Transport characteristics of a novel local drug delivery system using nordihydroguaiaretic acid (NDGA)-polymerized collagen fibers.

The use of nordihydroguaiaretic acid (NDGA)-polymerized collagen fibers as a novel local drug delivery system is introduced. The drug loading of these biocompatible fibers is illustrated with the anti-inflammatory agents dexamethasone and dexamethasone 21-phosphate. Capillary zone electrophoresis was used to measure the amount of drug released from the fibers into phosphate buffered saline with time. From these measurements and the use of a mathematical model, we were able to determine the diffusion coefficients for dexamethasone (D = 1.86 x 10(-14) m2/s) and dexamethasone 21-phosphate (D = 2.36 x 10(-13) m2/s) in the NDGA collagen fibers. These values have not been previously reported. These fibers can be used to load other agents as well. The diffusion coefficient of any agent loaded in these fibers can be determined using the techniques and mathematical method described. The rate of drug release from the fibers can be controlled using a PLGA coating. The overall importance of this paper is the potential broad application of this novel drug delivery system for the treatment of various human diseases.