Development of simvastatin electrospun fibers: a novel approach for sustained drug delivery

Abstract

In the present investigation simvastatin electrospun fibers were developed using electrospinning apparatus with drug–polymer w/w ratios of 1:1, 1:2, 1:3 and 1:4. Also solid mixtures were prepared with same ratios by employing kneading technique as conventional approach for comparison in drug release rate. Polyethylene oxide WSR coagulant 301, a hydrophilic matrix forming polymer, was used as carrier for sustained release of simvastatin. The ability of polyethylene oxide to control the drug release rate in both the formulations was also investigated. Studies were performed to characterize the optimized dosage form. Drug was crystalline in pure form. SEM surface morphology studies as well as powder X-ray diffractometry studies to developed fibers reveals that the crystalline drug was converted into amorphous form after fiber development. No physical incompatibility was found in FTIR and DSC studies of pure drug and physical mixture of drug, polymer. In vitro studies were performed in sodium phosphate buffer (pH 7.0) containing 0.5 % SLS. Simvastatin release was sustained over a period of 12 h in electrospinning fibers developed with drug to polymer w/w ratio 1:4 and 98.86 ± 0.42 % drug release was observed, interestingly with the same ratio there was a burst release of drug was obtained in case of solid mixtures “within span of 1 h”. Polyethylene oxide showed vast difference in drug release rate due to the techniques chosen to prepare formulations. The stability studies were also performed to the optimized product and no significant variance was observed in all the evaluation parameters. From the various mathematical models the drug release kinetics was estimated and found that the drug release followed zero order release rate kinetics with non fickian process as drug release mechanism.