Development of an implantable drug delivery catheter.

A microtextured, pillared drug delivery system has been designed and tested in rabbits. This model has allowed for the calculation of the mass transport rate indicating after a 4 week time period a pillar device's mass transport rate K1 [min-1] is K1p 1.54 x 10(-2) in contrast to the smooth control which is K1C .043 x 10(-2) and K1im IM which is 0.136 x 10(-2). As a result of these experiments, it is apparent a micropillared drug delivery system is an order magnitude faster than an intramuscular injection and is 30 times faster than the smooth control device. The etiology for this difference is related to close blood vessel proximity and minimal to no fibrous capsule formation with the micropillared implant. Finally, even after a 6-month implantation time, the pillared device has greater reproducibility regarding curve profile and there is no loss in magnitude or rate of mass transport, in contrast the smooth control devices in many instances resulted in complete occlusion with total loss of mass transport capabilities.