Systematic characterization of drug release profiles from finite-sized hydrogels

Casault, Sébastien; Slater, Gary W.

doi:10.1016/j.physa.2008.05.013

Cited by 16 publications

(8 citation statements)

References 25 publications

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“…To gain a quantitative understanding of how cross-linker concentration affected AuC–liposome release, the liposome release profiles were analyzed using mathematical models established in previous hydrogel-mediated drug release studies. 38 , 39 The use of polyacrylamide hydrogel allows us to hypothesize that the liposome release kinetics are primarily dominated by diffusional liposome efflux with negligible contributions from the hydrogel network. 40 Therefore, a diffusion-dominant Higuchi model was applied to analyze the liposome release profiles: M t = Kt 1/2 , where M t is drug release at time t in hours and K is the Higuchi constant.…”

Section: Resultsmentioning

confidence: 99%

“…Specifically, for the hydrogel sample with 0.6 vol % of the cross-linker, nearly 90% liposomes were released within 24 h. When the cross-linker concentration was increased to 0.7 and 0.8 vol %, within the first 24 h, only 25% and 17% liposomes were released, respectively. To gain a quantitative understanding of how cross-linker concentration affected AuC–liposome release, the liposome release profiles were analyzed using mathematical models established in previous hydrogel-mediated drug release studies. , The use of polyacrylamide hydrogel allows us to hypothesize that the liposome release kinetics are primarily dominated by diffusional liposome efflux with negligible contributions from the hydrogel network . Therefore, a diffusion-dominant Higuchi model was applied to analyze the liposome release profiles: M t = Kt 1/2 , where M t is drug release at time t in hours and K is the Higuchi constant. , Plotting the liposome release percentage against the square root of time yielded linear fittings with R 2 = 0.96, 0.97, and 0.97 for the three cross-linker concentrations of 0.6, 0.7, and 0.8 vol %, respectively (Figure B).…”

Section: Resultsmentioning

confidence: 99%

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Hydrogel Containing Nanoparticle-Stabilized Liposomes for Topical Antimicrobial Delivery

Gao¹,

Vecchio²,

Li³

et al. 2014

ACS Nano

199

143

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Adsorbing small charged nanoparticles onto the outer surfaces of liposomes has become an effective strategy to stabilize liposomes against fusion prior to “seeing” target bacteria, yet allow them to fuse with the bacteria upon arrival at the infection sites. As a result, nanoparticle-stabilized liposomes have become an emerging drug delivery platform for treatment of various bacterial infections. To facilitate the translation of this platform for clinical tests and uses, herein we integrate nanoparticle-stabilized liposomes with hydrogel technology for more effective and sustained topical drug delivery. The hydrogel formulation not only preserves the structural integrity of the nanoparticle-stabilized liposomes, but also allows for controllable viscoeleasticity and tunable liposome release rate. Using Staphylococcus aureus bacteria as a model pathogen, we demonstrate that the hydrogel formulation can effectively release nanoparticle-stabilized liposomes to the bacterial culture, which subsequently fuse with bacterial membrane in a pH-dependent manner. When topically applied onto mouse skin, the hydrogel formulation does not generate any observable skin toxicity within a 7-day treatment. Collectively, the hydrogel containing nanoparticle-stabilized liposomes hold great promise for topical applications against various microbial infections.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Hydrogel Containing Nanoparticle-Stabilized Liposomes for Topical Antimicrobial Delivery

Gao¹,

Vecchio²,

Li³

et al. 2014

ACS Nano

199

143

View full text Add to dashboard Cite

show abstract

“…The release profile refers to the variation with time of the cumulative relative amount of released drug M t /M ∞ , where M t is the amount of drug that has escaped from the formulation up to time t and M ∞ denotes the total amount of initially loaded drug which is expected to be fully released after a very long ("infinite") time. Widely used approximate empirical functions are the Peppas power law, M t /M ∞ = kt n [46,47], and the stretched exponential (known also as Weibull function), M t /M ∞ = 1 − e −(t/τ s ) b [48][49][50][51].…”

Section: Introductionmentioning

confidence: 99%

Exact Analytical Relations for the Average Release Time in Diffusional Drug Release

Kalosakas

2023

Processes

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Although analytical solutions for the problem of diffusion-controlled drug release from uniform formulations of simple geometries, like slabs, spheres, or cylinders, are well known, corresponding exact expressions for the average release times are not widely used. However, such exact analytical formulae are very simple and useful. When the drug is initially distributed homogeneously within the matrix, the average time of release from a sphere of radius R is tav=(1/15)R2/D and from a slab of thickness L is tav=(1/12)L2/D, where D is the corresponding drug diffusion coefficient. Regarding cylindrical tablets of height H and radius R, simple analytical expressions are obtained in the two opposite limits of either very long (H≫R) or very short (H≪R) cylinders. In the former case, of practically radial release, the average release time is tav=(1/8)R2/D, while in the latter case the same result as that of a slab with thickness H is recovered, tav=(1/12)H2/D, as expected. These simple and exact relations are useful not only for an estimate of the average release time from a drug carrier device when diffusion is the dominant mechanism of drug delivery, but also for the experimental determination of the drug diffusion coefficient in a release system of interest through the measured release profile, given the mean squared size of the formulation.

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“…The most common systems include coated systems, matrix tablets, eroding tablets and oral osmotic therapeutic systems. [1][2][3] The present work focuses on the development of a mathematical model and simulation tool that describes the sustained drug release observed in matrix tablets. Matrix tablets are devices that deliver a drug in a controlled manner over an extended period of time.…”

Section: Introductionmentioning

confidence: 99%

“…The design of controlled release systems has been an active area of research in pharmaceutical science and industry for decades. The most common systems include coated systems, matrix tablets, eroding tablets and oral osmotic therapeutic systems [1][2][3]. The present work focuses on the development of a mathematical model and simulation tool that describes the sustained drug release observed in matrix tablets.…”

Section: Introductionmentioning

confidence: 99%

Swallowing a cellular automaton pill: Predicting drug release from a matrix tablet

Buchla¹,

Hinow

Najera

et al. 2014

SIMULATION

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Matrix tablets are drug delivery devices designed to release a drug in a controlled manner over an extended period of time. We develop a cellular automaton (CA) model for the dissolution and release of a water-soluble drug and excipient from a matrix tablet of water-insoluble polymer. Cells of the CA are occupied by drug, excipient, water or polymer and the CA updating rules simulate the dissolution of drug and excipient and the subsequent diffusion of the dissolved substances. In addition we simulate the possible fracture of brittle drug and excipient powders during the tablet compression and the melting of the polymer during a possible thermal curing process. Different stirring mechanisms that facilitate the transport of dissolved drug in the fluid in which the tablet is immersed are modeled in the water cells adjacent to the boundary of the tablet. We find that our simulations can reproduce experimental drug release profiles. Our simulation tool can be used to streamline the formulation and production of sustained release tablets.

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Systematic characterization of drug release profiles from finite-sized hydrogels

Cited by 16 publications

References 25 publications

Hydrogel Containing Nanoparticle-Stabilized Liposomes for Topical Antimicrobial Delivery

Hydrogel Containing Nanoparticle-Stabilized Liposomes for Topical Antimicrobial Delivery

Exact Analytical Relations for the Average Release Time in Diffusional Drug Release

Swallowing a cellular automaton pill: Predicting drug release from a matrix tablet

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