Journal of Physical Chemistry B, Vol.113, No.45, 15090-15100, 2009
In-Vitro Release Kinetics and Stability of Anticardiovascular Drugs-Intercalated Layered Double Hydroxide Nanohybrids
We report the intercalation and characterization of pravastatin and fluvastatin drugs in Mg-II/Al-III layered double hydroxides (LDHs) to form novel nanohybrid hydroxides through the coprecipitation technique powder X-ray diffraction, Fourier transform infrared spectroscopy, and thermal analysis techniques reveal that the drugs are accommodated within the brucite layers. Structural characterization, computed results. and atomic force microscopy image analysis demonstrate that the fluvastatin anions are attached with the brucite as a monolayer, whereas the pravastatin anions form a multilayer The shift in the stretching frequency of carboxylate anion of statin drugs provides evidence that the drugs are electrostatically bonded to LDHs X-ray diffraction and thermal analysis studies performed after keeping the nanohybrid particles at 75 +/- 10% relative humidity atmosphere, indicate their physical stability due to proper confinement of drugs within the layers In-vitro release study of developed nanohybrid particles suggests that the significant reduction in release rate of fluvastatin anions from fluvastatin intercalated LDHs is due to its hydrophobic nature and it can be further controlled by varying the concentration in physiological medium After release, the data were fitted to the dissolution-diffusion kinetic model The mechanism of drugs diffusion in hydrophobic nanohybrid is probably due to heterogeneous diffusion via anion exchange, while in a hydrophilic nanohybrid, it is due to intraparticle diffusion via anion exchange with the anions in the physiological medium.