Study on Release Characteristics of pH-and Enzyme-Controlled Tablets of Berberine Hydrochloride for Colon-Specific Delivery in Rats

Objective:To study the release characteristics of berberine hydrochloride colon-specific tablets in rats.Methods:The rats were administrated orally with the colon-specific tablets of diameter 3mm and killed at different time points.The gastrointestinal tracts were removed and disposed.The contents of berberine,in different segments of the gastrointestinal tract,were determined by HPLC respectively,using internal standard method.The changes of berberine in gastrointestinal contents were studied to evaluate the release characteristics of the tablet.Results:The linear range of berberine in different contents of the gastrointestinal tract was 0.1~20.0μg·mL-1,the standard curve was in good linearity(r0.999).The detection limit of berberine was 0.1μg·mL-1.The drug was specifically released in caecum and colon and maintained at a higher concentration between 6~14h.Conclusion:The pH-and enzyme-controlled tablet of berberine hydrochloride is a carrier for targeting the colon.