| Abstract |
Nifedipine, a potent calcium-channel blocking agent, widely used for treating hypertension has been immobilized inside inorganic matrix materials. The drug was intercalated in Montmorillonite K10 clay by cation exchange, and loaded by an adsorption method inside the channels of mesoporous MCM-41. Spectroscopic evidence (FTIR, powder X-ray diffraction (XRD)) as well as elemental analysis thermal analysis and electron microscopy revealed the preparation of the drug-loaded materials. Release profiling in a simulated body fluid from MCM-41 is fast, indicating that a concentration peak is reached in a short period of time, while the release profile from KID is much slower. The release profile from MCM-41 leads to higher drug solubility compared even with neat drug solubility, which is advantageous in a drug known for its low solubility (ca. 20 mu g mL(-1)). The same is true for K10 clay although its slow release kinetics leave it behind. Spectroscopic data supports this fact by showing that intermolecular host-guest interactions occur thus leading to the observed kinetic effects in the release experiments. In addition it is found that nifedipine inside the host materials is more resistant to photodegradation than in its pure form thus showing another important feature of the hybrid organic/inorganic formulation, as evidenced by GC data. (C) 2013 Elsevier Inc. All rights reserved. |
