Effective ribavirin concentration in mice brain using cyclodextrin as a drug carrier: evaluation in a measles encephalitis model.

Ribavirin (RBV) is a water-soluble synthetic nucleoside with broad spectrum antiviral properties, but it is ineffective against major viral encephalitis because of a failure to cross the blood-brain barrier (BBB). The antiviral activity of the complex ribavirin/alpha-cyclodextrin was previously demonstrated to be stronger than free ribavirin, in an in vivo model of measles virus (MV) encephalitis in mice. The role of cyclodextrin (CD) on ribavirin uptake into the brain needs to be defined. Ribavirin specific extraction from brain tissue was developed, based on a solid phase extraction. It was quantified by high performance liquid chromatography at different time points after intraperitoneal injection of single or multiple doses of free ribavirin or of the complex ribavirin/alpha-cyclodextrin. Whatever the tested dose (40 or 100mg/kg), the amount of ribavirin in the brain was significantly higher (p<0.001) when the drug was injected as a complex with alpha-cyclodextrin, in healthy or measles virus-infected mice.