In vitro/in vivo correlations of sustained-release coated multiparticulate formulations of doxazosin

Thombre, Avinash G.; DeNoto, A.R.; Falkner, Fred C.; Lazar, Jeffrey D.

doi:10.1016/0378-5173(94)00137-5

Cited by 12 publications

(7 citation statements)

References 4 publications

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“…Due to insolubility, ethyl cellulose is often preferred combined with hydroxypropyl cellulose for controlled drug release [82,83,84,85]. Specifically, the drug release and water permeability of the films depend on hydroxypropyl cellulose concentration in the films (the higher hydroxypropyl cellulose concentration is, the more increased drug release and permeability are) [82,83,86]. Moreover, hydroxypropyl cellulose is utilized with other polymers, such as Carbopol 934, to improve drug reservoirs in FFS formulations [87,88].…”

Section: Formulation Design Of Controlled Drug Release Film-forminmentioning

confidence: 99%

Controlled Release Film Forming Systems in Drug Delivery: The Potential for Efficient Drug Delivery

Tran

2019

Pharmaceutics

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Despite many available approaches for transdermal drug delivery, patient compliance and drug targeting at the desired concentration are still concerns for effective therapies. Precise and efficient film-forming systems provide great potential for controlling drug delivery through the skin with the combined advantages of films and hydrogels. The associated disadvantages of both systems (films and hydrogels) will be overcome in film-forming systems. Different strategies have been designed to control drug release through the skin, including changes to film-forming polymers, plasticizers, additives or even model drugs in formulations. In the current review, we aim to discuss the recent advances in film-forming systems to provide the principles and review the methods of these systems as applied to controlled drug release. Advances in the design of film-forming systems open a new generation of these systems.

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Section: Formulation Design Of Controlled Drug Release Film-forminmentioning

confidence: 99%

Controlled Release Film Forming Systems in Drug Delivery: The Potential for Efficient Drug Delivery

Tran

2019

Pharmaceutics

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“…Films composed of EC and HPC have been studied both with regard to structure and permeability. It has been shown that EC and HPC phase separate in the films (Sakellariou et al, 1986(Sakellariou et al, , 1988 and that the permeability of the films and the release rate from formulations increases with increasing HPC content (Thombre et al, 1994;Marucci et al, 2009). Furthermore, the permeability of the films as well as the release of the pore forming HPC has been shown to be low below a critical HPC content, this being explained by that at low HPC concentrations the pore forming network is not interconnected through the film ( Sakellariou et al, 1988;Marucci et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Effect of ethanol on the water permeability of controlled release films composed of ethyl cellulose and hydroxypropyl cellulose

Larsson

Hjärtstam

Berndtsson

et al. 2010

European Journal of Pharmaceutics and Biopharmaceutics

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The robustness of controlled release formulations when co-ingested with alcohol is a current concern expressed by regulatory authorities, especially with regard to dose dumping. One such controlled release formulation commonly used is film coating composed of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC). The aim of this study was to investigate how the presence of ethanol in the dissolution medium affects the water permeability of such films. Film samples were prepared in various EC-HPC compositions, and the effect of different ethanol concentrations in the dissolution medium on the permeability was studied using a modified Ussing chamber and tritiated water. It was found that the effect of ethanol on the film permeability varied depending on the composition of the films. The results were interpreted in terms of swelling of the EC in the films, where the swelling increased with increasing ethanol concentration. Thus, for films with low HPC content (non-interconnected pores), the water permeability of the films increased with increasing ethanol concentration as the diffusion through the ethyl cellulose increased due to swelling. However, for films with higher HPC content (having interconnected pores through the films), the permeability decreased, likely due to the swelling of the ethyl cellulose blocking the pores. The interpretation of the results was supported by dynamic mechanic analysis and SEM analysis.

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“…Preparation of Free Polymer Films. The films were prepared from mixtures containing 94% w/w hydrous ethanol (95%) and 6% w/w polymers, as it has been shown that at this low polymer concentration EC and HPC do not phase separate [20]. The dry film consisted of 70% EC and 30% HPC.…”

Section: Methodsmentioning

confidence: 99%

“…Films made of EC and HPC have often been used as coating to control the drug release profile from oral formulations. 20 Although EC and HPC can be codissolved in a common solvent, phase separation occurs during the film formation process as the solvent evaporates. 21 This results in films presenting a phase separated microstructure with domains rich in EC and domains rich in HPC.…”

Section: Introductionmentioning

confidence: 99%

“…The 3D film structures were obtained using confocal laser scanning microscopy (CLSM). Films made of EC and HPC have often been used as coating to control the drug release profile from oral formulations . Although EC and HPC can be codissolved in a common solvent, phase separation occurs during the film formation process as the solvent evaporates .…”

Section: Introductionmentioning

confidence: 99%

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Investigation of the Effect of the Tortuous Pore Structure on Water Diffusion through a Polymer Film Using Lattice Boltzmann Simulations

et al. 2015

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Understanding how the pore structure influences the mass transport through a porous material is important in several applications, not the least in the design of polymer film coatings intended to control drug release. In this study, a polymer film made of ethyl cellulose and hydroxypropyl cellulose was investigated. The 3D structure of the films was first experimentally characterized using confocal laser scanning microscopy data and then mathematically reconstructed for the whole film thickness. Lattice Boltzmann simulations were performed to compute the effective diffusion coefficient of water in the film and the results were compared to experimental data. The local porosities and pore sizes were also analyzed to determine how the properties of the internal film structure affect the water effective diffusion coefficient. The results show that the top part of the film has lower porosity, lower pore size, and lower connectivity, which results in a much lower effective diffusion coefficient in this part, largely determining the diffusion rate through the entire film. Furthermore, the local effective diffusion coefficients were not proportional to the local film porosity, indicating that the results cannot be explained by a single tortuosity factor. In summary, the proposed methodology of combining microscopy data, mass transport simulations, and pore space analysis can give valuable insights on how the film structure affects the mass transport through the film.

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In vitro/in vivo correlations of sustained-release coated multiparticulate formulations of doxazosin

Cited by 12 publications

References 4 publications

Controlled Release Film Forming Systems in Drug Delivery: The Potential for Efficient Drug Delivery

Controlled Release Film Forming Systems in Drug Delivery: The Potential for Efficient Drug Delivery

Effect of ethanol on the water permeability of controlled release films composed of ethyl cellulose and hydroxypropyl cellulose

Investigation of the Effect of the Tortuous Pore Structure on Water Diffusion through a Polymer Film Using Lattice Boltzmann Simulations

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