The power law can describe the ‘entire’ drug release curve from HPMC-based matrix tablets: a hypothesis

Rinaki, Eleni; Valsami, Georgia; Macheras, Panos

doi:10.1016/s0378-5173(03)00079-6

Cited by 81 publications

(50 citation statements)

References 25 publications

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“…On the other hand, physiologically and bio-chemically based models are difficult to attain due to the extraordinary complexity of this process. An intermediate solution is perhaps the use of semi-empirical models [23]. Such a model which is fairly simple to employ in characterizing drug release is the power-law model:…”

Section: Effect To Drug Concentration Relationmentioning

confidence: 99%

“…These features of this model are of special interest in our study since we would like to look at the inter-patient variability from this standpoint. Following the fundamental law of physics which applies to well stirred, homogeneous systems, it follows that the mean square displacement of the walker, < x 2 > in the random walk model is proportional to time [23], [25]:…”

Section: Effect To Drug Concentration Relationmentioning

confidence: 99%

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Bridging the gap between modelling and control of anesthesia: An ambitious ideal

Ionescu

Copot

et al. 2014

ICFDA'14 International Conference on Fractional Differentiation and Its Applications 2014

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Abstract-This work focuses on the problematic of modeling the drug diffusion process that occurs in the human body when an anesthetic drug is taken up. This is performed here using emerging tools from fractional calculus, i.e. by using fractionalorder impedance models (FOIMs). A novel interpretation is given to the classical pharmacokinetic and pharmacodynamic models for drug uptake in the body. The major challenges that are encountered during this development consist of online identification of the patient model, introducing a logarithmic sampling time and embedding the proposed method in a closed loop control system.

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Section: Effect To Drug Concentration Relationmentioning

confidence: 99%

Section: Effect To Drug Concentration Relationmentioning

confidence: 99%

Bridging the gap between modelling and control of anesthesia: An ambitious ideal

Ionescu

Copot

et al. 2014

ICFDA'14 International Conference on Fractional Differentiation and Its Applications 2014

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“…The kinetics and mechanism of drug release for each system was investigated by fitting the release data into this equation (Rinaki et al, 2003).…”

Section: Drug Releasementioning

confidence: 99%

Effect of stearic acid on the properties of metronidazole/methocel K4M floating matrices

Lara-Hernández

Hernández-León

Villafuerte-Robles

2009

Braz. J. Pharm. Sci.

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The properties of metronidazole/Methocel K4M sustained release floating tablets have been studied varying the proportion of the lubricant, stearic acid, on formulations with and without sodium bicarbonate. The variables studied include technological properties of the tablets such as tablet hardness and ejection pressure, the drug release profile, the hydration kinetics and the floating behaviour. The presence of stearic acid and sodium bicarbonate improves the floating behaviour for more than 8 hours. The hydration volume, the tablet hardness and the ejection pressure decrease as the stearic acid content increases and the polymer content decreases. Drug dissolution increases with increasing proportions of stearic acid and decreasing proportions of the polymer in the tablets. The presence of sodium bicarbonate extends the differences in dissolution produced by stearic acid. These results are attributed to decreasing matrices coherence with an increasing quantity of stearic acid and a reducing polymer proportion. The carbon dioxide bubbles produced by sodium bicarbonate expand the matrices facilitating the dissolution, although their presence obstructs also the diffusion path through the hydrated gel layer. Uniterms:Metronidazole. Methocel K4M. Stearic acid. Matrices hydration. Gastric retention. Sodium bicarbonate. Sustained release. Drugs/release mechanism.Estudaram-se as propriedades de comprimidos flutuantes de metronidazol/Methocel K4M de liberação controlada, variando-se a proporção do lubrificante, ácido esteárico, nas formulações com e sem bicarbonato de sódio. As variáveis estudadas incluem propriedades tecnológicas dos comprimidos, tais como dureza, pressão de ejeção, perfil de liberação do fármaco, cinética de hidratação e comportamento de flutuação. A presença de ácido esteárico e do bicarbonato de sódio melhora o comportamento de flutuação para mais de 8 horas. O volume de hidratação, a dureza e a pressão de ejeção do comprimido decrescem à medida que o conteúdo de ácido esteárico e de polímero diminui. A dissolução do fármaco aumenta com o aumento das proporções de ácido esteárico e a diminuição das proporções de polímero nos comprimidos. A presença de bicarbonato de sódio amplia as diferenças na dissolução produzidas pelo ácido esteárico. Estes resultados são atribuídos à coesão decrescente das matrizes, com o aumento da quantidade de ácido esteárico e a redução da proporção de polímero. Bolhas de dióxido de carbono produzidas pelo bicarbonato de sódio expandem as matrizes, facilitando a dissolução, embora a presença delas obstrua, também, a difusão através da camada de gel hidratado. Unitermos:Metronidazol. Methocel K4M. Ácido esteárico. Hidratação das matrizes. Retenção gástrica. Bicarbonato de sódio. Fármacos/mecanismo de liberação.

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“…As a result of in vivo and in vitro characteristics and also the difficulties that are encountered in achieving predictable as well as reproducible in vivo/in vitro correlation, it is often difficult to develop formulation on many newly synthesized compounds due to their solubility issues [10,11]. Traditional approaches to drug solubilization include particle size reduction, pH adjustment, and addition of co-solvents and surfactants [12].…”

Section: Introductionmentioning

confidence: 99%

Bioavailability Improvement of SLMs Based Erythromycin Ethyl Succinate using Stearic Acid-Myrj-52-based SLM’s

Osonwa¹,

Majekodunmi²,

OnyechiN³

et al. 2017

JCCE

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Solid lipid microparticles of erythromycin ethyl succinate were prepared using solvent evaporation method to improve its bioavailability and efficacy. The solvent was allowed to evaporate after which the various entrapments were determined; the best entrapment was used in the in vivo studies to determine the bioavailability and efficacy. This study was done with albino mice. The best entrapment obtained was 83% with a loading capacity of 2.9% (Batch D) and was used in comparison with the unformulated drug to check for the in vivo efficacy. The results show higher efficacy with the formulated drug than with the pure drug both in vitro and in vivo. The in vitro test results were better despite that some enzymes which need to act on the solid lipid microparticles were not present in the in vitro assay and could lead to a reduction in the release of the drugs. In conclusion, there was improvement in efficacy, and hence bioavailability.

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The power law can describe the ‘entire’ drug release curve from HPMC-based matrix tablets: a hypothesis

Cited by 81 publications

References 25 publications

Bridging the gap between modelling and control of anesthesia: An ambitious ideal

Bridging the gap between modelling and control of anesthesia: An ambitious ideal

Effect of stearic acid on the properties of metronidazole/methocel K4M floating matrices

Bioavailability Improvement of SLMs Based Erythromycin Ethyl Succinate using Stearic Acid-Myrj-52-based SLM’s

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