NGHIÊN CỨU BÀO CHẾ VÀ ĐÁNH GIÁ HỆ VI TỰ NHŨ (SMEDDS) CHỨA OLMESARTAN MEDOXOMIL

Abstract

Background: Olmesartan medoxomil (OLM) is poorly water-soluble, which can limit dissolution and contribute to low oral bioavailability. Objectives: To develop and evaluate a selfmicroemulsifying drug delivery system (SMEDDS) to enhance OLM solubility and oral absorption. Materials and methods: Solubility and self-emulsification were screened to select the oil phase, surfactant, and co-surfactant. Pseudo-ternary phase diagrams were constructed and OLM loading of candidate formulas (1-3% w/w) was assessed. Selected systems were characterized for particle size, polydispersity index (PDI), zeta potential, thermodynamic stability, X-ray diffraction (XRD), and drug release in a gastrointestinal simulation system (GISS). Results: The A5/B1 SMEDDS (Capryol 90-Croduret 40-Transcutol HP) achieved 2% w/w OLM loading, rapidly self-emulsified, and produced particles of 14–17 nm with PDI < 0.1 and zeta potential of 10 mV, The system was thermodynamically stable with no OLM recrystallization detected from XRD in the test condition. In GISS, it released 80% of OLM after 10 min and 100% after 50 min, maintained till the end of the test, outperforming the raw drug and a reference product. Conclusions: The OLM-loaded SMEDDS forms a nano-sized emulsified system with low PDI and improves OLM solubility and in vitro release in simulated gastrointestinal media, providing a basis for further formulation optimization.