Validation of an UPLC-MS-MS Method for Quantitative Analysis of Vincristine in Human Urine After Intravenous Administration of Vincristine Sulfate Liposome Injection.

Vincristine sulfate liposome injection (VSLI) is a liposomal formulation of vincristine (VCR) sulfate, being developed for the systemic treatment of cancer. In this paper, we have developed and validated a method to quantify VCR in human urine to obtain the urinary excretion of VCR after intravenous administration of VSLI. The analyte was extracted from urine samples using liquid-liquid extraction after addition of vinblastine (VBL, used as internal standard) and chromatographed on an Acquity UPLC HSS T3 column with a gradient mobile phase at a flow rate of 0.4 mL/min. The multiple reactions monitoring transitions of m/z 413.2 → 353.2 and m/z 406.2 → 271.6 were used to quantify VCR and VBL, respectively. The lower limit of quantification was 0.5 ng/mL with a precision (RSD%) of 5.7% and an accuracy (RE%) of 6.7%. The calibration curve was linear up to 100.0 ng/mL. Intraday precision and accuracy ranged from 0.8 to 11.0% and from -12.4 to 11.3%, respectively. Interassay precision and accuracy ranged from 8.0 to 10.1% and from -7.7 to 3.6%, respectively. No significant matrix effect was observed for VCR. The method was successfully applied for pharmacokinetic study of VSLI to investigate the route and extent of VCR urinary excretion in Chinese subjects with lymphoma.

Determination of drug residues in urine of dogs receiving anti-cancer chemotherapy by liquid chromatography-electrospray ionization- tandem mass spectrometry: is there an environmental or occupational risk?

Cytotoxic drugs, previously used only in human medicine, are increasingly utilized for cancer treatment in veterinary practice. We developed and validated a liquid chromatography (LC)-electrospray ionization-tandem mass spectrometry (MS-MS) method to determine vincristine, vinblastine, cyclophosphamide, and doxorubicin in canine urine. Sample pretreatment consisted of liquid-liquid extraction, and LC separation was carried out on an RP C(18) column employing a 0.5% formic acid/methanol gradient system. The analytes were detected in positive ion mode using the MS-MS scan mode. The mean recoveries in six different urine samples were between 64.2% and 86.9%. Limits of quantitation were 0.5 microg/L for vincristine and vinblastine, 1 microg/L for cyclophosphamide, and 5 microg/L for doxorubicin; limits of detection were approximately 0.25 microg/L for vincristine, vinblastine, and cyclophosphamide and 0.5 microg/L for doxorubicin. It could be demonstrated that all investigated drugs are found in urine of dogs undergoing chemotherapy. In samples from day 1 after chemotherapy, as much as 63 microg/L vincristine, 111 microg/L vinblastine, and 762 microg/L doxorubicin could be detected. Cyclophosphamide showed only minor concentrations on day 1, but up to 2583 microg/L could be found directly after chemotherapy. These initial data show that there might be a potential contamination risk when administering cytotoxics in veterinary medicine.

Cytotoxic drug residues in urine of dogs receiving anticancer chemotherapy.

BACKGROUND: The presence of cytotoxic drug residues in urine of dogs may represent an exposure risk for pet owners and other people as well as a potential environmental contaminant. However, studies on cytotoxic drug residues in excretions of clinical patients are lacking in veterinary oncology. HYPOTHESIS: Variable concentrations of cytotoxic residues are present in urine samples, depending on sampling time and substance. ANIMALS: Client-owned dogs with lymphoma or mast cell tumors treated with standard chemotherapy protocols. METHODS: Urine samples were collected before, directly after, and on days after administration of chemotherapy. Measurement of vincristine, vinblastine, cyclophosphamide, and doxorubicin residues in canine urine was performed by a quantitative liquid chromatography tandem mass spectrometry (LC/MS/MS) method. RESULTS: Median cyclophosphamide residue concentration was 398.2 microg/L directly after treatment (d0) and was below the level of detection on days 1-3 (d1, d2, d3). Median vincristine residue concentration was 53.8 microg/L directly after treatment and was 20.2, 11.4, and 6.6 microg/L on days 1, 2, and 3. Median vinblastine residues were 144.9 (d0), 70.8 (d1), 35.6 (d2), and 18.7 microg/L (d3) with low concentrations detectable for 7 days after treatment. Median urine doxorubicin concentrations were 354.0 (d0), 165.6 (d1), 156.9 (d2), and 158.2 microg/L (d3). Low concentrations of doxorubicin were measurable up to 21 days after administration. CONCLUSIONS AND CLINICAL IMPORTANCE: Variable concentrations of chemotherapeutics were measured in urine samples, depending on sampling time point and drug. Findings may inform current chemoprotection guidelines and help minimize exposure risks.

Pharmacokinetics and urinary excretion of vincristine sulfate liposomes injection in metastatic melanoma patients.

Vincristine sulfate liposomes injection (VSLI) is a liposomal formulation of vincristine encapsulated in sphingosomes composed of sphinogomyelin and cholesterol (58/42; mol/mol). The pharmacokinetics and urinary excretion of VSLI were evaluated in 12 patients with metastatic melanoma after single-dose (2.0 mg/m2 every 2 weeks = 1 cycle) and multiple-dose (cycle 3, pharmacokinetics only) administrations (intravenous infusion over 1 hour). After VSLI infusion, total (released and encapsulated) vincristine concentrations in plasma remained relatively constant for 3 to 12 hours and thereafter declined, with interpatient variability seen in the rate of decline resulting in monoexponential or biexponential profiles. The area under the plasma concentration-time curve from time zero to infinity of total vincristine in plasma ranged from 4933 to 40495 h.ng/mL and total clearance ranged from 131 to 445 mL/h. The volume of distribution at steady state was 2650 +/- 731 mL, indicating VSLI was mainly confined within the plasma. The released vincristine concentrations in plasma were below the level of quantitation in 95% of samples. The pharmacokinetic parameters were similar between cycles 1 and 3, and trough plasma levels of total vincristine were below the level of quantitation of 1 ng/mL. Approximately 8% of the injected dose was excreted in the urine as unchanged vincristine (7%) or N-desformylvincristine (0.8%). Overall, VSLI exhibited a longer circulation half-life and higher area under the plasma concentration-time curve compared to conventional vincristine, whereas its route of elimination remained unchanged.

Effect of PSC 833, a P-glycoprotein modulator, on the disposition of vincristine and digoxin in rats.

PSC 833 has been used to overcome the phenomenon of multidrug resistance by inhibiting the P-glycoprotein (P-gp)-mediated efflux of antitumor drugs from tumor cells. Because P-gp expressed in several normal tissues may affect the disposition of its substrates, we examined the dose-dependent effect of PSC 833 on the disposition of vincristine (VCR) and digoxin (DGX) in rats. One-tenth milligram per kilogram PSC 833 was sufficient to significantly reduce the biliary excretion clearance of DGX from 3.0 ml/min/kg to 0.5 ml/min/kg, whereas 3 mg/kg PSC 833 was needed to significantly reduce the biliary excretion clearance of VCR from 36 ml/min/kg to 9 ml/min/kg. Three milligrams per kilogram PSC 833 significantly reduced the renal clearance of VCR by 30% but did not affect that of DGX significantly. The tissue-to-plasma DGX concentration ratio in the brain at 6 h after administration (0.34 versus 1.64), but not that of VCR at 2 h (1.07 versus 1.37), was significantly increased by PSC 833, 3 mg/kg. The differential effect of PSC 833 on the disposition of VCR and DGX may be ascribed to the different degree of contribution of P-gp to the disposition of these ligands.

Detection of genotoxic substances in cancer patients receiving antineoplastic drugs.

A short-term bacterial mutation test, the SOS Chromotest, has been used to detect the excretion in urine of genotoxic metabolites of antineoplastic drugs administered to cancer patients. In this test, the damage to the DNA of the test bacteria is expressed by the production of beta-galactosidase, which can be quantitatively assessed and is proportional to the concentration of the drug. Kinetic curves of excretion for adriamycin, bleomycin, dacarbazine, cis-platinum and vincristine and their mixtures have been constructed from standard curves relating the intensity of the beta-galactosidase response to the concentration of drugs dissolved in normal urine. Comparative data on extraction and concentration of the drugs from urine or serum by means of selective resin or silica columns are presented.

Analysis of vinca alkaloids in plasma and urine using high-performance liquid chromatography with electrochemical detection.

The reversed-phase high-performance liquid chromatography with electrochemical detection was used to quantify plasma and urine levels of vinblastine, vincristine, vindesine and a metabolite of vinblastine, desacetylvinblastine. Sample clean-up consisted of solid-phase extraction with a Bond Elut CN column. The extracts were separated on a Hypersil ODS column. The mobile phase consisted of a mixture of methanol and 10 mM phosphate buffer (pH 7.0). The limit of sensitivity using electrochemical detection was 100 pg on-column for all compounds with a signal-to-noise ratio of 3. Quantification of the compounds in human plasma and urine was possible down to 1 ng/ml (ca. 1 pmol). Pharmacokinetic results show that the sensitivity of the method is adequate for drug monitoring in clinical research.

Solid-phase extraction of vinblastine and vincristine from plasma and urine: variable drug recoveries due to non-reproducible column packings.

A sensitive and selective high-performance liquid chromatographic (HPLC) method for the determination of vinblastine and vincristine in plasma and urine is described. The drugs are isolated from 1.0 ml of the biological fluid with a solid-phase extraction column (Bond-Elut Diol). The HPLC method was combined with electrochemical detection at +850 mV versus an Ag/AgCl reference electrode. The detection limit is 100 pg for vinblastine and 250 pg for vincristine with a signal-to-noise ratio of 3, which permits the determination of these compounds in biological fluids at the nanogram level. Evaluation of the isolation method revealed that the drug recoveries and the reproducibility of the extraction procedure depend on the batch number of the solid-phase extraction column used.

The pharmacokinetics of [3H]-vincristine in man.

The pharmacokinetics, metabolism, and excretion of aromatically labeled tritiated vincristine (VCR) was examined in 4 patients. Clearance of radioactivity from the blood was triphasic with half-life t1/2 values of 0.85, 7.4, and 164 min. The initial phases probably represent distribution and binding to formed blood elements which exceeded 50% of the administered dose by 20 min. Excretion of radioactivity was principally fecal, with 33% recovered in the feces by 24 hr and 69% by 72 hr. Considerably less radioactivity (12%) was excreted in the urine over the 72-hr period. Approximately 40% of fecally excreted and 46% of urinary excreted radiolabel represented metabolites, which suggests that at least 34% of the VCR dose was excreted as metabolies. Plasma metabolites represented from less than 1% to 30% or more of radioactivity in plasma. Ultraviolet spectral analysis of all metabolites revealed preservation of the intact VCR dimer, which suggests that metabolism involves alteration of side groups.

Pharmacokinetics of vindesine and vincristine in humans.

Vindesine, a new Phase 1 Vinca alkaloid congener, exhibited serum pharmacokinetic behavior in humans compatible with a three-compartment, open mammilary model. The kinetic parameters included: t1/2 alpha=3.24+/-1.14 min, t1/2beta=99.0+/-44.5 min, t1/2gamma=1213+/-493 min, Vc (Valpha)=4.81+/-2.12 liters, Vbeta=58.2+/-50.5 liters, Vgamma=598+/-294 liters. Vincristine, studied only for the first 4 hr, behaved like a two-compartment system, with values of t1/2 alpha=3.37+/-0.72 min, t1/2beta=155+/-18 min, Valpha=4.53+/-0.49 liters, and Vbeta=57.3+/-21.1 liters. Urine excretion data demonstrated that most drug elimination occurred within the first 24 hr and amounted to 13.2+/-5.9% for vindesine and 9.5+/-5.1% for vincristine.

Distribution and excretion of (3H)vincristine in the rat and the dog.

The distribution and excretion of tritiated vincristine were studies in the rat and the dog. Biphasic curves for the disappearance of the drug from blood were found in both species, with an initial half-life of approximately 15 min and a secondary half-life of approximately 75 min. Tissue levels were high in 1 hr in the rat and declined rapidly, except in the brain where very low levels of drug were found at all times. The bile was found to be the major route of excretion. The peak rate of excretion in bile was found to occur earlier in the rat (10 min) than in the dog (60 min). Rats given a higher dose of vincristine (1.0 mg/kg) excreted a larger percentage of the dose in the bile than rats given a lower dose (0.1 mg/kg). In rats given a low dose of vincristine (0.1 mg/kg), more than 85% of the drug was excreted in the feces and the urine over 72 hr. Less than 10% of the total radioactivity in the bile and urine was metabolites whereas, in the plasma, metabolites accounted for 40% of the total radioactivity.