title: Effect of zinc oxide on the rheological and mucoadhesive properties of poloxamer 407-based mucoadhesive thermosensitive gel.
abstract: BACKGROUND
  To improve the therapeutic efficacy of drugs for hemorrhoid, mucoadhesive thermosensitive gel (MTG) system was developed.
  
  
  METHODS
  The MTG was prepared using poloxamer 407 (P407, 13% and 14%), polycarbophil (PC, 0.2% w/v), phenylephrine hydrochloride (0.25% w/v), lidocaine hydrochloride (1.88% w/v), and prednisolone acetate (0.05% w/v). Then, zinc oxide (ZnO) was added as an astringent as well as mucoadhesiveness-enhancing agent. Two kinds of poloxamer-based MTGs were compared in aspects of rheology, mucoadhesiveness, syringeability, and in vitro release study.
  
  
  RESULTS
  Both the two MTGs (13% and 14% P407) showed Newtonian behavior at 20°C whereas pseudoplastic flow at 37°C. The addition of ZnO into MTGs enhanced the mucoadhesiveness and syringeability and led the drug components to be released in accordance with Fickian mechanism.
  
  
  CONCLUSIONS
  Taken together, the MTG-containing ZnO can be a more effective and convenient delivery system for the treatment of hemorrhoid with a reduced dosage interval.
authors.affiliation: Laboratory of Excellency for Drug and Gene Delivery, College of Pharmacy, Seoul National University, Seoul, Republic of Korea.
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Park
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Jeong-Sook
authors.initials: JS
authors.lastname: Park
authors.forename: Han-Gon
authors.initials: HG
authors.lastname: Choi
authors.forename: Hyung Tae
authors.initials: HT
authors.lastname: Kim
authors.forename: Chong-Kook
authors.initials: CK
authors.lastname: Kim
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000268:Adhesiveness; D000818:Animals; D001252:Astringents / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers; D004548:Elasticity; D005782:Gels; D066298:In Vitro Techniques; D008012:Lidocaine / Q000737:chemistry / Q000378:metabolism; D009092:Mucous Membrane / Q000737:chemistry* / Q000378:metabolism; D010656:Phenylephrine / Q000737:chemistry / Q000378:metabolism; D020442:Poloxamer / Q000737:chemistry*; D011239:Prednisolone / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012212:Rheology; D013696:Temperature; D014783:Viscosity; D015034:Zinc Oxide / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000180:Acrylic Resins; D001252:Astringents; D004337:Drug Carriers; D005782:Gels; D020442:Poloxamer; D010656:Phenylephrine; C009935:prednisolone acetate; C030312:calcium polycarbophil; D008012:Lidocaine; D011239:Prednisolone; D015034:Zinc Oxide