title: Ronidazole pharmacokinetics in cats following delivery of a delayed-release guar gum formulation.
abstract: Ronidazole (RDZ) is the only known effective treatment for feline diarrhea caused by Tritrichomonas foetus. This study aimed to develop guar gum-coated colon-targeted tablets of RDZ and to determine the pharmacokinetics of this delayed-release formulation in cats. Guar gum-coated tablets were administered orally once to five healthy cats (mean dose 32.3 mg/kg). The tablets were then administered once daily for 5 days to four cats (mean dose 34.5 mg/kg), and absorption studies repeated on day 5. Plasma was collected and analyzed for RDZ concentration, and pharmacokinetic noncompartmental and deconvolution analysis were performed on the data. There was negligible RDZ release until after 6 h, and a delayed peak plasma concentration (mean Cmax 28.9 μg/mL) at approximately 14.5 h, which coincides with colonic arrival in cats. Maximum input rate (mg/kg per hour) occurred between 6 and 16 h. This delayed release of ronidazole from guar gum-coated tablets indicates that release of RDZ may be delayed to deliver the medication to a targeted area of the intestine. Repeated dosing with guar gum tablets to steady-state did not inhibit drug bioavailability or alter the pharmacokinetics. Such targeted RDZ drug delivery may provide improved efficacy and reduce adverse effects in cats.
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA. mark_papich@ncsu.edu
authors.forename: M G
authors.initials: MG
authors.lastname: Papich
authors.forename: D N
authors.initials: DN
authors.lastname: Levine
authors.forename: J L
authors.initials: JL
authors.lastname: Gookin
authors.forename: G S
authors.initials: GS
authors.lastname: Davidson
authors.forename: W C
authors.initials: WC
authors.lastname: Stagner
authors.forename: R B
authors.initials: RB
authors.lastname: Hayes
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002415:Cats / Q000097:blood / Q000378:metabolism*; D003692:Delayed-Action Preparations; D005685:Galactans / Q000737:chemistry*; D006207:Half-Life; D008297:Male; D008351:Mannans / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*; D012385:Ronidazole / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D013607:Tablets
chemical_list: D000981:Antiprotozoal Agents; D003692:Delayed-Action Preparations; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D013607:Tablets; D012385:Ronidazole; C007894:guar gum