[Study on preparation of konjac glucomannan-hydroxypropyl methyl cellulose compression coated tablets for colonic delivery and in vitro release].
OBJECTIVE
Prepare konjac glucomannan-hydroxypropyl methyl cellulose (HPMC) compression coated tablets and study the effects of the formulation, technics and in vitro dissolution condition on drug release behavior to elevate the colon-specific effects of preparation.


METHODS
Berberine hydrochloride core tablets were prepared by wet granulation technique and konjac glucomannan-HPMC mixture as the coating layer were used with compression coated technique. The effects of the formulation and technics on drug release behavior were investigated by dissolution test. The erosion of coat layer during dissolution test was investigated.


RESULTS
Drug almost not released in dissolution medium stimulating gastric and intestinal condition, and released completely by coating layer erosion and rupture by enzyme in stimulating colonic condition. Drug release decreased with decreasing the ratio of konjac glucomannan-HPMC and increasing coat weight (P < 0.05), compression force was not found to be a significant factor on drug release. Drug release increased with increasing the concentration of beta-mannase in dissolution medium (P < 0.05), rotation speed has no effect on drug release. The release of drug was correlative with erosion of coat layer. The mechanism of drug release were diffusion and erosion.


CONCLUSIONS
The konjac glucomannan-HPMC compression coated tablets was a promising delivery system for drugs to be delivered to the colon.
Zhang
Yu
Y
West China School of Pharmacy, Sichuan University, Chengdu.
Hou
Shi-xiang
SX
Lu
Yi
Y
Chen
Gang
G
Ju
Jing-hong
JH
D000284:Administration, Oral; D031056:Amorphophallus / Q000737:chemistry; D001599:Berberine / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D003106:Colon / Q000378:metabolism; D004339:Drug Compounding / Q000379:methods*; D016503:Drug Delivery Systems; D065347:Hypromellose Derivatives; D008351:Mannans / Q000737:chemistry* / Q000302:isolation & purification; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D013608:Tablets, Enteric-Coated
D008351:Mannans; D013608:Tablets, Enteric-Coated; D001599:Berberine; C022901:(1-6)-alpha-glucomannan; D065347:Hypromellose Derivatives; D008747:Methylcellulose