Berberine hydrochloride (BBH) has a variety of pharmacological activities such as antitumor, antimicrobial, anti-inflammation, and reduce irritable bowel syndrome. However, poor stability and low oral bioavailability limited its usage. Herein, an oil-in-water nanoemulsion system of BBH was developed to improve its stability and oral bioavailability. The pseudoternary phase diagrams were constructed for the determination of composition of various nanoemulsions. The nanoemulsions of BBH composed of Labrafil M 1944 CS (oil phase), RH-40 (surfactant), glycerin (co-surfactant), and water (aqueous phase). The O/W nanoemulsion of BBH showed a relative bioavailability of 440.40% compared with unencapsulated BBH and was stable in our 6-month stability study. Further, there was a significant increase in intestinal permeability of BBH as assessed by Caco-2 cell monolayers and a significant reduction in efflux of BBH by the multidrug efflux pump P-glycoprotein. This study confirmed that the nanoemulsion formulation could be used as an alternative oral formulation of BBH to improve its stability, oral bioavailability and permeability.
Keywords: Berberine hydrochloride; Caco-2 cells; bioavailability; nanoemulsion; transport.