Preclinical pharmacokinetics of a promising antineoplastic prototype piperazine-containing compound (LQFM018) in rats by a new LC-MS/MS bioanalytical method.

LQFM018 is a novel antineoplastic prototype, showing an expressive drug-triggered K562 leukemic cells death mechanism, through necroptotic signaling. Due to its promising effect, this study aimed to evaluate the pharmacokinetics of LQFM018 in rats, using a new validated bioanalytical LC-MS/MS-based method. Chromatographic column was an ACE® C18 (100 mm × 4.6 mm, 5 µm) eluted by a mobile phase composed of ammonium acetate 2 mM and formic acid 0.025%:methanol (50:50, v/v), under flow of 1.2 mL/min and injection volume of 3.0 µL. LQFM018 was extracted from rat plasma by a simple liquid-liquid method, using MTBE solvent. Rats were administered intraperitoneally at LQFM018 100 mg/kg dose and blood samples were collect at times of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 h. Bioanalytical-LC-MS/MS-based method was rapid, high throughput and sensitive with a good linearity ranging from 10 (LLOQ) to 15000 ng/mL, besides precise and accurate, ranging of 0.8-7.3% and 96.8-107.6%, respectively. The prototype LQFM018 was rapid and well absorbed, and highly distributed, apparently due to its high lipid solubility. These features are primordial for an anticancer agent in the treatment of deep tumors, such as bone marrow neoplasms, in which the drug might permeate easily tissue barriers. Also, LQFM018 has demonstrated a high clearance, according to a low t1/2in rats, indicating a relative fast elimination phase related to a possible intense hepatic biotransformation. These information support further studies to establish new understands on pharmacokinetics of promising antineoplastic prototype LQFM018 from preclinical and clinical evaluations.

Individualizing oral busulfan dose after using a test dose in patients undergoing hematopoietic stem cell transplantation: pharmacokinetic characterization.

BACKGROUND: Busulfan is an alkylating agent used for conditioning patients undergoing hematopoietic stem cell transplantation with a narrow therapeutic range and highly variable pharmacokinetics. High concentrations induce toxicity, especially hepatic veno-occlusive disease, also referred to as sinusoidal obstruction syndrome. This study aimed to assess busulfan pharmacokinetic variability in pretransplant conditioning regimens using an analytical method validated by high-performance liquid chromatography coupled to diode array detector (HPLC/PDA). METHODS: Eight patients who used the test dose (TD) of 1 mg/kg busulfan 10 days before conditioning were included, and 10 serial blood samples were collected to determine: the elimination half-life (t1/2), total area under the curve (AUCT), total clearance (Cl(T)/F), and plasma concentration at steady state (C(ss)), using a monocompartmental model and first-order kinetics. The instrumental conditions were: HPLC/PDA Shimadzu, column ACE C18 (150 mm × 4 mm); methanol/water/acetonitrile (65:20:15) eluent flow rate of 1 mL/min; 1,6-bis-(methanesulfonyloxy)-hexane; UV λ = 276 nm; analysis time 17 minutes; and derivatization with sodium diethylcarbamate. The dose was adjusted, and 4 blood samples per day were collected at days 2, 3, and 4 of treatment for new plasma determinations. RESULTS: Four patients needed higher doses; the mean dose administered was 1.02 ± 0.19 mg/kg. Mean results at TD: t1/2 = 2.88 ± 0.5 hours; Cl(T)/F = 0.18 ± 0.03 L · h(-1) · kg(-1); AUC(T) = 5461.00 ± 961.15 ng · mL(-1) · h(-1); and C(ss) = 911.3 ± 159.8 ng/mL. Mean results of samples collected during conditioning: t1/2 = 3.21 ± 0.9 hours; Cl(T)/F = 0.13 ± 0.02 L · h(-1) · kg(-1); AUC(T) = 7571 ± 1705 ng · mL(-1) · h(-1); and C(ss) = 1262.0 ± 284.3 ng/mL. CONCLUSIONS: High variability in the assessed pharmacokinetic parameters was observed, with a 38% variation in C(ss) between TD and conditioning regimen; Cl(T)/F decreased by 30%, suggesting drug accumulation after multiple-dose regimen. Although being lower than reported in the literature, this variation may be associated with toxicity of the proposed treatment, justifying patient monitoring and enhancing validity of previous pharmacokinetic evaluation using TD regimen.