The release kinetics of monolithic drug delivery devices based on poly(ethylene oxide) (PEG) was investigated. Water soluble PEG's with molecular weights of 600,000 and 4,000,000 and two blends were studied. The water-swelling and dissolution characteristics of the two polymers and two blends, along with the diffusivity of the drug etofylline in the water-penetrated polymer gels were analyzed. The higher molecular weight PEO and the two blends underwent swelling rather than polymer dissolution. As a result, a non-constant release induced by the prevailing diffusive control was observed. Conversely, the drug release from the lower molecular weight PEO was a result of equal rates of swelling and dissolution, which gave a constant release rate.
POLY(ETHYLENE OXIDE)-BASED DELIVERY SYSTEMS - INFLUENCE OF POLYMER MOLECULAR-WEIGHT AND GEL VISCOELASTIC BEHAVIOR ON DRUG-RELEASE MECHANISM
APICELLA, Antonio;
1994
Abstract
The release kinetics of monolithic drug delivery devices based on poly(ethylene oxide) (PEG) was investigated. Water soluble PEG's with molecular weights of 600,000 and 4,000,000 and two blends were studied. The water-swelling and dissolution characteristics of the two polymers and two blends, along with the diffusivity of the drug etofylline in the water-penetrated polymer gels were analyzed. The higher molecular weight PEO and the two blends underwent swelling rather than polymer dissolution. As a result, a non-constant release induced by the prevailing diffusive control was observed. Conversely, the drug release from the lower molecular weight PEO was a result of equal rates of swelling and dissolution, which gave a constant release rate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
