MgAl monolayer hydrotalcite increases the hypoglycemic effect of berberine by enhancing its oral bioavailability.

Berberine (BBR) is a potential novel agent to treat diabetes, but its oral bioavailability is restricted by the poor solubility, which greatly limits its clinical application. Here, a new drug delivery system of BBR-MgAl monolayer hydrotalcite (BBR/MLDH) was prepared to increase the solubility and bioavailability of BBR. The results showed that BBR/MLDH presented as a uniform hexagonal plate-like particle with a loading capacity of 28.61 %, a diameter of ∼70 nm and a thickness of ∼1.5 nm. The solubility and dissolution of BBR increased when loading onto MLDH. Compared with BBR, pharmacokinetics of BBR/MLDH in rats showed significant enhancement (P < 0.01) in area under the curve (AUC) and the peak plasma concentration (Cmax), suggesting the bioavailability of BBR was improved. Furthermore, BBR/MLDH showed more potent effects in reducing fasting blood glucose, ameliorating glucose tolerance and insulin resistance comparing to the equivalent dose of BBR. In a word, the solubility, oral bioavailability and hypoglycemic effect of BBR could be improved by loading onto MLDH.