for permeability determinations: utility for BCS class I biowaiver requests. Mol Pharm. 2006;3(6):686–94.

    Article  CAS  PubMed  Google Scholar 

  7. Cao X, Gibbs ST, Fang L, Miller HA, Landowski CP, Shin HC, et al. Why is it challenging to predict intestinal drug absorption and oral bioavailability in human using rat model. Pharm Res. 2006;23(8):1675–86.

    Article  CAS  PubMed  Google Scholar 

  8. Lennernas H. Human intestinal permeability. J Pharm Sci. 1998;87(4):403–10.

    Article  CAS  PubMed  Google Scholar 

  9. Lennernas H. Human in vivo regional intestinal permeability: importance for pharmaceutical drug development. Mol Pharm. 2014;11(1):12–23.

    Article  PubMed  Google Scholar 

  10. Lennernas H. Regional intestinal drug permeation: biopharmaceutics and drug development. Eur J Pharm Sci. 2014;57:333–41.

    Article  CAS  PubMed  Google Scholar 

  11. Dahan A, West BT, Amidon GL. Segmental-dependent membrane permeability along the intestine following oral drug administration: Evaluation of a triple single-pass intestinal perfusion (TSPIP) approach in the rat. Eur J Pharm Sci. 2009;36(2–3):320–9.

    Article  CAS  PubMed  Google Scholar 

  12. Dahan A, Miller JM, Hilfinger JM, Yamashita S, Yu LX, Lennernas H, et al. High-permeability criterion for BCS classification: segmental/pH dependent permeability considerations. Mol Pharm. 2010;7(5):1827–34.

    Article  CAS  PubMed  Google Scholar 

  13. Fairstein M, Swissa R, Dahan A. Regional-dependent intestinal permeability and BCS classification: elucidation of pH-related complexity in rats using pseudoephedrine. AAPS J. 2013;15(2):589–97.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Lozoya-Agullo I, Zur M, Wolk O, Beig A, Gonzalez-Alvarez I, Gonzalez-Alvarez M, et al. In-situ intestinal rat perfusions for human Fabs prediction and BCS permeability class determination: Investigation of the single-pass vs. the Doluisio experimental approaches. Int J Pharm. 2015;480(1–2):1–7.

    Article  CAS  PubMed  Google Scholar 

  15. Lozoya-Agullo I, Zur M, Beig A, Fine N, Cohen Y, Gonzalez-Alvarez M, et al. Segmental-dependent permeability throughout the small intestine following oral drug administration: single-pass vs. Doluisio approach to in-situ rat perfusion. Int J Pharm. 2016;515(1–2):201–208. https://doi.org/10.1016/j.ijpharm.2016.09.061.

  16. Amidon GL, Sinko PJ, Fleisher D. Estimating human oral fraction dose absorbed: a correlation using rat intestinal membrane permeability for passive and carrier-mediated compounds. Pharm Res. 1988;5(10):651–4.

    Article  CAS  PubMed  Google Scholar 

  17. Lennernas H, Crison JR, Amidon GL. Permeability and clearance views of drug absorption: a commentary. J Pharmacokinet Biopharm. 1995;23(3):333–43.

    Article  CAS  PubMed  Google Scholar 

  18. Doluisio JT, Billups NF, Dittert LW, Sugita ET, Swintosky JV. Drug absorption. I. An in situ rat gut technique yielding realistic absorption rates. J Pharm Sci. 1969;58(10):1196–200.

    Article  CAS  PubMed  Google Scholar 

  19. Doluisio JT, Tan GH, Billups NF, Diamond L. Drug absorption. II. Effect of fasting on intestinal drug absorption. J Pharm Sci. 1969;58(10):1200–2.

    Article  CAS  PubMed  Google Scholar 

  20. Dahan A, Amidon GL. Grapefruit juice and its constituents augment colchicine intestinal absorption: potential hazardous interaction and the role of p-glycoprotein. Pharm Res. 2009;26(4):883–92.

    Article  CAS  PubMed  Google Scholar 

  21. Fernandez-Teruel C, Gonzalez-Alvarez I, Casabo VG, Ruiz-Garcia A, Bermejo M. Kinetic modelling of the intestinal transport of sarafloxacin. Studies in situ in rat and in vitro in Caco-2 cells. J Drug Target. 2005;13(3):199–212.

    Article  CAS  PubMed  Google Scholar 

  22. Gonzalez-Alvarez I, Fernandez-Teruel C, Casabo-Alos VG, Garrigues TM, Polli JE, Ruiz-Garcia A, et al. In situ kinetic modelling of intestinal efflux in rats: functional characterization of segmental differences and correlation with in vitro results. Biopharm Drug Dispos. 2007;28(5):229–39.

    Article  CAS  PubMed  Google Scholar 

  23. Merino M, Peris-Ribera JE, Torres-Molina F, Sanchez-Pico A, Garcia-Carbonell MC, Casabo VG. Evidence of a specialized transport mechanism for the intestinal absorption of baclofen. Biopharm Drug Dispos. 1989;10(3):279–97.

    Article  CAS  PubMed  Google Scholar 

  24. Zur M, Hanson AS, Dahan A. The complexity of intestinal permeability: Assigning the correct BCS classification through careful data interpretation. Eur J Pharm Sci. 2014;61:11–7.

    Article  CAS  PubMed  Google Scholar 

  25. Ungell AL, Nylander S, Bergstrand S, Sjoberg A, Lennernas H. Membrane transport of drugs in different regions of the intestinal tract of the rat. J Pharm Sci. 1998;87(3):360–6.

    Article  CAS  PubMed  Google Scholar 

  26. DeSesso JM, Jacobson CF. Anatomical and physiological parameters affecting gastrointestinal absorption in humans and rats. Food Chem Toxicol. 2001;39(3):209–28.

    Article  CAS  PubMed  Google Scholar 

  27. Avdeef A, Tam KY. How well can the Caco-2/Madin-Darby canine kidney models predict effective human jejunal permeability? J Med Chem. 2010;53(9):3566–84.

    Article  CAS  PubMed  Google Scholar 

  28. Avdeef A. How well can in vitro brain microcapillary endothelial cell models predict rodent in vivo blood-brain barrier permeability? Eur J Pharm Sci. 2011;43(3):109–24.

    Article  CAS  PubMed  Google Scholar 

  29. Gutknecht J, Tosteson DC. Diffusion of weak acids across lipid bilayer membranes: effects of chemical reactions in the unstirred layers. Science. 1973;182(4118):1258–61.

    Article  CAS  PubMed  Google Scholar 

  30. Barry PH, Diamond JM. Effects of unstirred layers on membrane phenomena. Physiol Rev. 1984;64(3):763–872.

    Article  CAS  PubMed  Google Scholar 

  31. Youdim KA, Avdeef A, Abbott NJ. In vitro trans-monolayer permeability calculations: often forgotten assumptions. Drug Discov Today. 2003;8(21):997–1003.

    Article  CAS  PubMed  Google Scholar 

  32. Korjamo T, Heikkinen AT, Waltari P, Monkkonen J. The asymmetry of the unstirred water layer in permeability experiments. Pharm Res. 2008;25(7):1714–22.

    Article  CAS  PubMed  Google Scholar 

  33. Karlsson JP, Artursson P. A method for the determination of cellular permeability coefficients and aqueous boundary layer thickness in monolayers of intestinal epithelial (Caco-2) cells grown in permeable filter chambers. Int J Pharm. 1991;7:55–64.

    Article  Google Scholar 

  34. Avdeef A, Nielsen PE, Tsinman O. PAMPA--a drug absorption in vitro model 11. Matching the in vivo unstirred water layer thickness by individual-well stirring in microtitre plates. Eur J Pharm Sci. 2004;22(5):365–74.

    CAS  PubMed  Google Scholar 

  35. Avdeef A, Artursson P, Neuhoff S, Lazorova L, Grasjo J, Tavelin S. Caco-2 permeability of weakly basic drugs predicted with the double-sink PAMPA pKa(flux) method. Eur J Pharm Sci. 2005;24(4):333–49.

    Article  CAS  PubMed  Google Scholar 

  36. Katneni K, Charman SA, Porter CJ. An evaluation of the relative roles of the unstirred water layer and receptor sink in limiting the in-vitro intestinal permeability of drug compounds of varying lipophilicity. J Pharm Pharmacol. 2008;60(10):1311–9.

    Article  CAS  PubMed  Google Scholar 

  37. Velicky M, Bradley DF, Tam KY, Dryfe RA. In situ artificial membrane permeation assay under hydrodynamic control: permeability-pH profiles of warfarin and verapamil. Pharm Res. 2010;27(8):1644–58.

    Article  CAS  PubMed  Google Scholar 

  38. Wilson FA, Dietschy JM. The intestinal unstirred layer: its surface area and effect on active transport kinetics. Biochim Biophys Acta. 1974;363(1):112–26.

    Article  CAS  PubMed  Google Scholar 

  39. Balakrishnan A, Hussainzada N, Gonzalez P, Bermejo M, Swaan PW, Polli JE. Bias in estimation of transporter kinetic parameters from overexpression systems: Interplay of transporter expression level and substrate affinity. J Pharmacol Exp Ther. 2007;320(1):133–44.

    Article  CAS  PubMed  Google Scholar 

  40. Naruhashi K, Tamai I, Li Q, Sai Y, Tsuji A. Experimental demonstration of the unstirred water layer effect on drug transport in Caco-2 cells. J Pharm Sci. 2003;92(7):1502–8.

    Article  CAS  PubMed  Google Scholar 

  41. Hidalgo IJ, Hillgren KM, Grass GM, Borchardt RT. Characterization of the unstirred water layer in Caco-2 cell monolayers using a novel diffusion apparatus. Pharm Res. 1991;8(2):222–7.

    Article  CAS  PubMed  Google Scholar 

  42. Adson A, Raub TJ, Burton PS, Barsuhn CL, Hilgers AR, Audus KL, et al. Quantitative approaches to delineate paracellular diffusion in cultured epithelial cell monolayers. J Pharm Sci. 1994;83(11):1529–36.

    Article  CAS  PubMed  Google Scholar 

  43. Madara JL, Pappenheimer JR. Structural basis for physiological regulation of paracellular pathways in intestinal epithelia. J Membr Biol. 1987;100(2):149–64.

    Article  CAS  PubMed  Google Scholar 

  44. Avdeef A. Leakiness and size exclusion of paracellular channels in cultured epithelial cell monolayers-interlaboratory comparison. Pharm Res. 2010;27(3):480–9.

    Article  CAS  PubMed  Google Scholar 

  45. Oliver RE, Jones AF, Rowland M. What surface of the intestinal epithelium is effectively available to permeating drugs? J Pharm Sci. 1998;87(5):634–9.

    Article  CAS  PubMed  Google Scholar 

  46. Garberg P, Ball M, Borg N, Cecchelli R, Fenart L, Hurst RD, et al. In vitro models for the blood-brain barrier. Toxicol In Vitro. 2005;19(3):299–334.

    Article  CAS  PubMed  Google Scholar 

  47. Sun N, Avdeef A. Biorelevant pK(a) (37 degrees C) predicted from the 2D structure of the molecule and its pK(a) at 25 degrees C. J Pharm Biomed Anal. 2011;56(2):173–82.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Avdeef A. Absorption and drug development. Hoboken: Wiley-Interscience; 2012.

    Book  Google Scholar 

  49. Martin-Villodre A, Pla-Delfina JM, Moreno J, Perez-Buendia D, Miralles J, Collado EF, et al. Studies on the reliability of a bihyperbolic functional absorption model. I. Ring-substituted anilines. J Pharmacokinet Biopharm. 1986;14(6):615–33.

    Article  CAS  PubMed  Google Scholar 

  50. Castañer-Codes A, Merino M, Martin-Villodre A, Pla-Delfina JM. Absorción intestinal de la cefalosporinas orales en la rata: mecanismos de transporte I. Planteamiento y detección de no linealidad. Rev Farmacol Clín Exp. 1986;3:295–300.

    Google Scholar 

  51. Casabo VG, Nunez-Benito E, Martinez-Coscolla A, Miralles-Loyola E, Martin-Villodre A, Pla-Delfina JM. Studies on the reliability of a bihyperbolic functional absorption model. II. Phenylalkylamines. J Pharmacokinet Biopharm. 1987;15(6):633–43.

    Article  CAS  PubMed  Google Scholar 

  52. Diaz-Carbonell JV, Herraez M, Garcia-Estruch MJ, Del Campo A, Casabo VG, Pla-Delfina JM. Estudios sobre la aplicabilidad del modelo bihiperbólico de absorción. I. Anilidas y xilididas anestésicas en intestino delgado de rata. Cienc Ind Farm. 1987;6:232–7.

    CAS  Google Scholar 

  53. Diaz-Carbonell JV, Del Campo A, Casabo VG, Martín-Villorde A. Estudios sobre la aplicabilidad del modelo bihiperbólico de absorción.II. Anilidas y xilididas anestésicas en colon de rata. Cienc Ind Farm. 1987;6:238–41.

    CAS  Google Scholar 

  54. Collado EF, Fabra-Campos S, Peris-Ribera JE, Casabo VG, Martin-Villodre A, Pla-Delfina JM. Absorption-partition relationships for true homologous series of xenobiotics as a possible approach to study mechanisms of surfactants in absorptio. II Aromatic. Int J Pharm. 1988;44:187–96.

    Article  CAS  Google Scholar 

  55. Sanchez-Pico A, Peris-Ribera JE, Toledano C, Torres-Molina F, Casabo VG, Martin-Villodre A, et al. Non-linear intestinal absorption kinetics of cefadroxil in the rat. J Pharm Pharmacol. 1989;41(3):179–85.

    Article  CAS  PubMed  Google Scholar 

  56. Fabra-Campos S, Real JV, Gomez-Meseguer V, Merino M, Pla-Delfina JM. Biophysical absorption models for phenyl-alkyl acids in the absence and in the presence of surfactants. Studies in the rat small intestine. Eur J Drug Metab Pharmacokinet. 1991;3:32–42.

    Google Scholar 

  57. Miralles-Loyola E, Gomez-Perez B, Casabo VG, Martin-Villodre A, Martinez-Coscolla A, Pla-Delfina JM. Absorption mechanisms of secondary aliphatic amines in rat colon and small intestine. Eur J Drug Metab Pharmacokinet. 1991;Spec No 3:24–31.

  58. Garrigues TM, Segura-Bono MJ, Bermejo MV, Merino V, Plá-Delfina JM. Compared effects of synthetic and natural bile acid surfactants on xenobiotics absorption: II. Studies with sodium glycolate to confirm a hypothesis. Int J Pharm. 1994;101:209–17.

    Article  CAS  Google Scholar 

  59. Lozoya-Agullo I, Gonzalez-Alvarez I, Gonzalez-Alvarez M, Merino-Sanjuan M, Bermejo M. In Situ Perfusion Model in Rat Colon for Drug Absorption Studies: Comparison with Small Intestine and Caco-2 Cell Model. J Pharm Sci. 2015;104(9):3136–45.

    Article  CAS  PubMed  Google Scholar 

  60. Fernandez-Teruel C, Gonzalez-Alvarez I, Casabo VG, Ruiz-Garcia A, Bermejo M. Kinetic modelling of the intestinal transport of sarafloxacin. Studies in situ in rat and in vitro in Caco-2 cells. J Drug Target. 2005;13(3):199–212.

    Article  CAS  PubMed  Google Scholar 

  61. Gonzalez-Alvarez I, Fernandez-Teruel C, Garrigues TM, Casabo VG, Ruiz-Garcia A, Bermejo M. Kinetic modelling of passive transport and active efflux of a fluoroquinolone across Caco-2 cells using a compartmental approach in NONMEM. Xenobiotica. 2005;35(12):1067–88.

    Article  CAS  PubMed  Google Scholar 

  62. Tugcu-Demiroz F, Gonzalez-Alvarez I, Gonzalez-Alvarez M, Bermejo M. Validation of phenol red versus gravimetric method for water reabsorption correction and study of gender differences in Doluisio's absorption technique. Eur J Pharm Sci. 2014;62:105–10.

    Article  CAS  PubMed  Google Scholar 

  63. Beig A, Miller JM, Dahan A. Accounting for the solubility-permeability interplay in oral formulation development for poor water solubility drugs: the effect of PEG-400 on carbamazepine absorption. Eur J Pharm Biopharm. 2012;81(2):386–91.

    Article  CAS  PubMed  Google Scholar 

  64. Dahan A, Amidon GL. MRP2 mediated drug-drug interaction: indomethacin increases sulfasalazine absorption in the small intestine, potentially decreasing its colonic targeting. Int J Pharm. 2010;386(1–2):216–20.

    Article  CAS  PubMed  Google Scholar 

  65. Tugcu-Demiroz F, Gonzalez-Alvarez I, Gonzalez-Alvarez M, Bermejo M. Validation of phenol red versus gravimetric method for water reabsorption correction and study of gender differences in Doluisio's absorption technique. Eur J Pharm Sci. 2014;62:105–10.

    Article  CAS  PubMed  Google Scholar 

  66. Beig A, Lindley D, Miller JM, Agbaria R, Dahan A. Hydrotropic Solubilization of Lipophilic Drugs for Oral Delivery: The Effects of Urea and Nicotinamide on Carbamazepine Solubility-Permeability Interplay. Front Pharmacol. 2016;7:379.

    Article  PubMed  PubMed Central  Google Scholar 

  67. Beig A, Agbaria R, Dahan A. The use of captisol (SBE7-beta-CD) in oral solubility-enabling formulations: Comparison to HPbetaCD and the solubility-permeability interplay. Eur J Pharm Sci. 2015;77:73–8.

    Article  CAS  PubMed  Google Scholar 

  68. Masaoka Y, Tanaka Y, Kataoka M, Sakuma S, Yamashita S. Site of drug absorption after oral administration: assessment of membrane permeability and luminal concentration of drugs in each segment of gastrointestinal tract. Eur J Pharm Sci. 2006;29(3–4):240–50.

    Article  CAS  PubMed  Google Scholar 

  69. Collett A, Walker D, Sims E, He YL, Speers P, Ayrton J, et al. Influence of morphometric factors on quantitation of paracellular permeability of intestinal epithelia in vitro. Pharm Res. 1997;14(6):767–73.

    Article  CAS  PubMed  Google Scholar 

  70. Mayhew TM. A geometric model for estimating villous surface area in rat small bowel is justified by unbiased estimates obtained using vertical sections. J Anat. 1988;161:187–93.

    CAS  PubMed  PubMed Central  Google Scholar 

  71. Avdeef A, Sun N. A new in situ brain perfusion flow correction method for lipophilic drugs based on the pH-dependent Crone-Renkin equation. Pharm Res. 2011;28(3):517–30.

    Article  CAS  PubMed  Google Scholar 

  72. Hebden JM, Wilson CG, Spiller RC, Gilchrist PJ, Blackshaw E, Frier ME, et al. Regional differences in quinine absorption from the undisturbed human colon assessed using a timed release delivery system. Pharm Res. 1999;16(7):1087–92.

    Article  CAS  PubMed  Google Scholar 

  73. Rozehnal V, Nakai D, Hoepner U, Fischer T, Kamiyama E, Takahashi M, et al. Human small intestinal and colonic tissue mounted in the Ussing chamber as a tool for characterizing the intestinal absorption of drugs. Eur J Pharm Sci. 2012;46(5):367–73.

    Article  CAS  PubMed  Google Scholar 

  74. Sjoberg A, Lutz M, Tannergren C, Wingolf C, Borde A, Ungell AL. Comprehensive study on regional human intestinal permeability and prediction of fraction absorbed of drugs using the Ussing chamber technique. Eur J Pharm Sci. 2013;48(1–2):166–80.

    Article  PubMed  Google Scholar 

  75. Fagerholm U, Lennernas H. Experimental estimation of the effective unstirred water layer thickness in the human jejunum, and its importance in oral drug absorption. Eur J Pharm Sci. 1995;3:247–53.

    Article  CAS  Google Scholar 

  76. Bermejo M, Avdeef A, Ruiz A, Nalda R, Ruell JA, Tsinman O, et al. PAMPA--a drug absorption in vitro model 7. Comparing rat in situ, Caco-2, and PAMPA permeability of fluoroquinolones. Eur J Pharm Sci. 2004;21(4):429–41.

    Article  CAS  PubMed  Google Scholar 

  77. Ho NFH, Raub TJ, Burton PS, Barsuhn CL, Adson A, Audus KL, et al. Quantitative approaches to delineate passive transport mechanisms in cell culture monolayers. In: Amidon GL, Lee PI, Topp EM, editors. Transport processes in pharmaceutical systems. New York: Marcel Dekker; 2000. p. 219–316.

    Google Scholar 

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Corresponding author

Correspondence to Marival Bermejo.

Additional information

Isabel Lozoya-Agullo and Isabel Gonzalez-Alvarez should be considered as joint first co-authors.

Chemical compounds studied in this article: Acetaminophen (PubChem CID:1983); Antipyrine (PubChem CID:2206); Atenolol (PubChem CID:2249); Caffeine (PubChem CID:2519); Carbamazepine (PubChem CID:2554); Cimetidine (PubChem CID:2756); Codeine (PubChem CID: 5284371); Colchicine (PubChem CID:6167); Digoxin (PubChem CID: 2724385); Furosemide (PubChem CID:3440); Hydrocortisone (PubChem CID:5754); Ibuprofen (PubChem CID:3672); Metformin (PubChem CID:4091); Metoprolol (PubChem CID: 4171); Pravastatin (PubChem CID: 54687).

Appendix. Computational Method—Permeability Model

Appendix. Computational Method—Permeability Model

Computational Method—Multi-Peff Group Values Used to Determine Rat DRW Parameters

The model used here begins with the deconvolution of rat intestinal P eff , measured at a particular physiological pH (ideally near the microclimate value), into its three effective components: P eff ABL, P eff trans, and P eff para (ABL, transcellular, and paracellular permeability, respectively). All the P eff values for a particular data type (segment: colon/small intestine; method: SPIP/CLD,) are pooled into a single group nonlinear regression analysis to determine a series of parameters (see below) that define the ABL and paracellular limits (cf. Fig. 2) of the dynamic range window (DRW) for the particular data type.

Since each P eff is a composite of ABL/paracellular, and transcellular contributions, it is necessary to remove the latter (transcellular) part, so as to focus just on the ABL and paracellular components which define the DRW limits. This can be accomplished by employing the apparent octanol-water partition coefficient, D OCT , and making the approximation P eff trans = a + b log D OCT , with the constants a and b determined by regression analysis, along with all the other parameters defining the DRW limits (44). Alternatively, in place of D OCT , one could use the P C derived from Caco-2 P app values measured as a function of pH (with P C determined by the pK a FLUX method, as described by Avdeef et al.(35). This second approach was used in the analysis of the DRW limits of the human jejunum permeability (27). It was decided also to use the Caco-2 approximation in the present study.

The equation to deconvolve the three components of effective permeability may be stated as

$$ \frac{1}{P_{eff}}\kern0.5em =\left(\frac{1}{P_{eff}^{ABL}}\kern0.5em +\kern0.5em \frac{1}{P_{eff}^{trans}+{P}_{eff}^{para}}\right)\kern0.5em =\kern1em \frac{1}{k_{VF}}\kern0.5em \cdot \left(\frac{h_{ABL}}{D_{aq}}\kern0.5em +\kern0.5em \frac{1}{P_C+{P}_{para}}\right) $$
(4)

It is assumed that P eff trans in the rat intestine can be approximated using the P C values derived from Caco-2 measurements: P eff trans ≈ k VF ·P C Caco-2. It is assumed that P eff ABL = k VF ·D aq / h ABL , where D aq is the aqueous diffusivity of the molecule and h ABL is the ABL thickness (with reference to the actual surface area, i.e., smooth cylinder value multiplied by k VF ) in the perfusion experiment. Values of D aq (cm2·s−1) at 37°C were empirically estimated from the molecular weight, MW, as

$$ {D}_{aq}=0.991\times {10}^{-4}{\mathrm{MW}}^{-0.453} $$
(5)

which was derived from the analysis of mostly drug-like molecules (44). The thickness of the physical boundary layer, h ABL , depends on the effective agitation level in the perfusion experiment, which is expected to depend on flow rate used and animal handling. For in vitro (microtitre plate) methods, typical values are about 1500–2500 μm in unstirred solutions, and about 150 μm in solutions stirred at 450 RPM (rev·min−1).

P C represents the transcellular permeability contribution, associated with cell membranes (apical, basolateral and cytosol organelle) and any contributions from CM processes. For a molecule with a single ionizable group (ionization constant, pK a ), P C is defined by a sigmoidal function, as shown in Fig. 2 by the solid curve:

$$ {P}_C=\frac{P_0}{10^{\pm \left( pH-{pK}_a\right)}+1}+\frac{P_i}{10^{\pm \left({pK}_a- pH\right)}+1}+\cdots $$
(6)

where the ‘±’ is ‘+’ for acids and ‘-’ is for bases. The maximum possible value of P C is the permeability of the neutral species, P 0 ; the minimum possible P C value is the permeability of the ionized species, P i (most likely effected by CM transport). Figure 2 summarizes the relationship between these components of permeability.

P para can estimated from the differential flux equation describing size- and charge-restricted diffusion through a cylindrical channel containing charged groups, under sink boundary condition (42,77). Avdeef et al. (27) extended the model to include two populations of junctional pores: (i) high-capacity ε/δ, size-restricted and cation-selective pathways, and (ii) secondary (ε/δ) 2 low-capacity, “free diffusion” pathways independent on size and charge. The dual-pore population paracellular equation use in this study is

$$ {P}_{para}\kern0.5em =\frac{\varepsilon }{\delta}\cdot {D}_{aq}\cdot F\left(\frac{r_{HYD}}{R}\right)\cdot E\left(\Delta \phi \right)\kern0.5em +\kern0.5em {\left(\frac{\varepsilon }{\delta}\right)}_2\cdot {D}_{aq} $$
(7)

where most of the terms have been defined already (cf., Abbreviations). F(r HYD /R) is the Renkin hydrodynamic sieving function for cylindrical water channels, with values ranging from 0 to 1, defined as a function of molecular hydrodynamic radii (r HYD ) and pore radii (R), both usually expressed in Å units,

$$ F\left(\frac{r_{HYD}}{R}\right)={\left[1-\left(\frac{r_{HYD}}{R}\right)\right]}^2\cdot \left[1-2.104\left(\frac{r_{HYD}}{R}\right)+2.09{\left(\frac{r_{HYD}}{R}\right)}^3-0.95{\left(\frac{r_{HYD}}{R}\right)}^5\right] $$
(8)

Values of r HYD (Å) were estimated from the Sutherland-Stokes-Einstein spherical-particle empirical Eq. (44)

$$ {r}_{HYD}=\left(0.92+\frac{21.8}{MW}\right)\cdot \frac{10^8{k}_BT}{6\pi\;\eta\;{D}_{aq}} $$
(9)

where kB = Boltzmann constant, T = absolute temperature, and η = solvent kinematic viscosity (0.00696 cm2·s−1, 37°C).

The E(Δφ) term in Eq. 7 is a function of the potential drop, Δφ, across the electric field created by negatively-charged residues lining the junctional pores (42,77),

$$ E\left(\Delta \phi \right)={f}_{(0)}+{f}_{\left(+\right)}\cdot \frac{\kappa \cdot \left|\Delta \phi \right|}{1-{e}^{-\kappa \cdot \left|\Delta \phi \right|}}+{f}_{\left(-\right)}\cdot \frac{\kappa \cdot \left|\Delta \phi \right|}{e^{+\kappa \cdot \left|\Delta \phi \right|}-1} $$
(10)

where f (0) , f (+) , and f (−) are the concentration fractions of the molecule in the uncharged, cationic, and anionic forms, respectively. The constant, κ = (Ғ /NAkBT) = 0.037414 mV−1 at 37°C, where Ғ is the Faraday constant, and other symbols have their usual meaning. The average Δφ of −43 mV, from many Caco-2 studies. For very large channels (r < < R) or for channels not lined with a high charge density, E(Δφ) ~ 1.

In the case of very leaky cell junctions (R > 20 Å), it may not be possible to determine all of the parameters in Eq. (7). A simplified “free diffusion” form may be used.

$$ {P}_{para}\approx {\left(\frac{\varepsilon }{\delta}\right)}_2\cdot {D}_{aq} $$
(11)

Refinement of the Permeability Parameters which Define the Dynamic Range Window

The pCEL-X program (v4.03, in-ADME Research) can be used to determine the k VF , h ABL , ε/δ, (ε/δ)2, R, and Δφ parameters by a weighted nonlinear regression analysis based on the logarithmic form of Eq. 4, expanded with Eqs. 510:

$$ G\left({k}_{VF},{h}_{ABL},\frac{\varepsilon }{\delta },{\frac{\varepsilon }{\delta}}_2,R,\Delta \phi \right)=\log {k}_{VF}-\log \left[\frac{h_{ABL}}{D_{aq}}+\frac{1}{P_c^{6.5}\kern0.5em +\kern0.5em \frac{\varepsilon }{\delta}\cdot {D}_{aq}\cdot F\left(\frac{r_{HYD}}{R}\right)\kern0.5em \cdot \kern0.5em E\left(\Delta \phi \right)+\kern0.5em {\frac{\varepsilon }{\delta}}_2\cdot {D}_{aq}}\kern0.5em \right] $$
(12)

The partial derivatives of G with respect to ε/δ, (ε/δ)2, R, Δφ, h ABL , and k VF are calculated explicitly in the pCEL-X program, based on standard mathematical techniques. The weighted residuals function minimized was

$$ {R}_w\kern0.5em =\kern0.5em \sum \limits_i^n{\left(\frac{\log {P}_{eff,i}^{obs}-{G}_i^{calc}}{\sigma_i\left(\log\;{P}_{eff}\right)}\right)}^2 $$
(13)

where n is the number of P eff values used in the model refinement, and σ i (log P eff ) is the reported standard deviation of the logarithm of the ith measured rat intestinal permeability. The effectiveness of the refinement is characterized by the “goodness-of-fit”, GOF = [Rw/(n-nV)]1/2, where nV refers to the number of varied parameters. The expected value of GOF is 1 if the model is suitable for the data and the measured standard deviations accurately reflect the precision of the data.

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Lozoya-Agullo, I., Gonzalez-Alvarez, I., Zur, M. et al. Closed-Loop Doluisio (Colon, Small Intestine) and Single-Pass Intestinal Perfusion (Colon, Jejunum) in Rat—Biophysical Model and Predictions Based on Caco-2. Pharm Res 35, 2 (2018). https://doi.org/10.1007/s11095-017-2331-z

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