title: Microencapsulation of cytarabine using poly(ethylene glycol)-poly(epsilon-caprolactone) diblock copolymers as surfactant agents.
abstract: BACKGROUND
  The high water solubility and the low molecular weight of cytarabine (Ara-C) are major obstacles against its particulate formulation as a result of its low affinity to the commonly used hydrophobic polymers.
  
  
  METHODS
  Biodegradable cytarabine loaded-microparticles (Ara-C MPs) were elaborated using poly(-caprolactone) (PCL) and monomethoxy polyethylene glycol (mPEG)-PCL diblock copolymer in order to increase the hydrophilicity of the polymeric matrix. For this purpose, a series of mPEG-PCL diblock copolymers with different PCL block lengths were synthesized. Compositions and molecular weights of obtained copolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, size exclusion chromatography, and size exclusion chromatography-multi-angle laser light scattering. Ara-C MPs were prepared by double emulsion-solvent evaporation method. The effects of varying PCL block lengths on microparticle encapsulation efficiency, size, and zeta potential were evaluated.
  
  
  RESULTS
  Increasing the PCL block lengths of copolymers substantially increased the Ara-C encapsulation efficiency and the microparticle size but it decreased their zeta potential. Microparticles were spherical in shape, with a smooth surface and composed of homogenously distributed Ara-C-containing aqueous domains in the polymer matrix. The in vitro drug release kinetics of the optimized microparticles showed a hyperbolic profile with an initial burst release.
  
  
  CONCLUSIONS
  These results showed the important role of the amphiphilic diblock copolymers as stabilizing agent in the encapsulation of Ara-C in PCL microparticles, suggesting their potential use for the microparticulate formulations of other small hydrophilic bioactive molecules.
authors.affiliation: Pharmaceutical Technology Department, Laboratoire d'Automatique et de Génie de Procédés (LAGEP), Université Claude Bernard Lyon 1, ISPBL-Faculté de Pharmacie de Lyon, Villeurbanne, France.
authors.forename: Roudayna
authors.initials: R
authors.lastname: Diab
authors.forename: Misara
authors.initials: M
authors.lastname: Hamoudeh
authors.forename: Olivier
authors.initials: O
authors.lastname: Boyron
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Elaissari
authors.forename: Hatem
authors.initials: H
authors.lastname: Fessi
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000737:chemistry; D003561:Cytarabine / Q000008:administration & dosage* / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004339:Drug Compounding / Q000379:methods*; D004655:Emulsions; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000964:Antimetabolites, Antineoplastic; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D011091:Polyesters; D011108:Polymers; D013501:Surface-Active Agents; D003561:Cytarabine; C016240:polycaprolactone; D011092:Polyethylene Glycols