Formulation and Physicochemical Characterization of Imwitor 308 Based Self Microemulsifying Drug Delivery Systems

DOI Web Site Web Site 37 References
  • Zargar-Shoshtari Sara
    Drug Delivery Research Unit (2DRU), School of Pharmacy, University of Auckland
  • Wen Jingyuan
    Drug Delivery Research Unit (2DRU), School of Pharmacy, University of Auckland
  • Alany Raid Ghassan
    Drug Delivery Research Unit (2DRU), School of Pharmacy, University of Auckland

Search this article

Description

Self Microemulsifying Drug Delivery Systems (SMEDDS) are a novel alternative to the conventional transdermal delivery systems. SMEDDS are water-free systems, made up of oils and surfactants that can readily form a microemulsion upon dilution within an aqueous medium. Before SMEDDS can be used as a drug delivery system it is necessary to investigate the internal microstructure of the resulting microemulsion. Novel Imwitor 308 based SMEDDS were prepared and investigated. Phase behaviour of the comprising components was investigated through the construction of pseudoternary phase diagrams. The formed systems were characterized using visual inspection, measurement of electrical conductivity, viscosity and droplet size. Amongst the pseudoternary systems investigated, IPM/Cremophor EL (50% w/w)/Imwitor (50% w/w) and Myritol 318/Tween 85 (64% w/w)/ Transcutol P (20% w/w)/Imwitor (16% w/w) possessed the largest microemulsion area. Electrical conductivity and viscosity studies depict structural transitions from w/o microemulsion to bicontinuous or o/w microemulsion around 20—35% water. This was further supported by the droplet size and Fourier transform (FT)-IR measurements. The FT-IR data suggests that below the percolation threshold (φC) the water molecules are mainly bounded to the surfactant head group (bound water). Above this value, water molecule move to the outer phase of the microemulsion mainly interacting with each other though hydrogen bounding (free water). It was also found that pseudoternary systems with water content of less than 30% were stable at 32°C. Such systems may form stable microemulsion upon contact with the skin. Absorption of water may also result in a supersaturated solution with enhanced transdermal flux.

Journal

References(37)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top