The potential of nanofibers to increase solubility and dissolution rate of the poorly soluble and chemically unstable drug lovastatin

Polymer nanofibers represent a promising drug delivery system. However, as a large surface area is exposed to external conditions during the electrospinning process, they are usually used to incorporate drugs with good oxidative stability. Here, we introduce a new concept for the incorporation of a drug with low oxidative stability and extremely low solubility into poloxamer 188/poly(ethylene oxide) and Soluplus/poly(ethylene oxide) nanofibers, to improve its solubility and increase its dissolution rate. The electrospun products showed different morphologies and lower initial lovastatin contents than theoretically expected, which indicated oxidative drug degradation during electrospinning. The addition of antioxidants improved the lovastatin chemical stability in the nanofibers. The highest lovastatin dissolution rate and solubility were obtained for the Soluplus-based nanofibers, where no crystalline lovastatin was detected. The accelerated stability study has revealed the chemical stability of lovastatin in the poloxamer-based nanofibers with the addition of antioxidants, whereas in the Soluplus-based nanofibers lovastatin was not completely preserved. However, appropriate packaging of the formulation and storage under normal conditions is expected to assure its stability. These Soluplus-based nanofibers developed here with antioxidants represent a promising immediate release formulation to provide improved solubility and dissolution rate for poorly soluble and chemically unstable drugs, such as lovastatin.