Effect of carrier types on the physicochemical and dissolution characteristics of ofloxacin solid dispersion

Abstract

Solid dispersions of ofloxacin (OFX) and of a number of carriers including chitosan and the water soluble polymers polyethylene glycol (PEG) 4000, PEG 20000, and polyvinylpyrrolidone K-90 were prepared by solvent evaporation method in order to increase the dissolution of the drug. The solid dispersions were subjected to X-ray diffraction, DSC, and dissolution to characterize their physicochemieal and dissolution properties. The results demonstrated a decrease in drug crystallinity at higher amounts of carrier. Dissolution studies indicated that the dissolution rate of OFX was markedly increased in these solid dispersion systems compared with the pure drug. The results also showed that the increase in dissolution rate was higher when the weight fraction of carriers increased. An influence of molecular weight of PEG on OFX dissolution could also be observed. In solid dispersion with 1:9 ratio drug to carrier, PEG 4000 gave highest drug dissolution rate, whereas in 1:1 ratio, chitosan seems to be the best carrier for drug release. It was concluded that chitosan might be the carrier of choice for dissolution enhancement in solid dispersions with high content of drug.