De Piano, Raffaella ; Caccavo, Diego; Cascone, Sara; Festa, Caterina; Lamberti, Gaetano; Barba, Anna Angela Drug release from hydrogel-based matrix systems partially coated: experiments and modeling Journal Article Journal of Drug Delivery Science and Technology, 2020. Abstract | Links | BibTeX | Tags: drug release, Modeling, Tablets, Theophylline @article{Piano}2020,
title = {Drug release from hydrogel-based matrix systems partially coated: experiments and modeling},
author = {Raffaella {De Piano} and Diego Caccavo and Sara Cascone and Caterina Festa and Gaetano Lamberti and Anna Angela Barba},
url = {https://www.sciencedirect.com/science/article/abs/pii/S1773224720314350?via%3Dihub},
doi = {10.1016/j.jddst.2020.102146},
year = {2020},
date = {2020-10-07},
journal = {Journal of Drug Delivery Science and Technology},
abstract = {Hydrogel-based matrix systems are largely used as controlled drug delivery systems, since it is possible to get the desired drug release profile properly designing the system in term of composition, drug loading and shape. Meanwhile, the mathematical modeling of the phenomena involved in the drug release process is a useful tool to understand and to predict the complex behavior of these systems, in term of water up-take, matrix swelling and erosion, drug diffusion and release. Furthermore, the coating of the matrix is used to provide certain characteristics such as enteric resistance, meanwhile making more complex the mathematical description of the process. In this work cylindrical tablets made of hydroxyl-propyl-methyl-cellulose (HPMC) loaded with theophylline (TP), as obtained or coated by an impermeable painting on the lateral surface were dissolved in a USP II apparatus, and the release of TP, as well as of HPMC and the shape changes were monitored in time, for several rotational speeds of the impeller. The experimental data gathered were used to tune a previously proposed mathematical model. The model was found able to correctly describe all the observed phenomena, confirming its usefulness as a tool in design and production of pharmaceutics.},
keywords = {drug release, Modeling, Tablets, Theophylline},
pubstate = {published},
tppubtype = {article}
}
Hydrogel-based matrix systems are largely used as controlled drug delivery systems, since it is possible to get the desired drug release profile properly designing the system in term of composition, drug loading and shape. Meanwhile, the mathematical modeling of the phenomena involved in the drug release process is a useful tool to understand and to predict the complex behavior of these systems, in term of water up-take, matrix swelling and erosion, drug diffusion and release. Furthermore, the coating of the matrix is used to provide certain characteristics such as enteric resistance, meanwhile making more complex the mathematical description of the process. In this work cylindrical tablets made of hydroxyl-propyl-methyl-cellulose (HPMC) loaded with theophylline (TP), as obtained or coated by an impermeable painting on the lateral surface were dissolved in a USP II apparatus, and the release of TP, as well as of HPMC and the shape changes were monitored in time, for several rotational speeds of the impeller. The experimental data gathered were used to tune a previously proposed mathematical model. The model was found able to correctly describe all the observed phenomena, confirming its usefulness as a tool in design and production of pharmaceutics. |
Cascone, Sara Modeling and comparison of release profiles: Effect of the dissolution method Journal Article European Journal of Pharmaceutical Sciences, 106 , pp. 352-361, 2017, ISSN: 0928-0987. Abstract | Links | BibTeX | Tags: drug release, In silico, In vitro, Pharmacokinetics @article{Cascone2017,
title = {Modeling and comparison of release profiles: Effect of the dissolution method},
author = {Sara Cascone},
url = {http://www.sciencedirect.com/science/article/pii/S092809871730355X},
doi = {10.1016/j.ejps.2017.06.021},
issn = {0928-0987},
year = {2017},
date = {2017-08-30},
journal = {European Journal of Pharmaceutical Sciences},
volume = {106},
pages = {352-361},
abstract = {During the last decades, the study of the in vitro dissolution of pharmaceuticals has been strongly encouraged by the FDA in order to determine its relationship with the in vivo bioavailability of a drug. In this work immediate and extended release formulations containing diclofenac, a BCS class II drug, were studied using different dissolution methods. The release profiles obtained in USP Apparatus II and USP Apparatus IV were evaluated and compared to determine the effect of the fluid dynamic conditions on the release. The influence of the mixing conditions (i.e. the paddle rotation speed in USP Apparatus II or the inlet flow rate in USP Apparatus IV) on the drug release were evaluated, finding that, for the extended release formulations, they do not affect significantly the release profile. An in vitro device simulating the peristaltic contractions of the stomach during the digestion was used to simulate fluid dynamics closer to the real physiology. The tablets were found to behave in a completely different way if tested in the artificial stomach.
Both model-independent and model-dependent approaches were used to compare and fit the dissolution profiles, respectively. Fit factors were used as indicators of similarity of two dissolution profiles; model equations (such as zero-order, first-order, or Korsmeyer-Peppas equations) were used to fit the experimental data. With the identification of the best fitting model by the use of correlation factors and Akaike Information Criterion, the transport phenomena that determine the behavior of each formulation were identified.},
keywords = {drug release, In silico, In vitro, Pharmacokinetics},
pubstate = {published},
tppubtype = {article}
}
During the last decades, the study of the in vitro dissolution of pharmaceuticals has been strongly encouraged by the FDA in order to determine its relationship with the in vivo bioavailability of a drug. In this work immediate and extended release formulations containing diclofenac, a BCS class II drug, were studied using different dissolution methods. The release profiles obtained in USP Apparatus II and USP Apparatus IV were evaluated and compared to determine the effect of the fluid dynamic conditions on the release. The influence of the mixing conditions (i.e. the paddle rotation speed in USP Apparatus II or the inlet flow rate in USP Apparatus IV) on the drug release were evaluated, finding that, for the extended release formulations, they do not affect significantly the release profile. An in vitro device simulating the peristaltic contractions of the stomach during the digestion was used to simulate fluid dynamics closer to the real physiology. The tablets were found to behave in a completely different way if tested in the artificial stomach.
Both model-independent and model-dependent approaches were used to compare and fit the dissolution profiles, respectively. Fit factors were used as indicators of similarity of two dissolution profiles; model equations (such as zero-order, first-order, or Korsmeyer-Peppas equations) were used to fit the experimental data. With the identification of the best fitting model by the use of correlation factors and Akaike Information Criterion, the transport phenomena that determine the behavior of each formulation were identified. |
Barba, Anna Angela; D'Amore, Matteo; Cascone, Sara; Chirico, Serafina; Lamberti, Gaetano; Titomanlio, Giuseppe On the behavior of HPMC/Theophylline matrices for controlled drug delivery Journal Article Journal of Pharmaceutical Sciences, 98 (11), pp. 4100–4110, 2009, ISSN: 00223549. Abstract | Links | BibTeX | Tags: Diffusion, drug release, HPMC, Hydrogel Characterization, swellable hydrogels, Theophylline @article{Barba2009h,
title = {On the behavior of HPMC/Theophylline matrices for controlled drug delivery},
author = { Anna Angela Barba and Matteo D'Amore and Sara Cascone and Serafina Chirico and Gaetano Lamberti and Giuseppe Titomanlio},
url = {http://doi.wiley.com/10.1002/jps.21701},
doi = {10.1002/jps.21701},
issn = {00223549},
year = {2009},
date = {2009-11-01},
journal = {Journal of Pharmaceutical Sciences},
volume = {98},
number = {11},
pages = {4100--4110},
publisher = {Wiley Subscription Services, Inc., A Wiley Company},
abstract = {Design of systems for oral controlled release of drug could take advantages from the knowledge of which phenomena take place. In this work matrices obtained by powders compression (50:50, hydroxypropyl methylcellulose, a swelling hydrogel, and theophylline, a model drug) were immersed in water at 37 degrees C, allowing the water uptake and the drug release by lateral surface, confining the cylindrical matrices between glass slides. The tablets, after given immersion times, were withdrawn, cut in several annuli, and subsequently analyzed for the drug and the water concentration radial profiles. The data confirmed the pseudo-diffusive nature of the process, allowing to give a deep insight into the drug release process from swellable hydrogel matrices. In particular, it was confirmed the presence of nonhomogeneous gel layer, rich in water and poor in drug, with a profile of drug concentration which agrees well with a pseudo-diffusion phenomenon.},
keywords = {Diffusion, drug release, HPMC, Hydrogel Characterization, swellable hydrogels, Theophylline},
pubstate = {published},
tppubtype = {article}
}
Design of systems for oral controlled release of drug could take advantages from the knowledge of which phenomena take place. In this work matrices obtained by powders compression (50:50, hydroxypropyl methylcellulose, a swelling hydrogel, and theophylline, a model drug) were immersed in water at 37 degrees C, allowing the water uptake and the drug release by lateral surface, confining the cylindrical matrices between glass slides. The tablets, after given immersion times, were withdrawn, cut in several annuli, and subsequently analyzed for the drug and the water concentration radial profiles. The data confirmed the pseudo-diffusive nature of the process, allowing to give a deep insight into the drug release process from swellable hydrogel matrices. In particular, it was confirmed the presence of nonhomogeneous gel layer, rich in water and poor in drug, with a profile of drug concentration which agrees well with a pseudo-diffusion phenomenon. |