In Vivo/In Vitro Correlation of Intravitreal Drug Delivery from Biodegradable Polymer Implants

摘要

An approach for predicting the drug concentration in the vitreous body has been proposed for intravitreal drug delivery by biodegradable polymer implants. The release rates of a model drug, dexamethasone sodium m-sulfobenzoate (DMSB), from poly lactic acid implants were measured under in vitro and in vivo conditions using Japanese albino rabbits. The pharmacokinetic model assuming the cylindrical vitreous body was then solved together with the in vivo release ratea nd the other model parameters determined separately. The mathematical model successfully described the drug concentration-time profile in the vitreous body. The vivo concentration-time profile in the rabbit vitreous body agreed with the one predicted on the basis of the in vitro release profile. These findings may suggest that if the in vivo release profile is known or predicted, the in vivo concentration in the vitreous body can be evaluated by the help of computer simulation without carrying out the in vivo release experiment which is usually time-consuming for controlled release formulations.