Controlled Release of Tetracycline Hydrochloride Loaded Highly Absorbent Alginate Submicron Fibers from Centrifugally Spinning

Highly absorbent alginate/polyethylene oxide submicron fibers containing the hydrophilic model drug tetracycline hydrochloride were prepared through centrifugal spinning. Pre-treatment with ethanol before crosslinking with calcium chloride solution maintained the structure of submicron fibers. The crosslinked submicron fibers could absorb phosphate buffer over 8 hours continuously, and they absorbed more phosphate buffer than commercial alginate dressing (Kaltostat and Algisite M). The morphology and chemical structures of submicron fibers were also investigated. In-vitro drug release tests revealed that more than 70 % (86 % 75 % and 73 % for drug loaded CA1, CA2 and CA3 fibers, respectively) of the loaded drug could be released continuously from the fibers in 24 hours, which matches well with the change frequency guidance of wound dressing for exuding wounds with heavy to moderate exudate. TCH loaded submicron fibers maintained the inhibition effect on Gram-positive S. aureus (31.25±0.71 mm (TCH-CA1), 30.85±0.27 mm (TCH-CA2) and 28.75±1.01 mm (TCH-CA3)) and Gram-negative E. coli . (29.8±0.35 mm (TCH-CA1), 29.28±0.87 mm (TCH-CA2) 27.38±0.64 mm (TCH-CA3)). These drug-loaded alginate submicron fibers may have application in wound dressing for exuding wounds.