A systematic study of captopril-loaded polyester fiber mats prepared by electrospinning

In this study, drug-loaded nanofibers were prepared by electrospinning captopril (CPL) with aliphatic biodegradable polyesters. Poly(L-lactic acid) (PLLA), poly(lactic-co-glycolic acid) (PLGA), and poly(lactic-co-ε-caprolactone) (PLCL) were used as filament-forming matrix polymers, and the concentration of CPL in each fiber type was varied. Scanning electron microscopy indicated that the morphology and diameters of the fibers were influenced by the concentration of polymer in the spinning solution and the drug loading. CPL was found to be distributed in the polymer fibers in an amorphous manner using differential scanning calorimetry and X-ray diffraction. FTIR indicated that hydrogen bonding existed between the drug molecules and the carrier polymers. In vitro dissolution tests showed that drug release from the fibers was highly dependent on the release medium, temperature, and on the polymer used. A range of kinetic models were fitted to the drug-release data obtained, and indicated that release was diffusion controlled in all cases. The different polymer fibers have application in diverse areas of drug delivery, for instance as sub-lingual or sustained release systems. Furthermore, by combining different CPL-loaded fibers, it would be possible to produce a bespoke formulation with tailored drug-release properties.