Formulation and in vitro-in vivo evaluation of piribedil solid lipid micro- and nanoparticles.

Modification of the dissolution rate and, thus, the enhancement of the bioavailability of a dopaminergic drug, piribedil, which has a low aqueous solubility and short elimination half-life have been the aim in this study. Preparations of micron and submicron particles using solid lipid carriers have been performed for this purpose. For the avoidance of solvent residues resulting from the preparation technique, cold and hot homogenization methods have been used to prepare solid lipid particles. After obtaining an appropriate particle size, piribedil loading and preparation yield by the use of those two methods, various formulations have been prepared with different lipid, drug and surfactant materials. The factors mentioned were found to affect properties of the particles, and the release rate was found to be the fastest in acidic medium. Suspensions of pure piribedil and a formulation, selected according to the results obtained from in vitro dissolution and particle size experiments, were compared using tremor tests in mice. The same suspensions were applied perorally to rabbits and bioavailability of the solid lipid particle was found to be higher than the pure piribedil. After an in vitro-in vivo evaluation of piribedil solid lipid particles developed for Parkinson's disease therapy, it has been determined that release rate could be controlled and piribedil bioavailability could be improved.