Castellanos Gil, Eddy and Iraizoz Colarte, Antonio and Bataille, Bernard and Brouillet, Fabien and Caraballo, Isidoro
Estimation of the percolation thresholds in ternary lobenzarit disodium–dextran–HPMC hydrophilic matrices tablets: Effects of initial porosity.
(2009)
European Journal of Pharmaceutical Sciences, 38 (4). 312-319. ISSN 0928-0987
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(Document in English)
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Official URL: https://doi.org/10.1016/j.ejps.2009.07.013
Abstract
The aim of this work is to estimate the excipient percolation threshold for a new combined matrix native dextran (DT), series B110-1-2 (Mw 2×106): HPMC K4M CR: lobenzarit disodium (LBD) system and demonstrate the advantages of this ternary system with respect to previously reported binary dextran:LBD and HPMC:LBD tablets. The formulations studied were prepared with different amounts of excipient (DT:HPMC, 4:1 (wt/wt) for all tablets and relative polymer/drug particle size of 4.17) in the range of 10–70% (wt/wt). Dissolution studies were carried out using the paddle method (100rpm) and one face water uptake measurements were performed using a modified Enslin apparatus. The Higuchi's models as well as the non-linear regression were employed as empiric methods to study the released data. Values of diffusion exponent 0.588<n<0.784 (Korsmeyer equation) for dissolution profile and water uptake mechanism 0.715<n<0.960 (Davidson and Peppas equation) suggests anomalous or complex mechanisms in all cases. The critical points in ternary tablets were reduced from 44.75% (v/v) of excipient (correspond to purely native dextran) to 22.34% (v/v) (corresponding to mixture native dextran:HPMC, 4:1, wt/wt). The initial porosity (IP) of hydrophilic matrices above the values of 20% has an important influence on the percolation threshold as well as on establishment of the gel barrier responsible for the controlled release from the DT:HPMC:LBD tablets.
Item Type: | Article |
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HAL Id: | hal-00610199 |
Audience (journal): | International peer-reviewed journal |
Uncontrolled Keywords: | |
Institution: | Other partners > Universidad de La Habana - UH (CUBA) Other partners > Université de Montpellier 1 (FRANCE) Other partners > Universidad de Sevilla (SPAIN) |
Funders: | European Union Programme Alßan |
Statistics: | download |
Deposited On: | 16 Oct 2019 14:26 |
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