Pharmacokinetics and dose proportionality of BMS-204352 after intraarterial administration to rats.

BMS-204352 is a novel maxi-K channel opener that is being developed for the treatment for stroke. The current study was designed to evaluate the dose proportionality and pharmacokinetics of BMS-204352 in rats. In an open, parallel fashion, sixteen rats per gender received a single intraarterial dose of BMS-204352 as a 3-min infusion into the carotid artery at 0.4, 2.0, 5.0 and 10.0 mg/kg dose levels. Serial blood samples were collected for up to 24 h post-dose and plasma samples were analyzed for the concentrations of intact BMS-204352 using a validated liquid chromatographic mass spectrometric (LC/MS) method. Pharmacokinetic analysis was performed using a non-compartmental method. Results revealed a gender difference in the pharmacokinetics of BMS-204352 in rats at all doses excluding the first (i.e., 0.4 mg/kg) dose panel. BMS-204352 peak plasma concentration (C(max)) and area under the plasma concentration-time curve (AUC) values increased in a proportion greater than the increment in dose. Specifically, as dose increased in the ratio 1:5:12.5:25, C(max) increased in the ratio 1:7:18:31 in male rats and 1:7:22:51 in female rats. The respective AUC ratios were 1:6:20:42 in male rats and 1:12:29:77 in female rats. Mean total body clearance (CL(T)) values for BMS-204352 ranged from 879-3242 ml/h/kg over the four dose levels and generally decreased with increase in dose. Similarly, steady state volume of distribution (V(SS)) values ranged from 3621-8933 ml/kg over the four dose levels and generally decreased with increase in dose. However, mean residence time (MRT) and elimination half-life (T(1/2)) values for BMS-204352 were independent of dose and ranged from 2.42-4.54 to 2.08-4.70 h, respectively. In conclusion, BMS-204352 appears to exhibit dose-dependent pharmacokinetics in rats. In addition, there appeared to be some evidence of gender related differences in the pharmacokinetics of BMS-204352.

Pharmacokinetics and dose proportionality of BMS-204352 after intravenous administration to dogs.

BMS-204352 is a novel maxi-K channel opener that is being developed for the treatment for stroke. The current study was designed to evaluate the dose proportionality and pharmacokinetics of BMS-204352 in dogs. In an open, three-way crossover study, three beagle dogs received a single intravenous dose of BMS-204352 as a 6-min infusion into the femoral vein at 0.4, 0.9, and 2.0 mg/kg dose levels. There was at least a 1-week washout period between treatments. Serial blood samples were collected for up to 32 h post dose and plasma samples were analyzed for the concentrations of intact BMS-204352 using a validated liquid chromatographic mass spectrometric (LC/MS) method. Pharmacokinetic analysis was performed using a non-compartmental method. Results indicated that peak BMS-204352 concentrations (C(max)) and area under the plasma concentration-time curves (AUC) values increased in a dose proportional manner. Mean residence time (MRT, 18.2-21.9 h) and elimination half-life (T(half), 13.5-17 h) did not change with dose. There was no dose dependency in the mean BMS-204352 total body clearance (CLT, 134-158 ml/h/kg) and mean steady state volume of distribution (VSS, 2839-3291 ml/kg). The high VSS value indicated that BMS-204352 was distributed extensively in the extravascular tissues. In conclusion, BMS-204352 exhibits linear pharmacokinetics over the dose range tested (0.4-2 mg/kg).

High performance liquid chromatographic-mass spectrometric assay for the quantitation of BMS-204352 in dog K(3)EDTA plasma.

A high performance liquid chromatographic-mass spectrometric (LC/MS) assay was developed and validated for the determination of BMS-204352 in dog K(3)EDTA plasma. A 0.5 mL aliquot of control plasma was spiked with BMS-204352 and internal standard (IS) and buffered with 1 mL of 5 mM ammonium acetate. The mixture was then extracted with 3 mL of toluene. After separation and evaporation of the organic phase to dryness using nitrogen at 40 degrees C, the residue was reconstituted in the mobile phase and 25 microL of the sample were injected onto a Hypersil C(18) column (2 x 50 mm; 3 microm) at a flow rate of 0.5 mL/min. The mobile phase was consisted of two solvent mixtures (A and B). Solvent A was composed of 5 mM ammonium acetate and 0.1% triethylamine in 75:25 v/v water:methanol, pH adjusted to 5.5 with glacial acetic acid, and solvent B was 5 mM ammonium acetate in methanol. A linear gradient system was used to elute the analytes. The mass spectrometer was programmed to admit the de-protonated molecules at m/z 352.7 (IS) and m/z 357.9 (BMS-204352). Standard curves of BMS-204352 were linear (r(2) > or = 0.998) over the concentration range of 0.5-1000 ng/mL. The mean predicted quality control (QC) concentrations deviated less than 5.1% from the corresponding nominal values (ie 4, 80, 400 and 2000 ng/mL); the within- and between-assay precision of the assay were within 5.5% relative standard deviation. Stability of BMS-204352 was confirmed after at least three freeze/thaw cycles and BMS-204532 was stable in dog plasma when stored frozen at or below -20 degrees C for at least 16 weeks in spiked QC samples and for at least 4 1/2 weeks for in vivo study samples. BMS-204352 and IS were stable in the injection solvent at room temperature for at least 24 h. The assay was applied to delineate the pharmacokinetic disposition of BMS-204352 in dogs following a single intravenous dose administration. In conclusion, the assay is accurate, precise, specific, sensitive and reproducible for the pharmacokinetic analysis of BMS-204532 in dog plasma.