Application of the Higuchi model for drug release from dispersed matrices to particles of general shape

Brophy, Matthew; Deasy, P. B.

doi:10.1016/0378-5173(87)90008-1

Cited by 46 publications

(16 citation statements)

References 4 publications

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“…For a quantitative determination of the kinetics of DOX release, the experimental data were fit to an exponential relation for Fickian diffusion of a drug from spherical polymeric devices, the Higuchi equation [65–67]:

\frac{M_{t}}{M_{\infty}} = {k t}^{\frac{1}{2}}

where M t / M ∞ is the proportion of drug released at a given time, k is the rate constant of drug release, and t is time. The proportion of DOX release plotted against the square root of release time was approximately linear for the first 50% of drug release (Figure 7), in agreement with the limitations of the Higuchi model.…”

Section: Resultsmentioning

confidence: 99%

Tuning core vs. shell dimensions to adjust the performance of nanoscopic containers for the loading and release of doxorubicin

Lin

Lee

Zhu

et al. 2011

Journal of Controlled Release

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Detailed studies were performed to probe the effects of the core and shell dimensions of amphiphilic, shell crosslinked, knedel-like polymer nanoparticles (SCKs) on the loading and release of doxorubicin (DOX), a widely-used chemotherapy agent, in aqueous buffer, as a function of the solution pH. Effects of the nanoparticle composition were held constant, by employing SCKs constructed from a single type of amphiphilic diblock copolymer, poly(acrylic acid)-b-polystyrene (PAA-b-PS). A series of four SCK nanoparticle samples, ranging in number-average hydrodynamic diameter from 14–30 nm, was prepared from four block copolymers having different relative block lengths and absolute degrees of polymerization. The ratios of acrylic acid to styrene block lengths ranged from 0.65 to 3.0, giving SCKs with ratios of shell to core volumes ranging from 0.44 to 2.1. Although the shell thicknesses were calculated to be similar (1.5–3.1 nm by transmission electron microscopy (TEM) calculations and 3.5–4.9 nm by small angle neutron scattering (SANS) analyses), two of the SCK nanoparticles had relatively large core diameters (19 ± 2 and 20 ± 2 nm by TEM; 17.4 and 15.3 nm by SANS), while two had similar, smaller core diameters (11 ± 2 and 13 ± 2 nm by TEM; 9.0 and 8.9 nm by SANS). The SCKs were capable of being loaded with 1500–9700 DOX molecules per each particle, with larger numbers of DOX molecules packaged within the larger core SCKs. Their shell-to-core volume ratio showed impact on the rates and extents of release of DOX, with the volume occupied by the poly(acrylic acid) shell relative to the volume occupied by the polystyrene core correlating inversely with the diffusion-based release of DOX. Given that the same amount of polymer was used to construct each SCK sample, SCKs having smaller cores and higher acrylic acid vs. styrene volume ratios were present at higher concentrations than were the larger core SCKs, and gave lower final extents of release., Higher final extents of release and faster rates of release were observed for all DOX-loaded particle samples at pH 5.0 vs. pH 7.4, respectively, ca. 60% vs. 40% at 60 h, suggesting promise for enhanced delivery within tumors and cells. By fitting the data to the Higuchi model, quantitative determination of the kinetics of release was made, giving rate constants ranging from 0.0431 to 0.0540 h−½ at pH 7.4 and 0.106 to 0.136 h−½ at pH 5.0. In comparison, the non-crosslinked polymer micelle analogs exhibited rate constants for release of DOX of 0.245 and 0.278 h−½ at pH 7.4 and 5.0, respectively. These studies point to future directions to craft sophisticated devices for controlled drug release.

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\frac{M_{t}}{M_{\infty}} = {k t}^{\frac{1}{2}}

Section: Resultsmentioning

confidence: 99%

Tuning core vs. shell dimensions to adjust the performance of nanoscopic containers for the loading and release of doxorubicin

Lin

Lee

Zhu

et al. 2011

Journal of Controlled Release

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“…Consequently, Borphy et al have demonstrated that the fraction of drug release of any shape of matrix will follow the general equation of following type [83]. Consequently, Borphy et al have demonstrated that the fraction of drug release of any shape of matrix will follow the general equation of following type [83].…”

Section: Fitting Of the Higuchi Model And Diffusion Coefficient Calcumentioning

confidence: 99%

Biomimetic matrix mediated room temperature synthesis and characterization of nano-hydroxyapatite towards targeted drug delivery

2016

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The nucleation and growth of hydroxyapatite is closely associated with the extracellular matrix environment. Bovine Serum Albumin, Collagen and poly vinyl alcohol were used to mimic the extracellular matrix. An attempt to understand the role of these matrices on the synthesis and function of Hydroxyapatite has been made. XRD, FT-IR, XPS, TG-DTA, SEM and TEM confirmed the formation of hydroxyapatite synthesized by the biomimetic route. Further the role of organic matrix in controlling the nucleation and growth of hydroxyapatite particles in the nano level is understood by the in-depth analysis of the XPS spectra. The in vitro release of the anti-cancer drug methotrexate, in aqueous solution was studied and the in vitro release profile was assayed by elution in phosphate buffered saline with pH 7.4 and pH 5 at 37 º C. The percentage of loading and release profiles of drug were evaluated. The results show that the use of matrix increased the drug release efficiency from 44.5% to 66% at pH 7.4 and 78% to 98.92% at pH 5. These results suggest that the synthesized hydroxyapatite can be used as a pH responsive vehicle for delivering drugs. Further the release profile was predicted by Higuchi and Peppas model. The results suggested that the release mechanism was governed by the Fickian diffusion for initial 8 hrs followed by anomalous transport for longer time. The cytocompatibility of the materials was evaluated by in vitro cytotoxicity test. Both MTT and live/dead assay observations indicated that the material had no adverse impact on the cell proliferation. The results imply these composites to be bioactive having a good cytocompatibility. Although all the matrices showed good results, the one with poly vinyl alcohol exhibited higher biocompatibility and drug release efficiency. A plausible explanation was proposed for the enhanced drug delivery efficiency of these materials.

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“…The experimental data for short- and long-term release were modeled to measure the kinetics and establish the mechanism of DOX release. For short-term release, the experimental data was modeled using a variation of the Higuchi equation [ 9 , 39 , 40 , 41 ]:

where M t is the cumulative release at time t , M 0 is the intercept value at t = 0 and, K is the release constant that indicates the release velocity.…”

Section: Resultsmentioning

confidence: 99%

3D Nanoporous Anodic Alumina Structures for Sustained Drug Release

et al. 2017

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The use of nanoporous anodic alumina (NAA) for the development of drug delivery systems has gained much attention in recent years. The release of drugs loaded inside NAA pores is complex and depends on the morphology of the pores. In this study, NAA, with different three-dimensional (3D) pore structures (cylindrical pores with several pore diameters, multilayered nanofunnels, and multilayered inverted funnels) were fabricated, and their respective drug delivery rates were studied and modeled using doxorubicin as a model drug. The obtained results reveal optimal modeling of all 3D pore structures, differentiating two drug release stages. Thus, an initial short-term and a sustained long-term release were successfully modeled by the Higuchi and the Korsmeyer–Peppas equations, respectively. This study demonstrates the influence of pore geometries on drug release rates, and further presents a sustained long-term drug release that exceeds 60 days without an undesired initial burst.

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Application of the Higuchi model for drug release from dispersed matrices to particles of general shape

Cited by 46 publications

References 4 publications

Tuning core vs. shell dimensions to adjust the performance of nanoscopic containers for the loading and release of doxorubicin

Tuning core vs. shell dimensions to adjust the performance of nanoscopic containers for the loading and release of doxorubicin

Biomimetic matrix mediated room temperature synthesis and characterization of nano-hydroxyapatite towards targeted drug delivery

3D Nanoporous Anodic Alumina Structures for Sustained Drug Release

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