A novel dextran polymer hydrogel local antimicrobial therapy in dogs: A pilot study.

Our purpose was to evaluate physical, laboratory, and/or radiographic abnormalities associated with a novel dextran polymer hydrogel local antimicrobial agent impregnated with amikacin and clindamycin in dogs having tibial plateau leveling osteotomy implants removed due to suspected surgical site infection. A total of 28 client-owned dogs were enrolled and 20 completed the study. Routine plate explantation and bacterial cultures were performed and the polymer hydrogel was applied to the surgery site. No systemic antimicrobials were used after surgery. Serum biochemistry, hematology, urinalysis, physical examinations, and radiographs were monitored before surgery and up to 12 wk after surgery. Sixteen of the 20 dogs (80%) had a positive bacterial culture, 44% of which were methicillin resistant. There were no significant alterations of laboratory values, physical examination, or radiographs to indicate adverse reactions to the polymer hydrogel. There were no signs of inflammation or infection in any patient at the 12-week postoperative recheck.

Thérapie antimicrobienne innovatrice locale à l'hydrogel de polymère de dextrane chez les chiens : étude pilote. Notre but consistait à évaluer les anomalies physiques, de laboratoire et/ou radiographiques associées à un nouvel agent antimicrobien local d'hydrogel de polymère de dextrane imprégné d'amikacine et de clindamycine chez les chiens dont les implants d'ostéotomie de nivellement du plateau tibial avaient été enlevés en raison d'une infection suspectée du site de la chirurgie. Un total de 28 chiens appartenant à des clients ont été recrutés et 20 ont fait partie de l'étude. Une explantation de routine de la plaque et des cultures bactériennes ont été réalisées et l'hydrogel de polymère a été appliqué au site de la chirurgie. Aucun antimicrobien systémique n'a été utilisé après la chirurgie. Une biochimie sérique, l'hématologie, l'analyse d'urine, des examens physiques et des radiographies ont été réalisés avant la chirurgie et jusqu'à 12 semaines après la chirurgie. Seize des 20 chiens (80 %) avaient une culture bactérienne positive dont 44 % était résistante à la méthicilline. Il n'y avait aucune altération importante des valeurs de laboratoire, de l'examen physique ou des radiographies pour indiquer des réactions indésirables à l'hydrogel de polymère. Il n'y a eu aucun signe d'inflammation ou d'infection chez aucun patient lors d'un examen postopératoire à 12 semaines.(Traduit par Isabelle Vallières).

In vitro elution and antibacterial activity of clindamycin, amikacin, and vancomycin from R-gel polymer.

OBJECTIVE: To characterize the in vitro elution and bioactivity of 2 formulations of antibiotics in a novel, dissolvable, cross-linked dextran polymer matrix: Formulation 1-amikacin and clindamycin (AC); Formulation 2-amikacin, clindamycin, and vancomycin (ACV). STUDY DESIGN: Prospective, in vitro, experimental study. METHODS: Aliquots of the antibiotic impregnated polymer were incubated in PBS buffer for 10 days. PBS was changed every 24 hours and concentrations of the antibiotics eluted into saline were quantified. Antimicrobial activity of the eluent from each sampling period was tested for growth inhibition of Staphylococcus aureus. RESULTS: Both formulations of R-gel(™) had a rapid initial release of antibiotics within the first 24 hours and then the concentrations decreased gradually over 10 days. The concentration of amikacin, clindamycin, and vancomycin remained above the breakpoint minimum inhibitory concentration of each drug for a minimum of 9 days. No significant difference (P=.9938, P=.9843) was present in the elution pattern or total amount of antibiotic eluted from clindamycin or amikacin, respectively. Eluent from both groups demonstrated bioactivity against S. aureus for the entire 10-day study period. CONCLUSIONS: Amikacin and clindamycin together, or in combination with vancomycin, elute from R-gel(™) effectively and at gradually decreasing concentrations for at least 10 days. The antibiotics maintained their bioactivity following polymerization and elution from the R-gel(™) .

Disposition and metabolism of cumene in F344 rats and B6C3F1 mice.

Cumene is a high-production volume chemical that has been shown to be a central nervous system depressant and has been implicated as a long-term exposure carcinogen in experimental animals. The absorption, distribution, metabolism, and excretion of [(14)C]cumene (isopropylbenzene) was studied in male rats and mice of both sexes after oral or intravenous administration. In both species and sexes, urine accounted for the majority of the excretion (typically ≥ 70%) by oral and intravenous administration. Enterohepatic circulation of cumene and/or its metabolites was indicated because 37% of the total dose was excreted in bile in bile duct-cannulated rats with little excreted in normal rats. The highest tissue (14)C levels in rats were observed in adipose tissue, liver, and kidney with no accumulation observed after repeat dosing up to 7 days. In contrast, mice contained the highest concentrations of (14)C at 24 h after dosing in the liver, kidney, and lung, with repeat dosing accumulation of (14)C observed in these tissues as well as in the blood, brain, heart, muscle, and spleen. The metabolites in the expired air, urine, bile, and microsomes were characterized with 16 metabolites identified. The volatile organics in the expired air comprised mainly cumene and up to 4% α-methylstyrene. The major urinary and biliary metabolite was 2-phenyl-2-propanol glucuronide, which corresponded with the main microsomal metabolite being 2-phenyl-2-propanol.