Effect of drug encapsulation and sterilization process on physicochemical properties and release of combined steroid hormones from poly (ε-caprolactone) fibers

Abstract

Commercially available medications for contraception and other uterine medical conditions include oral pills, intramuscular injections, implantable devices etc. However, the side effects and limitations such as ease of use associated with the conventional techniques motivates the researchers to develop new drug delivery systems to address these issues. This article highlights the potential of electrospun fibers as a platform for use as a long-acting drug delivery system for contraceptive steroids. In this study, individual and combined hormonal contraceptive drugs (Levonorgestrel - LNG, and ethinylestradiol - EE) loaded poly (ε-caprolactone) (PCL) fibers were developed using electrospinning technique. The effect of drug loading and ethylene oxide (EtO) sterilization on the physicochemical properties of these fibers, as well as their drug release ability was then investigated to establish their use for sustained and prolonged drug delivery platform. The efficiency of drug encapsulation (DEE %) was found to be influenced by the amount of drug loaded. Morphological images demonstrated a smooth and continuous structure, with traces of drug crystals at higher concentrations on the fiber surfaces. In-vitro release data indicated that EE was released at a faster rate compared to LNG from both individually loaded and dual drug loaded fibers. No significant difference was observed in the release of LNG and EE from the fibers, with drug loaded individually or in combination. Drug release mechanism was found to be a combination of diffusion and erosion. The physicochemical and release properties of the electrospun fibers were not significantly affected by the sterilization process and thus proved to be a safe method of sterilizing the fibers. Furthermore, the drug-loaded fibers were found to be compatible with cellular structures, indicating their biocompatibility.