title: [Preparation of solid lipid nanoparticles loaded with all-trans retinoic acid and their evaluation in vitro and in vivo].
abstract: OBJECTIVE
  To prepare solid lipid nanoparticles (SLN) loaded with all trans retinoic acid using an ultrasonic technique with Compritol 888 ATO as matrix material, and investigate properties of nanoparticles in vitro and in vivo.
  
  
  METHODS
  Ultrasonic technique was adopted to prepare solid lipid nanoparticles in an aqueous system using all-trans retinoic acid (ATRA) as a model drug. Physicochemical proterties of SLN were investigated in detail. Drug release from two sorts of ATRA-SLN was investigated using a dialysis bag method. Compared with ATRA solution, the in vivo pharmacokinetics of two sorts of ATRA-SLN after intravenous injection to rats were studied.
  
  
  RESULTS
  Solid lipid nanoparticles loaded with all-trans retinoic acid was readily and quickly prepared by ultrasonic technique. The morphological investigation by Transmission Electron Microscopy (TEM) showed that the particles had round and uniform shapes. The mean diameters of them were (158 +/- 9) nm and (89 +/- 11) nm separately. The SLN dispersion was stable at 4 degrees C for more than one year. Drug loading was 3.3%, drug entrapment efficiency was more than 95%, the in vitro release was well in accordance with Weibull distribution. Compared with ATRA control solution, SLN could stay in the blood circulation for a longer time after intravenous injection.
  
  
  CONCLUSIONS
  The ultrasonic technique was appropriate for the preparation of solid lipid nanoparticles.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Lian-Dong
authors.initials: LD
authors.lastname: Hu
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
authors.forename: Fu-De
authors.initials: FD
authors.lastname: Cui
mesh_terms: D000818:Animals; D004337:Drug Carriers; D016503:Drug Delivery Systems; D004355:Drug Stability; D005227:Fatty Acids; D008297:Male; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size; D020442:Poloxamer / Q000737:chemistry; D011136:Polysorbates; D051381:Rats; D017208:Rats, Wistar; D014212:Tretinoin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D014465:Ultrasonics
chemical_list: D004337:Drug Carriers; D005227:Fatty Acids; D011136:Polysorbates; D020442:Poloxamer; C086409:glyceryl behenate; D014212:Tretinoin