No pharmacokinetic interaction between ipragliflozin and sitagliptin, pioglitazone, or glimepiride in healthy subjects.

AIMS: To investigate the effect of ipragliflozin on the pharmacokinetics of sitagliptin, pioglitazone or glimepiride and vice versa in healthy subjects. METHODS: Three trials with an open-label, randomized, two-way crossover design were conducted in healthy subjects. Ipragliflozin 150 mg, sitagliptin 100 mg, pioglitazone 30 mg or glimepiride 1-2 mg were administered alone or in combination. Primary endpoints were the area under the curve from the time of dosing to infinity (AUC(inf)) and the maximum observed plasma concentration (C(max)) of each drug. RESULTS: Multiple doses of ipragliflozin did not change the AUC(inf) and C(max) of a single dose of sitagliptin, pioglitazone or glimepiride. All geometric mean ratios and 90% CIs for AUC(inf) and C(max) , with and without ipragliflozin, were within the predefined range of 80-125% (AUC(inf) : sitagliptin 100.1 [96.9-103.5], pioglitazone 101.7 [96.6-107.0], glimepiride 105.1 [101.3-109.0], and C(max) : sitagliptin 92.4 [82.8-103.1], pioglitazone 98.6 [87.7-110.8], glimepiride 110.0 [101.9-118.8]). Similarly, multiple doses of sitagliptin, pioglitazone or glimepiride did not change the pharmacokinetics of a single dose of ipragliflozin (AUC(inf) : 95.0 [93.4-103.1], 100.0 [98.1-102.0], 99.1 [96.6-101.6]; and C(max) : 96.5 [90.4-103.1], 93.5 [86.3-101.2], 97.3 [89.2-106.2]). Ipragliflozin either alone or in combination with any of the three glucose-lowering drugs was well tolerated in healthy subjects. CONCLUSION: Ipragliflozin did not affect the pharmacokinetics of sitagliptin, pioglitazone or glimepiride and vice versa, suggesting that no dose-adjustments are likely to be required when ipragliflozin is given in combination with other glucose-lowering drugs in patients with type 2 diabetes mellitus.

Novel paclitaxel formulations for oral application: a phase I pharmacokinetic study in patients with solid tumours.

PURPOSE: To explore the pharmacokinetics (PKs) of paclitaxel and two major metabolites after three single oral administrations of a novel drinking solution and two capsule formulations in combination with cyclosporin A (CsA) in patients with advanced cancer. Moreover, the tolerability and safety of the formulations was studied. In addition, single nucleotide polymorphisms in the multidrug resistance (MDR1) gene were determined. PATIENTS AND METHODS: Ten patients were enrolled and randomized to receive CsA 10 mg/kg followed by oral paclitaxel 180 mg given as (1) drinking solution (formulation 1), (2) capsule formulation 2B, and (3) capsule formulation 2C on day 1, 8, or 15. RESULTS: The median C (max) of paclitaxel was 0.42 (0.23-0.96), 0.48 (0.08-0.59), and 0.39 (0.11-1.03) microg/ml and the area under the plasma concentration-time curve was 2.83 (1.69-5.12), 2.01 (1.57-3.04), and 2.67 (1.05-3.61) mug h/ml following administration of formulations 1, 2B, and 2C, respectively. The novel formulations were tolerated after single oral dose without causing relevant gastrointestinal or haematological toxicity. CONCLUSIONS: The PK and metabolism of paclitaxel were comparable between the oral formulations co-administered with CsA.

A pharmacokinetic and safety study of a novel polymeric paclitaxel formulation for oral application.

PURPOSE: To investigate the pharmacokinetics, safety, and tolerability of a new oral formulation of paclitaxel containing the polymer polyvinyl acetate phthalate in patients with advanced solid tumors. PATIENTS AND METHODS: A total of six patients received oral paclitaxel as single agent given as a single dose of 100 mg on day 1, oral paclitaxel 100 mg in combination with cyclosporin A (CsA) 10 mg/kg both given as a single dose on day 8, and i.v. paclitaxel (Taxol) 100 mg as a 3-h infusion on day 15. RESULTS: The AUC (mean +/- standard deviation) values of paclitaxel after oral administration without CsA and with CsA were 476 +/- 254 and 967 +/- 779 ng/ml h, respectively. T (max) was 4.0 +/- 0.9 h after oral paclitaxel without CsA, and 6.0 +/- 3.1 h after oral paclitaxel with CsA. The mean AUC after oral administration as single agent was 13% of the AUC after i.v. administration of paclitaxel, and increased to 26% after co-administration with CsA. No haematological toxicities were observed, and only mild (CTC-grade 1 and 2) non-hematological toxicities occurred after oral intake of paclitaxel with or without CsA. CONCLUSION: The AUC of the new polymeric paclitaxel formulation increased a factor 2 in combination with CsA, which confirms that CsA co-administration can also improve exposure to paclitaxel after oral administration of a polymeric formulation. Because of the delayed release of paclitaxel from this formulation, we hypothesize that a split-dose regimen of CsA where it is administered before and after paclitaxel administration will further increase the systemic exposure to paclitaxel up to therapeutic levels. The formulation was well tolerated at the dose of 100 mg without induction of severe toxicities.

Quantitative analysis of gemcitabine triphosphate in human peripheral blood mononuclear cells using weak anion-exchange liquid chromatography coupled with tandem mass spectrometry.

Gemcitabine triphosphate (dFdCTP) is a highly active metabolite of gemcitabine. It is formed intra-cellularly via the phosphorylation of gemcitabine by deoxycytidine kinase. The monitoring of dFdCTP in human peripheral blood mononuclear cells (PBMCs), in addition to plasma concentrations of gemcitabine and its metabolite 2',2'-difluorodeoxyuridine, is considered very useful in determining pharmacokinetic-pharmacodynamic relationships. We describe a novel sensitive assay for the quantification of dFdCTP in human PBMCs. The method is based on weak anion-exchange liquid chromatography and detection with tandem mass spectrometry (LC-MS/MS). The assay has been validated from 1 ng/ml (lower limit of quantification, LLOQ) to 25 ng/ml (upper limit of quantification, ULOQ) using 180 microl aliquots of PBMC extracts containing approximately 0.648 mg protein or 3.8 x 10(6) lysed PBMCs. The LLOQ is equivalent to 94 fmol/10(6) cells (1 ng/ml = 0.18 ng/180 microl or 0.18 ng/0.648 mg protein = 0.047 ng/10(6) cells or 94 fmol/10(6) cells). This highly sensitive assay is capable of quantifying about 200-fold lower concentrations of dFdCTP in human PBMCs than currently available methods.

A novel self-microemulsifying formulation of paclitaxel for oral administration to patients with advanced cancer.

To explore the parmacokinetics, safety and tolerability of paclitaxel after oral administration of SMEOF#3, a novel Self-Microemulsifying Oily Formulation, in combination with cyclosporin A (CsA) in patients with advanced cancer. Seven patients were enrolled and randomly assigned to receive oral paclitaxel (SMEOF#3) 160 mg+CsA 700 mg on day 1, followed by oral paclitaxel (Taxol) 160 mg+CsA 700 mg on day 8 (group I) or vice versa (group II). Patients received paclitaxel (Taxol) 160 mg as 3-h infusion on day 15. The median (range) area under the plasma concentration-time curve of paclitaxel was 2.06 (1.15-3.47) microg h ml(-1) and 1.97 (0.58-3.22) microg h ml(-1) after oral administration of SMEOF#3 and Taxol, respectively, and 4.69 (3.90-6.09) microg h ml(-1) after intravenous Taxol. Oral SMEOF#3 resulted in a lower median T(max) of 2.0 (0.5-2.0) h than orally applied Taxol (T(max)=4.0 (0.8-6.1) h, P=0.02). The median apparent bioavailability of paclitaxel was 40 (19-83)% and 55 (9-70)% for the oral SMEOF#3 and oral Taxol formulation, respectively. Oral paclitaxel administered as SMEOF#3 or Taxol was safe and well tolerated by the patients. Remarkably, the SMEOF#3 formulation resulted in a significantly lower T(max) than orally applied Taxol, probably due to the excipients in the SMEOF#3 formulation resulting in a higher absorption rate of paclitaxel.