Oral ciclopirox olamine displays biological activity in a phase I study in patients with advanced hematologic malignancies.

The antimycotic ciclopirox olamine is an intracellular iron chelator that has anticancer activity in vitro and in vivo. We developed an oral formulation of ciclopirox olamine and conducted the first-in-human phase I study of this drug in patients with relapsed or refractory hematologic malignancies (Trial registration ID: NCT00990587). Patients were treated with 5-80 mg/m² oral ciclopirox olamine once daily for five days in 21-day treatment cycles. Pharmacokinetic and pharmacodynamic companion studies were performed in a subset of patients. Following definition of the half-life of ciclopirox olamine, an additional cohort was enrolled and treated with 80 mg/m² ciclopirox olamine four times daily. Adverse events and clinical response were monitored throughout the trial. Twenty-three patients received study treatment. Ciclopirox was rapidly absorbed and cleared with a short half-life. Plasma concentrations of an inactive ciclopirox glucuronide metabolite were greater than those of ciclopirox. Repression of survivin expression was observed in peripheral blood cells isolated from patients treated once daily with ciclopirox olamine at doses greater than 10 mg/m², demonstrating biological activity of the drug. Dose-limiting gastrointestinal toxicities were observed in patients receiving 80 mg/m² four times daily, and no dose limiting toxicity was observed at 40 mg/m² once daily. Hematologic improvement was observed in two patients. Once-daily dosing of oral ciclopirox olamine was well tolerated in patients with relapsed or refractory hematologic malignancies, and further optimization of dosing regimens is warranted in this patient population.

Evaluation of an osmotic pump for microdialysis sampling in an awake and untethered rat.

The feasibility of using an osmotic pump in place of a syringe pump for microdialysis sampling in rat brain was investigated. The use of an osmotic pump permits the rat to be free from the constraints of the standard tethered system. The in vitro flow rates of a microdialysis syringe pump (set at 10.80 microl/h) and the osmotic pump (pump specifications were 11.35 microl/h) with no probe attached were compared, yielding results of 10.87 microl/h+/-1.7% and 10.95 microl/h+/-8.0%, respectively. The average of four flow rate experiments in vivo yielded R.S.D.s less than 10% and an average flow rate of 11.1 microl/h. Following the flow rate studies, in vivo sampling of neurotransmitters was accomplished with the osmotic pump coupled to a microdialysis probe implanted in the brain. Finally, after determination of basal levels of 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindole-3-acetic acid (5-HIAA) in the rats, the rats were dosed with benserazide followed by l-3,4-dihydroxyphenylalanine (l-DOPA). The results from the dosing study showed at least a 10-fold increase in compounds in the l-DOPA metabolic pathway (DOPAC and HVA) and a slight or no increase in 5-HIAA (serotonin metabolic pathway.) These results indicate that the osmotic pump is a viable alternative to the syringe pump for use in microdialysis sampling.

Rapid fabrication of poly(dimethylsiloxane)-based microchip capillary electrophoresis devices using CO2 laser ablation.

The use of CO(2) laser ablation for the patterning of capillary electrophoresis (CE) microchannels in poly(dimethylsiloxane)(PDMS) is described. Low-cost polymer devices were produced using a relatively inexpensive CO(2) laser system that facilitated rapid patterning and ablation of microchannels. Device designs were created using a commercially available software package. The effects of PDMS thickness, laser focusing, power, and speed on the resulting channel dimensions were investigated. Using optimized settings, the smallest channels that could be produced averaged 33 microm in depth (11.1% RSD, N= 6) and 110 microm in width (5.7% RSD, N= 6). The use of a PDMS substrate allowed reversible sealing of microchip components at room temperature without the need for cleanroom facilities. Using a layer of pre-cured polymer, devices were designed, ablated, and assembled within minutes. The final devices were used for microchip CE separation and detection of the fluorescently labeled neurotransmitters aspartate and glutamate.