A novel evaluation method of gastric mucoadhesive property in vitro and the mucoadhesive mechanism of tetracycline-sucralfate acidic complex for eradication of Helicobacter pylori.
OBJECTIVE
The gastric mucoadhesive property of tetracycline-sucralfate acidic complex (CO) was evaluated by using a novel method in vitro to compare with the in vivo test. The mucoadhesive mechanism of the acidic complex was also studied.


METHODS
The gastric mucosa removed from a rat was placed covering the end of a plunger and secured in a disposable syringe. The acidic test medium was gradually infused in and then flowed out. Two different kinds of CO, tetracycline, or a physical mixture (PM) were introduced into the device to compare their mucoadhesive properties. The tetracycline content in the residue on the mucosa was measured. The results were compared with those of the in vivo test. The acidic response of CO and the protein binding capacity of a sucrose octasulfate group (SOS) in sucralfate or CO were evaluated.


RESULTS
The mucoadhesive properties of CO were clearly superior to those of PM. The remaining amounts of tetracycline in each test sample, determined by the in vitro test, were in agreement with those of the in vivo test. The excellent mucoadhesive property of CO appeared to be caused by the rapid response to the acid and resulting mucoadhesive gel formation. Furthermore, the binding capacity of SOS to the protein was clearly greater than that of PM. The excessive acid treatment during the preparation of CO tended to decrease the mucoadhesive property.


CONCLUSIONS
CO appeared to be potentially useful for the eradication of Helicobacter pylori because of the direct delivery of tetracycline to the gastric mucosa for an extended period of time.
Higo
Shoichi
S
Product Research Department, Chugai Pharmaceutical Co. Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513, Japan. higosui@chugai-pharm.co.jp
Ori
Kazutomo
K
Takeuchi
Hirofumi
H
Yamamoto
Hiromitsu
H
Hino
Tomoaki
T
Kawashima
Yoshiaki
Y
D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry; D005753:Gastric Mucosa / Q000378:metabolism; D016481:Helicobacter Infections; D016480:Helicobacter pylori; D013392:Sucralfate; D013752:Tetracycline
D000900:Anti-Bacterial Agents; D013392:Sucralfate; D013752:Tetracycline