The bioavailability of cytarabine in dogs with meningoencephalitis of unknown etiology through iontophoresis and rectal delivery

Abstract

Background: Cytarabine (CA) is used to treat dogs with meningoencephalitis of unknown etiology (MUE) by subcutaneous or intravenous administration.
 Aim: The objective was to investigate transdermal iontophoresis and rectal administration as alternative routes of CA delivery.
 Methods: Two client-owned dogs with MUE were studied. The ActivaPatch® IONTOGOTM 12.0 iontophoresis drug delivery system delivered 200 mg/m2 CA transdermally. Blood samples were collected by sparse sampling technique after initiation of the device. At another visit, 100 mg/m2 CA was administered rectally. Blood samples were collected by sparse sampling technique after administration. Plasma CA concentrations were measured by high-pressure liquid chromatography.
 Results: The concentration of plasma CA after transdermal and rectal administration was below the limits of quantification (0.1 μg/ml) in all samples suggesting inadequate bioavailability with transdermal and rectal administration.
 Conclusion: Transdermal and rectal CA administration are not reasonable alternative routes of delivery.

Novel subcutaneous cytarabine infusion with the Omnipod system in dogs with meningoencephalomyelitis of unknown etiology

“…However, oral, rectal, and transdermal administration of CA are associated with poor bioavailability. [11][12][13] The Omnipod system is an SC insulin delivery system used for the management of diabetes mellitus in humans (Insulet Corp). The Omnipod is a wireless, self-powered, tubeless, disposable, waterproof, continuous insulin management system that consists of a "pod" (insulin pump) and a smartphone-like device (Personal Diabetes Manager [PDM]) that communicates with the pod using Bluetooth technology.…”