Modeling the diffusion-erosion crossover dynamics in drug release

Gomes-Filho, Márcio S.; Oliveira, Fernando A.; Barbosa, Marco Aurélio A.

doi:10.1103/physreve.105.044110

Cited by 10 publications

(5 citation statements)

References 71 publications

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“…In this limit, the dependence of the exponential term in eqn (25) on f is much stronger than that of 1 À f, and accordingly 1 À f can be safely replaced by 1 À f [this replacement is fully correct provided F(E) = F(E)]. With this (second) simplification, eqn (28) is modified as…”

Section: B Simplificationsmentioning

confidence: 99%

“…, due to the fractal-like carrier structure. The interplay of Fickian diffusion and carrier dissolution and/or erosion 26–28 and the release after rupture of carrier particles 29 were analyzed as well.…”

Section: Introductionmentioning

confidence: 99%

“…The focus is there on the non-Fickian diffusion related to the carrier structural heterogeneity on the length scale much smaller than the carrier size, e.g., due to the fractal-like carrier structure. The interplay of Fickian diffusion and carrier dissolution and/or erosion [26][27][28] and the release after rupture of carrier particles 29 were analyzed as well.…”

Section: Introductionmentioning

confidence: 99%

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Release of molecules from nanocarriers

Zhdanov

2023

Phys. Chem. Chem. Phys.

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Section: B Simplificationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Release of molecules from nanocarriers

Zhdanov

2023

Phys. Chem. Chem. Phys.

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“…There exist many Monte Carlo calculations applied in various drug delivery devices for different situations. However, in the majority of these cases, the release is determined mainly by diffusion and/or matrix bulk degradation or erosion [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ]. Corresponding applications in conjugated polymer–drug systems containing labile bonds and the subsequent diffusion of the detached drug particles are rare [ 60 ].…”

Section: Introductionmentioning

confidence: 99%

Interplay between Diffusion and Bond Cleavage Reaction for Determining Release in Polymer–Drug Conjugates

Kalosakas

2023

Materials

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In conjugated polymeric drug delivery systems, both the covalent bond degradation rate and the diffusion of the freely moving drug particles affect the release profile of the formulation. Using Monte Carlo simulations in spherical matrices, the release kinetics resulting from the competition between the reaction and diffusion processes is discussed. For different values of the relative bond cleavage rate, varied over four orders of magnitude, the evolution of (i) the number of bonded drug molecules, (ii) the fraction of the freely moved detached drug within the polymer matrix, and (iii) the resulting fractional release of the drug is presented. The characteristic release time scale is found to increase by several orders of magnitude as the cleavage reaction rate constant decreases. The two extreme rate-limiting cases where either the diffusion or the reaction dominates the release are clearly distinguishable. The crossover between the diffusion-controlled and reaction-controlled regimes is also examined and a simple analytical formula is presented that can describe the full dependence of the release time on the bond cleavage rate constant. This simple relation is provided simply by the sum of the characteristic time for purely diffusional release and the bond cleavage decay time, which equals the inverse of the reaction rate constant.

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“…Data on diffusion kinetics (such as the diffusion coefficient and energy barrier) are critical in pharmaceutical design. − Numerous experimental studies have been conducted to obtain these data for the processes of loading drugs into carriers and releasing them from carriers. − Ideally, if the drug content over the time is accurately measured as it enters the carrier, the relevant diffusion kinetic data can be very easily determined. However, in practice, it is often difficult to accurately distinguish between drug moieties within and outside a carrier .…”

Section: Introductionmentioning

confidence: 99%

Diffusion Kinetics-Based Loading of Lipoic Acid into Cyclodextrin Metal–Organic Frameworks via a Solvent-Free Method and Mechanism of Stability Enhancement

Yang

Zhou

et al. 2023

J. Phys. Chem. C

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It is difficult to accurately distinguish the amount of a drug inside versus outside of a carrier during drug loading, which limits the ability to determine the kinetic data (the drug diffusion coefficient, energy barrier, etc.). Here, we demonstrated the feasibility of determining the drug diffusion coefficient and content without distinguishing whether it is inside or outside of a carrier. Specifically, the sample of gamma-cyclodextrin metal−organic frameworks (CD-MOF) loaded with unstable and viscous alphalipoic acid (LA) was examined. Furthermore, the LA stability was enhanced by the CD-MOF via a straightforward and unambiguous solvent-free method, and the mechanism behind it was thoroughly explored based on the diffusion coefficient. For the first time, a combination of mathematical modeling and new experimental measurements was used to determine the diffusion coefficient of LA in CD-MOF crystals. Accordingly, the strong adhesion free energy (−8.64 ± 0.56 kcal•mol −1 ) between LA and the dicyclodextrin cavity in the CD-MOF was determined. Furthermore, the nature of the adhesion force was identified to be the chemisorption dominated by hydrogen binding employing a combination of molecular modeling (docking and density functional theory, DFT) and experimental methods (solid-state nuclear magnetic resonance, ssNMR). Finally, this study revealed that the stability enhancement of LA in the CD-MOF is due to the combined actions of the high binding free energy of LA with the dicyclodextrin cavity and its steric hindrance, together with the accelerating roles of the CD-MOF cage environment.

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Modeling the diffusion-erosion crossover dynamics in drug release

Cited by 10 publications

References 71 publications

Release of molecules from nanocarriers

Release of molecules from nanocarriers

Interplay between Diffusion and Bond Cleavage Reaction for Determining Release in Polymer–Drug Conjugates

Diffusion Kinetics-Based Loading of Lipoic Acid into Cyclodextrin Metal–Organic Frameworks via a Solvent-Free Method and Mechanism of Stability Enhancement

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