Physicochemical characterization and evaluation of microemulsion system for parenteral delivery of rutaecarpine

摘要

To develop a parenteral preparation containing poorly water-soluble rutaecarpine using O/W microemulsion system, the solubility of rutaecarpine in water, ethanol, various oils and surfactants were investigated. Among the surfactants and oils tested, Tween 20/PEG 400 and castor oil were chosen as the surfactant system and oil phase of the microemulsion, as rutaecarpine was most soluble in them, respectively. Pseudoternary phase diagrams were constructed to obtain the concentration range of oil, surfactant and cosurfactant for microemulsion formation, and the stability test and pharmacokinetics of rutaecarpine delivered by microemulsion formation were then evaluated. The rutaecarpine (300 μg/g)-loaded microemulsion composed of 10.8 % PEG 400, 7.2% Tween 80, 20% caster oil and 72% water was stable for at least 6 months. It gave significantly higher AUC of rutaecarpine than did suspension, suggesting that the bioavailability of rutaecarpine in this microemulsion system could be enhanced. Thus, the microemulsion system composed of castor oil, PEG 400, Tween 80 and water could be a more stable and effective parenteral dosage form for rutaecarpine. Keywords: microemulsion; rutaecarpine; parenteral delivery; pharmacokinetics; stability