INVESTIGATIONS ON THE ADSORPTION OF QUERCETIN ON A MEDICINAL CARBONICADSORBENT - CONTROLLED-RELEASE AND STABILITY

The process of adsorption/desorption of quercetin (which is therapeuti cally used in the Ukraine owing to its antioxidant and radical scaveng ing activities) on the surface of the medicinal carbonic adsorbent ''D nieper'' was studied. Owing to a high adsorption capacity, the adsorbe nt could be used as a carrier for immobilised drugs. On the basis of d esorption data, liberation of quercetin from the complex quercetin-ads orbent can be characterized as rapid initial with subsequent sustained release. On the surface of the adsorbent, quercetin does not loose it s antioxidative activity. However, adsorption leads to instability of quercetin as well as of kaempferol and rutin caused mainly by oxidatio n during storage.