Shelby L. Mancini(1), Peter J. Early(1*), Bethany O. Pastina(2), Natasha J. Olby(1), Christopher L. Mariani(1) and Karen R. Munana(1)
1- NC State University Veterinary Hospital, 1052 William Moore Drive, Raleigh, NC, 27607, USA
2- Veterinary Medical Center of Long Island, 75 Sunrise Highway, West Islip, NY, 11795-2033, USA
Background: Cytarabine (CA) is used to treat dogs with meningoencephalitis of unknown etiology (MUE) by subcutaneous (SC) or intravenous (IV) 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® IONTOGO™ 12.0 iontophoresis drug delivery system delivered 200 mg/m^2 CA transdermally. Blood samples were collected by sparse sampling technique after initiation of the device. At another visit, 100 mg/m^2 CA was administered rectally. Blood samples were collected by sparse sampling technique after administration. Plasma CA concentrations were measured by high-pressure liquid chromatography (HPLC).
Results: The concentration of plasma CA after transdermal and rectal administration was below the limits of quantification (0.1ug/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.
Keywords: Dog, Meningoencephalitis, Cytarabine, Bioavailability.