Design of pH-independent controlled release matrix tablets for acidic drugs Export

@article{citeulike:490694, abstract = {The rate and extent of drug release from most controlled release systems are influenced by the pH of the dissolution medium for drugs with pH-dependent solubility. This dependency of drug release on pH may lead to additional inter- and intra-subject variability in drug absorption. In the present study, a pH-independent controlled release matrix system for acidic drugs was designed by incorporating release-modifiers in the formulation. Controlled release matrix tablets were prepared by compression of divalproex sodium, Methocel K4M and Eudragit E 100 or Fujicalin as the release-modifier. For formulations without any release-modifier, the extent and rate of drug release at pH 6.8 was much higher than that at pH 1.0. Formulations containing Eudragit E 100 provided drug release that was essentially independent of pH. This was achieved because Eudragit E 100 significantly increased the drug release in acidic medium and slightly decreased the release rate at higher pH. The increased release in the acidic medium can be attributed to the elevation of the micro-environmental pH in the swollen polymer gel layer. Formulations containing Fujicalin were less effective than those containing Eudragit E 100. This was attributed to the relative inability to elevate the pH and shorter residence time of Fujicalin in the matrix relative to Eudragit E 100.}, author = {Rao, Venkatramana M. and Engh, Kevin and Qiu, Yihong}, citeulike-article-id = {490694}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/S0378-5173(02)00622-1}, citeulike-linkout-1 = {http://www.sciencedirect.com/science/article/B6T7W-47HK8MF-2/2/e7ef9b96f60cc07878efcba0de41a193}, day = {18}, doi = {10.1016/S0378-5173(02)00622-1}, journal = {International Journal of Pharmaceutics}, keywords = {25082005, presentacion}, month = {February}, number = {1-2}, pages = {81--86}, posted-at = {2006-02-03 09:43:15}, priority = {0}, title = {Design of pH-independent controlled release matrix tablets for acidic drugs}, url = {http://dx.doi.org/10.1016/S0378-5173(02)00622-1}, volume = {252}, year = {2003} }

TY - JOUR ID - citeulike:490694 L3 - citeulike-article-id:490694 N2 - The rate and extent of drug release from most controlled release systems are influenced by the pH of the dissolution medium for drugs with pH-dependent solubility. This dependency of drug release on pH may lead to additional inter- and intra-subject variability in drug absorption. In the present study, a pH-independent controlled release matrix system for acidic drugs was designed by incorporating release-modifiers in the formulation. Controlled release matrix tablets were prepared by compression of divalproex sodium, Methocel K4M and Eudragit E 100 or Fujicalin as the release-modifier. For formulations without any release-modifier, the extent and rate of drug release at pH 6.8 was much higher than that at pH 1.0. Formulations containing Eudragit E 100 provided drug release that was essentially independent of pH. This was achieved because Eudragit E 100 significantly increased the drug release in acidic medium and slightly decreased the release rate at higher pH. The increased release in the acidic medium can be attributed to the elevation of the micro-environmental pH in the swollen polymer gel layer. Formulations containing Fujicalin were less effective than those containing Eudragit E 100. This was attributed to the relative inability to elevate the pH and shorter residence time of Fujicalin in the matrix relative to Eudragit E 100. IS - 1-2 JF - International Journal of Pharmaceutics EP - 86 TI - Design of pH-independent controlled release matrix tablets for acidic drugs VL - 252 SP - 81 KW - 25082005 KW - presentacion AU - Rao, Venkatramana AU - Engh, Kevin AU - Qiu, Yihong PY - 2003/02/18/ UR - http://dx.doi.org/10.1016/S0378-5173(02)00622-1 ER -