title: Development of an osmotically-driven pellet coated with acrylic copolymers (Eudragit® RS 30 D) for the sustained release of oxymatrine, a freely water soluble drug used to treat stress ulcers (I): in vitro and in vivo evaluation in rabbits.
abstract: OBJECTIVE
  To develop an osmotically-driven pellet coated with polymeric film for sustained release of oxymatrine (OMT), a freely water soluble drug.
  
  
  METHODS
  Pellet containing OMT and sodium chloride (NaCl), an osmotically active agent, were prepared by extrusion/spheronization and then coated with acrylic copolymers (Eudragit(®) RS 30 D) by the fluidized bed coating process. In vitro release and swelling behavior studies were employed to optimize and to evaluate the sustained-release behavior from the osmotically-driven pellets with film coated. Finally, in vivo evaluation in rabbits was employed to investigate the sustained plasma level of OMT and its active metabolite matrine.
  
  
  RESULTS
  It was found that the F3 formulation, prepared with 20% NaCl and an 8% coating level, showed a continuous NaCl-induced water influx into the pellets providing a gradual sustained release of OMT for over 12 h. Finally, we confirmed that oral OMT with sustained release led to a gradual sustained plasma profile of both OMT, with a reduction in its bioavailability, and MT with an increase in the bioavailability compared with that of oral OMT with immediate release.
  
  
  CONCLUSIONS
  The pharmaceutical parameters obtained suggested the potential usefulness of oral OMT with sustained release for the treatment of stress ulcers, as well as reducing the risk of MT-induced side effects.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Piao
authors.forename: Shihong
authors.initials: S
authors.lastname: Liu
authors.forename: Hongze
authors.initials: H
authors.lastname: Piao
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Li
authors.forename: Fude
authors.initials: F
authors.lastname: Cui
mesh_terms: D000180:Acrylic Resins / Q000008:administration & dosage*; D000470:Alkaloids / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D003692:Delayed-Action Preparations; D008297:Male; D009997:Osmotic Pressure; D011807:Quinolizines / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D011817:Rabbits; D012965:Sodium Chloride / Q000494:pharmacology; D012995:Solubility; D013276:Stomach Ulcer / Q000188:drug therapy*; D013315:Stress, Psychological / Q000150:complications*; D000093842:Matrines
chemical_list: D000180:Acrylic Resins; D000470:Alkaloids; D003692:Delayed-Action Preparations; D011807:Quinolizines; D012965:Sodium Chloride; C050528:Eudragit RS; C037573:oxymatrine; D000093842:Matrines