Effect of zinc oxide on the rheological and mucoadhesive properties of poloxamer 407-based mucoadhesive thermosensitive gel.
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.
Park
Tae-Hwan
TH
Laboratory of Excellency for Drug and Gene Delivery, College of Pharmacy, Seoul National University, Seoul, Republic of Korea.
Kim
Sung Tae
ST
Park
Jeong-Sook
JS
Choi
Han-Gon
HG
Kim
Hyung Tae
HT
Kim
Chong-Kook
CK
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
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