MORPHOLOGY AND DRUG RELEASE OF PH-SENSITIVEMICROSPHERES CONTAINING FLAVONOIDS

摘要

In this work we developed pH-sensitive microspherical dosage forms for poorly water soluble flavonoids(quercetin and naringenin) by using Eudragit L100 as enteric polymer. The systems were produced by waterin oil (w/o) solvent evaporation method, optimizing the formulation and preparation conditions in order toobtain high encapsulation efficiency and production yield. The synthesized microspheres were characterizedin terms of particle size distribution, drug loading, morphology and in vitro release properties. The performedanalyses evidenced that the microspheres were free- flowing and spherical in shape, both quercetin andnaringenin were microencapsulated in the amorphous state and the drug content was near to the theoreticalone. Preliminary in vitro dissolution studies, carried out using a pH-change method, showed that thesamples exhibit a typical biphasic drug release trend, due to the pH dependent solubility of the entericpolymers used. In particular, the samples have a fairly gastroresistance followed by an about completerelease in simulated intestinal fluid.