@article{Simone}2019,
title = {Effect of binder and load solubility properties on HPMC granules produced by wet granulation process},
author = {Veronica {De Simone} and Annalisa Dalmoro and Gaetano Lamberti and Diego Caccavo and Matteo D'Amore and Anna Angela Barba},
url = {https://www.sciencedirect.com/science/article/pii/S1773224718311043},
doi = {10.1016/j.jddst.2018.12.030},
year = {2019},
date = {2019-02-01},
journal = {Journal of Drug Delivery Science and Technology},
volume = {49},
pages = {513-520},
abstract = {Hydroxypropyl methylcellulose (HPMC) is one of the most important hydrophilic ingredients used in hydrogel matrices preparation (tablets or granules). In this work, HPMC was used to produce granules loaded with hydrophilic and hydrophobic active molecules to investigate their possible use as release dosage forms for pharmaceutical and nutraceutical applications. Unloaded and vitamins loaded HPMC granules were produced by wet granulation to investigate the effect of molecule solubility and granulation liquid type, on physical, mechanical and release properties. Water-soluble vitamin B12 and water-insoluble vitamin D2 were used as model molecules. Due to their different solubility, two granulation liquid phases were also used: distilled water for granules with B12, and ethanol-water for granules with D2. Results showed that use of ethanol in the liquid phase reduces the granulation yield and produces granules having a less defined shape, a smaller mean size, a less hard structure and a worse flowability. Moreover, ethanol slightly enhances the polymer erosion rate. Results also emphasized that the vitamins solubility does not affect either the physical and the mechanical properties of the produced granules. However, it plays a significant relevant role on the molecule release mechanism, being B12 and D2 were released by diffusion and erosion mechanism, respectively.},
keywords = {Granulation, HPMC},
pubstate = {published},
tppubtype = {article}
}

@article{Simone}2018b,
title = {Wet-granulation process: phenomenological analysis and process parameters optimization},
author = {Veronica {De Simone} and Diego Caccavo and Gaetano Lamberti and Matteo D'Amore and Anna Angela Barba},
url = {https://www.sciencedirect.com/science/article/pii/S0032591018307800},
doi = {10.1016/j.powtec.2018.09.053},
year = {2018},
date = {2018-12-01},
journal = {Powder Technology},
volume = {340},
pages = {411-419},
abstract = {Wet granulation is a size-enlargement process applied in many industrial fields, such as pharmaceutical, nutraceutical, zootecnichal, to improve flowability and compressibility properties of powders. In this work analysis of the particle size distribution (PSD) of granules was performed to understand the phenomena involved during the granulation process and to optimize the operating conditions. Hydroxypropyl methylcellulose (HPMC) granules were produced spraying distilled water as liquid binder on powders in a low-shear granulator. The experimental campaign was planned using the full factorial design statistical technique varying two factors (impeller rotation speed and binder flow rate), each at three intensities. PSDs of HPMC granules at different granulation times were obtained by an ad hoc dynamic image analysis device based on the free falling particle scheme. PSD measurements showed that wet granules size depends on the simultaneous presence of nucleation, agglomeration and breakage phenomena. The process parameters optimization was carried out using response surface methodology (RSM) and using the granulation yield (% w/w of wet granules within the size range 2000\textendash10,000 μm) as the main variable of interest.},
keywords = {Granulation, HPMC},
pubstate = {published},
tppubtype = {article}
}

@article{Caccavo2017b,
title = {HPMC-Based Granules for Prolonged Release of Phytostrengtheners in Agriculture},
author = {Diego Caccavo and Sara Cascone and Pietro Apicella and Gaetano Lamberti and Anna Angela Barba},
url = {http://www.tandfonline.com/doi/full/10.1080/00986445.2017.1362398},
doi = {10.1080/00986445.2017.1362398 },
issn = {0098-6445},
year = {2017},
date = {2017-12-01},
journal = {Chemical Engineering Communications},
volume = {204},
number = {12},
pages = {1333-1340},
abstract = {One of the main aim in agriculture is to guarantee soil wellness, which is a fundamental requirement to produce high quality crops with high yields. Focused on this aim, periodical administrations of nutrients or phytostrengtheners are often necessary. The most relevant disadvantages of these administrations are the high dosage number required and the low availability of the substance within the soil. For these reasons, a crucial goal to increase the economic and environmental sustainability of the cultivation process is to reduce the dosage number, which can be obtained increasing the active substance availability in the soil. A granular HPMC (HydroxyPropyl MethylCellulose) matrix, produced using the wet granulation process, was used to encapsulate a phytostrengthener and to guarantee its controlled release. The granular product was characterized in terms of granules properties and phytostrengtheners leaching within the soil. The results showed good flowability and mechanical properties of the granules as well as the possibility to reduce the product leaching with the phytostrengtheners encapsulation in the HPMC matrices.},
keywords = {Granulation, HPMC},
pubstate = {published},
tppubtype = {article}
}

@article{Larsson2017,
title = {Effects of HPMC substituent pattern on water up-take, polymer and drug release: an experimental and modelling study},
author = {Diego Caccavo and Gaetano Lamberti and Anna Angela Barba and Susanna Abrahms\'{e}n-Alami and Anna Virid\'{e}n and Anette Larsson},
url = {http://www.sciencedirect.com/science/article/pii/S0378517317305720},
doi = {10.1016/j.ijpharm.2017.06.064},
issn = {0378-5173},
year = {2017},
date = {2017-08-07},
journal = {International Journal of Pharmaceutics},
volume = {528},
number = {1-2},
pages = {705-713},
abstract = {The purpose of this study was to investigate the hydration behavior of two matrix formulations containing the cellulose derivative hydroxypropyl methylcellulose (HPMC). The two HPMC batches investigated had different substitution pattern along the backbone; the first one is referred to as heterogeneous and the second as homogenous. The release of both the drug molecule theophylline and the polymer was determined. Additionally, the water concentrations at different positions in the swollen gel layers were determined by Magnetic Resonance Imaging. The experimental data was compared to predicted values obtained by the extension of a mechanistic Fickian based model. The hydration of tablets containing the more homogenous HPMC batch showed a gradual water concentration gradient in the gel layer and could be well predicted. The hydration process for the more heterogeneous batch showed a very abrupt step change in the water concentration in the gel layer and could not be well predicted. Based on the comparison between the experimental and predicted data this study suggests, for the first time, that formulations with HPMC of different heterogeneities form gels in different ways. The homogeneous HPMC batch exhibits a water sorption behavior ascribable to a Fick´s law for the diffusion process whereas the more heterogeneous HPMC batches does not. This conclusion is important in the future development of simulation models and in the understanding of drug release mechanism from hydrophilic matrices. },
keywords = {Erosion, HPMC, Hydrogel Characterization, Hydrogel Modeling, Mathematical modeling},
pubstate = {published},
tppubtype = {article}
}