Characteristics of Cholesteryl Cetyl Carbonate Liquid Crystals as Drug Delivery Systems

A thermotropic liquid crystals of cholesteryl cetyl carbonate was investigated as a novel nanosystem for delivery of lipophilic drugs. The aims were to synthesize, characterize and develop a formulation for amphotericin B (AmB) in cholesteryl cetyl carbonate liquid crystals. Cholesteryl cetyl carbonate was synthesized and identified by thin layer chromatography (TLC), flash column chromatography, Fourier transformed infrared (FTIR) spectroscopy, mass spectrometry (MS) and Nuclear magnetic resonance spectroscopy (NMR). X-ray diffraction (XRD), transmission electron microscope (TEM), polarized light microscope and differential scanning calorimetry (DSC) were employed to characterize liquid crystals properties. Cholesteryl cetyl carbonate structure is composed of three parts; steroid planar nucleus, hydrocarbon chains and carbonate linkage between the two parts of steroid ring and hydrocarbon chain from fatty alcohol. The phase transition temperatures appeared at around 8 and 36degC and cubic-shaped formation were observed in a micrograph at room temperature. The formulations of AmB in liquid crystals after physical mixing with a sugar revealed high content uniformity and had good characteristics of dry powder forms. It caused low toxicity to red blood cells.