CHARACTERIZATION OF SOLUBLE, SALT-LOADED, DEGRADABLE PLGA FILMS AND THEIR RELEASE OF TETRACYCLINE

A local drug delivery system has been designed to release tetracycline over a period of 30 days from poly (lactide-co-glycolide) films. Inco rporation of either soluble salt excipients or low molecular weight po lymeric species has been found to modulate the release kinetics of the system. The following research describes the fabrication of the deliv ery system, monitors tetracycline release from the system, and fully c haracterizes the degradation of the polymer films via scanning electro n microscopy, gel permeation chromatography, differential scanning cal orimetry, Fourier-transform infrared spectroscopy, and X-ray diffracti on techniques. Results show that the modulation via use of salts occur s without changing the inherent degradation rate of the system. We sug gest that this phenomenon may be due to the increased amount of swelli ng and uptake of buffer by the films loaded with soluble salt. Uptake, therefore, may be creating microscopic pores that permit further diff usion of tetracycline from the polymer matrix as well as allow the fre e monomers to leave the system, thereby preventing autocatalysis withi n the system. (C) 1998 John Wiley & Sons, Inc.