This work describes the deterministic interaction of a diffusing particle of efavirenz through concentration gradient. Simulated pharmacokinetic data from patients on efavirenz are used. The Fourier’s Equation is used to infer on transfer of movement between solution particles. The work investigates diffusion using Fick’s analogy, but in a different variable space. Two important movement fluxes of a solution particle are derived an absorbing one identified as conductivity and a dispersing one identified as diffusivity. The Fourier’s Equation can be used to describe the process of gain/loss of movement in formation of a solution particle in an individual.
References
[1]
Mehrer, H. and Stolwijk, N.A. (2009) Heroes and Highlights in the History of Diffusion. Diffusion Fundamentals, 11, 1-32.
[2]
Narasimhan, T.N. (1999) Fourier’s Heat Conduction Equation: History, Influence and Connections. Reviews of Geophysics, 37, 151-172. http://dx.doi.org/10.1029/1998RG900006
[3]
Feldman, J. (2007) The Heat Equation (One Space Dimension). http://www.math.ubc.ca/feldman/m267/heat1d.pdf
[4]
Crank, J. (1975) The Mathematics of Diffusion. 2nd Edition, Oxford University Press, Oxford.
[5]
De Kee, D., Liu, Q. and Hinestroza, J. (2005) Viscoelastic (Non-Fickian) Diffusion. The Canadian Journal of Chemical Engineering, 83, 913-929. http://dx.doi.org/10.1002/cjce.5450830601
[6]
Nemaura, T. (2015) Modeling Transportation of Efavirenz: Inference on Possibility of Mixed Modes of Transportation and Kinetic Solubility. Frontiers in Pharmacology http://dx.doi.org/10.3389/fphar.2015.00121
[7]
Nemaura, T. (2014) Projections of Pharmacokinetic Parameter Estimates from Middose Plasma Concentrations in Individuals on Efavirenz; a Novel Approach. African Journal of Pharmacy and Pharmacology, 8, 929-952.
[8]
Argyrakis, P., Chumak, A.A., Maragakis, M. and Tsakiris, N. (2009) Negative Diffusion Coefficient in a Two-Dimensional Lattice-Gas System with Attractive Nearest-Neighbor Interactions. Physical Review B, 80, 1-7. http://dx.doi.org/10.1103/PhysRevB.80.104203
[9]
Apostolova, N., Funes, H.A., Blas-Garcia, A., Galindo, M.J., Alvarez, A. and Esplugues, J.V. (2015) Efavirenz and the CNS: What We Already Know and Questions That Need to Be Answered. Journal of Antimicrobial Chemotherapy, 70, 2693-708. http://dx.doi.org/10.1093/jac/dkv183
[10]
Petropoulos, J.H., Sanopoulou, M. and Papadokostaki, K.G. (2009) Beyond Fick: How Best to Deal with Non-Fickian Behavior in a Fickian Spirit. Diffusion Fundamentals, 11, 1-21.
[11]
Philibert, J. (2005) One and a Half Century of Diffusion: Fick, Einstein, Before and Beyond. Diffusion Fundamentals, 2, 1-10.
[12]
Fu, Y. and Kao, W. J. (2010) Drug Release Kinetics and Transport Mechanisms of Non-Degradable and Degradable Polymeric Delivery Systems. Expert Opinion on Drug Delivery, 7, 429-444. http://dx.doi.org/10.1517/17425241003602259