COMPARISON OF CONVECTIVE TRANSPORT OF DRUG BETWEEN INTRAVITREAL INJECTION AND CONTROLLED RELEASE IMPLANT

摘要

It is important to know the drug distribution following administration of drug in order to properly treat with adequate dosage and thus, avoid damage to tissues due to excessive high concentrations. A computer model was developed to determine drug distribution by convective-diffusive transport processes in a rabbit eye. When compared with pure diffusion within vitreous, the ratio of the amount of a model compound, fluorescein, reaching the retina to that cleared by aqueous outflow increased by 93% and 84% for intravitreal injection and implant, respectively, with maximum vitreous outflow (glaucomatous eye). The result shows that the combined "convective" effect due to the vitreous outflow and "wash out" effect by aqueous outflow has significant impact on drug distribution for both intravitreal injection and implant. These two effects should be considered in the design of drug delivery strategies.